Subseasonal Variations of Wintertime North Pacific Evaporation, Cold Air Surges and Water Vapor Transport

Subseasonal Variations of Wintertime North Pacific Evaporation, Cold Air Surges and Water Vapor... AbstractThis study addresses subseasonal variations of oceanic evaporation ( E ) over the North Pacific during winter, and the connection with the cold air surges (CAS) and atmospheric water vapor transport using the OAFlux and ERA-Interim daily data. By performing an empirical orthogonal function (EOF) analysis, two dominant modes of subseasonal evaporation anomaly ( E′ ) are identified: a zonally wave-train like pattern (EOF1), and an east positive–west negative dipolar pattern (EOF2) in the midlatitude basin. Further analyses yield the following conclusions. (1) The Siberian high (SH)-related CAS has a crucial role in generation of the EOF1 mode of E′. When the dry and cold airmass passes the warm Kuroshio current and its extension (KOE) region, the increased air–sea temperature and moisture differences and intensified wind speed lead to the above-normal oceanic E , and vice versa. (2) The Aleutian low (AL)-related CAS contributes to the EOF2 mode of E′. The intensified AL transports dramatically colder and drier airmass toward the KOE region, and slightly warmer and wetter one toward the west coast of North America, leading to the east positive–west negative structure of E′ in the midlatitude basin. (3) A quasi-linear relationship exists between E′ and divergent water vapor transport anomalies over the KOE region. Positive (negative) E′ is generally accompanied by anomalous vapor source (sink). (4) The divergent water vapor transport anomalies associated with the two EOFs are preliminarily decided by their individual lower-level wind fields anomalies, and secondly by the meridional inhomogeneity of subseasonal specific humidity anomalies. Hydroclimate effects on precipitation over the pan-North Pacific region are also discussed. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of Climate American Meteorological Society

Subseasonal Variations of Wintertime North Pacific Evaporation, Cold Air Surges and Water Vapor Transport

Loading next page...
 
/lp/ams/subseasonal-variations-of-wintertime-north-pacific-evaporation-cold-OnfdYQ9iGC
Publisher
American Meteorological Society
Copyright
Copyright © American Meteorological Society
ISSN
1520-0442
D.O.I.
10.1175/JCLI-D-17-0140.1
Publisher site
See Article on Publisher Site

Abstract

AbstractThis study addresses subseasonal variations of oceanic evaporation ( E ) over the North Pacific during winter, and the connection with the cold air surges (CAS) and atmospheric water vapor transport using the OAFlux and ERA-Interim daily data. By performing an empirical orthogonal function (EOF) analysis, two dominant modes of subseasonal evaporation anomaly ( E′ ) are identified: a zonally wave-train like pattern (EOF1), and an east positive–west negative dipolar pattern (EOF2) in the midlatitude basin. Further analyses yield the following conclusions. (1) The Siberian high (SH)-related CAS has a crucial role in generation of the EOF1 mode of E′. When the dry and cold airmass passes the warm Kuroshio current and its extension (KOE) region, the increased air–sea temperature and moisture differences and intensified wind speed lead to the above-normal oceanic E , and vice versa. (2) The Aleutian low (AL)-related CAS contributes to the EOF2 mode of E′. The intensified AL transports dramatically colder and drier airmass toward the KOE region, and slightly warmer and wetter one toward the west coast of North America, leading to the east positive–west negative structure of E′ in the midlatitude basin. (3) A quasi-linear relationship exists between E′ and divergent water vapor transport anomalies over the KOE region. Positive (negative) E′ is generally accompanied by anomalous vapor source (sink). (4) The divergent water vapor transport anomalies associated with the two EOFs are preliminarily decided by their individual lower-level wind fields anomalies, and secondly by the meridional inhomogeneity of subseasonal specific humidity anomalies. Hydroclimate effects on precipitation over the pan-North Pacific region are also discussed.

Journal

Journal of ClimateAmerican Meteorological Society

Published: Aug 30, 2017

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve Freelancer

DeepDyve Pro

Price
FREE
$49/month

$360/year
Save searches from
Google Scholar,
PubMed
Create lists to
organize your research
Export lists, citations
Read DeepDyve articles
Abstract access only
Unlimited access to over
18 million full-text articles
Print
20 pages/month
PDF Discount
20% off