<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE article PUBLIC "-//NLM//DTD Journal Publishing DTD v3.0 20080202//EN" "https://jats.nlm.nih.gov/nlm-dtd/publishing/3.0/journalpublishing3.dtd">
<article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" article-type="research-article" specific-use="SMUR" dtd-version="3.0" xml:lang="en">
<front>
<journal-meta>
<journal-id journal-id-type="publisher">EGUsphere</journal-id>
<journal-title-group>
<journal-title>EGUsphere</journal-title>
<abbrev-journal-title abbrev-type="publisher">EGUsphere</abbrev-journal-title>
<abbrev-journal-title abbrev-type="nlm-ta">EGUsphere</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub"></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/egusphere-2025-6541</article-id>
<title-group>
<article-title>Parameterization and Evaluation of Nonhydrostatic Effect in the Orographic Gravity Wave Drag in China Meteorological Administration Global Forecast System (CMA-GFS) v4.0 Model</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Zhang</surname>
<given-names>Rongrong</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Ai</surname>
<given-names>Zhenzhen</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Xu</surname>
<given-names>Xin</given-names>
<ext-link>https://orcid.org/0000-0002-4495-3677</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Xue</surname>
<given-names>Haile</given-names>
<ext-link>https://orcid.org/0000-0003-4774-7059</ext-link>
</name>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
<xref ref-type="aff" rid="aff5">
<sup>5</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Chen</surname>
<given-names>Qiying</given-names>
</name>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
<xref ref-type="aff" rid="aff5">
<sup>5</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>State Key Laboratory of Severe Weather Meteorological Science and Technology, Key  laboratory of Mesoscale Severe Weather/Ministry of Education, School of Atmospheric Sciences,  Nanjing University, Nanjing 210023, China</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Jiangsu Meteorological Observatory, Jiangsu Meteorological Bureau, Nanjing 210000, China</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>Jiangsu Key Laboratory of Severe Storm Disaster Risk/Key Laboratory of Transportation  Meteorology of CMA, Nanjing 210000, China</addr-line>
</aff>
<aff id="aff4">
<label>4</label>
<addr-line>State Key Laboratory of Severe Weather Meteorological Science and Technology, CMA Earth  System Modeling and Prediction Centre, Beijing 100081, China</addr-line>
</aff>
<aff id="aff5">
<label>5</label>
<addr-line>Key Laboratory of Earth System Modeling and Prediction, China Meteorological  Administration, Beijing 100081, China</addr-line>
</aff>
<pub-date pub-type="epub">
<day>12</day>
<month>02</month>
<year>2026</year>
</pub-date>
<volume>2026</volume>
<fpage>1</fpage>
<lpage>41</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2026 Rongrong Zhang et al.</copyright-statement>
<copyright-year>2026</copyright-year>
<license license-type="open-access">
<license-p>This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit <ext-link ext-link-type="uri"  xlink:href="https://creativecommons.org/licenses/by/4.0/">https://creativecommons.org/licenses/by/4.0/</ext-link></license-p>
</license>
</permissions>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2026/egusphere-2025-6541/">This article is available from https://egusphere.copernicus.org/preprints/2026/egusphere-2025-6541/</self-uri>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2026/egusphere-2025-6541/egusphere-2025-6541.pdf">The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2026/egusphere-2025-6541/egusphere-2025-6541.pdf</self-uri>
<abstract>
<p>The China Meteorological Administration Global Forecast System (CMA-GFS) v4.0 model was upgraded to a higher resolution of 0.125&amp;deg; in May 2023. To be compatible with its fine resolution, the parameterization scheme of orographic gravity wave drag (OGWD) in CAM-GFS is revised herein by accounting for the nonhydrostatic effect (NHE) on the wave momentum flux of subgrid-scale orographic gravity waves. The performance of the revised OGWD scheme is then evaluated for the 10-day medium-range forecast in December 2023. Results show that the revised OGWD scheme can better capture the large-scale circulation in the Northern Hemisphere (NH), particularly in the high latitudes. The easterly (westerly) wind biases in the NH polar stratosphere (troposphere) are decreased. The underestimation of East Asia subtropical jet is also alleviated. Quantitative evaluation shows that the revised OGWD scheme reduces both the mean bias and root mean square error of 500-hPa geopotential height in the NH after the 6th forecast day, reaching 11.59 % and 5.06 %, respectively, by day 10. The decrease of easterly biases in the polar stratosphere is owing to the weakening of stratospheric zonal OGWD by the NHE. It is also contributed by the secondary circulation induced by the weakened OGWD, which increases the thermal contrast between middle and high latitudes by adiabatic warming/cooling. For the decrease of westerly biases in the NH polar troposphere, it is due to the fact that the enhanced stratospheric winds suppress the upward propagation of Rossby waves into the stratosphere, resulting in greater convergence of Eliassen-Palm flux in the mid-upper troposphere.</p>
</abstract>
<counts><page-count count="41"/></counts>
<funding-group>
<award-group id="gs1">
<funding-source>National Natural Science Foundation of China</funding-source>
<award-id>U2342226</award-id>
</award-group>
</funding-group>
</article-meta>
</front>
<body/>
<back>
</back>
</article>