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<front>
<journal-meta>
<journal-id journal-id-type="publisher">ADGEO</journal-id>
<journal-title-group>
<journal-title>Advances in Geosciences</journal-title>
<abbrev-journal-title abbrev-type="publisher">ADGEO</abbrev-journal-title>
<abbrev-journal-title abbrev-type="nlm-ta">Adv. Geosci.</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">1680-7359</issn>
<publisher><publisher-name>Copernicus Publications</publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/adgeo-10-31-2007</article-id>
<title-group>
<article-title>Comparison of East Asian winter monsoon indices</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Gao Hui</surname>
<given-names></given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Laboratory of Climate Study, Beijing Climate Center, China</addr-line>
</aff>
<pub-date pub-type="epub">
<day>26</day>
<month>04</month>
<year>2007</year>
</pub-date>
<volume>10</volume>
<fpage>31</fpage>
<lpage>37</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2007 Gao Hui</copyright-statement>
<copyright-year>2007</copyright-year>
<license license-type="open-access">
<license-p>This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 2.5 Generic License. To view a copy of this licence, visit <ext-link ext-link-type="uri"  xlink:href="https://creativecommons.org/licenses/by-nc-sa/2.5/">https://creativecommons.org/licenses/by-nc-sa/2.5/</ext-link></license-p>
</license>
</permissions>
<self-uri xlink:href="https://adgeo.copernicus.org/articles/10/31/2007/adgeo-10-31-2007.html">This article is available from https://adgeo.copernicus.org/articles/10/31/2007/adgeo-10-31-2007.html</self-uri>
<self-uri xlink:href="https://adgeo.copernicus.org/articles/10/31/2007/adgeo-10-31-2007.pdf">The full text article is available as a PDF file from https://adgeo.copernicus.org/articles/10/31/2007/adgeo-10-31-2007.pdf</self-uri>
<abstract>
<p>Four East Asian winter monsoon (EAWM) indices are
compared in this paper. In the research periods, all the indices show
similar interannual and decadal-interdecadal variations, with predominant
periods centering in 3&amp;ndash;4 years, 6.5 years and 9&amp;ndash;15 years, respectively.
Besides, all the indices show remarkable weakening trends since the 1980s.
The correlation coefficient of each two indices is positive with a
significance level of 99%.

&lt;br&gt;&lt;br&gt;
Both the correlation analyses and the composites indicate that in stronger
EAWM years, the Siberian high and the higher-level subtropical westerly jet
are stronger, and the Aleutian low and the East Asia trough are deeper. This
circulation pattern is favorable for much stronger northwesterly wind and
lower air temperature in the subtropical regions of East Asia, while it is
on the opposite in weaker EAWM years. Besides, EAWM can also exert a
remarkable leading effect on the summer monsoon. After stronger (weaker)
EAWM, less (more) summer precipitation is seen over the regions from the
Yangtze River valley of China to southern Japan, while more (less) from
South China Sea to the tropical western Pacific.</p>
</abstract>
<counts><page-count count="7"/></counts>
</article-meta>
</front>
<body/>
<back>
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</article>