利用掩星数据研究全球对流层顶断裂带变化

A study on variations of the global tropopause break area by using radio occultation data

应用掩星数据研究全球对流层顶断裂带的变化.介绍了温度递减率定义下的对流层顶的判别原理和算法,并且把由掩星数据判别的对流层顶与探空仪数据获得的对流层顶作比对,验证掩星对流层顶数据的可靠性.进一步给出了通过生成的对流层顶数据获得对流层顶断裂带的原理和算法.选用2006年7月到2008年12月COSMIC掩星数据,分析了南北半球不同季节对流层顶断裂带的经度变化,对两个半球断裂带进行了对比,暖季对流层顶断裂带的纬度最高,南半球断裂带在38°S附近,北半球断裂带则在42°N附近,季节过渡月份5月两个半球的对流层顶断裂带纬度都达到了最低点.对北半球对流层顶断裂带参数变化进行了讨论,发现了全球六个对流层顶断裂带异常变化的地区.其中四个地区都处在海陆交界处,进一步对大陆和海洋的对流层顶断裂带的月变化进行了对比,发现大陆地区对流层顶断裂带所处纬度更高、断裂程度更大.

The variations of the global tropopause break area is discussed based on Global Positioning System（GPS） radio occultation（RO） data. The algorithm of LRT tropopause is defined by WMO and results are compared with operational radiosonde data to validate its veracity. A new algorithm of detecting tropopause break is put forward in this paper . Using the 2.5 years （2006.7~2008.12） the Constellation Observing System for Meteorology Ionosphere and Climate （COSMIC） data , the longitudinal variations of tropopause break in different seasons is analyzed and the difference between southern hemisphere and northern hemisphere is discussed. Tropopause break latitude is higher in summer than in winter and it is 38~S in southern hemisphere and 42~N in northern hemisphere. The lowest latitude of two hemispheres both emerge in May. The parameters of tropopause break are discussed, six abnormal variation areas are found in which there are four areas lying in the area marching with land and ocean. Thereby the paper continues discussing the mensal variation between land and ocean. Results on higher latitude and bigger breaking degree in the land than in the ocean are updated.