EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Fire aerosols slow down the global water cycle

Fang Li1, David Lawrence2, Yiquan Jiang3, and Xiaohong Liu4
Fang Li et al.
  • 1Institute of Atmospheric Physics, Chinese Academy of Sciences, China (
  • 2National Center for Atmospheric Research, Boulder, CO, USA (
  • 3China Meteorological Administration–Nanjing University Joint Laboratory for Climate Prediction Studies, and Jiangsu Collaborative Innovation Center of Climate Change, School of Atmospheric Sciences, Nanjing University, Nanjing, China (
  • 4Department of Atmospheric Sciences, Texas A&M University, College Station, Texas, USA (

Fire is an important Earth system process and the largest source of global primary carbonaceous aerosols. Earlier studies have focused on the influence of fire aerosols on radiation, surface climate, air quality, and biogeochemical cycle. The impact of fire aerosols on the global water cycle has not been quantified and related mechanisms remain largely unclear. This study provides the first quantitative assessment and understanding of the influence of fire aerosols on the global water cycle. This is done by quantifying the difference between simulations with and without fire aerosols using the fully-coupled Community Earth System Model (CESM). Results show that presentday fire aerosols weaken the global water cycle significantly. They decrease the continental precipitation, evapotranspiration, and runoff by 4.1±1.8, 2.5±0.5, and 1.5±1.4 ×103 km3 yr-1 as well as ocean evaporation, precipitation, and water vapor transport from ocean to land by 8.1±1.9, 6.6±2.3, and 1.5±1.4 ×103 km3 yr-1. The impacts of fire aerosols are most clearly seen in the tropics and the Arctic-boreal zone. Fire aerosols affect the global water cycle mainly by cooling the surface which reduces ocean evaporation, land soil evaporation and plant transpiration. The decreased water vapor load in the atmosphere leads to a decrease in precipitation, which contributes to reduced surface runoff and sub-surface drainage.

How to cite: Li, F., Lawrence, D., Jiang, Y., and Liu, X.: Fire aerosols slow down the global water cycle, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4394,, 2022.

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