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Differences in Cloud Vertical Structures between the Tibetan Plateau and Eastern China Plains during Rainy Season as Measured by CloudSat/CALIPSO

Differences in Cloud Vertical Structures between the Tibetan Plateau and Eastern China Plains... Hindawi Advances in Meteorology Volume 2019, Article ID 6292930, 11 pages https://doi.org/10.1155/2019/6292930 Research Article Differences in Cloud Vertical Structures between the Tibetan Plateau and Eastern China Plains during Rainy Season as Measured by CloudSat/CALIPSO Mingjian Yi Anhui Academy of Environmental Sciences Research, Hefei, Anhui, China Correspondence should be addressed to Mingjian Yi; mjyi@ustc.edu.cn Received 30 May 2019; Accepted 2 September 2019; Published 25 September 2019 Academic Editor: Anthony R. Lupo Copyright © 2019 Mingjian Yi. 'is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Cloud vertical structures over the Tibetan Plateau (TP) and Eastern China Plains (ECP) were analyzed by using data in rainy seasons from 2006 to 2009, in order to clarify the cloud development over adjacent regions but with distinct topographies. Results indicate that the largest occurrences of cloud top height over the TP are at 7-8 km above mean sea level, which is about 4 km lower than that over the ECP. Mixed-phase clouds dominated more than 30% over the TP, while it is lower than 10% over the ECP. 'e infrequent mixed-phase clouds over the ECP are attributed to the unique dynamic and moisture situations over the downstream areas of the TP. Ice clouds have similar occurrences over the two regions. 'e prominent distinctions are manifested by the probability density of cloud thickness. 'e probability density of cloud thickness around 4–8 km is about 2% higher over the TP than the ECP. However, there is almost no ice cloud thicker than 10 km over the TP, while it is about 1% over the ECP. Compared with those over the ECP, every cloud layer within multilayered clouds is generally higher and thinner over the TP, which is closely related to the elevated surface and the resulting thinner troposphere. 'e significant differences in cloud vertical structures between the TP and the ECP present in this study emphasize that topographical characteristics and the resulting moisture and circulation conditions have strong impacts on the cloud vertical structures. is highly variable with geographic locations [8, 9], knowledge 1. Introduction of the characteristics of CVS is very necessary on distinct Clouds are very important to Earth’s climate system. One of topographies such as the Tibetan Plateau (TP hereafter) and the most direct effects imposed by clouds is the modification the adjacent Eastern China Plains (ECP hereafter). of the radiative fluxes both at the top of the atmosphere and However, studies are very rare to examine CVS differ- at the earth’s surface. 'is radiative effect is largely related to ences between the TP and the ECP for a long time because it the cloud vertical structure (CVS) [1–3]. Because the CVS is difficult to make routine observations in the plateau, which leads to the lack of available data. Before the application of affects atmospheric circulation by determining the vertical gradient of radiative heating or cooling [4–6], it is very measurements of remote sensors onboard satellites, a few studies have focused on the clouds over the TP mainly based fundamental to accurately describe the geometrical prop- erties like the cloud top height and the cloud layer thickness, on the observations of the two Qinghai-Xizang Plateau as well as the microphysical properties like cloud phase and Meteorology Experiments carried out in 1979 and 1998, particle size under various cloud conditions. 'e effects of respectively [10, 11]. Fortunately, a lot of remote sensing CVS on atmospheric radiation and circulation have been data have been accumulated continually in recent years. 'e studied by a great number of numerical simulations [7]. 'e measurements of clouds provided by the International parameterization of CVS in the models proved to be critical Satellite Cloud Climatology Project (ISCCP) and Moderate for the performance of numerical simulations. Since the CVS Resolution Imaging Spectroradiometer (MODIS) almost 2 Advances in Meteorology study, we focused on the TP and the ECP to investigate their cover the whole globe [12]. 'ese newly available mea- surements have assembled a few features of the CVS over the characteristic CVS. Rather than the deep convective clouds, which constituted only a tiny part of the total amount of TP [13]. For instance, low-level clouds often cover the southern slope of the TP [14]. A lot of deep stratus clouds clouds (about 1%), all cloud types over both the TP and the (primarily the nimbostratus and altostratus) locating on the ECP in rainy season (from May to August) are analyzed. lee side of the TP during winter and spring are generated and maintained by the frictional and blocking effects [15]. On the 2. Data and Methods contrary, a lot of medium stratiform clouds locating at the eastern TP in cold seasons result from the dynamic effect of In this study, cloud information available in the joint the plateau [16]. Although the strongest convection occurs CloudSat/CALIPSO product 2B-GEOPROF-LIDAR [24, 28] over the Asian monsoon region to the south of the TP, the was used. 'e 2B-GEOPROF-LIDAR combined CloudSat convective clouds over the TP are shallower and less fre- CPR and CALIPSO Lidar cloud mask data, containing the quent, and embedded in small-size convective systems [17], cloud top heights and cloud base heights (above sea level) of and the DCSs over the TP were both weaker and smaller up to 5 layers at the CloudSat horizontal resolution of than those over its south slope [18]. Moreover, Precipitation ∼1.1 km (across and along track). 'e satellites orbit the Radar (PR) observations from the Tropical Rainfall Mea- earth roughly 14.5 times per day and provide more than 460 suring Mission (TRMM) satellite have been analyzed to 000 profiles. During hundreds of days in rainy seasons in compare the precipitation type and structure characteristics year 2006–2009, the total profiles collected all over the globe ° ° over the TP and East Asia, implying a large amount of clouds is more than 200 million. For each 1 × 1 grid in middle over the TP are weak convective ones [19]. In addition, Yan latitudes, the average number of profiles is more than 3000. et al. indicated that the topography-induced compression 'e data of cloud top height (CTH) were principally effect is also shown in the range in the variation of cloud used in this study. 'e CTH was defined as the distance from thickness and cloud top height corresponding to different sea level to the cloud top. Its value was from 0 to 25 km. 'e precipitation intensity, which is much smaller over the TP occurrences of CTH were the probability of cloud tops were than its neighboring regions [20]. Zhao et al. have indicated detected at a certain range of height (every 500 m here) in a that the convection over the Naqu region in the TP could period of time [29, 30]. Furthermore, the occurrences of impact rainstorms in the middle and lower reaches of the CTH for each rainy season in years 2006–2009 were selected Yangtze River Basin via a three-dimensional water vapor and then averaged for the designated areas (e.g., the TP and ° ° flux vortex structure [21]. 'ese studies have advanced the the ECP) or for each 1 × 1 grid box to get a higher hori- knowledge of the differences in CVS over the TP and its zontal resolution. surrounding regions. Regions defined in this study are highlighted with Nevertheless, Li et al. have pointed out that there is a polylines in Figure 1. 'e TP is the area closed by polylines ° ° ° ° large underestimation of low-level clouds and over- within 28 –39 N and 70 –101 E; the ECP is the area closed by ° ° ° ° estimation of middle-level clouds over the TP in both ISCCP polylines within 29 –37 N and 113 –120 E. D2 and the MODIS/Terra cloud products [22]. In addition, In addition, another CloudSat product called 2B- the measurements of the PR onboard TRMM satellite, de- GEOPROF was used in this study. 'e 2B-GEOPROF was termined mainly by large precipitation-sized hydrometeors, derived directly from the radar echo of the CPR [8]. It cannot be directly used to depict the vertical structures of presented a complete picture of cloud body and gave a direct clouds. 'is dilemma has been changed since the CloudSat view of the different detection results of clouds between the and CALIPSO satellites were launched and began collecting CPR and the Lidar (e.g., Figures 2(b) and 2(d)). 'e monthly data routinely [23]. 'e CPR on CloudSat operates at means from ECMWF Interim Reanalysis project [31] were 94 GHz and directly probes optically thick cloud layers along also used to illustrate the moisture condition, vertical ve- the satellite orbit [8]. 'e Cloud-Aerosol Lidar with Or- locity, tropopause height, and temperature profiles over the thogonal Polarization (Lidar) on CALIPSO has the unique TP and the ECP in rainy seasons. ability to sense optically thin cloud layers. By combining the two complementary measurements from the two sensors, 3. Comparing CVS with TP and ECP the merged products are generated by CloudSat Project, which is expected to produce a complete picture of the 3.1. Cloud Top. To catch a glimpse of the characteristics of occurrences of clouds and aerosols in the atmosphere the CVS over the TP and the ECP, we took two tracks [24, 25]. Sun et al. has used the CloudSat data to analyze the numbered 01630 and 01578 as examples to present the CVS associated with northward advance of the East Asian profiles of radar reflectivity factor and the cloud layers along summer monsoon [26]. Luo et al. has used the joint the tracks (Figure 2). 'e track numbered 01630 passed the CloudSat/CALIPSO data to compare deep convective clouds TP at UTC 07:35 on 18 Aug, 2006. 'e surface altitude over the TP and Asian monsoon regions, confirming sig- almost is 5 km above the footprints in the TP along the track. nificant differences in the deep convective cloud structures A few isolating and small convective clouds were detected by between the two regions [17]. Chen et al. have found that the CPR. 'ey extended from the surface to the high altitude, convective clouds over the TP are thinner than those over with the top height of about 13 km and the thickness of about east China, and the lifetimes of the deep cloud systems over 7 km. 'ere were still some cloud layers revealed by the the TP are shorter than those over east China [27]. In this information of Lidar above the cloud top detected by the Advances in Meteorology 3 40N 40N 35N 35N 30N 30N 25N 25N 70E 80E 90E 100E 110E 120E 130E 70E 80E 90E 100E 110E 120E 130E 3 6 9 12 15 (%) 369 12 15 (%) (a) (b) Figure 1: Occurrence averaged vertically for (a) range A and (b) range B both ranges A and B are defined as in Figure 3. 'e left closed region represents the TP, and the right closed region represents the ECP. CPR. 'ese cloud layers were over 15 km in height but less the western part of the TP and decreases gradually from west to east. It is clear that the great bigger occurrences over than 2 km in thickness. Detected by the Lidar but not the CPR, they were likely to be tenuous. 'e track numbered the TP than its surrounding regions, indicating that the 01578 passed the ECP at UTC 18:23 on 14 Aug, 2006. 'e topography conditions are the leading factor in affecting surface is flat and has an averaged altitude below 200 m along the CTH over the TP. However, the distribution of aver- the track. 'ere was a deep convective cloud detected by the aged occurrences of range B is not significantly related to CPR. It extended vertically from near the surface to about the topographies. It increases gradually from west to east 17 km, with a thickness of more than 15 km and a horizontal and peaks in the ECP and the offshore regions. 'e different scale of about hundreds of kilometers. Surrounding the top characteristics in horizontal distribution of clouds suggest of the deep convective cloud, there was a large cloud anvil that it is other one rather than topographies dominating the CTH over the ECP. detected by the Lidar. It is clear that there are different characteristics in size and thickness of the convective clouds Since the CTH is much different over the TP and the ECP, the cross sections of the occurrences along longitude over the TP and the ECP in rainy season. In addition, Figure 2 also revealed two pieces of important information. and latitude were examined to get more detailed vertical Firstly, a lot of tenuous clouds and anvils were omitted by the variation of it, as shown in Figure 4. 'e maximum oc- CPR but detected by the Lidar, indicating the 2B-GEO- currence in the vertical direction is located at the height of 7- PROF-LIDAR data combined from both the CPR and the 8 km. Although the upper boundary of CTH over the TP is Lidar have the potential of providing a more complete about 18 km, the occurrences of the CTH ranging from 10 to picture of the occurrences of clouds than the data from the 18 km are very tiny. From the TP to the ECP, the upper boundary of CTH descends slightly, but the height of the CPR only. Secondly, some high-level clouds and anvils overlapped over the low-level clouds formed multilayered maximum occurrence (HMO) increases greatly. 'e in- creasing of the HMO is sharpest over the Sichuan Basin clouds. Since more clouds were obtained from 2B-GEO- PROF-LIDAR, it was used rather than 2B-GEOPROF to located just on the east of the TP. It gets to the peak value exceeding 12 km over the ECP. On the contrary, the oc- analyze the detail CVS over the TP and the ECP in this study. Cloud top height is the most intuitive parameter currences of the CTH ranging from 3 to 10 km are very small reflecting the CVS. 'e vertical variation of the occurrences over the ECP. It is clearly found that the cloud top is elevated of CTH is presented in Figure 3. 'e maximum of the from the TP to the ECP, although the surface elevation occurrences (about 6.5%) over the TP is at the height of continues to fall. 7.5 km. 'is height is slightly larger than the average top 'e variation of CTH over the TP is also notable along height of low-level clouds reported in[25]. 'e reason is that latitude. Most cloud top is above 15 km in the south of the TP, which has intense convection in boreal summer. Al- we defined only the core plateau as the TP (Figure 1), where the average altitude of the surface is much higher. By added though the TP is adjacent to it, the most CTH over the TP is only 6–8 km. Low CTH is the most important characteristic with the higher elevation of surface, the average height of cloud tops is higher too. 'e occurrences over the ECP are of the TP’s clouds differing with that of its surrounding large near the surface (about 3% at 1 km), but the globe regions and the ECP. Without big mountains disturbing the maximum (about 5%) is found at the height of 11.5 km, boundary layer, the variation of CTH over the ECP is rather which is 4 km higher than that of the TP. monotonous. 'e HMO over the ECP descends gradually To realize the horizontal distribution of the clouds over with the increased latitude and always keeps over 10 km. the TP and the ECP, we averaged the occurrences of CTH 'e comparison of CTH over the TP and ECP shows that vertically for the range A and range B over the TP and the the clouds is much lower (from sea level) over the TP than its ECP, respectively, where the most concentrated cloud tops surrounding regions and the ECP, although they maintain on the highly elevated surface. 'is is consistent with pre- were found (Figure 3). 'e distribution of averaged oc- currences of range A shows a good correspondence with vious reports of the weaker deep convection and shallower deep clouds over the TP [17, 18]. topography (Figure 1(a)). 'e occurrences are biggest in 4 Advances in Meteorology 40N 40N 2006-08-18 0735UTC 01630 2006-08-14 1823UTC 01578 35N 35N 30N 30N 70E 80E 90E 100E 100E 110E 120E 130E 0 2500 5000 7500 m 0 2500 5000 7500 m (a) (d) 18 18 15 15 12 12 9 9 6 6 3 3 0 0 30N 32N 34N 36N 38N 40N 30N 32N 34N 36N 38N 40N –30 –20 –10 0 10 20 30 dBz –30 –20 –10 0 10 20 30 dBz (b) (e) 18 18 15 15 12 12 9 9 6 6 3 3 0 0 30N 32N 34N 36N 38N 40N 30N 32N 34N 36N 38N 40N L1 L2 L3 L4 L1 L2 L3 L4 (c) (f) Figure 2: Two cases of clouds over the TP (left panel) and ECP (right panel) detected by CPR and Lidar. (a) and (d): location of the tracks (black solid line) over different elevation area (color shading); (b) and (e): radar reflectivity measured in dBZ (color shading) along the tracks; and (c) and (f): vertical stratification of the clouds, L1 to L4 represent the separate cloud layers from bottom to top. 3.2.CloudClassification. As emphasized by Li et al. [22], the heights are below 6.0 km, between 6.0 and 9.2 km, and cloud classification should be modified over the TP. Ele- above 9.2 km, respectively. Accordingly, the cloud top vated by the surface mountains, the low-level clouds and heights of the three cloud types over the ECP are below middle-level clouds over the TP are difficult to be dis- 5.5 km, between 5.5 and 9.0 km, and above 9.0 km, tinguished as usual. A feasible scheme for classifying respectively. clouds over the TP and the ECP is thus necessary. Wood Figure 6 shows the horizontal distribution of occur- [32] had pointed out that the portion of the cloud profile rences for warm clouds, mixed-phase clouds, and ice clouds. colder than − 20 C is deemed pure ice, and the portion of 'e warm clouds are infrequent over the TP. Meanwhile, the the profile warmer than 0 C is considered pure liquid. We warm clouds have the largest occurrences just east to the TP also considered the cloud top temperature to be crucial in and show prevalence in the downstream of the TP. It clear classifying clouds, and thereby the climatologically av- that the characteristics of downstream flows of plateau are favorable for the development of warm clouds, which often eraged temperature profiles over the TP and the ECP were examined primarily (Figure 5). 'e temperature is slightly develop in stably stratified and weak turbulence low-level lower over the TP than that over the ECP at the height of atmosphere [17, 21]. 'e largest occurrences of mixed-phase below 10 km. 'e difference between them is about 2 C at clouds are found to locate just over the TP, where it is more the height of 5 km and then decreases with height. We than 30%. On the contrary, the mixed-phase clouds are treated the freezing level (the height of 0 C) as the bor- infrequent over the ECP. 'e occurrences of them are less derline separating warm clouds from mixed-phase clouds, than 10% in a big area of the ECP. Compared to the warm and the crystal level (the height of − 20 C) as the borderline clouds and mixed-phase clouds, the ice clouds have the most between the mixed-phase clouds and ice clouds. 'ere- insignificant difference between the TP and the ECP. 'e fore, the warm clouds, mixed-phase clouds, and ice clouds occurrences of ice clouds decrease gradually with increased over the TP are defined, respectively, as that whose top latitude over the both regions. It seems to be more closely Altitude (km) Altitude (km) Altitude (km) Altitude (km) Advances in Meteorology 5 0 2 4 68 Frequency (%) TP ECP Figure 3: 'e regionally averaged occurrence of CTH over the TP and the ECP. 20 20 20 15 15 15 10 10 10 5 5 5 0 0 0 70E 80E 90E 100E 110E 120E 130E 25N 30N 35N 40N 25N 30N 35N 40N (a) (b) (c) 2 4 6 810 12 (%) ° ° ° Figure 4: Cross sections of occurrence of CTH along longitude (a) averaged between 30 N and 35 N and latitude (b) averaged between 80 E ° ° ° and 95 E and (c) averaged between 110 E and 120 E. 'e thick solid line represents the height of maximum values. related to its location of latitude rather than the topographies two regions. 'e PD of cloud thickness around 4–8 km is of lower boundary. about 2% higher over the TP than that over ECP. However, We also examined the thicknesses of the warm clouds, there is almost no ice cloud thicker than 10 km over the TP, mixed-phase clouds, and ice clouds. Figure 7 shows the while it is about 1% over the ECP. probability density (PD) of the thicknesses of the three cloud 'e comparison of cloud classification and its thickness types individually. 'e warm clouds are generally thin, with reveals that there are two representative forms of cloud over thickness hardly more than 3 km over the TP. However, the the TP, the one is mixed-phase cloud and the other is medium-thickness ice cloud. On the contrary, there are two thickness of some warm clouds over the ECP is large (up to 6 km), although their PD is small. Most mixed-phase clouds representative forms of the cloud over the ECP too, the one over the TP are less than 3 km, while a large number of is low-level warm cloud, and the other is large-thickness ice mixed-phase clouds over the ECP are thicker than 5 km. 'e cloud. 'e reasons for the difference in the CVS between the thickness of ice clouds is significantly different between the TP and the ECP are discussed in Section 4. Altitude (km) Altitude (km) 6 Advances in Meteorology 9.2 km 9.0 km 6.0 km 5.5 km –60 –40 –20 0 20 t (°C) t, TP t, ECP Figure 5: Vertical profiles of temperature. 40N 40N 35N 35N 30N 30N 25N 25N 70E 80E 90E 100E 110E 120E 130E 70E 80E 90E 100E 110E 120E 130E 5 10 15 20 25 30 35 40 (%) 10 20 30 40 50 60 (%) (a) (b) 40N 35N 30N 25N 70E 80E 90E 100E 110E 120E 130E 10 20 30 40 50 60 70 80 (%) (c) Figure 6: Occurrence distributions of (a) warm clouds, (b) mixed-phase clouds, and (c) ice clouds. 3.3. Multilayered Clouds. In addition to top height and single-layered clouds and multilayered clouds during rainy classification, vertical stratification of the clouds is also an seasons are presented in Table 1. Single-layered clouds are important property of the CVS. 'e measurements of the prominent type over both the TP (62%) and the ECP clouds as combined observed by the CPR and the Lidar (51%), two-layered clouds ranks second with a similar have an outstanding ability to identify more than one cloud percentages over the TP (21%) and over the ECP (20%), and layer overlapped. It is easy to collect the information of the three-layered clouds are much less (only 3% over the TP number of cloud layers, top height, and base height of each and 4% over the ECP). Since the clouds with four to five cloud layer for a given profile by using the 2B-GEOPROF- layers are rare (less than 1%), they are not discussed in this LIDAR data. 'e statistic results of the occurrences of study. Altitude (km) Advances in Meteorology 7 60 20 45 15 30 10 15 5 0 0 0369 12 15 0369 12 15 Thickness (km) Thickness (km) (a) (b) 0 3 69 12 15 Thickness (km) (c) Figure 7: Probability density of thickness for (a) warm clouds, (b) mixed-phase clouds, and (c) ice clouds. probability of cloud layers to be overlapped. High cirrus Table 1: Occurrence of multilayered clouds (%). from residual deep convective clouds also has contribution Region Clear sky Single-layered Two-layered 'ree-layered to the occurrences of multilayered clouds. TP 12.92 62.29 20.74 3.03 Figure 9 shows the mean top height of the cloud layer of ECP 23.63 50.65 20.25 4.26 single-layered and multilayered clouds and its variance. 'e single-layered clouds over the TP and the ECP are almost the same in mean top height. But the mean top height of cloud Figure 8 shows the occurrences of single-layered clouds, layers over the TP is higher than that over the ECP. Es- two-layered clouds, and three-layered clouds. 'e distri- pecially, this bias in top height is largest in the lowest cloud bution of single-layered clouds shows a good agreement with layers and becomes smaller and smaller in the upper cloud the topographies of high land. Larger occurrences of single- layers. On the contrary, the cloud layers over the TP are layered clouds are a significant characteristic of the TP, thinner than that over the ECP, including both the single- especially over the western parts. 'e steady mechanical layered clouds and the multilayered clouds (Table 2). lifting on the windward slope sustained by low-level westerly flows is favorable for the forming of continuous shallow 4. Discussion clouds. Weak convections prevailing in the summer TP may also play a role in it. 'e distribution of multilayered clouds, As mentioned in Section 3, mixed-phase clouds and me- both the two-layered clouds and three-layered clouds, does dium-thickness ice clouds are most representative over the not show a significant consistency with the topographies. TP, while warm clouds and large-thickness ice clouds are 'e occurrences of multilayered clouds is depressive towards most representative over the ECP. We put forward that the high latitude. We found the largest occurrences of multi- differences in the CVS are mainly attributed to the distinct layered clouds to south of the TP, where the deep con- topographies and resulting moisture condition and atmo- vections are most frequent. As presented in Figure 2, deep spheric circulation. During most of the year, the TP has the convective clouds generally cover a vast area and have a highest rate of warming in the northern hemisphere. 'e bulky vertical extent as huge umbrellas, increasing the low-level warming sustains strong lifting to initiate the PDF (%) PDF (%) PDF (%) 8 Advances in Meteorology 40N 40N 35N 35N 30N 30N 25N 25N 70E 80E 90E 100E 110E 120E 130E 70E 80E 90E 100E 110E 120E 130E 30 40 50 60 70 80 (%) 10 20 30 40 50 (%) (a) (b) 40N 35N 30N 25N 70E 80E 90E 100E 110E 120E 130E 48 12 16 20 (%) (c) Figure 8: Occurrence distributions of (a) single-layered clouds, (b) two-layered clouds, and (c) three-layered clouds. Single-layered Two-layered Three-layered TP ECP Figure 9: Mean top height of the cloud layers of (a) single-layered, (b) two-layered, and (c) three-layered clouds. 'e error bars represent standard errors of the means. Table 2: Average thickness of cloud layers of single-layered and multilayered clouds (km). Two-layered 'ree-layered Region Single-layered FL SL FL SL TL TP 3.24± 2.35 2.02± 1.62 2.13± 1.49 1.56± 1.22 1.56± 1.11 1.79± 1.18 ECP 3.84± 3.55 2.20± 2.32 2.37± 1.76 1.59± 1.76 1.59± 1.19 1.87± 1.27 Statistical results are expressed as mean± variance. 'e FL, SL, and TL mean the first, second, and third cloud layer from surface to upper. convective motion. As shown in Figure 10, the TP has the the increased depression of the dew point with height, it is largest vertical velocity in the Eastern Asia between 30 N and clearly found that the air becomes more and more un- 35 N. In addition, because the low-level air approaches saturated in high levels. A dry environment is unfavorable saturation nearest, it is favorable for the development of for deep convection because the entrainment of drier en- convections and clouds formed within them. However, from vironmental air leads to stronger evaporative cooling and Altitude (km) Advances in Meteorology 9 80E 100E 120E 30N 40N 30N 40N 0.15 Pa/s (a) (b) (c) 4 6 8 10 12 14 16 °C ° ° Figure 10: Cross sections of depression of the dew point and vertical velocity along longitude (a) averaged between 30 N and 35 N and ° ° ° ° latitude (b) averaged between 80 E and 95 E and (c) averaged between 110 E and 120 E. A scale of vertical velocity is shown on the lower- right of the figure, and its units is Pa/s. 'e thick dashed line represents dynamic tropopause. buoyancy of saturated updrafts. In addition, the increased negative buoyancy so that the convections over the TP are difficult in transit from shallow to deep. On the contrary, the saturation level with height of environment air is more convection over the TP is usually small in size (Figure 2). favorable compared with that of the TP for maintaining and Because small-size clouds are more likely to be diluted by enhancing the deep convection too (Figure 10). mixing with dry air, they are not expected to have bulky vertical extent. 5. Conclusion Located downstream of the TP, the circulation of the ECP is significantly influenced by the blocking and frictional 'e CVS that is important in the atmospheric radiation was effects of big mountains. 'e downstream low-level con- examined over two designated regions, the TP and the ECP, vergence sustains large-scale steady lifting, while the mid- by using the 2B-GEOPROF-LIDAR data. Based on the case tropospheric westerly flows slowed down by the analysis and statistic calculation of the clouds during rainy mountainous surface generate downstream midlevel di- season in 2006–2009, the characteristics of cloud top height, vergence, resulting in the lifting is confined to the low cloud type, cloud thickness, and the number of vertical cloud troposphere. Figure 10 shows that the downstream flows are layers were revealed. Many distinct cloud features between climatologically weak uplifting or sinking and are most the TP and the ECP were clarified. unsaturated in midlevels. 'is environment is unfavorable Without the influence of topographies on clouds, the for the generation and development of clouds in midlevels, analysis of clouds over the ECP was documented and resulting in the smaller occurrences of mixed-phase clouds regarded as a reference. Over the ECP, the maximum oc- over the ECP. But why large-thickness ice clouds have a currence of CTH is found to be 5.1% occurring at 11.5 km. higher occurrence over the ECP than those over the TP? 'is 'is height is above the crystal level so that the ice clouds are could be explained in terms of the impacts of Asian mon- the predominant cloud type. A lot of ice clouds have soon. Deep convective clouds are the main source of large- thickness more than 10 km. Mixed-phase clouds are another thickness ice clouds. Kuang and Bretherton [33] had put type that has lower cloud top height between the crystal level forth that the development of deep convection depends on and the freezing level. 'ey are infrequent over the ECP. the moisture content of the free troposphere. Under the Warm clouds have no occurrences as large as the ice clouds. control of Asian summer monsoon, abundant water vapor is 'ey are lower top and shallow extent, prevailing down- converged over the ECP by the transportation of monsoon stream of the TP. From the statistical results of multiply flows, making shallow convections rapidly develop into deep layers of clouds, it is found that single-layered clouds are ones after moisture is added [34]. Strong synoptic-scale dominant with an averaged occurrence of more than 50%, systems occurs frequently over the ECP in summertime, and although a rather remarkable percentage of clouds have the deep convections associated with them are much larger more than one vertical cloud layer. 'e percentage of in size than that over the TP. Large-size clouds shield them multilayered clouds decreases sharply with the increased from deleterious effects of environment to maintain the number of their vertical cloud layers. Pressure (hPa) Height (km) 10 Advances in Meteorology As is well known, the main body of the TP is the highest monthly data. 'is work was funded by the National Basic region on the earth. 'e most notable difference of CVS with Research Program of China (41105031 and 91337213), Key that over the ECP is the height of maximum occurrence of Research and Development Plan of Anhui Province CTH. It is found to be 6.6% at 7.5 km, which is 4 km lower (1804a0802196), and National Key Research and Develop- than that of the ECP. 'e height of maximum occurrence is ment Plan (2018YFC0213806). below the crystal level but above the ice level. 'erefore, mixed-phase clouds rather than ice clouds become the References predominant type. Mixed-phase clouds over the TP are [1] F. Richter, K. Barfus, F. H. Berger, and U. Gorsdorf, ¨ “'e usually thinner than 5 km. 'e PD of cloud thickness influence of cloud top variability from radar measurements on manifests the prominent distinctions of ice clouds between 3-D radiative transfer,” Atmospheric Chemistry and Physics, the TP and the ECP. 'e PD of cloud thickness is about 2% vol. 7, no. 17, pp. 4699–4708, 2007. higher over the TP around 4–8 km but extremely lower [2] T. Varnai ´ and R. Davies, “Effects of cloud heterogeneities on exceeding 10 km, while it is about 1% over the ECP. shortwave radiation: comparison of cloud-top variability and Moreover, the cloud layers of multilayered clouds are higher internal heterogeneity,” Journal of the Atmospheric Sciences, and thinner over the TP than over the ECP. vol. 56, no. 24, pp. 4206–4224, 1999. 'ese distinct features in the CVS over the TP and the [3] P. J. Webster and G. L. Stephens, “Tropical upper-tropo- ECP are closely related to the atmospheric environment spheric extended clouds: inferences from winter MONEX,” Journal of the Atmospheric Sciences, vol. 37, no. 7, pp. 1521– affected by topographies. Initiated by low-level warming, 1541, 1980. convective activities are frequent over the TP. But the [4] Z. Feng, X. Dong, B. Xi, C. Schumacher, P. Minnis, and convections are difficult to transit from shallow to deep due M. Khaiyer, “Top-of-atmosphere radiation budget of con- to the rapidly diminished moisture with height. Shallow vective core/stratiform rain and anvil clouds from deep convections prevailing over the TP increase the PD of convective systems,” Journal of Geophysical Research: At- mixed-phase clouds and ice clouds with medium thickness. mospheres, vol. 116, no. 23, 2011. Located downstream of the TP, the lifting over the ECP is [5] W. Li, C. Schumacher, and S. A. McFarlane, “Radiative climatologically confined to the lower troposphere, leading heating of the ISCCP upper level cloud regimes and its impact to the less of mixed-phase clouds. On the contrary, the ECP on the large-scale tropical circulation,” Journal of Geophysical is under the control of Asian monsoon, which has routinely Research: Atmospheres, vol. 118, no. 2, pp. 592–604, 2013. intense synoptic-scale cyclone activities in summer. Deep [6] T. Vaillant de Guelis, H. Chepfer, V. Noel et al., “'e link between outgoing longwave radiation and the altitude at convections and strong precipitations usually occur asso- which a spaceborne lidar beam is fully attenuated,” Atmo- ciated with the development of synoptic-scale systems, spheric Measurement Techniques, vol. 10, no. 12, pp. 4659– resulting in the increased probability of ice clouds that 4685, December 2017. consist of deep convective clouds and high cirrus from their [7] J. Wang and W. B. Rossow, “Effects of cloud vertical structure residual. on atmospheric circulation in the GISS GCM,” Journal of Based on the analysis of properties of the CVS, an ex- Climate, vol. 11, no. 11, pp. 3010–3029, 1998. tended knowledge of the clouds over the plateau and the [8] G. G. Mace, R. Marchand, Q. Zhang, and G. Stephens, “Global plains was presented. 'ese detailed characteristics of the hydrometeor occurrence as observed by CloudSat: initial CVS present a close linkage of it and the circulation envi- observations from summer 2006: CLOUDSAT hydrometeor ronment on different topographies. 'ese results are critical occurrence,” GeophysicalResearch Letters, vol. 34, no. 9, 2007. [9] E. Weisz, J. Li, W. P. Menzel, A. K. Heidinger, B. H. Kahn, and in understanding the impacts of topographies on the climate C.-Y. Liu, “Comparison of AIRS, MODIS, CloudSat and and may be necessary for the parameterization of clouds in CALIPSO cloud top height retrievals,” Geophysical Research numerical models. Letters, vol. 34, no. 17, 2007. [10] J. Yang, S. Tao, Z. Gu, and D. Ye, Meteorology of Tibetan Data Availability Plateau, Science Press, Beijing, China, 1960. [11] D. Ye and Y. Gao, Meteorology of theQinghai-Xizang Plateau, 'e CloudSat/CALIPSO data used to support the findings of Science Press, Beijing, China, 1979. this study may be released upon application to the CloudSat [12] W. B. Rossow and R. A. Schiffer, “Advances in understanding Data Processing Center (CloudSat DPC), who can be clouds from ISCCP,” Bulletin of the American Meteorological contacted at cloudsat@colostate.edu. Society, vol. 80, no. 11, pp. 2261–2287, 1999. [13] B.-C. Gao, P. Yang, G. Guo, S. K. Park, W. J. Wiscombe, and B. Chen, “Measurements of water vapor and high clouds over Conflicts of Interest the Tibetan plateau with the terra modis instrument,” IEEE Transactions on Geoscience and Remote Sensing, vol. 41, no. 4, 'e author declares that there are no conflicts of interest pp. 895–900, 2003. regarding the publication of this paper. [14] Y. Kurosaki and F. Kimura, “Relationship between topog- raphy and daytime cloud activity around Tibetan plateau,” Acknowledgments Journal of the Meteorological Society of Japan, vol. 80, no. 6, pp. 1339–1355, 2002. 'e author greatly appreciates the NASA CloudSat project [15] R. Yu, B. Wang, and T. Zhou, “Climate effects of the deep for providing the CloudSat/CALIPSO dataset and the continental stratus clouds generated by the Tibetan plateau,” ECMWF Interim Reanalysis project for providing the Journal of Climate, vol. 17, no. 13, pp. 2702–2713, 2004. Advances in Meteorology 11 [16] Y. Li, R. Yu, and Y. Xu, “'e formation and diurnal changes Cooperative Institute for Research in the Atmosphere (CIRA), OF stratiform clouds IN southern China,” Acta Meteorologica Fort Collins, CO, USA, 2008. [33] Z. Kuang and C. S. Bretherton, “A mass-flux scheme view of a Sinica, vol. 61, no. 6, pp. 733–743, 2003. [17] Y. Luo, R. Zhang, W. Qian, Z. Luo, and X. Hu, “In- high-resolution simulation of a transition from shallow to deep cumulus convection,” Journal of the Atmospheric Sci- tercomparison of deep convection over the Tibetan plateau- ences, vol. 63, no. 7, pp. 1895–1909, 2006. Asian monsoon region and subtropical north America in [34] M. Yi, Y. Fu, P. Liu, Y. Gao, and X. Hong, “Analysis of the boreal summer UsingCloudSat/CALIPSO data,” Journal of variation of atmospheric composition in the upper tropo- Climate, vol. 24, no. 8, pp. 2164–2177, 2011. sphere during a strong convection in eastern China in [18] G. Gao, Q. Chen, H. Cai, Y. Li, and Z. Wang, “Comprehensive summer,” Chinese Journal of Atmospheric Sciences, vol. 36, characteristics of summer deep convection over Tibetan no. 5, pp. 901–911, 2012. plateau and its south slope from the global precipitation measurement core observatory,” Atmosphere, vol. 10, no. 1, 9 pages, 2019. [19] Y. Fu, G. Liu, G. Wu et al., “Tower mast of precipitation over the central Tibetan Plateau summer,” Geophysical Research Letters, vol. 33, no. 5, 2006. [20] Y. Yan, Y. Liu, and J. Lu, “Cloud vertical structure, pre- cipitation, and cloud radiative effects over Tibetan Plateau and its neighboring regions,” Journal of Geophysical Research: Atmospheres, vol. 121, no. 10, pp. 5864–5877, 2016. [21] Y. Zhao, X. Xu, L. Liu et al., “Effects of convection over the Tibetan plateau on rainstorms downstream of the Yangtze River basin,” Atmospheric Research, vol. 219, pp. 24–35, 2019. [22] Y. Li, X. Liu, and B. Chen, “Cloud type climatology over the Tibetan Plateau: a comparison of ISCCP and MODIS/TERRA measurements with surface observations,” Geophysical Re- search Letters, vol. 33, no. 17, 2006. [23] G. L. Stephens, D. G. Vane, R. J. Boain et al., “'e cloudsat mission and the A-train,” Bulletin of the American Meteo- rological Society, vol. 83, no. 12, pp. 1771–1790, 2002. [24] G. G. Mace et al., “A description of hydrometeor layer oc- currence statistics derived from the first year of merged Cloudsat and CALIPSO data,” Journal of Geophysical Re- search, vol. 114, 2009. [25] C. M. Naud and Y.-H. Chen, “Assessment of ISCCP cloud- iness over the Tibetan plateau using CloudSat-CALIPSO,” J. Geophys. Res., vol. 115, no. 10, 2010. [26] G. Sun, Y. Li, and J. Lu, “Cloud vertical structures associated with northward advance of the East Asian summer monsoon,” Atmospheric Research, vol. 215, pp. 317–325, 2019. [27] J. Chen, X. Wu, Y. Yin, Q. Huang, and H. Xiao, “Charac- teristics of cloud systems over the Tibetan plateau and east China during boreal summer,” Journal of Climate, vol. 30, no. 9, pp. 3117–3137, 2017. [28] G. Stephens, D. Winker, J. Pelon et al., “CloudSat and CALIPSO within the A-train: ten years of actively observing the earth system,” Bulletin of the American Meteorological Society, vol. 99, no. 3, pp. 569–581, 2018. [29] S.-W. Kim, E.-S. Chung, S.-C. Yoon, B.-J. Sohn, and N. Sugimoto, “Intercomparisons of cloud-top and cloud-base heights from ground-based Lidar, CloudSat and CALIPSO measurements,” International Journal of Remote Sensing, vol. 32, no. 4, pp. 1179–1197, 2011. [30] K. L. Verlinden, D. W. J. 'ompson, and G. L. Stephens, “'e three-dimensional distribution of clouds over the southern hemisphere high latitudes,”Journalof Climate, vol. 24, no. 22, pp. 5799–5811, 2011. [31] D. P. Dee, “'e ERA-Interim reanalysis: configuration and performance of the data assimilation system,” Quarterly Journal of the Royal Meteorological Society, vol. 137, no. 656, pp. 553–597, 2011. [32] N. 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Differences in Cloud Vertical Structures between the Tibetan Plateau and Eastern China Plains during Rainy Season as Measured by CloudSat/CALIPSO

Yi, Mingjian
Advances in Meteorology , Volume 2019 – Sep 25, 2019
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Copyright © 2019 Mingjian Yi. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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Hindawi Advances in Meteorology Volume 2019, Article ID 6292930, 11 pages https://doi.org/10.1155/2019/6292930 Research Article Differences in Cloud Vertical Structures between the Tibetan Plateau and Eastern China Plains during Rainy Season as Measured by CloudSat/CALIPSO Mingjian Yi Anhui Academy of Environmental Sciences Research, Hefei, Anhui, China Correspondence should be addressed to Mingjian Yi; mjyi@ustc.edu.cn Received 30 May 2019; Accepted 2 September 2019; Published 25 September 2019 Academic Editor: Anthony R. Lupo Copyright © 2019 Mingjian Yi. 'is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Cloud vertical structures over the Tibetan Plateau (TP) and Eastern China Plains (ECP) were analyzed by using data in rainy seasons from 2006 to 2009, in order to clarify the cloud development over adjacent regions but with distinct topographies. Results indicate that the largest occurrences of cloud top height over the TP are at 7-8 km above mean sea level, which is about 4 km lower than that over the ECP. Mixed-phase clouds dominated more than 30% over the TP, while it is lower than 10% over the ECP. 'e infrequent mixed-phase clouds over the ECP are attributed to the unique dynamic and moisture situations over the downstream areas of the TP. Ice clouds have similar occurrences over the two regions. 'e prominent distinctions are manifested by the probability density of cloud thickness. 'e probability density of cloud thickness around 4–8 km is about 2% higher over the TP than the ECP. However, there is almost no ice cloud thicker than 10 km over the TP, while it is about 1% over the ECP. Compared with those over the ECP, every cloud layer within multilayered clouds is generally higher and thinner over the TP, which is closely related to the elevated surface and the resulting thinner troposphere. 'e significant differences in cloud vertical structures between the TP and the ECP present in this study emphasize that topographical characteristics and the resulting moisture and circulation conditions have strong impacts on the cloud vertical structures. is highly variable with geographic locations [8, 9], knowledge 1. Introduction of the characteristics of CVS is very necessary on distinct Clouds are very important to Earth’s climate system. One of topographies such as the Tibetan Plateau (TP hereafter) and the most direct effects imposed by clouds is the modification the adjacent Eastern China Plains (ECP hereafter). of the radiative fluxes both at the top of the atmosphere and However, studies are very rare to examine CVS differ- at the earth’s surface. 'is radiative effect is largely related to ences between the TP and the ECP for a long time because it the cloud vertical structure (CVS) [1–3]. Because the CVS is difficult to make routine observations in the plateau, which leads to the lack of available data. Before the application of affects atmospheric circulation by determining the vertical gradient of radiative heating or cooling [4–6], it is very measurements of remote sensors onboard satellites, a few studies have focused on the clouds over the TP mainly based fundamental to accurately describe the geometrical prop- erties like the cloud top height and the cloud layer thickness, on the observations of the two Qinghai-Xizang Plateau as well as the microphysical properties like cloud phase and Meteorology Experiments carried out in 1979 and 1998, particle size under various cloud conditions. 'e effects of respectively [10, 11]. Fortunately, a lot of remote sensing CVS on atmospheric radiation and circulation have been data have been accumulated continually in recent years. 'e studied by a great number of numerical simulations [7]. 'e measurements of clouds provided by the International parameterization of CVS in the models proved to be critical Satellite Cloud Climatology Project (ISCCP) and Moderate for the performance of numerical simulations. Since the CVS Resolution Imaging Spectroradiometer (MODIS) almost 2 Advances in Meteorology study, we focused on the TP and the ECP to investigate their cover the whole globe [12]. 'ese newly available mea- surements have assembled a few features of the CVS over the characteristic CVS. Rather than the deep convective clouds, which constituted only a tiny part of the total amount of TP [13]. For instance, low-level clouds often cover the southern slope of the TP [14]. A lot of deep stratus clouds clouds (about 1%), all cloud types over both the TP and the (primarily the nimbostratus and altostratus) locating on the ECP in rainy season (from May to August) are analyzed. lee side of the TP during winter and spring are generated and maintained by the frictional and blocking effects [15]. On the 2. Data and Methods contrary, a lot of medium stratiform clouds locating at the eastern TP in cold seasons result from the dynamic effect of In this study, cloud information available in the joint the plateau [16]. Although the strongest convection occurs CloudSat/CALIPSO product 2B-GEOPROF-LIDAR [24, 28] over the Asian monsoon region to the south of the TP, the was used. 'e 2B-GEOPROF-LIDAR combined CloudSat convective clouds over the TP are shallower and less fre- CPR and CALIPSO Lidar cloud mask data, containing the quent, and embedded in small-size convective systems [17], cloud top heights and cloud base heights (above sea level) of and the DCSs over the TP were both weaker and smaller up to 5 layers at the CloudSat horizontal resolution of than those over its south slope [18]. Moreover, Precipitation ∼1.1 km (across and along track). 'e satellites orbit the Radar (PR) observations from the Tropical Rainfall Mea- earth roughly 14.5 times per day and provide more than 460 suring Mission (TRMM) satellite have been analyzed to 000 profiles. During hundreds of days in rainy seasons in compare the precipitation type and structure characteristics year 2006–2009, the total profiles collected all over the globe ° ° over the TP and East Asia, implying a large amount of clouds is more than 200 million. For each 1 × 1 grid in middle over the TP are weak convective ones [19]. In addition, Yan latitudes, the average number of profiles is more than 3000. et al. indicated that the topography-induced compression 'e data of cloud top height (CTH) were principally effect is also shown in the range in the variation of cloud used in this study. 'e CTH was defined as the distance from thickness and cloud top height corresponding to different sea level to the cloud top. Its value was from 0 to 25 km. 'e precipitation intensity, which is much smaller over the TP occurrences of CTH were the probability of cloud tops were than its neighboring regions [20]. Zhao et al. have indicated detected at a certain range of height (every 500 m here) in a that the convection over the Naqu region in the TP could period of time [29, 30]. Furthermore, the occurrences of impact rainstorms in the middle and lower reaches of the CTH for each rainy season in years 2006–2009 were selected Yangtze River Basin via a three-dimensional water vapor and then averaged for the designated areas (e.g., the TP and ° ° flux vortex structure [21]. 'ese studies have advanced the the ECP) or for each 1 × 1 grid box to get a higher hori- knowledge of the differences in CVS over the TP and its zontal resolution. surrounding regions. Regions defined in this study are highlighted with Nevertheless, Li et al. have pointed out that there is a polylines in Figure 1. 'e TP is the area closed by polylines ° ° ° ° large underestimation of low-level clouds and over- within 28 –39 N and 70 –101 E; the ECP is the area closed by ° ° ° ° estimation of middle-level clouds over the TP in both ISCCP polylines within 29 –37 N and 113 –120 E. D2 and the MODIS/Terra cloud products [22]. In addition, In addition, another CloudSat product called 2B- the measurements of the PR onboard TRMM satellite, de- GEOPROF was used in this study. 'e 2B-GEOPROF was termined mainly by large precipitation-sized hydrometeors, derived directly from the radar echo of the CPR [8]. It cannot be directly used to depict the vertical structures of presented a complete picture of cloud body and gave a direct clouds. 'is dilemma has been changed since the CloudSat view of the different detection results of clouds between the and CALIPSO satellites were launched and began collecting CPR and the Lidar (e.g., Figures 2(b) and 2(d)). 'e monthly data routinely [23]. 'e CPR on CloudSat operates at means from ECMWF Interim Reanalysis project [31] were 94 GHz and directly probes optically thick cloud layers along also used to illustrate the moisture condition, vertical ve- the satellite orbit [8]. 'e Cloud-Aerosol Lidar with Or- locity, tropopause height, and temperature profiles over the thogonal Polarization (Lidar) on CALIPSO has the unique TP and the ECP in rainy seasons. ability to sense optically thin cloud layers. By combining the two complementary measurements from the two sensors, 3. Comparing CVS with TP and ECP the merged products are generated by CloudSat Project, which is expected to produce a complete picture of the 3.1. Cloud Top. To catch a glimpse of the characteristics of occurrences of clouds and aerosols in the atmosphere the CVS over the TP and the ECP, we took two tracks [24, 25]. Sun et al. has used the CloudSat data to analyze the numbered 01630 and 01578 as examples to present the CVS associated with northward advance of the East Asian profiles of radar reflectivity factor and the cloud layers along summer monsoon [26]. Luo et al. has used the joint the tracks (Figure 2). 'e track numbered 01630 passed the CloudSat/CALIPSO data to compare deep convective clouds TP at UTC 07:35 on 18 Aug, 2006. 'e surface altitude over the TP and Asian monsoon regions, confirming sig- almost is 5 km above the footprints in the TP along the track. nificant differences in the deep convective cloud structures A few isolating and small convective clouds were detected by between the two regions [17]. Chen et al. have found that the CPR. 'ey extended from the surface to the high altitude, convective clouds over the TP are thinner than those over with the top height of about 13 km and the thickness of about east China, and the lifetimes of the deep cloud systems over 7 km. 'ere were still some cloud layers revealed by the the TP are shorter than those over east China [27]. In this information of Lidar above the cloud top detected by the Advances in Meteorology 3 40N 40N 35N 35N 30N 30N 25N 25N 70E 80E 90E 100E 110E 120E 130E 70E 80E 90E 100E 110E 120E 130E 3 6 9 12 15 (%) 369 12 15 (%) (a) (b) Figure 1: Occurrence averaged vertically for (a) range A and (b) range B both ranges A and B are defined as in Figure 3. 'e left closed region represents the TP, and the right closed region represents the ECP. CPR. 'ese cloud layers were over 15 km in height but less the western part of the TP and decreases gradually from west to east. It is clear that the great bigger occurrences over than 2 km in thickness. Detected by the Lidar but not the CPR, they were likely to be tenuous. 'e track numbered the TP than its surrounding regions, indicating that the 01578 passed the ECP at UTC 18:23 on 14 Aug, 2006. 'e topography conditions are the leading factor in affecting surface is flat and has an averaged altitude below 200 m along the CTH over the TP. However, the distribution of aver- the track. 'ere was a deep convective cloud detected by the aged occurrences of range B is not significantly related to CPR. It extended vertically from near the surface to about the topographies. It increases gradually from west to east 17 km, with a thickness of more than 15 km and a horizontal and peaks in the ECP and the offshore regions. 'e different scale of about hundreds of kilometers. Surrounding the top characteristics in horizontal distribution of clouds suggest of the deep convective cloud, there was a large cloud anvil that it is other one rather than topographies dominating the CTH over the ECP. detected by the Lidar. It is clear that there are different characteristics in size and thickness of the convective clouds Since the CTH is much different over the TP and the ECP, the cross sections of the occurrences along longitude over the TP and the ECP in rainy season. In addition, Figure 2 also revealed two pieces of important information. and latitude were examined to get more detailed vertical Firstly, a lot of tenuous clouds and anvils were omitted by the variation of it, as shown in Figure 4. 'e maximum oc- CPR but detected by the Lidar, indicating the 2B-GEO- currence in the vertical direction is located at the height of 7- PROF-LIDAR data combined from both the CPR and the 8 km. Although the upper boundary of CTH over the TP is Lidar have the potential of providing a more complete about 18 km, the occurrences of the CTH ranging from 10 to picture of the occurrences of clouds than the data from the 18 km are very tiny. From the TP to the ECP, the upper boundary of CTH descends slightly, but the height of the CPR only. Secondly, some high-level clouds and anvils overlapped over the low-level clouds formed multilayered maximum occurrence (HMO) increases greatly. 'e in- creasing of the HMO is sharpest over the Sichuan Basin clouds. Since more clouds were obtained from 2B-GEO- PROF-LIDAR, it was used rather than 2B-GEOPROF to located just on the east of the TP. It gets to the peak value exceeding 12 km over the ECP. On the contrary, the oc- analyze the detail CVS over the TP and the ECP in this study. Cloud top height is the most intuitive parameter currences of the CTH ranging from 3 to 10 km are very small reflecting the CVS. 'e vertical variation of the occurrences over the ECP. It is clearly found that the cloud top is elevated of CTH is presented in Figure 3. 'e maximum of the from the TP to the ECP, although the surface elevation occurrences (about 6.5%) over the TP is at the height of continues to fall. 7.5 km. 'is height is slightly larger than the average top 'e variation of CTH over the TP is also notable along height of low-level clouds reported in[25]. 'e reason is that latitude. Most cloud top is above 15 km in the south of the TP, which has intense convection in boreal summer. Al- we defined only the core plateau as the TP (Figure 1), where the average altitude of the surface is much higher. By added though the TP is adjacent to it, the most CTH over the TP is only 6–8 km. Low CTH is the most important characteristic with the higher elevation of surface, the average height of cloud tops is higher too. 'e occurrences over the ECP are of the TP’s clouds differing with that of its surrounding large near the surface (about 3% at 1 km), but the globe regions and the ECP. Without big mountains disturbing the maximum (about 5%) is found at the height of 11.5 km, boundary layer, the variation of CTH over the ECP is rather which is 4 km higher than that of the TP. monotonous. 'e HMO over the ECP descends gradually To realize the horizontal distribution of the clouds over with the increased latitude and always keeps over 10 km. the TP and the ECP, we averaged the occurrences of CTH 'e comparison of CTH over the TP and ECP shows that vertically for the range A and range B over the TP and the the clouds is much lower (from sea level) over the TP than its ECP, respectively, where the most concentrated cloud tops surrounding regions and the ECP, although they maintain on the highly elevated surface. 'is is consistent with pre- were found (Figure 3). 'e distribution of averaged oc- currences of range A shows a good correspondence with vious reports of the weaker deep convection and shallower deep clouds over the TP [17, 18]. topography (Figure 1(a)). 'e occurrences are biggest in 4 Advances in Meteorology 40N 40N 2006-08-18 0735UTC 01630 2006-08-14 1823UTC 01578 35N 35N 30N 30N 70E 80E 90E 100E 100E 110E 120E 130E 0 2500 5000 7500 m 0 2500 5000 7500 m (a) (d) 18 18 15 15 12 12 9 9 6 6 3 3 0 0 30N 32N 34N 36N 38N 40N 30N 32N 34N 36N 38N 40N –30 –20 –10 0 10 20 30 dBz –30 –20 –10 0 10 20 30 dBz (b) (e) 18 18 15 15 12 12 9 9 6 6 3 3 0 0 30N 32N 34N 36N 38N 40N 30N 32N 34N 36N 38N 40N L1 L2 L3 L4 L1 L2 L3 L4 (c) (f) Figure 2: Two cases of clouds over the TP (left panel) and ECP (right panel) detected by CPR and Lidar. (a) and (d): location of the tracks (black solid line) over different elevation area (color shading); (b) and (e): radar reflectivity measured in dBZ (color shading) along the tracks; and (c) and (f): vertical stratification of the clouds, L1 to L4 represent the separate cloud layers from bottom to top. 3.2.CloudClassification. As emphasized by Li et al. [22], the heights are below 6.0 km, between 6.0 and 9.2 km, and cloud classification should be modified over the TP. Ele- above 9.2 km, respectively. Accordingly, the cloud top vated by the surface mountains, the low-level clouds and heights of the three cloud types over the ECP are below middle-level clouds over the TP are difficult to be dis- 5.5 km, between 5.5 and 9.0 km, and above 9.0 km, tinguished as usual. A feasible scheme for classifying respectively. clouds over the TP and the ECP is thus necessary. Wood Figure 6 shows the horizontal distribution of occur- [32] had pointed out that the portion of the cloud profile rences for warm clouds, mixed-phase clouds, and ice clouds. colder than − 20 C is deemed pure ice, and the portion of 'e warm clouds are infrequent over the TP. Meanwhile, the the profile warmer than 0 C is considered pure liquid. We warm clouds have the largest occurrences just east to the TP also considered the cloud top temperature to be crucial in and show prevalence in the downstream of the TP. It clear classifying clouds, and thereby the climatologically av- that the characteristics of downstream flows of plateau are favorable for the development of warm clouds, which often eraged temperature profiles over the TP and the ECP were examined primarily (Figure 5). 'e temperature is slightly develop in stably stratified and weak turbulence low-level lower over the TP than that over the ECP at the height of atmosphere [17, 21]. 'e largest occurrences of mixed-phase below 10 km. 'e difference between them is about 2 C at clouds are found to locate just over the TP, where it is more the height of 5 km and then decreases with height. We than 30%. On the contrary, the mixed-phase clouds are treated the freezing level (the height of 0 C) as the bor- infrequent over the ECP. 'e occurrences of them are less derline separating warm clouds from mixed-phase clouds, than 10% in a big area of the ECP. Compared to the warm and the crystal level (the height of − 20 C) as the borderline clouds and mixed-phase clouds, the ice clouds have the most between the mixed-phase clouds and ice clouds. 'ere- insignificant difference between the TP and the ECP. 'e fore, the warm clouds, mixed-phase clouds, and ice clouds occurrences of ice clouds decrease gradually with increased over the TP are defined, respectively, as that whose top latitude over the both regions. It seems to be more closely Altitude (km) Altitude (km) Altitude (km) Altitude (km) Advances in Meteorology 5 0 2 4 68 Frequency (%) TP ECP Figure 3: 'e regionally averaged occurrence of CTH over the TP and the ECP. 20 20 20 15 15 15 10 10 10 5 5 5 0 0 0 70E 80E 90E 100E 110E 120E 130E 25N 30N 35N 40N 25N 30N 35N 40N (a) (b) (c) 2 4 6 810 12 (%) ° ° ° Figure 4: Cross sections of occurrence of CTH along longitude (a) averaged between 30 N and 35 N and latitude (b) averaged between 80 E ° ° ° and 95 E and (c) averaged between 110 E and 120 E. 'e thick solid line represents the height of maximum values. related to its location of latitude rather than the topographies two regions. 'e PD of cloud thickness around 4–8 km is of lower boundary. about 2% higher over the TP than that over ECP. However, We also examined the thicknesses of the warm clouds, there is almost no ice cloud thicker than 10 km over the TP, mixed-phase clouds, and ice clouds. Figure 7 shows the while it is about 1% over the ECP. probability density (PD) of the thicknesses of the three cloud 'e comparison of cloud classification and its thickness types individually. 'e warm clouds are generally thin, with reveals that there are two representative forms of cloud over thickness hardly more than 3 km over the TP. However, the the TP, the one is mixed-phase cloud and the other is medium-thickness ice cloud. On the contrary, there are two thickness of some warm clouds over the ECP is large (up to 6 km), although their PD is small. Most mixed-phase clouds representative forms of the cloud over the ECP too, the one over the TP are less than 3 km, while a large number of is low-level warm cloud, and the other is large-thickness ice mixed-phase clouds over the ECP are thicker than 5 km. 'e cloud. 'e reasons for the difference in the CVS between the thickness of ice clouds is significantly different between the TP and the ECP are discussed in Section 4. Altitude (km) Altitude (km) 6 Advances in Meteorology 9.2 km 9.0 km 6.0 km 5.5 km –60 –40 –20 0 20 t (°C) t, TP t, ECP Figure 5: Vertical profiles of temperature. 40N 40N 35N 35N 30N 30N 25N 25N 70E 80E 90E 100E 110E 120E 130E 70E 80E 90E 100E 110E 120E 130E 5 10 15 20 25 30 35 40 (%) 10 20 30 40 50 60 (%) (a) (b) 40N 35N 30N 25N 70E 80E 90E 100E 110E 120E 130E 10 20 30 40 50 60 70 80 (%) (c) Figure 6: Occurrence distributions of (a) warm clouds, (b) mixed-phase clouds, and (c) ice clouds. 3.3. Multilayered Clouds. In addition to top height and single-layered clouds and multilayered clouds during rainy classification, vertical stratification of the clouds is also an seasons are presented in Table 1. Single-layered clouds are important property of the CVS. 'e measurements of the prominent type over both the TP (62%) and the ECP clouds as combined observed by the CPR and the Lidar (51%), two-layered clouds ranks second with a similar have an outstanding ability to identify more than one cloud percentages over the TP (21%) and over the ECP (20%), and layer overlapped. It is easy to collect the information of the three-layered clouds are much less (only 3% over the TP number of cloud layers, top height, and base height of each and 4% over the ECP). Since the clouds with four to five cloud layer for a given profile by using the 2B-GEOPROF- layers are rare (less than 1%), they are not discussed in this LIDAR data. 'e statistic results of the occurrences of study. Altitude (km) Advances in Meteorology 7 60 20 45 15 30 10 15 5 0 0 0369 12 15 0369 12 15 Thickness (km) Thickness (km) (a) (b) 0 3 69 12 15 Thickness (km) (c) Figure 7: Probability density of thickness for (a) warm clouds, (b) mixed-phase clouds, and (c) ice clouds. probability of cloud layers to be overlapped. High cirrus Table 1: Occurrence of multilayered clouds (%). from residual deep convective clouds also has contribution Region Clear sky Single-layered Two-layered 'ree-layered to the occurrences of multilayered clouds. TP 12.92 62.29 20.74 3.03 Figure 9 shows the mean top height of the cloud layer of ECP 23.63 50.65 20.25 4.26 single-layered and multilayered clouds and its variance. 'e single-layered clouds over the TP and the ECP are almost the same in mean top height. But the mean top height of cloud Figure 8 shows the occurrences of single-layered clouds, layers over the TP is higher than that over the ECP. Es- two-layered clouds, and three-layered clouds. 'e distri- pecially, this bias in top height is largest in the lowest cloud bution of single-layered clouds shows a good agreement with layers and becomes smaller and smaller in the upper cloud the topographies of high land. Larger occurrences of single- layers. On the contrary, the cloud layers over the TP are layered clouds are a significant characteristic of the TP, thinner than that over the ECP, including both the single- especially over the western parts. 'e steady mechanical layered clouds and the multilayered clouds (Table 2). lifting on the windward slope sustained by low-level westerly flows is favorable for the forming of continuous shallow 4. Discussion clouds. Weak convections prevailing in the summer TP may also play a role in it. 'e distribution of multilayered clouds, As mentioned in Section 3, mixed-phase clouds and me- both the two-layered clouds and three-layered clouds, does dium-thickness ice clouds are most representative over the not show a significant consistency with the topographies. TP, while warm clouds and large-thickness ice clouds are 'e occurrences of multilayered clouds is depressive towards most representative over the ECP. We put forward that the high latitude. We found the largest occurrences of multi- differences in the CVS are mainly attributed to the distinct layered clouds to south of the TP, where the deep con- topographies and resulting moisture condition and atmo- vections are most frequent. As presented in Figure 2, deep spheric circulation. During most of the year, the TP has the convective clouds generally cover a vast area and have a highest rate of warming in the northern hemisphere. 'e bulky vertical extent as huge umbrellas, increasing the low-level warming sustains strong lifting to initiate the PDF (%) PDF (%) PDF (%) 8 Advances in Meteorology 40N 40N 35N 35N 30N 30N 25N 25N 70E 80E 90E 100E 110E 120E 130E 70E 80E 90E 100E 110E 120E 130E 30 40 50 60 70 80 (%) 10 20 30 40 50 (%) (a) (b) 40N 35N 30N 25N 70E 80E 90E 100E 110E 120E 130E 48 12 16 20 (%) (c) Figure 8: Occurrence distributions of (a) single-layered clouds, (b) two-layered clouds, and (c) three-layered clouds. Single-layered Two-layered Three-layered TP ECP Figure 9: Mean top height of the cloud layers of (a) single-layered, (b) two-layered, and (c) three-layered clouds. 'e error bars represent standard errors of the means. Table 2: Average thickness of cloud layers of single-layered and multilayered clouds (km). Two-layered 'ree-layered Region Single-layered FL SL FL SL TL TP 3.24± 2.35 2.02± 1.62 2.13± 1.49 1.56± 1.22 1.56± 1.11 1.79± 1.18 ECP 3.84± 3.55 2.20± 2.32 2.37± 1.76 1.59± 1.76 1.59± 1.19 1.87± 1.27 Statistical results are expressed as mean± variance. 'e FL, SL, and TL mean the first, second, and third cloud layer from surface to upper. convective motion. As shown in Figure 10, the TP has the the increased depression of the dew point with height, it is largest vertical velocity in the Eastern Asia between 30 N and clearly found that the air becomes more and more un- 35 N. In addition, because the low-level air approaches saturated in high levels. A dry environment is unfavorable saturation nearest, it is favorable for the development of for deep convection because the entrainment of drier en- convections and clouds formed within them. However, from vironmental air leads to stronger evaporative cooling and Altitude (km) Advances in Meteorology 9 80E 100E 120E 30N 40N 30N 40N 0.15 Pa/s (a) (b) (c) 4 6 8 10 12 14 16 °C ° ° Figure 10: Cross sections of depression of the dew point and vertical velocity along longitude (a) averaged between 30 N and 35 N and ° ° ° ° latitude (b) averaged between 80 E and 95 E and (c) averaged between 110 E and 120 E. A scale of vertical velocity is shown on the lower- right of the figure, and its units is Pa/s. 'e thick dashed line represents dynamic tropopause. buoyancy of saturated updrafts. In addition, the increased negative buoyancy so that the convections over the TP are difficult in transit from shallow to deep. On the contrary, the saturation level with height of environment air is more convection over the TP is usually small in size (Figure 2). favorable compared with that of the TP for maintaining and Because small-size clouds are more likely to be diluted by enhancing the deep convection too (Figure 10). mixing with dry air, they are not expected to have bulky vertical extent. 5. Conclusion Located downstream of the TP, the circulation of the ECP is significantly influenced by the blocking and frictional 'e CVS that is important in the atmospheric radiation was effects of big mountains. 'e downstream low-level con- examined over two designated regions, the TP and the ECP, vergence sustains large-scale steady lifting, while the mid- by using the 2B-GEOPROF-LIDAR data. Based on the case tropospheric westerly flows slowed down by the analysis and statistic calculation of the clouds during rainy mountainous surface generate downstream midlevel di- season in 2006–2009, the characteristics of cloud top height, vergence, resulting in the lifting is confined to the low cloud type, cloud thickness, and the number of vertical cloud troposphere. Figure 10 shows that the downstream flows are layers were revealed. Many distinct cloud features between climatologically weak uplifting or sinking and are most the TP and the ECP were clarified. unsaturated in midlevels. 'is environment is unfavorable Without the influence of topographies on clouds, the for the generation and development of clouds in midlevels, analysis of clouds over the ECP was documented and resulting in the smaller occurrences of mixed-phase clouds regarded as a reference. Over the ECP, the maximum oc- over the ECP. But why large-thickness ice clouds have a currence of CTH is found to be 5.1% occurring at 11.5 km. higher occurrence over the ECP than those over the TP? 'is 'is height is above the crystal level so that the ice clouds are could be explained in terms of the impacts of Asian mon- the predominant cloud type. A lot of ice clouds have soon. Deep convective clouds are the main source of large- thickness more than 10 km. Mixed-phase clouds are another thickness ice clouds. Kuang and Bretherton [33] had put type that has lower cloud top height between the crystal level forth that the development of deep convection depends on and the freezing level. 'ey are infrequent over the ECP. the moisture content of the free troposphere. Under the Warm clouds have no occurrences as large as the ice clouds. control of Asian summer monsoon, abundant water vapor is 'ey are lower top and shallow extent, prevailing down- converged over the ECP by the transportation of monsoon stream of the TP. From the statistical results of multiply flows, making shallow convections rapidly develop into deep layers of clouds, it is found that single-layered clouds are ones after moisture is added [34]. Strong synoptic-scale dominant with an averaged occurrence of more than 50%, systems occurs frequently over the ECP in summertime, and although a rather remarkable percentage of clouds have the deep convections associated with them are much larger more than one vertical cloud layer. 'e percentage of in size than that over the TP. Large-size clouds shield them multilayered clouds decreases sharply with the increased from deleterious effects of environment to maintain the number of their vertical cloud layers. Pressure (hPa) Height (km) 10 Advances in Meteorology As is well known, the main body of the TP is the highest monthly data. 'is work was funded by the National Basic region on the earth. 'e most notable difference of CVS with Research Program of China (41105031 and 91337213), Key that over the ECP is the height of maximum occurrence of Research and Development Plan of Anhui Province CTH. It is found to be 6.6% at 7.5 km, which is 4 km lower (1804a0802196), and National Key Research and Develop- than that of the ECP. 'e height of maximum occurrence is ment Plan (2018YFC0213806). below the crystal level but above the ice level. 'erefore, mixed-phase clouds rather than ice clouds become the References predominant type. Mixed-phase clouds over the TP are [1] F. Richter, K. Barfus, F. H. Berger, and U. Gorsdorf, ¨ “'e usually thinner than 5 km. 'e PD of cloud thickness influence of cloud top variability from radar measurements on manifests the prominent distinctions of ice clouds between 3-D radiative transfer,” Atmospheric Chemistry and Physics, the TP and the ECP. 'e PD of cloud thickness is about 2% vol. 7, no. 17, pp. 4699–4708, 2007. higher over the TP around 4–8 km but extremely lower [2] T. Varnai ´ and R. Davies, “Effects of cloud heterogeneities on exceeding 10 km, while it is about 1% over the ECP. shortwave radiation: comparison of cloud-top variability and Moreover, the cloud layers of multilayered clouds are higher internal heterogeneity,” Journal of the Atmospheric Sciences, and thinner over the TP than over the ECP. vol. 56, no. 24, pp. 4206–4224, 1999. 'ese distinct features in the CVS over the TP and the [3] P. J. Webster and G. L. Stephens, “Tropical upper-tropo- ECP are closely related to the atmospheric environment spheric extended clouds: inferences from winter MONEX,” Journal of the Atmospheric Sciences, vol. 37, no. 7, pp. 1521– affected by topographies. Initiated by low-level warming, 1541, 1980. convective activities are frequent over the TP. But the [4] Z. Feng, X. Dong, B. Xi, C. Schumacher, P. Minnis, and convections are difficult to transit from shallow to deep due M. Khaiyer, “Top-of-atmosphere radiation budget of con- to the rapidly diminished moisture with height. Shallow vective core/stratiform rain and anvil clouds from deep convections prevailing over the TP increase the PD of convective systems,” Journal of Geophysical Research: At- mixed-phase clouds and ice clouds with medium thickness. mospheres, vol. 116, no. 23, 2011. Located downstream of the TP, the lifting over the ECP is [5] W. Li, C. Schumacher, and S. A. McFarlane, “Radiative climatologically confined to the lower troposphere, leading heating of the ISCCP upper level cloud regimes and its impact to the less of mixed-phase clouds. On the contrary, the ECP on the large-scale tropical circulation,” Journal of Geophysical is under the control of Asian monsoon, which has routinely Research: Atmospheres, vol. 118, no. 2, pp. 592–604, 2013. intense synoptic-scale cyclone activities in summer. Deep [6] T. Vaillant de Guelis, H. Chepfer, V. Noel et al., “'e link between outgoing longwave radiation and the altitude at convections and strong precipitations usually occur asso- which a spaceborne lidar beam is fully attenuated,” Atmo- ciated with the development of synoptic-scale systems, spheric Measurement Techniques, vol. 10, no. 12, pp. 4659– resulting in the increased probability of ice clouds that 4685, December 2017. consist of deep convective clouds and high cirrus from their [7] J. Wang and W. B. Rossow, “Effects of cloud vertical structure residual. on atmospheric circulation in the GISS GCM,” Journal of Based on the analysis of properties of the CVS, an ex- Climate, vol. 11, no. 11, pp. 3010–3029, 1998. tended knowledge of the clouds over the plateau and the [8] G. G. Mace, R. Marchand, Q. Zhang, and G. Stephens, “Global plains was presented. 'ese detailed characteristics of the hydrometeor occurrence as observed by CloudSat: initial CVS present a close linkage of it and the circulation envi- observations from summer 2006: CLOUDSAT hydrometeor ronment on different topographies. 'ese results are critical occurrence,” GeophysicalResearch Letters, vol. 34, no. 9, 2007. [9] E. Weisz, J. Li, W. P. Menzel, A. K. Heidinger, B. H. Kahn, and in understanding the impacts of topographies on the climate C.-Y. Liu, “Comparison of AIRS, MODIS, CloudSat and and may be necessary for the parameterization of clouds in CALIPSO cloud top height retrievals,” Geophysical Research numerical models. Letters, vol. 34, no. 17, 2007. [10] J. Yang, S. Tao, Z. Gu, and D. Ye, Meteorology of Tibetan Data Availability Plateau, Science Press, Beijing, China, 1960. [11] D. Ye and Y. Gao, Meteorology of theQinghai-Xizang Plateau, 'e CloudSat/CALIPSO data used to support the findings of Science Press, Beijing, China, 1979. this study may be released upon application to the CloudSat [12] W. B. Rossow and R. A. Schiffer, “Advances in understanding Data Processing Center (CloudSat DPC), who can be clouds from ISCCP,” Bulletin of the American Meteorological contacted at cloudsat@colostate.edu. Society, vol. 80, no. 11, pp. 2261–2287, 1999. [13] B.-C. Gao, P. Yang, G. Guo, S. K. Park, W. J. Wiscombe, and B. Chen, “Measurements of water vapor and high clouds over Conflicts of Interest the Tibetan plateau with the terra modis instrument,” IEEE Transactions on Geoscience and Remote Sensing, vol. 41, no. 4, 'e author declares that there are no conflicts of interest pp. 895–900, 2003. regarding the publication of this paper. [14] Y. Kurosaki and F. Kimura, “Relationship between topog- raphy and daytime cloud activity around Tibetan plateau,” Acknowledgments Journal of the Meteorological Society of Japan, vol. 80, no. 6, pp. 1339–1355, 2002. 'e author greatly appreciates the NASA CloudSat project [15] R. Yu, B. Wang, and T. Zhou, “Climate effects of the deep for providing the CloudSat/CALIPSO dataset and the continental stratus clouds generated by the Tibetan plateau,” ECMWF Interim Reanalysis project for providing the Journal of Climate, vol. 17, no. 13, pp. 2702–2713, 2004. Advances in Meteorology 11 [16] Y. Li, R. Yu, and Y. Xu, “'e formation and diurnal changes Cooperative Institute for Research in the Atmosphere (CIRA), OF stratiform clouds IN southern China,” Acta Meteorologica Fort Collins, CO, USA, 2008. [33] Z. Kuang and C. S. Bretherton, “A mass-flux scheme view of a Sinica, vol. 61, no. 6, pp. 733–743, 2003. [17] Y. Luo, R. Zhang, W. Qian, Z. Luo, and X. Hu, “In- high-resolution simulation of a transition from shallow to deep cumulus convection,” Journal of the Atmospheric Sci- tercomparison of deep convection over the Tibetan plateau- ences, vol. 63, no. 7, pp. 1895–1909, 2006. Asian monsoon region and subtropical north America in [34] M. Yi, Y. Fu, P. Liu, Y. Gao, and X. Hong, “Analysis of the boreal summer UsingCloudSat/CALIPSO data,” Journal of variation of atmospheric composition in the upper tropo- Climate, vol. 24, no. 8, pp. 2164–2177, 2011. sphere during a strong convection in eastern China in [18] G. Gao, Q. Chen, H. Cai, Y. Li, and Z. Wang, “Comprehensive summer,” Chinese Journal of Atmospheric Sciences, vol. 36, characteristics of summer deep convection over Tibetan no. 5, pp. 901–911, 2012. plateau and its south slope from the global precipitation measurement core observatory,” Atmosphere, vol. 10, no. 1, 9 pages, 2019. [19] Y. Fu, G. Liu, G. Wu et al., “Tower mast of precipitation over the central Tibetan Plateau summer,” Geophysical Research Letters, vol. 33, no. 5, 2006. [20] Y. Yan, Y. Liu, and J. Lu, “Cloud vertical structure, pre- cipitation, and cloud radiative effects over Tibetan Plateau and its neighboring regions,” Journal of Geophysical Research: Atmospheres, vol. 121, no. 10, pp. 5864–5877, 2016. [21] Y. Zhao, X. Xu, L. Liu et al., “Effects of convection over the Tibetan plateau on rainstorms downstream of the Yangtze River basin,” Atmospheric Research, vol. 219, pp. 24–35, 2019. [22] Y. Li, X. Liu, and B. Chen, “Cloud type climatology over the Tibetan Plateau: a comparison of ISCCP and MODIS/TERRA measurements with surface observations,” Geophysical Re- search Letters, vol. 33, no. 17, 2006. [23] G. L. Stephens, D. G. Vane, R. J. Boain et al., “'e cloudsat mission and the A-train,” Bulletin of the American Meteo- rological Society, vol. 83, no. 12, pp. 1771–1790, 2002. [24] G. G. Mace et al., “A description of hydrometeor layer oc- currence statistics derived from the first year of merged Cloudsat and CALIPSO data,” Journal of Geophysical Re- search, vol. 114, 2009. [25] C. M. Naud and Y.-H. Chen, “Assessment of ISCCP cloud- iness over the Tibetan plateau using CloudSat-CALIPSO,” J. Geophys. Res., vol. 115, no. 10, 2010. [26] G. Sun, Y. Li, and J. Lu, “Cloud vertical structures associated with northward advance of the East Asian summer monsoon,” Atmospheric Research, vol. 215, pp. 317–325, 2019. [27] J. Chen, X. Wu, Y. Yin, Q. Huang, and H. Xiao, “Charac- teristics of cloud systems over the Tibetan plateau and east China during boreal summer,” Journal of Climate, vol. 30, no. 9, pp. 3117–3137, 2017. [28] G. Stephens, D. Winker, J. Pelon et al., “CloudSat and CALIPSO within the A-train: ten years of actively observing the earth system,” Bulletin of the American Meteorological Society, vol. 99, no. 3, pp. 569–581, 2018. [29] S.-W. Kim, E.-S. Chung, S.-C. Yoon, B.-J. Sohn, and N. Sugimoto, “Intercomparisons of cloud-top and cloud-base heights from ground-based Lidar, CloudSat and CALIPSO measurements,” International Journal of Remote Sensing, vol. 32, no. 4, pp. 1179–1197, 2011. [30] K. L. Verlinden, D. W. J. 'ompson, and G. L. Stephens, “'e three-dimensional distribution of clouds over the southern hemisphere high latitudes,”Journalof Climate, vol. 24, no. 22, pp. 5799–5811, 2011. [31] D. P. Dee, “'e ERA-Interim reanalysis: configuration and performance of the data assimilation system,” Quarterly Journal of the Royal Meteorological Society, vol. 137, no. 656, pp. 553–597, 2011. [32] N. 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