AGS-PRF: Refining the Climate Role of Tropical Cyclones: Key Constituents of the Hadley Cell?

最近关于热带气旋与气候关系的研究表明，热带气旋活动增强的年份可能导致随后冬季大气向极地热输送减少，这可能是由于热带气旋向极地的大气热输送显著。支持这一假设的几项研究表明，由于tc向极地输送湿润静态能量，tc对半球纬向可用势能的短期显著减少负有责任。首席研究员（PI）过去的研究也表明，北太平洋西部的tc是向南半球输送干静态能量的重要原因。在本项目中，PI将对tc经向能量输送进行全面量化，为确定tc的气候作用奠定基础。他将验证一个假设，即北半球的tc构成了北半球到南半球在北方夏秋季节的全球大气干静态能（DSE）输送的很大一部分，这是由于与tc相关的对流层上层赤道向外流喷流。通过分析北太平洋东部、北大西洋和西太平洋地区tc的经向DSE复合输送，PI将确定每个盆地内的平均响应是否显著。接下来，PI将通过每个Best-Track TC从再分析中量化赤道的纬向综合跨半球DSE输送，以确定在周至年的时间尺度上相对于总大气的总干静态能量输送的重要性。最后，PI将检查耦合模式比对项目（CMIP5）的模拟，以比较再分析的结果，以确定总环流模式中tc作用的保真度。

Recent research on the relationship between tropical cyclones (TC) and climate, suggests that years with enhanced TC activity may lead to decreased atmospheric poleward heat transports during the following winter possibly due to significant atmospheric poleward heat transports by TCs. Supporting this hypothesis are several studies showing that TCs are responsible for significant short-term reductions in hemispheric zonal available potential energy due to poleward moist static energy transports by TCs. Past research by the Principal Investigator (PI) has also shown that Western North Pacific TCs are responsible for significant cross-hemispheric transports of dry static energy into the Southern Hemisphere. In this project, the PI will undertake a comprehensive quantification of meridional energy transports by TCs to serve as a foundation for establishing the climate role of TCs. He will test the hypothesis that Northern Hemisphere TCs constitute a significant portion of global atmospheric dry static energy (DSE) transports from the Northern Hemisphere to the Southern Hemisphere during boreal summer and fall due to the upper tropospheric equator ward outflow jets associated with the TCs. Analyzing the composited meridional DSE transports by TCs within the Eastern North Pacific, North Atlantic, and West Pacific, the PI will determine whether the mean response is significant within each basin. Next the PI will quantify zonally integrated cross-hemispheric DSE transports at the equator by each Best-Track TC from reanalysis to determine the significance of aggregate dry static energy transports relative to the total atmosphere on time scales ranging from weeks to years. Finally the PI will examine Coupled Model Intercomparison Project (CMIP5) simulations to compare results from reanalysis to determine the fidelity of the role of TCs as evidenced in general circulation models.