期刊名称：Journal of Advances in Modeling Earth Systems
电子版ISSN：1942-2466
出版年度：2014
卷号：6
期号：3
页码：1-20
DOI：10.1002/2014MS000327
出版社：John Wiley & Sons, Ltd.
摘要：Climate modes, such as the El Niño Southern Oscillation (ENSO), influence Tropical Cyclones (TCs) interannual activity through their effect on large‐scale atmospheric environment. These climate modes also induce interannual variations of subsurface oceanic stratification, which may also influence TCs. Changes in oceanic stratification indeed modulate the amplitude of TCs‐induced cooling, and hence the negative feedback of air‐sea interactions on the TC intensity. Here we use a dynamical downscaling approach that couples an axisymmetric TC model to a simple ocean model to quantify this interannual oceanic control on TC activity. We perform twin experiments with contrasted oceanic stratifications representative of interannual variability in each TC‐prone region. While subsurface oceanic variations do not significantly affect the number of moderate (Category 3 or less) TCs, they do induce a 30% change of Category 5 TC‐days globally, and a 70% change for TCs exceeding 85 m s−1. TCs in the western Pacific and the southwestern Indian Ocean are most sensitive to oceanic interannual variability (with a ∼10 m s−1 modulation of the intensity of strongest storms at low latitude), owing to large upper ocean variations in response to ENSO. These results imply that a representation of ocean stratification variability should benefit operational forecasts of intense TCs and the understanding of their climatic variability.
