TRMM-Based Optical and Microphysical Features of Precipitating Clouds in Summer Over the Yangtze–Huaihe River Valley, China
- 97 Downloads
The optical and microphysical features of precipitating clouds are key information for studying the satellite-based precipitation estimation, cloud radiative effects, aerosol–cloud–precipitation interactions, cloud and precipitation parameterization in weather and climate models. In this study, 15-year synchronous spectral and radar observations from the TRMM satellite were used to statistically explore the optical and microphysical features of precipitating clouds (PCs), including cloud effective radius (CER), cloud optical thickness (COT), cloud water path (CWP), thermal infrared brightness temperature at channel 4 (TB4) of cloud top, and storm top height (STH) and their relationships with surface rain rates in summer over Yangtze–Huaihe River Valley (YHRV). Results show that the optical and microphysical features of PCs/stratiform PCs/convective PCs vary with geographical locations in summer over YHRV, due to the different ambient meteorological and topographical conditions. Higher CER/COT/CWP/STH and lower TB4 mainly locate at areas of bigger rain rates. For PCs, their spatial distribution of CER is mainly dominated by stratiform PCs, while their spatial distribution of COT/CWP is mainly dominated by convective PCs. Moreover, stratiform precipitation is the dominant form in summer over YHRV and, thus, most PCs present vertical structures of optical and microphysical features as stratiform PCs. Stratiform PCs are usually thicker and contain more water vapor with bigger cloud particles than convective PCs (including deep and shallow convective PCs). In addition, existing shallow convective PCs are associated with lower storm heights and warmer cloud tops. Finally, surface rain rates of PCs (convective/stratiform PCs) increase gradually with the increment of CER/COT/CWP/STH, especially under 5 (15/5) mm/h. Similar relationship between surface rain rates and COT/CWP for shallow convective PCs is also found under 0.75 mm/h. Surface rain rate of PCs (convective/stratiform PCs) with cold cloud tops (TB4 < 247 K) obviously increases as TB4 decreases. Differently, for shallow convective PCs with warmer cloud tops (TB4 > 264 K), surface rain rate usually increases as CER decreases, which suggests that aerosol indirect effects are dominant in lower PCs, because over pollution regions abundant aerosols enter into lower clouds more easily and then suppress the development of shallow convective PCs.
KeywordsOptical feature microphysical feature precipitating clouds TRMM Yangtze–Huaihe River Valley
We appreciate the comments and suggestions of the editors and anonymous reviewers. Many thanks are extended to Japan Aerospace Exploration Agency and Goddard Space Flight Center for providing PR 2A25 and VIRS data. This work is jointly supported by the National Key Projects of Ministry of Science and Technology of China (2016YFA0602100 and 2017YFC1501402), the National Natural Science Foundation of China (41675009, 41675041, 41601550, 41620104009, 41230419 and 41505004), the Startup Foundation for Introducing Talent of NUIST, the Startup Foundation for Anhui Meteorological Bureau (RC201703), Jiangsu Provincial Natural Science Fund Project (BK20150910), Natural Science Foundation of Anhui Province (1808085MD99), Huaihe river basin meteorological open fund (HRM201507), the Open Project Program (KLME1508) of the Key Laboratory of Meteorological Disaster of Ministry of Education at Nanjing University of Information Science and Technology, and The Startup Foundation for Introducing Talent of NUIST.
- Fu Y., F. Chen, G., Liu, et al. (2016). Recent trends of summer convective and stratiform precipitation in Mid-Eastern China, Scientific Reports, 6, 33044. https://doi.org/10.1038/srep33044.
- Guo J. P., Deng, M. J., Fan, J. et al. (2014). Precipitation and air pollution at mountain and plain stations in northern China: Insights gained from observations and modeling, Journal of Geophysical Research-Atmosphere, 119 (8), 4793–4807. 10.10022013JD021161.Google Scholar
- Awaka J., Iguchi, T., Okamoto, K. (1998). Early results on rain type classification by the Tropical Rainfall Measuring Mission (TRMM) precipitation radar. Proc 8th URSI Commission F Open Symp, Aveiro, Portugal, 143–146.Google Scholar
- Yang, Y. J., Fu, Y. F., Chen, F. J. et al. (2014). Spectral characteristics of precipitating clouds during the Meiyu over the Yangtze-Huaihe River Valley from merged TRMM precipitation radar and visible/infrared scanner data. Proceedings of the SPIE 9259, Remote Sensing of the Atmosphere, Clouds, and Precipitation V, Beijing, China, 13 October, SPIE, 92591 K, https://doi.org/10.1117/12.2069118.