Dynamical and Thermodynamic Elements of Modeled Climate Change at the East African Margin of Convection
Dynamical and Thermodynamic Elements of Modeled Climate Change at the East African Margin of Convection
复制标题
DOI：
10.1002/2017gl075486
复制
发表时间：
2018-01
影响因子：
5.2
通讯作者：
A. Giannini;B. Lyon;R. Seager;N. Vigaud
中科院分区：
文献类型：
--
作者：
A. Giannini;B. Lyon;R. Seager;N. Vigaud
我们提出了一个动态的解释模式预测的世纪末湿润赤道东非。在目前这一代全球气候模型中，与变暖相关的大气水分含量增加并不是解释降雨量增加的主要过程，因为即使在雨季，区域环流也只是微弱的收敛。相反，预测的未来更潮湿的条件通常与气候模型中热带太平洋海面温度的厄尔尼诺趋势一致。此外，邻近刚果盆地和海洋大陆对流核心的水汽辐合减弱导致近地面风减弱，这增加了从刚果盆地核心向东非边缘的水汽平流。由于区域气候学模拟存在重大偏差，而且迄今为止观测到的和模拟的热带太平洋海面温度趋势之间存在分歧，因此对预测的总体信心有限。
We propose a dynamical interpretation of model projections for an end‐of‐century wetting in equatorial East Africa. In the current generation of global climate models, increased atmospheric moisture content associated with warming is not the dominant process explaining the increase in rainfall, as the regional circulation is only weakly convergent even during the rainy seasons. Instead, projected wetter future conditions are generally consistent with the El Niño‐like trend in tropical Pacific sea surface temperatures in climate models. In addition, a weakening in moisture convergence over the adjacent Congo Basin and Maritime Continent cores of convection results in the weakening of near‐surface winds, which increases moisture advection from the Congo Basin core toward the East African margin. Overall confidence in the projections is limited by the significant biases in simulation of the regional climatology and disagreement between observed and modeled tropical Pacific sea surface temperature trends to date.