Suárez-Molina D, Cuevas E, Alonso-Pérez S, Cana L, Montero G, Oliver A
Territorial Delegation of AEMET in the Canary Islands, State Meteorological Agency of Spain (AEMET), Las Palmas, 35017, Spain.
Izaña Atmospheric Research Center (IARC), State Meteorological Agency of Spain (AEMET), Santa Cruz de Tenerife, 38001, Spain.
Heliyon. 2024 May 17;10(10):e31262. doi: 10.1016/j.heliyon.2024.e31262. eCollection 2024 May 30.
Dust events in the Canary Islands have been documented since the late 19th century. However, during the past few years, several severe dust episodes have occurred in the Canary Islands, resulting in significant impacts on various sectors, such as aviation, air quality, and health, among others. These recent severe events have drawn the attention of both scientists and the general population, raising questions about whether these episodes are now more frequent and more severe. This study analyzes 483 dust events recorded in the Canary Islands over the last 40 years. Data analysis reveals that the average number of dust event days per year is approximately 24 days, and these events have an average duration of 1.8 days, both of which show a statistically significant decreasing trend over the series. Seasonal examination indicates that events occurring in the first and fourth quarters of the year have twice the duration of those in the other quarters. Furthermore, on an annual basis, events in the first quarter exhibit negative trends in both average and minimum visibilities. This suggests that dust events in the Canary Islands are becoming shorter in duration but more intense in terms of visibility. In this article, the Dust Adversity Index (DAI) is introduced to objectively compare the severity of events. Finally, anomalies in geopotential have been utilized to determine the prevailing synoptic patterns during dust events. It is evident that the dominant synoptic pattern during the first and fourth quarters of the year consists of a low cut-off system located to the west of the Canary Islands and a high-pressure system to the north of the Iberian Peninsula.
自19世纪末以来，加那利群岛的沙尘事件就有记录。然而，在过去几年里，加那利群岛发生了几次严重的沙尘事件，对航空、空气质量和健康等各个领域产生了重大影响。这些近期的严重事件引起了科学家和公众的关注，引发了关于这些事件现在是否更频繁、更严重的疑问。本研究分析了过去40年加那利群岛记录的483次沙尘事件。数据分析显示，每年沙尘事件日的平均数量约为24天，这些事件的平均持续时间为1.8天，两者在整个序列中均呈现出具有统计学意义的下降趋势。季节性检查表明，一年中第一季度和第四季度发生的事件持续时间是其他季度的两倍。此外，从年度来看，第一季度的事件在平均能见度和最低能见度方面均呈现负趋势。这表明加那利群岛的沙尘事件持续时间正在缩短，但在能见度方面更加严重。在本文中，引入了沙尘逆境指数（DAI）来客观比较事件的严重程度。最后，利用位势异常来确定沙尘事件期间盛行的天气形势。很明显，一年中第一季度和第四季度的主要天气形势是加那利群岛以西的低切断系统和伊比利亚半岛以北的高压系统。
