基于云水资源及其相关组成量和特征量的定义和计算式,本研究在中国气象科学研究院自主研发的CAMS云微物理方案中增加了相应的的计算方案,建立了云水资源的数值模拟定量估算方法(CWR-NQ).通过仅改变边界条件,实现了华北地区连续一年云水资源的数值模拟估算和检验.主要结果如下:(1)模式能够保持稳定连续运行,且连续一年模拟后,区域内大气水凝物和总水物质的收入项与支出项相差小于0.2%,符合守恒性的要求.(2)将模拟的水汽年平均空间分布、总云量的年平均空间分布、年累积降水的空间分布以及逐日降水强度与观测资料对比,结果较为一致.(3)与云水资源的诊断估算方法对比发现,在云水资源的组成量中,水汽平流量及其总量、地表蒸发和地面降水量、云净凝结量和大气水物质总量等物理量的偏差不到5%,主要差别在于云凝结(Chv)和云蒸发(Cvh),但净凝结(云凝结-云蒸发)的偏差不到1%.(4)研究了华北区域云水资源时间特性和空间特征,详细分析了水汽辐合与降水在月、季尺度的正相关性以及时、日尺度上水汽辐合到降水存在的滞后,指出状态量在时、日时间尺度上的重要性,分析了不同空间尺度对状态量、平流量、源汇项和总量的影响,指出了平流量在不同空间尺度下的巨大差异,导致水汽、水凝物总量和云水资源等特征量的空间尺度差异.
Based on the concept of cloud water resource (CWR) and the cloud microphysical scheme developed by the Chinese Academy of Meteorological Sciences (CAMS), a coupled mesoscale and cloud-resolving model system is developed in the study for CWR numerical quantification (CWR-NQ) in North China for 2017. The results show that (1) the model system is stable and capable for performing 1-yr continuous simulation with a water budget error of less than 0.2%, which indicates a good water balance. (2) Compared with the observational data, it is confirmed that the simulating capability of the CWR-NQ approach is decent for the spatial distribution of yearly cumulative precipit- ation, daily precipitation intensity, yearly average spatial distribution of water vapor. (3) Compared with the CWR diagnostic quantification (CWR-DQ), the results from the CWR-NQ differ mainly in cloud condensation and cloud evaporation. However, the deviation of the net condensation (condensation minus evaporation) between the two methods is less than 1%. For other composition variables, such as water vapor advection, surface evaporation, precip- itation, cloud condensation, and total atmospheric water substances, the relative differences between the CWR-NQ and the CWR-DQ are less than 5%. (4) The spatiotemporal features of the CWR in North China are also studied. The positive correlation between water vapor convergence and precipitation on monthly and seasonal scales, and the lag of precipitation relative to water vapor convergence on hourly and daily scales are analyzed in detail, indicating the significance of the state term on hourly and daily scales. The effects of different spatial scales on the state term, ad- vection term, source–sink term, and total amount are analyzed. It is shown that the advective term varies greatly at different spatiotemporal scales, which leads to differences at different spatiotemporal scales in CWR and related characteristic quantities.