Observed holiday aerosol reduction and temperature cooling over East Asia

Abstract

The air pollution in Chinese Spring Festival (CSF) period over eastern China was investigated using the long-term observations from 2001 to 2012 over 323 stations. The dominant feature of the pollutants around the CSF holidays is the significant reduction of concentration. During the 10 day period around the CSF (but excluding the Lunar New Year's Day, LNYD), PM 10 experiences a reduction of −9.24%. In association with the aerosol reduction, temperature significantly drops over eastern China. From the third day before the LNYD to the second day after, the daily mean temperature anomaly is −0.81 • C, respectively. From the third day to seventh day after the LNYD, the significant negative temperature anomalies move out of China, extending to a broad area from the South China Sea to the western North Pacific. Between the 8th and the 12th days, the significant temperature anomalies can still be found over 140 • N. The reduced downward longwave flux might play an important role in holiday cooling. The possible atmospheric feedback is discernable. The thermal and circulation configuration accompanying the cooling favors baroclinic interaction between upper and lower troposphere for the midlatitude cyclone. The anomalous cyclone becomes mature during the third to the seventh day after the LNYD and disappears 12 days later. The anomalous northern winds in association with the cyclone decrease the temperature and also help disperse the holiday aerosols over eastern China.

Aerosol and monsoon climate interactions over Asia

“…Gong et al . [] reported a cooling episode during the Chinese New Year Festival when a dramatic increase in air pollution emissions and the aerosol burden due to fireworks during the holiday occurred. Using long‐term temperature records, Yang et al .…”

East Asian Study of Tropospheric Aerosols and their Impact on Regional Clouds, Precipitation, and Climate (EAST‐AIRCPC)

“…Temperature is an important climate indicator and important for human life owing to its physical links to the radiative and heat flux budgets. Aerosols may alter both temperature (Gong et al, ; Z. Li et al, ) and the diurnal temperature range (DTR) by the direct effect or by indirectly modulating clouds or both. Z. Li et al () argued that the cooling trend from the 1960s to the 1990s in central‐eastern China in the midst of widespread warming across China (Ding et al, ) was caused at least partially by the rapid increase in air pollution, consistent with the long‐term trends of changes in surface solar radiation (Luo et al, ) and visibility (Chen & Wang, ).…”

Distinct weekly cycles of thunderstorms and a potential connection with aerosol type in China

“…Likewise, particulate matter up to 10 µm in size, another measure of surface pollution, is also low during the weekend and high on weekdays [ Gong et al , ]. The reduction in pollution levels is also seen during the traditional Chinese spring festival when most people do not work [ Gong et al , ]. This observational finding suggests that aerosol concentrations are sensitive to human activities to such a degree that it could have a footprint in nature.…”