{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,6]],"date-time":"2025-12-06T16:46:13Z","timestamp":1765039573876,"version":"build-2065373602"},"reference-count":38,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2021,9,12]],"date-time":"2021-09-12T00:00:00Z","timestamp":1631404800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100012165","name":"Key Technologies Research and Development Program","doi-asserted-by":"publisher","award":["2018YFC1507302"],"award-info":[{"award-number":["2018YFC1507302"]}],"id":[{"id":"10.13039\/501100012165","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Nanjing Joint Center of Atmospheric Research Program","award":["NJCAR2018ZD01"],"award-info":[{"award-number":["NJCAR2018ZD01"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Satellite data are the main source of information for operational data assimilation systems, and Advanced Microwave Sounding Unit-A (AMSU-A) data are one of the types of satellite data that contribute most to the reduction of numerical forecast errors. However, the assimilation of AMSU-A data over land lags behind that over the ocean. In this respect, the accuracy of cloud detection over land is one of the factors affecting the assimilation of AMSU-A data, especially for the window and low-peaking channel (23\u201353.59 GHz and 89 GHz) data. Strong surface emissivity and high spatial and temporal variability make it difficult to distinguish between the radiative contributions of clouds and the atmosphere. Based on the differences in the response characteristics of different channels to clouds, five AMSU-A window and low-peaking channels (channels 1\u20134 and 15) were selected to develop a new index for cloud detection over land. Case studies showed that the AMSU-A cloud index can detect most of the convective clouds; additionally, by further matching the MHS (Microwave Humidity Sounder) cloud detection index, we can effectively distinguish between cloudy and clear-sky observations. Batch test results also verified the accuracy and stability of the new cloud detection method. By referring to the MODIS (Moderate Resolution Imaging Spectroradiometer) cloud product, the POD (probability of detection) of the cloud fields of view with the new method was nearly 84%. By using the new cloud detection method to remove the cloudy data, the bias and standard deviation of the observation-minus-simulated brightness temperature (O\u2212B) were significantly reduced, with the bias of O\u2212B for channels 2\u20134 being below 1.0 K and the standard deviation of channels 5 and 6 being nearly 1.0 K.<\/jats:p>","DOI":"10.3390\/rs13183646","type":"journal-article","created":{"date-parts":[[2021,9,12]],"date-time":"2021-09-12T21:48:01Z","timestamp":1631483281000},"page":"3646","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Development and Evaluation of a New Method for AMSU-A Cloud Detection over Land"],"prefix":"10.3390","volume":"13","author":[{"given":"Zhiwen","family":"Wu","sequence":"first","affiliation":[{"name":"Centre of Data Assimilation for Research and Application, Nanjing University of Information Science and Technology, Nanjing 210044, China"}]},{"given":"Juan","family":"Li","sequence":"additional","affiliation":[{"name":"National Meteorological Centre, China Meteorological Administration, Beijing 100081, China"},{"name":"Numerical Weather Prediction Centre, China Meteorological Administration, Beijing 100081, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1172-8040","authenticated-orcid":false,"given":"Zhengkun","family":"Qin","sequence":"additional","affiliation":[{"name":"Centre of Data Assimilation for Research and Application, Nanjing University of Information Science and Technology, Nanjing 210044, China"}]}],"member":"1968","published-online":{"date-parts":[[2021,9,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1038\/nature14956","article-title":"The quiet revolution of numerical weather prediction","volume":"525","author":"Bauer","year":"2015","journal-title":"Nature"},{"key":"ref_2","unstructured":"English, S.J., McNally, A., Niels, B., Kirsti, S., Marco, M., Andras, H., Michael, R., Marta, J., Michele, S.D., and Alan, J.G. (2013). Impact of satellite data. Technical Memorandum 711, ECMWF."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2315","DOI":"10.1002\/qj.2300","article-title":"Impact of GPS radio occultation measurements in the ECMWF system using adjoint-based diagnostics","volume":"140","author":"Cardinali","year":"2014","journal-title":"Q. J. R. Meteorol. Soc."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1415","DOI":"10.1007\/s00376-021-0326-5","article-title":"Use of Microwave Radiances from Metop-C and Fengyun-3 C\/D Satellites for a Northern European Limited-area Data Assimilation System","volume":"38","author":"Lindskog","year":"2021","journal-title":"Adv. Atmos. Sci."},{"key":"ref_5","unstructured":"Baker, N., Hogan, T., Campbell, W., Pauley, R., and Swadley, S. (2005). The impact of AMSU-A radiance assimilation in the U.S. Navy\u2019s Operational Global Atmospheric Prediction System (NOGAPS). Nav. Res. Lab., NRL\/MR\/7500-7505-8836."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2485","DOI":"10.1175\/MWR-D-14-00223.1","article-title":"Improved tropical storm forecasts with GOES-13\/15 imager radiance assimilation and asymmetric vortex initialization in HWRF","volume":"143","author":"Zou","year":"2015","journal-title":"Mon. Wea. Rev."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1109\/TGRS.2015.2498971","article-title":"Impact of Satellite Radiance Data on Simulations of Bay of Bengal Tropical Cyclones Using the WRF-3DVAR Modeling System","volume":"54","author":"Routray","year":"2016","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Zou, C.-Z., and Wang, W. (2011). Intersatellite calibration of AMSU-A observations for weather and climate applications. J. Geophys. Res. Atmos., 116.","DOI":"10.1029\/2011JD016205"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1439","DOI":"10.1007\/s00382-013-1958-7","article-title":"Uncertainty of AMSU-A derived temperature trends in relationship with clouds and precipitation over ocean","volume":"43","author":"Weng","year":"2014","journal-title":"Clim. Dyn."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1245","DOI":"10.1007\/s00382-019-05057-9","article-title":"Impacts of AMSU-A inter-sensor calibration and diurnal correction on satellite-derived linear and nonlinear decadal climate trends of atmospheric temperature","volume":"54","author":"Xia","year":"2020","journal-title":"Clim. Dyn."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2717","DOI":"10.5194\/gmd-11-2717-2018","article-title":"An update on the RTTOV fast radiative transfer model (currently at version 12)","volume":"11","author":"Saunders","year":"2018","journal-title":"Geosci. Model Dev."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"75","DOI":"10.1175\/MWR-D-12-00079.1","article-title":"Evaluating Added Benefits of Assimilating GOES Imager Radiance Data in GSI for Coastal QPFs","volume":"141","author":"Qin","year":"2013","journal-title":"Mon. Weather Rev."},{"key":"ref_13","unstructured":"Geer, A.J., Bauer, P., and English, S.J. (2012). Assimilating AMSU-A Temperature Sounding Channels in the Presence of Cloud and Precipitation, European Centre for Medium-Range Weather Forecasts."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Weng, F., Zhao, L., Ferraro, R.R., Poe, G., Li, X., and Grody, N.C. (2003). Advanced microwave sounding unit cloud and precipitation algorithms. Radio Sci., 38.","DOI":"10.1029\/2002RS002679"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"731","DOI":"10.1002\/qj.2960","article-title":"Impacts from assimilation of one data stream of AMSU-A and MHS radiances on quantitative precipitation forecasts","volume":"143","author":"Zou","year":"2017","journal-title":"Q. J. R. Meteorol. Soc."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Qin, Z., Wu, Z., and Li, J. (2020). Impact of the One-Stream Cloud Detection Method on the Assimilation of AMSU-A Data in GRAPES. Remote Sens., 12.","DOI":"10.3390\/rs12223842"},{"key":"ref_17","unstructured":"English, S.J., Renshaw, R.J., Dibben, P.C., and Eyre, J.R. (1997, January 20\u201326). The AAPP module for identifying precipitation, ice cloud, liquid water and surface type on the AMSU-A grid. Proceedings of the 9th International TOVS Study Conference, Igls, Austria."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2347","DOI":"10.1175\/MWR-D-10-05012.1","article-title":"A Land and Ocean Microwave Cloud Classification Algorithm Derived from AMSU-A and -B, Trained Using MSG-SEVIRI Infrared and Visible Observations","volume":"139","author":"Aires","year":"2011","journal-title":"Mon. Weather Rev."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1934","DOI":"10.1002\/qj.905","article-title":"Satellite cloud and precipitation assimilation at operational NWP centres","volume":"137","author":"Bauer","year":"2011","journal-title":"Q. J. R. Meteorol. Soc."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1214","DOI":"10.1002\/qj.426","article-title":"The direct assimilation of cloud-affected satellite infrared radiances in the ECMWF 4D-Var","volume":"135","author":"McNally","year":"2009","journal-title":"Q. J. R. Meteorol. Soc."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2024","DOI":"10.1002\/qj.830","article-title":"Observation errors in all-sky assimilation","volume":"137","author":"Geer","year":"2011","journal-title":"Q. J. R. Meteorol. Soc."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"4709","DOI":"10.1175\/MWR-D-15-0445.1","article-title":"All-Sky Microwave Radiance Assimilation in NCEP\u2019s GSI Analysis System","volume":"144","author":"Zhu","year":"2016","journal-title":"Mon. Weather Rev."},{"key":"ref_23","unstructured":"Peter, W., Alan, J.G., and Niels, B. (2019). Investigations into the Assimilation of AMSU-A in the Presence of Cloud and Precipitation, ECMWF."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"256","DOI":"10.1016\/S0034-4257(00)00171-1","article-title":"A Comparative Study of Land Surface Emissivity Retrieval from NOAA Data","volume":"75","author":"Sobrino","year":"2001","journal-title":"Remote Sens. Environ."},{"key":"ref_25","unstructured":"Krzeminski, B., Bormann, N., Karbou, F., and Bauer, P. (2008, January 7\u201313). Towards a better use of AMSU over land at ECMWF. Proceedings of the 16th International TOVS Study Conference, Angra dos Reis, Brazil."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"14887","DOI":"10.1029\/2001JD900085","article-title":"A new neural network approach including first guess for retrieval of atmospheric water vapor, cloud liquid water path, surface temperature, and emissivities over land from satellite microwave observations","volume":"106","author":"Aires","year":"2001","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"948","DOI":"10.1109\/TGRS.2004.837503","article-title":"Microwave land emissivity calculations using AMSU measurements","volume":"43","author":"Karbou","year":"2005","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"2333","DOI":"10.1256\/qj.05.216","article-title":"Microwave land emissivity and skin temperature for AMSU-A and -B assimilation over land","volume":"132","author":"Karbou","year":"2006","journal-title":"Q. J. R. Meteorol. Soc."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1073","DOI":"10.1175\/2007JTECHA1053.1","article-title":"Cloud detection with MODIS. Part II: Validation","volume":"25","author":"Ackerman","year":"2008","journal-title":"J. Atmos. Ocean. Technol."},{"key":"ref_30","unstructured":"Rossow, W.B., Walker, A.W., Beuschel, D.E., and Roiter, M.D. (1996). International Satellite Cloud Climatology Project (ISCCP) Documentation of New Cloud Datasets, World Meteorological Organization. WMO\/TD 737."},{"key":"ref_31","first-page":"1","article-title":"MODIS atmosphere L2 cloud product (06_L2)","volume":"10","author":"Platnick","year":"2015","journal-title":"NASA MODIS Adapt. Process. Syst. Goddard Space Flight Cent. USA."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1050","DOI":"10.1016\/j.jqsrt.2010.11.009","article-title":"Validation of the community radiative transfer model","volume":"112","author":"Ding","year":"2011","journal-title":"J. Quant. Spectrosc. Radiat. Transf."},{"key":"ref_33","unstructured":"National Centers for Environmental Prediction, National Weather Service, NOAA, and US Department of Commerce (2000). NCEP FNL Operational Model Global Tropospheric Analyses, Continuing from July 1999, Updated Daily."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"3889","DOI":"10.1175\/MWR-D-12-00340.1","article-title":"Assimilating AMSU-A radiances in the TC core area with NOAA operational HWRF (2011) and a hybrid data assimilation system: Danielle (2010)","volume":"141","author":"Zhang","year":"2013","journal-title":"Mon. Weather Rev."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Rees, W. (2012). Physical Principles of Remote Sensing, Cambridge University Press.","DOI":"10.1017\/CBO9781139017411"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1007\/s13351-016-5076-4","article-title":"Development and initial assessment of a new land index for microwave humidity sounder cloud detection","volume":"30","author":"Qin","year":"2016","journal-title":"J. Meteorol. Res."},{"key":"ref_37","first-page":"434","article-title":"A new cloud detection algorithm based on brightness temperature variation for FY-3C Microwave Humidity Sounder Over land","volume":"76","author":"Zhu","year":"2018","journal-title":"Acta Meteorol. Sin."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Xu, W., and Lyu, D. (2021). Evaluation of Cloud Mask and Cloud Top Height from Fengyun-4A with MODIS Cloud Retrievals over the Tibetan Plateau. Remote Sens., 13.","DOI":"10.3390\/rs13081418"}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/18\/3646\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:01:28Z","timestamp":1760166088000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/13\/18\/3646"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,9,12]]},"references-count":38,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2021,9]]}},"alternative-id":["rs13183646"],"URL":"https:\/\/doi.org\/10.3390\/rs13183646","relation":{},"ISSN":["2072-4292"],"issn-type":[{"type":"electronic","value":"2072-4292"}],"subject":[],"published":{"date-parts":[[2021,9,12]]}}}