Abstract
The outbreak of COVID-19 unprecedently impacts the world in many aspects. Air pollutants have been largely reduced in cities worldwide, as reported by numerous studies. We investigated the daily concentrations of SO2, NO2, CO and PM2.5 monitored across the Xinjiang Uygur Autonomous Region (Xinjiang), China, from 2019 through 2020. The variation in NO2 showed responding dips when the local governments imposed mobility restriction measures, while SO2, CO and PM2.5 did not consistently correspond to NO2. This difference indicates that the restriction measures targeted traffic majorly. Sampling from two snow pits separately dug in 2019 and 2020 in Urumqi No.1 (UG1), we analysed water-stable isotopes, soluble ions, black and organic carbon (BC and OC). BC and OC show no differences in the snow-pit profiles dated from 2018 to 2020. The concentrations of human activity induced soluble ions (K+, Cl−, SO42− and NO3−) in the snow shrank to 20 %–30% in 2020 of their respective concentrations in 2019, while they increased 2–3.5-fold in 2019 from before 2018. We suggest that the pandemic has already left marks in the cryosphere and outlook that more evidence would be exposed in ice cores, tree rings, and other archives in the future.
Highlights
At the end of 2019, a novel virus known as severe acute respiratory syndrome coronavirus 2 25 (SARS-CoV-2) was first reported in Wuhan, China and started spreading worldwide in the months (WHO, 2020)
We suggest that the pandemic has already left marks in the cryosphere and outlook that more evidence would be exposed in ice cores, tree rings, and other archives in the future
The unprecedented Covid-19 has been shocking the world in many aspects
Summary
At the end of 2019, a novel virus known as severe acute respiratory syndrome coronavirus 2 25 (SARS-CoV-2) was first reported in Wuhan, China and started spreading worldwide in the months (WHO, 2020). The Xinjiang Uygur Autonomous Region (hereafter “Xinjiang”) spans over 1.6 million km, one sixth of China’s total land area, and is populated with ~ 25 million inhabitants (SBX, 2020) With such a large area and relatively small population, Xinjiang has a population 60 density around 1/15 of the China’s average, and its populations are highly concentrated in the major cities in each prefecture-level administrative district (Mao et al, 2016; Wu et al, 2015). The chimney-alike distribution of pollutant 75 sources within a vast and relatively slightly polluted background (Xinjiang) drives us to study the shutoff effect of employing lockdown controls by the local governments on the air quality in the major cities during the pandemic. We try to find records of the Covid-19 pandemic in a Tien-shan glacier, 85 Urumqi Glacier No 1 (UG1), for it has the conventional snow-pit sampling for the long term (Figure 1)
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