资源环境科技发展态势分析平台

In this study, we examined the relationship between the mid-latitude circulation and the extended winter (November-February) precipitation over the Arabian Peninsula by using observational and NCEP/NCAR reanalysis data (1948-2012). Special emphasis is given to a mid-latitude circumglobal wave train (CGT) that is known to influence the precipitation in the northern hemisphere during both winter and summer seasons. We found a linkage between mid-latitude CGT and winter precipitation over the Arabian Peninsula. The CGT wavelike pattern is associated with anomalous trough above western parts and high pressure over eastern parts of Arabian Peninsula. At lower levels, the CGT is associated with anomalous low over northwestern and high over southeastern parts of the Arabian Peninsula and adjacent parts of the Arabian Sea. The anomalous circulation is further associated with a precipitation pattern over the Arabian Peninsula entailing significantly enhanced precipitation over the central and northwestern parts and reduced precipitation over southeastern parts of the Arabian Peninsula. We further examined the global teleconnection pattern using a precipitation index summarizing winter precipitation over the Arabian Peninsula. The upper-level signature associated with the precipitation index resembles the CGT-like wave pattern with anomalous low over northwestern parts and high over southeastern parts of the Arabian Peninsula. The imprint of the CGT on winter precipitation over the Arabian Peninsula is distinct from that of the North Atlantic Oscillation (NAO), despite the two modes of variability bear some similarities in their upper-level atmospheric pattern above the Arabian Peninsula.