中国科学院物理研究所的Zhou Tianjun及研究团队提出，中亚缺水地区的农业领域的干旱现象因内部气候变化而加剧。相关论文于2023年1月12日发表在《自然—地球科学》杂志上。
课题组通过对大型集成模拟的分析表明，1992年以来，中亚南部农业干旱的加剧可以归因于与太平洋年代际震荡(IPO)相关的人为作用力和内部变率。尽管1992年之前，太平洋年代际震荡由负向正的相变抵消了人为引起的土壤湿度下降，但研究人员发现，此后的由正到负的相变，使生长季早期的外部作用力干燥速率增加了一倍。
尽管降水量会增加，但由于气候变暖的影响，人为引起的土壤水分流失可能会在下个世纪进一步加剧，研究模拟预测显示，这一趋势不会被太平洋年代际震荡相变所抵消。相反，这种内部变异性可以在短期内调节干燥速率，预计太平洋年代际震荡趋势的幅度为-2(+2)个标准差，将放大(削弱)近75%(60%)的表面土壤水分的外部作用力下降的程度。研究结果突出表明，在气候敏感地区，政策制定者需要考虑人为作用力和太平洋年代际震荡的自然可变性之间的相互作用。
据悉，2021年，一场严重的农业干旱席卷了中亚，导致农作物和牲畜大量死亡。近几十年来，人为活动对该地区土壤湿度下降的产生的影响尚不清楚。
附：英文原文
Title: Agricultural drought over water-scarce Central Asia aggravated by internal climate variability
Author: Jiang, Jie, Zhou, Tianjun
Issue&Volume: 2023-01-12
Abstract: A severe agricultural drought swept Central Asia in 2021, causing mass die-offs of crops and livestock. The anthropogenic contribution to declines in soil moisture in this region over recent decades has remained unclear. Here we show from analysis of large ensemble simulations that the aggravation of agricultural droughts over southern Central Asia since 1992 can be attributed to both anthropogenic forcing and internal variability associated with the Interdecadal Pacific Oscillation (IPO). Although the negative-to-positive phase transition of IPO before 1992 offset human-induced soil moisture decline, we find that the positive-to-negative phase transition thereafter has doubled the externally forced rate of drying in the early growing season. Human-induced soil moisture loss will probably be further aggravated in the following century due to warming, albeit with increasing precipitation, and our simulations project that this trend will not be counterbalanced by the IPO phase change. Instead, this internal variability could modulate drying rates in the near term with an amplitude of -2 (+2) standard deviation of the IPO trend projected to amplify (weaken) the externally forced decrease in surface soil moisture by nearly 75% (60%). The findings highlight the need for the interplay between anthropogenic forcing and the natural variability of the IPO to be considered by policymakers in this climate-sensitive region.
DOI: 10.1038/s41561-022-01111-0
Source: https://www.nature.com/articles/s41561-022-01111-0