利用探空秒数据估算北京地区日最大混合层高度

研究利用北京地区L波段探空秒数据和地面日最大位温, 采用气块法反演北京地区日最大混合层高度(MMH)的可行性。将08时探空秒数据以及常规探空数据反演结果分别与对应的微脉冲激光雷达反演结果相比较, 发现前者与激光雷达反演结果的一致性好于后者, 常规探空数据垂直空间分辨率低可能是导致其反演结果误差较大的原因。分别用春夏秋冬的探空秒数据反演结果与激光雷达反演结果相比较, 发现春夏秋反演结果的一致性较好, 而冬季较差。利用08时探空秒数据结合地面日最大位温, 采用气块法反演北京地区2010—2017年的MMH, 发现MMH 每年均表现出春夏秋冬逐次递减的分布特征。通过对长期资料的统计分析发现, 北京地区日地面最高气温与850 hPa温度差定义的热力稳定度与MMH之间存在较强的正相关性。

Estimating the Daily Atmospheric Maximum Mixing Height with 1-Second Sounding Data over Beijing Area

Basing on the 1-second sounding data from L-band radar and the daily max potential surface air temperature over Beijing, the possibility of deriving the daily maximum mixing layer height (MMH) over Beijing region by the parcel method was studied. By comparing the inversion results of the 1-second sounding data and the conventional sounding data at local time 08:00 with the inversion results from a micro pulse lidar (MPL), it is found that the consistency between the former and the MPL results is better than the latter. The reason for the larger bias from the conventional data results may be due to their lower vertical resolution. By comparing the inversion results of the 1-second sounding data in spring, summer, autumn and winter respectively with the results from the MPL, it is found that the consistency is better in spring, summer and autumn, but it is worse in winter. Long-term data results of the MMH over Beijing area from 2010 to 2017 were obtained using the 1-second sounding data at local time 08:00 and the daily maximum potential surface air temperature. It is found that the MMH almost showed a decreasing characteristic from spring to summer, to autumn and to winter successively. With the long-term results, it is found that the thermal stability defined by the difference of the daily max surface air temperature and temperature at the layer of 850 hPa was strongly positively correlated with the MMH in Beijing area.