Severe Cold Winters in East Asia Linked to First Winter of La Niña Events and in North America Linked to Second Winter
Abstract
La Niña often persists for two years, unlike El Niño. Five single-year and 8 multi-year La Niña events occurred over 71 boreal winters (1950/51-2020/21). Atmospheric reanalysis data show a marked increase in diabatic heating over the tropical northwestern Pacific (TNWP) in first winters of La Niña events in addition to a decrease in diabatic heating over the tropical eastern Pacific, common to first and second winters. Linear baroclinic model experiments indicate that combinations of the heating form different atmospheric teleconnections in the mid-latitudes; first winters with the increased heating over the TNWP form teleconnection across the North Pacific, leading to cold winters in Japan. In second winters with the reduced heating over the TNWP (∼50% of first winters), teleconnection shifts east, resulting in severe cold winters in northwestern North America, whereas there is no impact on Japan.
- Publication:
-
Geophysical Research Letters
- Pub Date:
- April 2022
- DOI:
- 10.1029/2021GL095334
- Bibcode:
- 2022GeoRL..4995334N
- Keywords:
-
- multiyear La Niña;
- cold air mass;
- teleconnection