Moisture Transport and Contribution to the Continental Precipitation

• Published in: Atmosphere
• Main Authors: Yazhu Yang, Chunlei Liu, Niansen Ou, Xiaoqing Liao, Ning Cao, Ni Chen, Liang Jin, Rong Zheng, Ke Yang, Qianye Su
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2022
• Subjects: moisture transport; convergence; precipitation; trend; Meteorology. Climatology; QC851-999; Antarctic; Greenland; Antarc*
• Online Access: https://doi.org/10.3390/atmos13101694; https://doaj.org/article/7f5dc5be263748518767127237eb9566

Understanding the water cycle change under a warming climate is essential, particularly the ocean to land moisture transport, which affects the precipitation over land areas and influences society and the ecosystem. Using ERA5 data from 1988 to 2020, the time series of moisture transport and the trend across the boundary of each continent, including Eurasia, Africa, North America, South America, Antarctic, Australia, and Greenland, have been investigated. The inflow and outflow sections of the moisture have been identified for each continent. The trends of moisture convergence over Eurasia, Africa, North America, and Antarctic are all positive, with the values of 2.59 ± 3.12, 2.60 ± 3.17, 12.98 ± 2.28, and 0.32 ± 0.47 (in 10 6 kg/s/decade), respectively, but only the trend over North America is statistically significant at a 0.1 significance level. The moisture convergence trend of −0.59 ± 3.63 (in 10 6 kg/s/decade) over South America is negative but insignificant. The positive trend of 0.10 ± 0.35 (in 10 6 kg/s/decade) over Greenland is very weak. The precipitation, evaporation, and moisture convergence are well balanced at middle and low latitudes, but the combination of moisture convergence and evaporation is systematically lower than the precipitation over Antarctic and Greenland. Contributions of evaporation and moisture convergence (or transport) to the continental precipitation vary with the continent, but the moisture convergence dominates the precipitation variability over all continents, and the significant correlation coefficients between the anomaly time series of continental mean moisture convergence and precipitation are higher than 0.8 in all continents.