Options
Significant changes in cloud radiative effects over Southwestern United States during the COVID-19 flight reduction period
Citation
Wang, J., Lin, Y., Wang, X., Gu, Y., & Yim, S. H.-L. (2024). Significant changes in cloud radiative effects over Southwestern United States during the COVID-19 flight reduction period. Science of The Total Environment, 910. Article 168656. https://doi.org/10.1016/j.scitotenv.2023.168656
Abstract
Aircraft-induced clouds (AICs) are one of the most visible anthropogenic atmospheric phenomena, which mimic the natural cirrus clouds and perturb global radiation budget by reducing incoming shortwave (SW) radiation and trapping outgoing longwave (LW) radiation. The COVID-19 pandemic has caused a 70 % global decline in flight numbers from mid-March to October 2020, which provided a unique opportunity to examine the climatic impact of AICs. Among various regions, Western Europe and the Contiguous United States experienced the most substantial reduction in air traffic during the COVID-19 pandemic. Interestingly, only the Southwestern United States demonstrated a significant decrease in cirrus clouds, leading to notable changes in shortwave (SW) and longwave (LW) cloud radiative effects. Such changes were likely due to the reduction in AICs. However, further investigations indicated that this region also experienced abnormal high pressure and low relative humidity in the middle and upper atmosphere, resulting in unusual subsidence and dryness that prohibit the formation and maintenance of cirrus cloud. While it remains challenging to quantify the exact climatic impact of reduced AICs, the remarkable anomalies documented in this study provide valuable observational benchmark for future modelling studies of the climatic impact AICs.
Date Issued
2024
Publisher
Elsevier
Journal
Science of the Total Environment
DOI
10.1016/j.scitotenv.2023.168656
Project
RG74/22
Grant ID
MOE-MOET2EP10121-0008
80NSSC23K0119
Funding Agency
Ministry of Education, Singapore
National Science Foundation, United States
NASA ROSES CCST grant