Effects of Aerosols on the Precipitation of Convective Clouds: A Case Study in the Yangtze River Delta of China
Effects of Aerosols on the Precipitation of Convective Clouds: A Case Study in the Yangtze River Delta of China
复制标题
气溶胶对对流云降水的影响：以中国长三角地区为例
DOI：
10.1029/2018jd029924
复制
发表时间：
2019
影响因子：
4.4
通讯作者：
Yang Xiu Qun
中科院分区：
文献类型：
--
作者：
Liu Chong;Wang Ti Jian;Chen Pu Long;Li Meng Meng;Zhao Ming;Zhao Kun;Wang Ming Huai;Yang Xiu Qun
气溶胶是影响大气水循环和气候变化的关键因素。气溶胶作为云形成的凝结核，对区域降水有重要影响。本研究利用天气研究预报模式中的全耦合化学模块(Weather Research and Forecast/Chem)，对中国所在的长江三角洲地区的对流云降水进行了数值模拟。为了研究其对降水的影响，进行了四个数值试验。基本情况使用全部排放清单(我们称为100%情况)，其他三种情况基于不同百分比的减排量设计(我们称为50%情况、10%情况和1%情况)。与其他个例相比，50%个例的网格点小时最大降水量最大，可达44.1毫米/小时，比100%个例增加5%。50%情况下，最强降水延迟约1小时，降水面积增加6.5%。研究表明，气溶胶对区域降水的影响是一个非线性过程，相关系数为0.5 2(p<；0.0 1)，表明云凝结核(>；2 5 0 cm−3，高度0.5~3 km)与降水有很强的正相关关系。对这次对流降水的动力学和微物理过程的进一步分析表明，50%个例的上升速度和云水混合比较大，但对流中心相对较低。降水的形成主要受雨积雪的影响，但融雪成雨的作用不容忽视。
Aerosol is a critical factor affecting the atmospheric hydrological cycle and climate change. Acting as cloud condensation nuclei for cloud formation, aerosols have a significant impact on regional precipitation. This study uses the fully coupled chemistry module (Weather Research and Forecasting/Chem) within the Weather Research and Forecasting model to simulate convective cloud precipitation in the Yangtze River Delta of China. To investigate the impact of on precipitation, four numerical experiments are conducted. The base case uses the full emission inventory (which we call the 100% case), and the other three cases are designed based on reduced emissions for different percentages (which we call the 50% case, the 10% case, and the 1% case). Compared to the other cases, the grid point hour maximum precipitation of the 50% case is the largest, which can reach 44.1 mm/hr and has an increase of 5% over the 100% case. The strongest precipitation is delayed by about 1 hr in the 50% case, and precipitation area is increased by 6.5%. This study indicates that the influence of aerosols on regional precipitation is a nonlinear process, with a correlation coefficient of 0.52 (p<0.01) showing a strong positive correlation between cloud condensation nuclei (>250 cm−3, height of 0.5–3 km) and precipitation. Further analysis of the dynamics and microphysical processes of this convective precipitation shows that the 50% case has an area with higher rising velocity and bigger cloud water mixing ratio than the other cases but has a relatively low convective center. The formation of precipitation is mainly influenced by the accretion of snow by rain, but the role of the snow melting into rain cannot be ignored.