Climate Influences Affecting Atlantic Tropical Cyclones Variability and ENSO-QBO Relationships

该方案由两项研究举措组成，一项侧重于大西洋地区强热带气旋与西非降水有关的年际和较长期变率，另一项则研究平流层准分子轨道如何调制赤道强烈对流，从而影响ENSO的较长期变率。PI表明，强烈的大西洋飓风活动的反复变化与西非萨赫勒地区降雨量的同时变化密切相关。正在进行的研究试图建立一个物理过程的概念模型，将飓风变异性和萨赫勒干旱与观测到的全球范围气候变化联系起来。国际和平研究所计划审查西非地方和区域反馈进程的影响，以及影响热带大西洋和更偏远地区情况的更大规模因素。该计划的这一部分将有助于我们理解支配大西洋热带气旋的发生、加强、移动和寿命的过程的气候变异性，同时还将改进对大西洋飓风活动的季节性预测。第二项研究计划(约占总工作量的35-40%)旨在了解平流层QBO变化、风切变和平流层下部温度异常与赤道西太平洋上集中的深对流之间的明显联系。QBO引起的对流振荡似乎与ENSO循环变化有很强的物理联系。这项研究之所以重要，是因为它寻求增加对气候年际变化的理解。

This program consists of two research initiatives, one that focuses on interannual and longer term variability of intense tropical cyclone in the Atlantic region as related to West African rainfall and the other which examines how the stratospheric QBO modulates intense equatorial convection and, thereby, affects the longer term variability of the ENSO. The PI has shown that recurrent variations of intense Atlantic hurricane activity are closely correlated with concurrent variations of rainfall in the West Africa Sahel region. Ongoing studies seek to develop a conceptual model of the physical processes linking both hurricane variability and Sahel drought with observed global-scale climate variations. The PI plans to examine the effects of local and regional feedback processes in West Africa as well as larger scale factors affecting conditions in the tropical Atlantic and in more remote areas. This portion of the program will contribute to our understanding of the climatological variability of processes governing the genesis,intensification, movement an longevity of Atlantic tropical cyclones while also providing improvements to seasonal forecasts of Atlantic hurricane activity. The second, but subordinant (about 35-40% of the total effort) research initiative is directed to understanding an apparent association between variable stratospheric QBO, induced wind shear and temperature anomalies in the lower stratosphere in relation to concentrated deep convection over the equatorial West Pacific. QBO induced convective oscillations appears to have a strong physical link with ENSO cycle variations. This research is important because it seeks to increase understanding of the interannual variability of climate.