Beyranvand Azar, Azizi Ghasem, Alizadeh Omid, Darvishi Boloorani Ali
Department of Physical Geography, University of Tehran, Tehran, Iran.
Institute of Geophysics, University of Tehran, Tehran, Iran.
Sci Rep. 2023 Sep 27;13(1):16158. doi: 10.1038/s41598-023-42173-3.
We detected sources of dust in the Middle East that contribute to dust events in Western Iran in different seasons. By the analysis of the synoptic data, we identified 309 dusty days in Western Iran during the period 2000-2016. A dusty day is diagnosed if under low horizontal visibility (< 1 km), the dust in suspension is reported at least once a day in at least three synoptic stations. We identified dust sources in the Middle East based on the analysis of the MOD04L2 data from MODIS, the backward HYSPLIT trajectory model, and synoptic conditions. The most influential sources affecting Western Iran are located on the shore and northwest of Lake Tharthar, Hour-al-Azim Marsh, the shore of Razzaza, Habbaniyah Lakes, and West Hammar Marsh, which contributed to 110, 79, 59, 56, and 51 dusty days, respectively. The fluctuation of the surface water area largely contributes to the variability of dusty days in Western Iran. Indeed, the peak dust activity in Western Iran was during the period 2008-2012 in response to the substantial shrinkage of the main water bodies in Iraq. The main sources of dust influencing Western Iran are located in northern and eastern Saudi Arabia in spring, Deir ez-Zur in Syria's Aleppo and Raqqa in summer, and Syria's Homs and Al-Hasakah in winter and spring. Sources of dust in Western Iraq and in most parts of entire Iraq have, respectively, led to the formation of summer and spring dust events in Western Iran. Decreased precipitation in the Middle East from autumn 2007 to 2012 and the occurrence of severe droughts have also contributed to the shrinkage of lakes and wetlands, as well as the reduced agricultural productivity in the Middle East, all of which contributed to the intensification of dust activity in Western Iran in recent decades.
我们探测到中东地区的沙尘源，这些沙尘源在不同季节导致伊朗西部出现沙尘天气。通过对天气数据的分析，我们确定了2000年至2016年期间伊朗西部有309个沙尘日。当水平能见度较低（<1公里）且至少三个天气观测站每天至少报告一次悬浮沙尘时，判定为沙尘日。我们基于对MODIS的MOD04L2数据、HYSPLIT反向轨迹模型以及天气状况的分析，确定了中东地区的沙尘源。影响伊朗西部的最主要沙尘源位于塔尔塔尔湖沿岸及西北部、胡尔-阿齐姆沼泽、拉扎扎湖沿岸、哈巴尼亚湖以及西哈马尔沼泽，这些地区分别导致了110天、79天、59天、56天和51天的沙尘天气。地表水域面积的波动在很大程度上导致了伊朗西部沙尘日的变化。事实上，伊朗西部沙尘活动的高峰期出现在2008年至2012年期间，这是由于伊拉克主要水体大幅萎缩所致。影响伊朗西部的沙尘主要来源春季位于沙特阿拉伯北部和东部，夏季位于叙利亚阿勒颇的代尔祖尔和拉卡，冬季和春季位于叙利亚的霍姆斯和哈塞克。伊拉克西部和整个伊拉克大部分地区的沙尘源分别导致了伊朗西部夏季和春季沙尘天气的形成。2007年秋季至2012年中东地区降水量减少以及严重干旱的发生，也导致了湖泊和湿地萎缩，以及中东地区农业生产力下降，所有这些都促使近几十年来伊朗西部沙尘活动加剧。
