<?xml version="1.0" encoding="UTF-8"?>
<gmd:MD_Metadata xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                 xmlns:gco="http://www.isotc211.org/2005/gco"
                 xmlns:gmd="http://www.isotc211.org/2005/gmd"
                 xmlns:srv="http://www.isotc211.org/2005/srv"
                 xmlns:gmx="http://www.isotc211.org/2005/gmx"
                 xmlns:gts="http://www.isotc211.org/2005/gts"
                 xmlns:gsr="http://www.isotc211.org/2005/gsr"
                 xmlns:gmi="http://www.isotc211.org/2005/gmi"
                 xmlns:gml="http://www.opengis.net/gml"
                 xmlns:xlink="http://www.w3.org/1999/xlink"
                 xsi:schemaLocation="http://www.isotc211.org/2005/gmd http://www.isotc211.org/2005/gmx/gmx.xsd">
   <gmd:fileIdentifier>
      <gco:CharacterString>edu.ucar.opensky::articles:23380</gco:CharacterString>
   </gmd:fileIdentifier>
   <gmd:language>
      <gmd:LanguageCode codeList="http://www.loc.gov/standards/iso639-2/"
                        codeListValue="eng; USA"/>
   </gmd:language>
   <gmd:characterSet>
      <gmd:MD_CharacterSetCode codeListValue="utf8"
                               codeList="http://www.isotc211.org/namespace/resources/codeList.xml#MD_CharacterSetCode"/>
   </gmd:characterSet>
   <gmd:hierarchyLevel>
      <gmd:MD_ScopeCode codeList="http://standards.iso.org/ittf/PubliclyAvailableStandards/ISO_19139_Schemas/resources/codelist/ML_gmxCodelists.xml#MD_ScopeCode"
                        codeListValue="document"/>
   </gmd:hierarchyLevel>
   <gmd:contact>
      <gmd:CI_ResponsibleParty>
         <gmd:organisationName>
            <gco:CharacterString>UCAR/NCAR - Library</gco:CharacterString>
         </gmd:organisationName>
         <gmd:positionName>
            <gco:CharacterString>OpenSky Support</gco:CharacterString>
         </gmd:positionName>
         <gmd:contactInfo>
            <gmd:CI_Contact>
               <gmd:address>
                  <gmd:CI_Address>
                     <gmd:deliveryPoint>
                        <gco:CharacterString>PO Box 3000</gco:CharacterString>
                     </gmd:deliveryPoint>
                     <gmd:city>
                        <gco:CharacterString>Boulder</gco:CharacterString>
                     </gmd:city>
                     <gmd:administrativeArea>
                        <gco:CharacterString>CO</gco:CharacterString>
                     </gmd:administrativeArea>
                     <gmd:postalCode>
                        <gco:CharacterString>80307-3000</gco:CharacterString>
                     </gmd:postalCode>
                     <gmd:electronicMailAddress>
                        <gco:CharacterString>opensky@ucar.edu</gco:CharacterString>
                     </gmd:electronicMailAddress>
                  </gmd:CI_Address>
               </gmd:address>
               <gmd:onlineResource>
                  <gmd:CI_OnlineResource>
                     <gmd:linkage>
                        <gmd:URL>http://opensky.ucar.edu/</gmd:URL>
                     </gmd:linkage>
                     <gmd:name>
                        <gco:CharacterString>homepage</gco:CharacterString>
                     </gmd:name>
                  </gmd:CI_OnlineResource>
               </gmd:onlineResource>
            </gmd:CI_Contact>
         </gmd:contactInfo>
         <gmd:role>
            <gmd:CI_RoleCode codeList="codeListLocation#CI_RoleCode" codeListValue="pointOfContact">pointOfContact</gmd:CI_RoleCode>
         </gmd:role>
      </gmd:CI_ResponsibleParty>
   </gmd:contact>
   <gmd:dateStamp>
      <gco:DateTime>2025-12-25T15:09:12.860358</gco:DateTime>
   </gmd:dateStamp>
   <gmd:metadataStandardName>
      <gco:CharacterString>ISO 19115-2 Geographic Information - Metadata - Part 2:
                    Extensions for Imagery and Gridded Data</gco:CharacterString>
   </gmd:metadataStandardName>
   <gmd:metadataStandardVersion>
      <gco:CharacterString>ISO 19115-2:2009(E)</gco:CharacterString>
   </gmd:metadataStandardVersion>
   <gmd:dataSetURI>
      <gco:CharacterString>https://n2t.org/ark:/85065/d7zp49bf</gco:CharacterString>
   </gmd:dataSetURI>
   <gmd:identificationInfo>
      <gmd:MD_DataIdentification>
         <gmd:citation>
            <gmd:CI_Citation>
               <gmd:title>
                  <gco:CharacterString>Improving air quality forecasting with the assimilation of GOCI aerosol optical depth (AOD) retrievals during the KORUS-AQ period</gco:CharacterString>
               </gmd:title>
               <gmd:date>
                  <gmd:CI_Date>
                     <gmd:date>
                        <gco:DateTime>2020-05-20T00:00:00Z</gco:DateTime>
                     </gmd:date>
                     <gmd:dateType>
                        <gmd:CI_DateTypeCode codeList="codeListLocation#CI_DateTypeCode" codeListValue="publication">publication</gmd:CI_DateTypeCode>
                     </gmd:dateType>
                  </gmd:CI_Date>
               </gmd:date>
               <gmd:identifier>
                  <gmd:RS_Identifier>
                     <gmd:code>
                        <gco:CharacterString>https://n2t.org/ark:/85065/d7zp49bf</gco:CharacterString>
                     </gmd:code>
                  </gmd:RS_Identifier>
               </gmd:identifier>
               <gmd:identifier>
                  <gmd:RS_Identifier>
                     <gmd:code>
                        <gco:CharacterString>https://doi.org/10.5194/acp-20-6015-2020</gco:CharacterString>
                     </gmd:code>
                  </gmd:RS_Identifier>
               </gmd:identifier>
               <gmd:citedResponsibleParty>
                  <gmd:CI_ResponsibleParty>
                     <gmd:individualName>
                        <gmx:Anchor xlink:href="https://orcid.org/0000-0002-6970-8950"
                                    xlink:title="Ha, So-Young"
                                    xlink:actuate="onRequest">Ha, So-Young</gmx:Anchor>
                     </gmd:individualName>
                     <gmd:role>
                        <gmd:CI_RoleCode codeList="codeListLocation#CI_RoleCode" codeListValue="author">author</gmd:CI_RoleCode>
                     </gmd:role>
                  </gmd:CI_ResponsibleParty>
               </gmd:citedResponsibleParty>
               <gmd:citedResponsibleParty>
                  <gmd:CI_ResponsibleParty>
                     <gmd:individualName>
                        <gmx:Anchor xlink:href="https://orcid.org/0000-0003-4917-7686"
                                    xlink:title="Liu, Zhiquan"
                                    xlink:actuate="onRequest">Liu, Zhiquan</gmx:Anchor>
                     </gmd:individualName>
                     <gmd:role>
                        <gmd:CI_RoleCode codeList="codeListLocation#CI_RoleCode" codeListValue="author">author</gmd:CI_RoleCode>
                     </gmd:role>
                  </gmd:CI_ResponsibleParty>
               </gmd:citedResponsibleParty>
               <gmd:citedResponsibleParty>
                  <gmd:CI_ResponsibleParty>
                     <gmd:individualName>
                        <gco:CharacterString>Sun, Wei</gco:CharacterString>
                     </gmd:individualName>
                     <gmd:role>
                        <gmd:CI_RoleCode codeList="codeListLocation#CI_RoleCode" codeListValue="author">author</gmd:CI_RoleCode>
                     </gmd:role>
                  </gmd:CI_ResponsibleParty>
               </gmd:citedResponsibleParty>
               <gmd:citedResponsibleParty>
                  <gmd:CI_ResponsibleParty>
                     <gmd:individualName>
                        <gco:CharacterString>Lee, Y.</gco:CharacterString>
                     </gmd:individualName>
                     <gmd:role>
                        <gmd:CI_RoleCode codeList="codeListLocation#CI_RoleCode" codeListValue="author">author</gmd:CI_RoleCode>
                     </gmd:role>
                  </gmd:CI_ResponsibleParty>
               </gmd:citedResponsibleParty>
               <gmd:citedResponsibleParty>
                  <gmd:CI_ResponsibleParty>
                     <gmd:individualName>
                        <gco:CharacterString>Chang, L.</gco:CharacterString>
                     </gmd:individualName>
                     <gmd:role>
                        <gmd:CI_RoleCode codeList="codeListLocation#CI_RoleCode" codeListValue="author">author</gmd:CI_RoleCode>
                     </gmd:role>
                  </gmd:CI_ResponsibleParty>
               </gmd:citedResponsibleParty>
               <gmd:citedResponsibleParty>
                  <gmd:CI_ResponsibleParty>
                     <gmd:organisationName>
                        <gco:CharacterString>UCAR/NCAR - Library</gco:CharacterString>
                     </gmd:organisationName>
                     <gmd:role>
                        <gmd:CI_RoleCode codeList="codeListLocation#CI_RoleCode" codeListValue="publisher">publisher</gmd:CI_RoleCode>
                     </gmd:role>
                  </gmd:CI_ResponsibleParty>
               </gmd:citedResponsibleParty>
            </gmd:CI_Citation>
         </gmd:citation>
         <gmd:abstract>
            <gco:CharacterString>The Korean Geostationary Ocean Color Imager (GOCI) satellite has monitored the East Asian region in high temporal (e.g., hourly) and spatial resolution (e.g., 6km) every day for the last decade, providing unprecedented information on air pollutants over the upstream region of the Korean Peninsula. In this study, the GOCI aerosol optical depth (AOD), retrieved at the 550 nm wavelength, is assimilated to enhance the quality of the aerosol analysis, thereby making systematic improvements to air quality forecasting over South Korea. For successful data assimilation, GOCI retrievals are carefully investigated and processed based on data characteristics such as temporal and spatial distribution. The preprocessed data are then assimilated in the three-dimensional variational data assimilation (3D-Var) technique for the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem). For the Korea-United States Air Quality (KORUS-AQ) period (May 2016), the impact of GOCI AOD on the accuracy of surface PM2.5 prediction is examined by comparing with effects of other observations including Moderate Resolution Imaging Spectroradiometer (MODIS) sensors and surface PM2.5 observations. Consistent with previous studies, the assimilation of surface PM2.5 measurements alone still underestimates surface PM2.5 concentrations in the following forecasts, and the forecast improvements last only for about 6 h. When GOCI AOD retrievals are assimilated with surface PM2.5 observations, however, the negative bias is diminished and forecast skills are improved up to 24 h, with the most significant contributions to the prediction of heavy pollution events over South Korea.</gco:CharacterString>
         </gmd:abstract>
         <gmd:pointOfContact>
            <gmd:CI_ResponsibleParty>
               <gmd:organisationName>
                  <gco:CharacterString>UCAR/NCAR - Library</gco:CharacterString>
               </gmd:organisationName>
               <gmd:positionName>
                  <gco:CharacterString>OpenSky Support</gco:CharacterString>
               </gmd:positionName>
               <gmd:contactInfo>
                  <gmd:CI_Contact>
                     <gmd:address>
                        <gmd:CI_Address>
                           <gmd:deliveryPoint>
                              <gco:CharacterString>PO Box 3000</gco:CharacterString>
                           </gmd:deliveryPoint>
                           <gmd:city>
                              <gco:CharacterString>Boulder</gco:CharacterString>
                           </gmd:city>
                           <gmd:administrativeArea>
                              <gco:CharacterString>CO</gco:CharacterString>
                           </gmd:administrativeArea>
                           <gmd:postalCode>
                              <gco:CharacterString>80307-3000</gco:CharacterString>
                           </gmd:postalCode>
                           <gmd:electronicMailAddress>
                              <gco:CharacterString>opensky@ucar.edu</gco:CharacterString>
                           </gmd:electronicMailAddress>
                        </gmd:CI_Address>
                     </gmd:address>
                     <gmd:onlineResource>
                        <gmd:CI_OnlineResource>
                           <gmd:linkage>
                              <gmd:URL>http://opensky.ucar.edu/</gmd:URL>
                           </gmd:linkage>
                           <gmd:name>
                              <gco:CharacterString>homepage</gco:CharacterString>
                           </gmd:name>
                        </gmd:CI_OnlineResource>
                     </gmd:onlineResource>
                  </gmd:CI_Contact>
               </gmd:contactInfo>
               <gmd:role>
                  <gmd:CI_RoleCode codeList="codeListLocation#CI_RoleCode" codeListValue="pointOfContact">pointOfContact</gmd:CI_RoleCode>
               </gmd:role>
            </gmd:CI_ResponsibleParty>
         </gmd:pointOfContact>
         <gmd:resourceFormat>
            <gmd:MD_Format>
               <gmd:name>
                  <gco:CharacterString>PDF</gco:CharacterString>
               </gmd:name>
               <gmd:version/>
            </gmd:MD_Format>
         </gmd:resourceFormat>
         <gmd:descriptiveKeywords>
            <gmd:MD_Keywords>
               <gmd:keyword>
                  <gco:CharacterString>Text</gco:CharacterString>
               </gmd:keyword>
               <gmd:type>
                  <gmd:MD_KeywordTypeCode codeList="codeListLocation#MD_KeywordTypeCode" codeListValue="theme">theme</gmd:MD_KeywordTypeCode>
               </gmd:type>
               <gmd:thesaurusName>
                  <gmd:CI_Citation>
                     <gmd:title>
                        <gco:CharacterString>Resource Type</gco:CharacterString>
                     </gmd:title>
                     <gmd:date>
                        <gmd:CI_Date>
                           <gmd:date>
                              <gco:DateTime>2016-01-01T00:00:00Z</gco:DateTime>
                           </gmd:date>
                           <gmd:dateType>
                              <gmd:CI_DateTypeCode codeList="codeListLocation#CI_DateTypeCode" codeListValue="publication">publication</gmd:CI_DateTypeCode>
                           </gmd:dateType>
                        </gmd:CI_Date>
                     </gmd:date>
                  </gmd:CI_Citation>
               </gmd:thesaurusName>
            </gmd:MD_Keywords>
         </gmd:descriptiveKeywords>
         <gmd:resourceConstraints>
            <gmd:MD_LegalConstraints>
               <gmd:useLimitation>
                  <gco:CharacterString>Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.</gco:CharacterString>
               </gmd:useLimitation>
               <gmd:otherConstraints>
                  <gco:CharacterString>None</gco:CharacterString>
               </gmd:otherConstraints>
            </gmd:MD_LegalConstraints>
         </gmd:resourceConstraints>
         <gmd:language>
            <gmd:LanguageCode codeList="codeListLocation#LanguageCode" codeListValue="eng">eng</gmd:LanguageCode>
         </gmd:language>
         <gmd:topicCategory>
            <gmd:MD_TopicCategoryCode>geoscientificInformation</gmd:MD_TopicCategoryCode>
         </gmd:topicCategory>
      </gmd:MD_DataIdentification>
   </gmd:identificationInfo>
</gmd:MD_Metadata>
