MOPITT与MLS观测的CO浓度在200 hPa的差异及其原因分析

具有较优垂直分辨率和反演精度的MLS（Microwave Limb Sounder）数据与MOPITT（Measurements of Pollution in the Troposphere）数据在上对流层—下平流层（UT-LS）区域有一个交集,因而将MOPITT与MLS测量的200 hPa高度上CO数据进行对比分析。比较结果显示,两者在中低纬度分布较为接近,在非洲中西部、南美中北部和东南亚地区均有大范围高值中心区存在;MOPITT CO在浓度值上明显高于MLS CO,并且MOPITT CO浓度在低纬度存在约35 ppb（10-6）的全球性系统性偏差。通过CALIOP云层数据对MOPITT和MLS CO差异原因进行分析,表明CO高值区的形成与旺盛的对流有关。

Differences between CO Concentrations from MOPITT Data and MLS Data at 200 hPa and Their Cause Analysis

Data from the microwave limb sounder (MLS) has better vertical resolution and inversion accuracy but intersects with measurements of pollution in the troposphere (MOPITT) data from the upper troposphere-lower stratosphere (UT-LS) region. In this paper, we compare MOPITT CO data with MLS CO data at 200 hPa. The results indicate that the CO distributions of both are similar in the middle and low latitudes, and high CO concentrations occur in Midwest, South-Central, and South-East Asia. In general, the concentration values of MOPITT CO are higher than those of MLS, and MOPITT CO shows a global system bias of about 35 ppb (10^-6) at low latitudes. The difference between MOPITT and MLS CO values was analyzed using CALIOP cloud data, and it was found that the occurrence of high CO concentration zones is related to strong convection.