Minor impacts of major volcanic eruptions on hurricanes in dynamically-downscaled last millennium simulations
Minor impacts of major volcanic eruptions on hurricanes in dynamically-downscaled last millennium simulations
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DOI：
10.1007/s00382-021-06057-4
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发表时间：
2022-02
期刊：
影响因子：
4.6
通讯作者：
Brandon Benton;Marc J. Alessi;D. A. Herrera;Xiaolu Li;C. Carrillo;T. Ault
中科院分区：
文献类型：
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作者：
Brandon Benton;Marc J. Alessi;D. A. Herrera;Xiaolu Li;C. Carrillo;T. Ault
火山喷发对飓风统计数据的影响使用了两个来自共同体地球系统模型(CESM)最后千年集合(LME)的长期模拟。第一种是非强制控制模拟，其中所有边界条件在其850CE值(LME控制)保持不变。第二种是“完全强迫”的模拟，模拟了从公元850年到现在火山、太阳和土地利用变化的辐射变化(LME强迫)。大型热带火山喷发在这段时间内产生的辐射强迫变化最大，这构成了本研究的重点。天气研究和预报(WRF)模式被用来动态地缩减150个LME控制年，并为1100年至1850年之间的所有中纬度火山喷发额外施加8400个LME控制年。这段时间是基于计算考虑而选择的。对于每一次喷发，两年的时间都会动态缩小。这些火山喷发中有23次在北半球，19次在南半球。通过对ERA-I历史再分析数据采用相同的缩减尺度方法，并将缩小尺度的风暴路径和强度与国际气候管理最佳路径档案(IBTrACS)数据库进行比较，检验了缩减尺度方法的有效性。然后，根据缩减的控制和缩减的强制LME模拟计算飓风统计数据。结果表明，北半球平均所有喷发对飓风的影响都是中等的，其中最大的影响来自气溶胶强迫最大的火山。更具体地说，北半球喷发后飓风频率、强度和寿命的减少是显而易见的。也有强有力的证据表明，喷发强度与这些诊断的变化之间存在相关性。北半球和南半球喷发的总体影响都很小。虽然北半球喷发的频率、强度和寿命都会减少，但南半球的喷发却产生了相反的影响。
The effects of volcanic eruptions on hurricane statistics are examined using two long simulations from the Community Earth System Model (CESM) Last Millennium Ensemble (LME). The first is an unforced control simulation, wherein all boundary conditions were held constant at their 850 CE values (LMEcontrol). The second is a “fully forced” simulation with time evolving radiative changes from volcanic, solar, and land use changes from 850 CE through present (LMEforced). Large tropical volcanic eruptions produce the greatest change in radiative forcing during this time period, which comprise the focus of this study. The Weather Research and Forecasting (WRF) model is used to dynamically downscale 150 control years of LMEcontroland an additional 84 years of LMEforcedfor all mid-latitude volcanic eruptions between 1100 and 1850 CE. This time period was selected based on computational considerations. For each eruption, 2 years are dynamically downscaled. 23 of these volcanic eruptions are in the Northern Hemisphere and 19 are in the Southern Hemisphere. The effectiveness of the downscaling methodology is examined by applying the same downscaling approach to historical ERA-I reanalysis data and comparing the downscaled storm tracks and intensities to the International Best Track Archive for Climate Stewardship (IBTrACS) database. Hurricane statistics are then computed from both the downscaled control and downscaled forced LME simulations. Results suggest moderate effects on hurricanes from the average of all northern hemisphere eruptions, with the largest effects being from the volcanoes with the most aerosol forcing. More specifically, reductions in hurricane frequency, intensity, and lifetime following northern hemisphere eruptions are apparent. Strong evidence is also shown for correlation between eruption strength and changes in these diagnostics. The aggregate effect from both northern and southern hemisphere eruptions is minor. While reductions in frequency, intensity, and lifetime from northern hemisphere eruptions occur, the opposite effect is observed from southern hemisphere eruptions.