Interannual variability in the Saharan dust source activation—Toward understanding the differences between 2007 and 2008
Interannual variability in the Saharan dust source activation—Toward understanding the differences between 2007 and 2008
复制标题
撒哈拉沙尘源激活的年际变化——了解 2007 年和 2008 年之间的差异
DOI：
10.1002/2015jd024302
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
I. Tegen
中科院分区：
文献类型：
--
作者：
R. Wagner;K. Schepanski;B. Heinold;I. Tegen
撒哈拉沙尘源的激活具有昼夜和季节循环以及强烈的年际变化的特点。在这里，还不清楚的年际变化的原因进行了调查，使用2007年和2008年的例子，这是观测到的沙尘源激活（DSA）事件的数量有明显的差异的年份。对来自卫星观测的尘埃图像的详细分析表明，2007/2008年之交DSA的突然增加在几个月内从北非东部向西北部蔓延。每日生活津贴在2008年全年都保持在这一大幅提高的水平上。对区域模型和全球再分析结果以及卫星数据进行了审查，以确定不同每日生活津贴模式的驱动因素，结果表明，许多个别因素促成了2008年每日生活津贴的提高。这包括萨赫勒地区降雨分布的变化、北非上空的风场、西非热低压强度的差异以及从地中海传播到撒哈拉沙漠的寒潮的发生。至少其中一些影响的决定因素似乎是海面温度的差异，特别是在热带印度洋和太平洋以及地中海，影响大规模和局部大气环流模式，最终促进撒哈拉DSA。2007年暴雨后，冲积沉积物作为尘源的活化也起着重要作用。其对强化每日生活津贴的贡献仍是进一步研究活动的一部分。
The activation of Saharan dust sources is characterized by a diurnal and seasonal cycle and a strong interannual variability. Here reasons for the still unclear interannual changes were investigated using the example of 2007 and 2008, which were years with a clear difference in the number of observed dust source activation (DSA) events. A detailed analysis of dust images derived from satellite observations showed that a sudden increase of DSA at the turn of the year 2007/2008 spreads within some months from eastern to northwestern parts of North Africa. The DSA remains on this significantly enhanced level during the whole year 2008. An examination of regional model and global reanalysis results, and satellite data, was performed to identify drivers for the different DSA patterns, which revealed that many individual factors contributed to the enhanced DSA in 2008. This includes changes in the Sahel rainfall distribution, the wind field over North Africa, differences in the strength of the West African Heat Low, and the occurrence of cold surges propagating from the Mediterranean into the Sahara. The determining factor of at least some of these influences appears to be differences in sea surface temperatures, especially in the tropical Indian and Pacific Oceans, and in the Mediterranean Sea, affecting the large‐scale and local atmospheric circulation patterns and finally fostering Saharan DSA. The activation of alluvial sediments as dust sources after heavy rainfalls in 2007 also plays an important role. Its contribution to the enhanced DSA remains part of further research activity.
影响因子：
6.3
作者：
DeMott, P. J.;Prenni, A. J.;Kreidenweis, S. M.
通讯作者：
Kreidenweis, S. M.