North Atlantic and Pacific Quasi‐Stationary Parts of Atmospheric Rivers and Their Implications for East Asian Monsoon Onset

Using a global space‐time diagram of column water vapor (CWV) at 30° N latitude from daily reanalysis data, we find two quasi‐stationary parts of atmospheric rivers (QSARs) that feature locally enhanced CWV and evolve from the Eastern Pacific/Atlantic basins in the winter to the Western Pacific/Atla...

Full description

Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Lee, Hung‐i, Mitchell, Jonathan L., Tripati, Aradhna, Lora, Juan M., Chen, Ge, Ding, Qinghua
Format: Article in Journal/Newspaper
Language:English
Published: American Geophysical Union (AGU) 2019
Subjects:
Online Access:https://archimer.ifremer.fr/doc/00592/70439/68539.pdf
https://archimer.ifremer.fr/doc/00592/70439/68540.pdf
https://doi.org/10.1029/2019GL084272
https://archimer.ifremer.fr/doc/00592/70439/
Description
Summary:Using a global space‐time diagram of column water vapor (CWV) at 30° N latitude from daily reanalysis data, we find two quasi‐stationary parts of atmospheric rivers (QSARs) that feature locally enhanced CWV and evolve from the Eastern Pacific/Atlantic basins in the winter to the Western Pacific/Atlantic in the summer. East Asian Summer Monsoon onset coincides with the time CWV in the Pacific QSAR first exceeds 40 mm, which also typically occurs just before it makes landfall. QSARs exist in 39‐year (1979–2017) daily climatological CWV, demonstrating the seasonal cycles of these features are quasi‐stationary and potentially useful for monsoon onset prediction. East Asian Summer Monsoon onset is particularly predictable following El Niño‐Southern Oscillation, consistently occurring 25–40 days after the QSAR crosses the dateline. Analysis of local wave activity reveals QSARs as fronts of wave breakings, thus opening a new window into dynamics of subtropical monsoon extensions.