Prolonged Drought Enhances Northwest China Dust Storm Activity

Abstract

The patterns and forcing mechanism of dust storms in arid Northwest China remain unclear and debated due to lack of reliable long‐term geological records. Here we present a ∼1,600‐year dust storm history in Northwest China based on the sedimentary coarse fraction (>63 μm) retrieved from Lake Hurleg and Lake Qinghai on the northeastern Tibetan Plateau (NETP). The NETP dust storm history, which agrees well with those from North China, shows two prolonged intervals of high dust storm occurrences during the Medieval Warm Period and the past century, and two prolonged weakened dust storm intervals from ∼400 to 700 CE and during the Little Ice Age. The temporal variation in NETP dust storm activities is out‐of‐phase with moisture records over central Asia, with enhanced dust storms corresponding to warm‐dry intervals, and vice versa. The prolonged centennial warm‐dry climates over arid Northwest China to arid central Asia could have led to decreased soil moisture, deteriorated vegetation cover, and increased dust particle supply and dust storm activities; while the prolonged centennial cold‐wet climates could have increased soil moisture, vegetation cover, and decreased dust storm activities. We contend that whilst human impact could be responsible for the obviously increased eolian dust flux in the most recent century, it is most likely that the prolonged natural hydroclimatic conditions regulate the global dust storm activity before the Anthropocene.

Warmth Favored Dust Activities on the Northeastern Qinghai‐Tibet Plateau

“…Notably, the TSI and NAO are also recognized as indicators of westerlies intensity and have a great influence on precipitation (Cui et al., 2021; Wang et al., 2017). When TSI and NH temperature increases, the meltwater flows into the North Atlantic, a more negative NAO along with decreased evaporation led to relatively dry westerly circulation over northern China, which consequently contributes to insufficient water vapor transport and drought (F. Chen et al., 2019; Du et al., 2020; Lu et al., 2019; J. Zhang et al., 2022b).…”

“…Dust storms are more intense under warm‐dry conditions when natural factors prevail; moreover, the cold‐warm shift (especially a dramatic temperature reversal) is the likely cause for the occurrence of mega dust storms. In the context of global warming, extreme climatic anomalies, worldwide permafrost thawing, and the period of higher temperature often occurred, increasing evaporation led to prolonged drought, lower vegetation cover and higher soil erosion (He et al., 2015; J. Zhang et al., 2022b). The increased solar irradiation led to a warmer weather which has potential to decrease sea ices and make more meltwaters enter into the ocean; the lower sea surface temperature and evaporation destroyed the air‐sea moisture transport, and the strengthening and southward shift of mid‐latitude westerly and steepening of the meridional temperature gradient (Han et al., 2019) contributed to the strong surface wind.…”

“…Dust storms are more intense under warm-dry conditions when natural factors prevail; moreover, the cold-warm shift (especially a dramatic temperature reversal) is the likely cause for the occurrence of mega dust storms. In the context of global warming, extreme climatic anomalies, worldwide permafrost thawing, and the period of higher temperature often occurred, increasing evaporation led to prolonged drought, lower vegetation cover and higher soil erosion (He et al, 2015;J. Zhang et al, 2022b).…”

“…TSI and NH temperature increases, the meltwater flows into the North Atlantic, a more negative NAO along with decreased evaporation led to relatively dry westerly circulation over northern China, which consequently contributes to insufficient water vapor transport and drought (F. Chen et al, 2019;Du et al, 2020;Lu et al, 2019;J. Zhang et al, 2022b).…”

“…(2015) and J. Zhang et al. (2022b). Despite these findings, the underlying mechanism behind dust activities remains unclear and warrants further investigation, particularly through the analysis of longer‐term archives.…”