Decadal shift of the influence of Arctic Oscillation on dust weather frequency in spring over the Middle East during 1974–2019
Decadal shift of the influence of Arctic Oscillation on dust weather frequency in spring over the Middle East during 1974–2019
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1974—2019年北极涛动对中东地区春季沙尘天气频率影响的年代际变化
DOI：
10.1002/joc.7375
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Mehdi Hamidi
中科院分区：
文献类型：
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作者：
Yijie Sun;Rui Mao;Daoyi Gong;Ying Li;Seong-Joong Kim;Xiao-Xiao Zhang;Xuezhen Zhang;Mehdi Hamidi
沙尘天气对中东地区的人类健康和气候变化产生影响。在这项研究中，我们研究了1974-2019年期间北极涛动（AO）对中东地区春季沙尘天气频率的影响。结果表明，AO对中东沙尘天气频率的影响存在年代际变化，AO指数与沙尘天气频率的相关系数从1974-1994年的-0.52（P1）变化到1995-2013年的0.49（P2）。P1期间，北方阿拉伯半岛与沙尘天气频率呈负相关; P2期间，阿拉伯半岛中部和西南部与沙尘天气频率呈正相关。在对流层中低层，负位势高度异常与P1期间南欧上空AO的负相位相关联，而负位势高度异常与P2期间东北非洲上空AO的正相位相关联。负高度异常导致出现更多低气压系统，从而导致中东出现沙尘天气。研究发现，AO对沙尘天气影响的年代际变化与P2期间AO相关的波列传播北移有关。在P1期间，AO波列的北方分支在北大西洋中纬度地区占主导地位，穿过南欧至阿拉伯半岛，导致南欧对流层中低层高度距平为负。在P2期间，AO波列向北传播，其南分支控制了北大西洋低纬地区，经北方至阿拉伯半岛，对东北非洲负高度距平的形成起了重要作用。
Dust weather has an impact on human health and climate change in the Middle East. In this study, we examined the influence of the Arctic Oscillation (AO) on spring dust weather frequency over the Middle East at an interannual timescale during 1974–2019. The results show that there was an interdecadal shift of the influence of AO on dust weather frequency in the Middle East, with a correlation coefficient between the AO index and dust weather frequency changing from −0.52 during 1974–1994 period (P1) to 0.49 during 1995–2013 period (P2). During P1, negative correlations between AO index and dust weather frequency were found over the northern Arabian Peninsula, and during P2, positive ones were mostly over the central and southwestern Arabian Peninsula. In the lower and middle troposphere, negative geopotential height anomalies are associated with the negative phase of the AO over South Europe during P1, whereas negative geopotential height anomalies are associated with the positive phase of the AO over Northeast Africa during P2. The negative height anomalies resulted in the occurrence of more low‐pressure systems and, thus, dust weather in the Middle East. It is found that the interdecadal shift of the influence of the AO on dust weather was related to an AO‐related northward displacement of wave train propagation during P2. Specifically, during P1 period, the northern branch of AO‐related wave train dominated over the middle latitudes of the North Atlantic across South Europe to the Arabian Peninsula, which resulted in the negative height anomaly over South Europe in the lower and middle troposphere. However, during P2 period, the AO‐related wave train propagation moved northward, and then, the southern branch of the AO‐related wave train dominated over the low latitudes of the North Atlantic across northern Africa to the Arabian Peninsula, which played an important role in the formation of the negative height anomalies over Northeast Africa.