Climatology of Tibetan Plateau Vortices and Connection to Upper-level Flow in Reanalysis Data and a High-resolution Model Simulation
Source: LASG Viewed: time(s) Time: 2017-3-2
National Centre for Atmospheric Science, University of Reading, UK
10:00 am, 2 March, 2017
No.303, Keyan Building
Mesoscale Tibetan Plateau Vortices (TPVs) are one of the major precipitation-bearing systems on the Tibetan Plateau. Most TPVs originate and stay on the TP, while a smaller number moves off the plateau to the east, where they can cause extreme precipitation events. We identify and track TPVs in reanalysis data and in a high-resolution, present-day climate model simulation of the MetOffice Unified Model (UPSCALE) using the TRACK algorithm developed by Hodges et al. (1994). The aim of the study is to connect the TPV activity to the upper-level flow (position and strength of the subtropical jet stream), to determine favourable conditions for TPV development and maintenance, and to assess how well the model represents the TPV climatology and variability. We find that the reanalysis data sets and the model show similar results for the statistical measures of TPVs (genesis, track, and lysis density).