Weakening Dust Storm Intensity in Arid Central Asia Due to Global Warming Over the Past 160 Years

Abstract

Dust storms occur frequently in arid central Asia (ACA) and greatly influence the regional ecology/environment, human health, and security, as well as the global climate. To date, neither the patterns nor the underlying mechanisms of dust storms in ACA are fully understood, partly due to the lack of long-term historical records. Here, we reconstruct a dust storm history of the past ∼160 years in northwest China, based on high-resolution sedimentary proxies retrieved from Lake Karakul (located in the core zone of ACA). We find that changes in the sedimentary coarse fraction (grain size > 64 µm) in Lake Karakul are correlated with both historical and modern observed dust storms. The reconstructed dust storm intensity shows a decreasing trend since AD 1850s, with three high occurrence intervals at AD 1870s-1910s, AD 1930s-1940s, and AD 1960s-1980s. We contend that changes in temperature and wind speed could have dominated the frequency and intensity of dust storms in northwest China during the record periods: temperature controls the wind speed and then the dust storm frequency/intensity; lower temperature corresponding to higher wind speed, and higher dust storm frequency/intensity, and vice versa. The observed anthropogenic global warming could have led to a decrease in atmospheric temperature gradients and decline in wind speed and then decreasing dust storm frequency/intensity. Providing this stands, less and weaker dust storms are expected under a continuously anthropogenic warming scenario.

Stronger winds increase the sand-dust storm risk in northern China

“…However, this decreasing trend can be well explained by the reduced cyclone frequency (less wind) in northern China due to warming in Mongolia and cooling in northern China, resulting in the decrease of the meridional temperature gradient. 11 Dust records in Lake Karakul 20 and Lake Daihai 21 also provide evidence from a longer time scale for the idea that a lower wind speed in a warmer climate will cause fewer sand-dust storms.…”

Prolonged Drought Enhances Northwest China Dust Storm Activity

“…Dust storm records in arid Northwest China have been generally suggested to be controlled by natural climate variability (F. An et al., 2012; Chen et al., 2013; He et al., 2015; Zhang et al., 2020). The dust storm outbreak is related to both changes in particle supply and wind intensity.…”

“…One notable example is that the landforms, 14 C dating, and dendrochronologies indicate that the Tarim Basin of the inner Asian desert belt was characterized by wetter-than-present conditions during the LIA, and the Lop Nor was sustained at 800 m above sea level (with an area of ∼19,800 km 2 ) in this wet period (see Figure S12h in Supporting Information S1; Putnam et al, 2016). Dust storm records in arid Northwest China have been generally suggested to be controlled by natural climate variability (F. Chen et al, 2013;He et al, 2015;Zhang et al, 2020). The dust storm outbreak is related to both changes in particle supply and wind intensity.…”

“…Lake sediments continuously record eolian dust falls, and therefore have been widely used to reconstruct long-term dust storm histories (Chen et al, 2020;He et al, 2015;Zhang et al, 2020;. In this study, we present a ∼1,600-year dust storm history based on sedimentary grainsize from Lake Hurleg and Lake Qinghai on the northeastern Tibetan Plateau (NETP) (Figure 1; see hydroclimatic backgrounds in Text S1 Panel (a) Map showing locations of Lake Hurleg (HL; red star), Lake Qinghai (QH; red cross), and other sites of dust (blue dots) and moisture (pink dots) records mentioned in text, including Wulungu (WLG; X.…”

Long-term adaptive response of an oceanic diatom to copper deficiency

“…Increased stratification in oligotrophic gyres is affecting nutrient supply from deep waters and phytoplankton production in the surface (Behrenfeld et al, 2006). In addition, some modeling results indicate global warming could alter supply of aeolian dust (Zhang et al, 2020;Zong et al, 2021), an important source of nutrients to ocean systems and occasionally having negative effects on phytoplankton due to toxicity of Cu-rich aerosol input (Paytan et al, 2009;Jordi et al, 2012). Changes in resource availability are thus expected in the future ocean and may exert a significant impact on productivity and biogeochemical cycles (Joos et al, 1999;Boyd and Doney, 2002;Behrenfeld et al, 2006).…”