Investigating tropical cyclone‐climate feedbacks using the TRMM Microwave Imager and the Quick Scatterometer
Investigating tropical cyclone‐climate feedbacks using the TRMM Microwave Imager and the Quick Scatterometer
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DOI：
10.1029/2007gc001842
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发表时间：
2008-09
期刊：
影响因子：
3.7
通讯作者：
R. Sriver;M. Huber;J. Nusbaumer
中科院分区：
文献类型：
--
作者：
R. Sriver;M. Huber;J. Nusbaumer
热带降雨测量使命（TRMM）微波成像仪（TMI）和快速散射仪（QuikScat）的海表温度（SST）和近地面风用于计算全球综合热带气旋引起的SST异常和功率耗散（PD）。我们估计热带气旋引起的上层海洋冷却比我们之前基于再分析ERA40和NCEP表面数据的估计高出35%。1998年至2006年，TMI的年平均全球PD估计值为1.55 × 1019 J（重叠年份比ERA 40 PD大约高30%）。2000年至2006年，QuikScat PD估计为1.7 × 1020 J。根据这些结果，我们得出结论，气旋引起的冷却信号似乎在ERA40和NCEP再分析中表现不足，正如最近的观测和模拟研究所假设的那样。此外，我们观察到PD和海洋表面冷却之间存在强烈的正相关关系，为气旋引起的气候反馈的可能性提供了进一步的证据。这些结果支持了热带气旋通过增强垂直混合冷却热带上层海洋，在热带表层海洋热量收支中发挥积极作用的假设，这可能代表海洋混合层下的净变暖。因此，就垂直混合对调节海洋的纬向翻转环流和向极地的热量输送的重要性而言，热带气旋可能是地球气候系统的重要贡献者。这进一步证实了Emanuel（2001，2002）和Sriver和Huber（2007 b）的结果，即与海温变暖相关的综合气旋强度未来可能的变化可能通过增强垂直混合和增加海洋热量输送提供可能的气候反馈，从而缓冲热带地区对温度升高的影响，同时放大高纬度地区的变暖。
Sea surface temperature (SST) and near‐surface winds from the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) and the Quick Scatterometer (QuikScat) are used to calculate globally integrated tropical cyclone‐induced SST anomalies and power dissipation (PD). We estimate tropical cyclone‐induced upper ocean cooling to be ∼35% higher than our previous estimates based on reanalyzed ERA40 and NCEP surface data. Annually averaged, global PD estimates from TMI are ∼5 × 1019 J for the years 1998 to 2006 (roughly 30% greater than ERA40 PD for overlapping years). QuikScat PD is estimated to be ∼1.7 × 1020 J for the years 2000 to 2006. On the basis of these results, we conclude that the cyclone‐induced cooling signal appears to be underrepresented in ERA40 and NCEP reanalysis, as postulated in recent observational and modeling studies. Furthermore, we observe a strong positive relationship between PD and ocean surface cooling, providing further evidence for the likelihood of cyclone‐induced climatic feedbacks. These results support the hypothesis that tropical cyclones play an active role in the tropical surface ocean heat budget by cooling the tropical upper oceans through enhanced vertical mixing, which likely represents a net warming beneath the oceanic mixed layer. Thus, to the degree that vertical mixing is important for regulating the ocean's meridional overturning circulation and poleward heat transport, tropical cyclones may be an important contributor to Earth's climate system. This further confirms the results of Emanuel (2001, 2002) and Sriver and Huber (2007b) that possible future changes in integrated cyclone intensity associated with warmer SST may provide possible climatic feedbacks through enhanced vertical mixing and increased ocean heat transport, thus buffering the tropics to increased temperatures while amplifying the warming at higher latitudes.