Assessing the Modern Multi‐Decadal Scale Aridification Over the Northern China From a Historical Perspective

Abstract

Northern China (35°–50°N; 105°–125°E) has experienced a multidecadal aridification since 1950s, which was mainly manifested by multi‐decadal scale decreases of regional precipitation and soil moisture, and brought severe influences on societal and economic developments. However, the position of this aridification among the historical aridification events over northern China during the last millennium has not been fully assessed. Furthermore, the contributions from anthropogenic forcings, natural forcings, and internal variability on this aridification have not been quantitatively differentiated. In this study, observations, proxy reconstructions, and model simulations from community Earth system model last millennium ensemble archive were used to assess this aridification from a historical perspective, and differentiate the contributions from different forcings and internal variability. It was found that duration and magnitude of this aridification are more prominent than most of aridifications during the last millennium. The comparisons between control experiment and sensitivity experiments show that the external forcings, especially anthropogenic forcings, result in a significant larger aridification rate than other historical aridifications. Only combined impacts from internal variability (i.e., Pacific Decadal oscillation, PDO and Atlantic Multidecadal oscillation (AMO)) and anthropogenic forcings (e.g., greenhouses gas emission, anthropogenic aerosol emission, and land use cover changes) can result in such a severer aridification than historical aridifications. The results also confirm that the phase shifts of PDO and AMO trigger this aridification over the northern China, and, whether external forcings contribute to these phase shifts were also discussed.

Influence of the North Atlantic sea surface temperature on decadal variability of the July precipitation in north China

“…Based on observations, proxy reconstructions and model simulations, Qin et al . (2022) further verified that the decadal aridification that occurred in north China since 1960s is closely related to the phase changes of the AMO. Further study found that the relationship between the precipitation in north China and AMO is also significant in summer (Zhang et al ., 2018).…”

“…Recent studies show that the Atlantic multidecadal oscillation (AMO) can synergistically regulate the decadal variability of precipitation in north China together with PDO (Yang et al, 2017). Based on observations, proxy reconstructions and model simulations, Qin et al (2022) further verified that the decadal aridification that occurred in north China since 1960s is closely related to the phase changes of the AMO. Further study found that the relationship between the precipitation in north China and AMO is also significant in summer (Zhang et al, 2018).…”

Future risk of decadal megadrought events over eastern China based on IPO-constrained precipitation

“…Superimposed by complex interactions between sea surface temperature (SST) and atmospheric circulation, these sources cause a large uncertainty on projected megadrought over eastern China [21][22][23] .Moreover, regional megadrought is strongly affected by both internal variability and external forcing, through inducing local circulation changes [24][25][26][27] . Based on proxy reconstructions and model simulations during last millennium, historical megadroughts over eastern China are mainly trigged by internal variability and modulated by natural and anthropogenic forcings, e.g., volcanic eruption, solar radiation, anthropogenic aerosol and GHGs emissions [28][29][30][31] . Thus, reducing the uncertainty due to internal variability will largely improve megadrought projection over eastern China.…”