基于地震监测应用的地表温度和长波辐射数据对比分析

A comparative analysis between land surface temperature and outgoing long wave radiation based on the application of earthquake monitoring

从数据本身特征及其应用2个方面对地震监测中常用的地表温度(land surface temperature,LST)和长波辐射(outgoing longwave radiation,OLR)数据进行了对比分析。利用全球数据进行的对比分析结果表明,2种数据在高纬度和中纬度地区具有空间分布上的一致性,但在赤道及低纬度地区则表现出明显差异,认为这一差异与云量分布关系密切;根据我国大陆的云量分布特点选择特征点进行LST和OLR的对比分析表明,云量大于65%的区域,二者的同步性较差,云量低于65%的区域,则同步性较好。据此,以同步性较好的青海地区和同步性较差的中南部区域为试验区,对比了2种数据的涡度计算结果。研究表明,在地震监测应用中,利用2种数据获得的地震异常信息在时、空、强特征上表现为相同或不同都是可能的,LST主要是对增温现象的反映,而OLR则侧重于对整个地-气系统异常的综合反映。

Land surface temperature （ LST） and outgoing long wave radiation （ OLR） , which are commonly used in seismic monitoring, were compared and analyzed from their own characteristics and seismic applications. The analytical results of the global data show that LST and OLR at high latitudes and mid - latitudes have the consistency in spatial distribution, but show a significant difference in equatorial and low -latitude regions, and this difference is closely related to the global total cloud amount. The results of feature points selected according to the cloudiness distribution in China ’ s mainland show that LST and OLR have poor synchronization in the region whose cloud amount is greater than 65% and show better synchronization in the region whose cloud amount is less than 65%. On such a basis, the authors selected Qinghai region where the synchronization is relatively good and mid-south China where the synchronization is poor as the test areas. The results achieved show that the spatial, temporal and intensity characteristics of two types of data can be either identical or different, as shown by the comparison between the two computing results using the vorticity method. LST mainly reflects the warming temperature phenomenon whereas OLR is focused on a comprehensive reflection of the whole earth -atmosphere system.