Article
Boreal Summer Synoptic-Scale Waves over the Western North Pacific in Multimodel Simulations
Journal of Climate
Zhao Haikun; Jiang Xianan; Wu Liguang
Abstract
During boreal summer,vigoroussynoptic-scalewave(SSW)activity,oftenevidentassoutheast–northwestoriented wave trains, prevails over the western North Paci?c (WNP). In spite of their active role for regional weather and climate, modeling studies on SSWs are rather limited. In this study, a comprehensive survey on climatemodelcapabilityinrepresentingtheWNPSSWsisconductedbyanalyzingsimulationsfrom27recent general circulation models (GCMs). Results suggest that it is challenging for GCMs to realistically represent the observed SSWs. Only 2 models out of the 27 GCMs generally well simulate both the intensity and spatial pattern of the observed SSW mode. Plausible key processes for realistic simulations of SSW activity are further explored. It is illustrated that GCM skill in representing the spatial pattern of the SSW is highly correlatedtoitsskillinsimulatingthesummermeanpatternsofthelow-levelconvergenceassociatedwiththe WNP monsoon trough and conversion from eddy available potential energy (EAPE) to eddy kinetic energy (EKE). Meanwhile, simulated SSW intensity is found to be signi?cantly correlated to the amplitude of 850-hPa vorticity, divergence, and conversion from EAPEto EKE over the WNP. The observed modulations of SSW activity by the Madden–Julian oscillation are able to be captured in several model simulations.
Zhao H, Jiang X, Wu L. Boreal Summer Synoptic-Scale Waves over the Western North Pacific in Multi-model Simulations[J]. Journal of Climate, 2016, 29(12).
