Details:

Journal Title:
Journal of Geophysical Research: Atmospheres
Personal Author:
Zhang, L. ; Xie, Z. ; Deng, Y. ; Huang, W.
Zhang, L. ; Xie, Z. ; Deng, Y. ; Huang, W. Less -
NOAA Program & Office:
OAR (Oceanic and Atmospheric Research)
Description:
Recent changes in the Earth's climate have led to renewed interest in extreme cold wave (ECW) events. This study identifies the ECW patterns over the Chinese mainland, their corresponding large‐scale meteorological patterns (LMPs) and their favorable planetary wave patterns over 1961–2015. A self‐organizing map classifies ECWs into northeast, nationwide, northwest–south and Qinghai–Tibetan Plateau clusters. The cold anomalies are primarily contributed by the anomalous wind advecting climatological mean temperature for the leading three clusters, but diabaitic heating for the Qinghai–Tibetan Plateau cluster. The associated LMPs are primarily characterized by a dipole with a positive height anomaly over Siberia and a negative height anomaly extending from Japan to the Iranian Plateau, which displaces southwestward among the four ECW clusters. The LMPs induce anomalous northerly flows extending from the upper troposphere to the near‐surface, which deepen the negative height anomaly southwestward from the East Asian trough and accumulate cold air masses over the key regions within the dipole that are phase‐locked with the LMPs (i.e., baroclinic growth). Such baroclinic growth of the LMP is larger during periods of a planetary wave (wavenumbers 1–5) resembling the Northern Annular Mode (NAM). Meanwhile, the negative (positive) phase of the NAM provides more direct contribution to the LMP of the northeast and nationwide (Qinghai‐Tibetan Plateau) ECW clusters and thus are likely to favor the occurrence of ECWs. The negative phase of NAM‐like planetary waves exhibit a positive trend after the transition year of 1987, and could potentially increase the occurrence frequency of nationwide ECWs.
Keywords:
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Atmospheric Science Earth And Planetary Sciences (miscellaneous) Geophysics Space And Planetary Science
Source:
Journal of Geophysical Research: Atmospheres, 126(22)
DOI:
https://doi.org/10.1029/2021jd035005
ISSN:
2169-897X;2169-8996;
Format:
PDF
Publisher:
American Geophysical Union (AGU)
Document Type:
Journal Article
Funding:
Grant no. NA20OAR4310380
Rights Information:
Other
Compliance:
Library
Main Document Checksum:
[+]
urn:sha256:9534250ce5d1d405a3ae6f3a4da9ce526902702ad4e096691ad282a8a22b4b09
Download URL:
https://repository.library.noaa.gov/view/noaa/59860/noaa_59860_DS1.pdf
File Type:

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