Seasonal Dependence of Cold Surges and their Interaction with the Madden–Julian Oscillation over Southeast Asia

作者：Prince Xavier, See Yee Lim, Muhammad Firdaus Ammar Bin Abdullah, Michael Bala, Sheeba Nettukandy Chenoli, Asteria Satyaning Handayani, Charline Marzin, Donaldi Sukma Permana, Fredolin Tangang, K. D. Williams, Diong Jeong Yik · 发表于：Journal of Climate · 年份：2019 · DOI：10.1175/jcli-d-19-0048.1 · 被引用次数：74 · 研究领域：Climate variability and models、Meteorological Phenomena and Simulations、Tropical and Extratropical Cyclones Research

Abstract Northeasterly cold surges strongly influence the rainfall patterns over the Malay Peninsula during the northeast monsoon season. This study looks at the changes in the cold surges and Madden–Julian oscillation (MJO) characteristics through the northeast monsoon season and their interaction. Nearly 75% of the cold surge events tend to cross the equator around the Java Sea area (100°–110°E) in February–March with drier conditions prevailing over the Malay Peninsula and increased rainfall over Java. Both the cold surges and the MJO undergo seasonal variations with well-defined regional features. Wavelet analysis shows that MJO amplitude and high-frequency rainfall variations over Southeast Asia peak in November–December. MJO amplitude is suppressed during February and March. This is linked to the high-frequency surges of meridional winds that are prominent during the early part of the season, but February–March is dominated by low-frequency (~20–90 days) cross-equatorial monsoon flow. These prolonged periods of strong meridional flow at the equator interact with the MJO both dynamically and thermodynamically and act as a barrier for convection from propagating from the Indian Ocean to the Maritime Continent (MC). These interactions may have implications for weather and seasonal forecasting over the region. An evaluation of the properties of cold surges and their interaction with the seasonal cycle in the Met Office Unified Model is performed. The atmosphere–ocean couple...