{"id":12851,"date":"2019-05-29T09:32:48","date_gmt":"2019-05-29T09:32:48","guid":{"rendered":"https:\/\/www.nwpsaf.eu\/site\/?page_id=12851"},"modified":"2026-04-28T08:05:00","modified_gmt":"2026-04-28T08:05:00","slug":"monitoring-winds-quality-evaluation-amv-amv-use-in-nwp-ukmo","status":"publish","type":"page","link":"https:\/\/nwp-saf.eumetsat.int\/site\/monitoring\/winds-quality-evaluation\/amv\/amv-use-in-nwp\/monitoring-winds-quality-evaluation-amv-amv-use-in-nwp-ukmo\/","title":{"rendered":"AMV usage in the Met Office NWP model"},"content":{"rendered":"<h2>Use of AMVs in the Met Office model<\/h2>\n\n<h3>Physical characteristics<\/h3>\n<h4>Global Model (coupled atmosphere-ocean)<\/h4>\n<ul>\n<li>GC4 global coupled atmosphere-land-ocean-seaice\n<li>GA8 atmospheric configuration\n<ul>\n<li>Grid-point model: 2560&#215;1920 grid points<\/li>\n<li>Horizontal resolution: Forecast N1280 (~10 km in mid-latitudes)<\/li>\n<li>Vertical resolution: 70 vertical levels, hybrid-eta configuration, lid ~80 km<\/li>\n<li>Forecast range: out to T+168 (7 days)<\/li>\n<\/ul>\n<li>GL9 land configuration\n<li>GO6 ocean (with GSI8 sea ice) configuration at ORCA025 tri-polar grid 1\/4 deg resolution\n<\/ul>\n<h4>UKV Model<\/h4>\n<ul>\n<li>Grid-point model: 622&#215;810 grid points (inner), 950&#215;1025 grid (total)<\/li>\n<li>Horizontal resolution: variable stretching from ~1.5 km (outer domain) to ~4 km (inner)<\/li>\n<li>Vertical resolution: 70 vertical levels, lid ~40 km (different levels from global)<\/li>\n<li>Forecasts to T+120 at 03\/15 UTC, T+54 or T+12 otherwise<\/li>\n<\/ul>\n<h3>Data assimilation method<\/h3>\n<h4>Global Model<\/h4>\n<ul>\n<li>Type: Hybrid incremental 4D-Var, Errors of the day (EOTD) information provided by global ensemble (N640 ensemble differences reconfigured to modes at N320) every 6 hours. EOTD now uses the lagging-and-shifting technique with a one lag and two shifts configuration &#8211; see Fig 12 of Lorenc (2017)<\/li>\n<li>Resolution: N320 L70 (~40 km, PF timestep = 10 mins)<\/li>\n<li>Analysis times (T): 00, 06, 12, 18 Z<\/li>\n<li>Time window: 6 hrs, T \u00b1 3 hr<\/li>\n<li>Time constraints (model runtime):<\/li>\n<li>Main forecast run: 20 min before time window ends<\/li>\n<li>Update run: 3 hr 15 min after time window ends<\/li>\n<\/ul>\n<h4>UKV Model<\/h4>\n<ul>\n<li>Type: Incremental 4D-Var (except for radar rainrate)<\/li>\n<li>Resolution: ~4.5 km fixed resolution<\/li>\n<li>Analysis times (T): 00, 01, 02,..,21,22,23 Z<\/li>\n<li>Time window: 1 hour (centred on nominal analysis time i.e. 0830-0930 for 09 UTC run).<\/li>\n<li>Time constraints (model runtime):<\/li>\n<li>T+45 mins from analysis time (e.g. 0945 for 09 UTC run)<\/li>\n<li>T+80 mins from analysis time for 11 UTC and 23 UTC<\/li>\n<\/ul>\n<h3>AMV types assimilated<\/h3>\n<h4>Global Model<\/h4>\n<ul>\n<li>Meteosat-10 IR, cloudy WV 7.3, VIS and HRVIS<\/li>\n<li>Meteosat-9 IR, cloudy WV 7.3, VIS and HRVIS<\/li>\n<li>Himawari-9 IR, VIS, cloudy WV 6.7<\/li>\n<li>GOES-16 IR, VIS and IR3.8<\/li>\n<li>GOES-18 IR, VIS and IR3.8<\/li>\n<li>NESDIS and direct broadcast Terra IR<\/li>\n<li>NESDIS and direct broadcast Aqua IR, cloudy WV, clear sky WV<\/li>\n<li>CIMSS and direct broadcast NOAA-18 IR<\/li>\n<li>CIMSS and direct broadcast NOAA-19 IR<\/li>\n<li>CIMSS Metop-B IR<\/li>\n<li>EUMETSAT Metop-B IR (single satellite product)<\/li>\n<li>EUMETSAT Metop-C IR (single satellite product)<\/li>\n<li>CIMSS LeoGeo IR<\/li>\n<li>NESDIS and direct broadcast Suomi NPP VIIRS IR<\/li>\n<li>NESDIS NOAA-20 VIIRS IR<\/li>\n<\/ul>\n<h4>UKV Model<\/h4>\n<ul>\n<li>Meteosat-10 IR produced using the NWC SAF software over the wider UKV domain<\/li>\n<\/ul>\n<h3>Global quality control<\/h3>\n<h4>Blacklisting in space<\/h4>\n<ul>\n<li>All geostationary winds beyond 68&amp;deg satellite zenith angle<\/li>\n<li>All winds reporting in height at or above 160 hPa and all extratropical (polewards of 20N\/S) winds above 200 hPa<\/li>\n<li>All VIS winds at 700 hPa and above<\/li>\n<li>MSG WV, Himawari WV 6.7, and GOES WV below 400 hPa<\/li>\n<li>All polar WV and CSWV winds below 600 hPa<\/li>\n<li>All MSG IR, VIS and HRVIS winds below 600 hPa over land north of 0 degrees<\/li>\n<li>All Himawari and GOES IR and visible winds below 600 hPa over land north of 20N<\/li>\n<li>All polar winds below 600 hPa over land and sea ice<\/li>\n<li>All polar winds below 400 hPa over Greenland and Antarctica<\/li>\n<li>Low and mid level winds dependent on topography<\/li>\n<li>All VIIRS and AVHRR polar winds at or above 350 hPa in SH<\/li>\n<li>MSG IR below 600 hPa in the Mediterranean, Red Sea and Gulf<\/li>\n<li>MSG VIS and IR, and GOES-16 IR below 600 hPa over sea near Guinea<\/li>\n<li>All LeoGeo above 300 hPa<\/li>\n<li>LeoGeo winds down-weighted in thinning to only use where no conventional AMV available<\/li>\n<li>All obs polewards of 89 degrees<\/li>\n<\/ul>\n<h4>QI thresholds<\/h4>\n<p>QI1 &#8211; EUMETSAT QI with first guess check<br \/>\nQI2 &#8211; EUMETSAT QI without first guess check<br \/>\nRFF &#8211; Recursive Filter Function (CIMSS\/NESDIS)<\/p>\n<p>For information on how the quality indicators are formulated see Holmlund (1998, <i>Weather<br \/>\nForecasting<\/i> <b>13<\/b> 1093-1104) and<br \/>\nHayden and Purser (1995, <i>Journal of Applied Meteorology<\/i> <b>34<\/b> 3-15).<\/p>\n<p>All thresholds are applied to QI2<\/p>\n<ul>\n<li>MSG: 85<\/li>\n<li>Himawari: 70<\/li>\n<li>GOES: 50<\/li>\n<li>All polar winds: 60<\/li>\n<li>LeoGeo: 70<\/li>\n<\/ul>\n<h4>Thinning<\/h4>\n<ul>\n<li>All AMVs thinned in 200 km by 200 km by 100 hPa boxes.<\/li>\n<li>Wind selected by lowest error for all geostationary winds<\/li>\n<li>Wind selected by closest to centre of box for all polar winds.<\/li>\n<li>Assimilated in 2-hour time slots<\/li>\n<\/ul>\n<h4>Background check<\/h4>\n<ul>\n<li>Background check: comparison with 6-hour forecast from previous model run (symmetric)<\/li>\n<\/ul>\n<h3>UKV quality control<\/h3>\n<p>Background check is applied and QI threshold of 80 for all winds.<br \/>\nOnly one set of 15 min winds are considered in each hourly assimilation window.<\/p>\n<h4>Blacklisting in space<\/h4>\n<ul>\n<li>All geostationary winds beyond 68 deg satellite zenith angle<\/li>\n<li>All observations at or above 200 hPa<\/li>\n<li>Reject WV below 950 hpa<\/li>\n<li>Low and mid level winds dependent on topography<\/li>\n<\/ul>\n<h4>Thinning<\/h4>\n<ul>\n<li>AMVs thinned to 25 km by 100 hPa<\/li>\n<li>Wind selected by lowest error<\/li>\n<\/ul>\n<h3>Observation errors<\/h3>\n<p>Observation errors calculated individually for each wind using estimates of the error in vector, error in height and variation in the background wind column. For more information see <a href=https:\/\/cgms-info.org\/html\/IWW09_PROC\/groups\/cps\/documents\/document\/pdf_conf_p51_s5_22_forsythe_v.pdf\">AMV errors: a new approach in NWP (9IWW paper)<\/a>.<\/p>\n<p>The mean profile and zonal plots in the table below give an indication of the typical observation errors used. Statistics calculated for June 2012 with QI2 &gt; 80.<\/p>\n<table border=\"1\" width=\"70%\" cellspacing=\"0\" cellpadding=\"2\" align=\"center\">\n<tbody>\n<tr>\n<td align=\"center\" width=\"30%\">Satellite<\/td>\n<td align=\"center\" width=\"70%\">All latitudes<\/td>\n<\/tr>\n<tr>\n<td align=\"center\">Meteosat-10<\/td>\n<td align=\"center\"><input src=\"http:\/\/nwp-saf.eumetsat.int\/monitoring\/amv\/amvusage\/ukplots\/stats4_1912_m11ir108_AllLat.gif\" type=\"image\" width=\"400\" \/><br \/>\n                   <input src=\"http:\/\/nwp-saf.eumetsat.int\/monitoring\/amv\/amvusage\/ukplots\/stats4_1912_m11vis08_AllLat.gif\" type=\"image\" width=\"400\" \/><br \/>\n                   <input src=\"http:\/\/nwp-saf.eumetsat.int\/monitoring\/amv\/amvusage\/ukplots\/stats4_1912_m11hrvis_AllLat.gif\" type=\"image\" width=\"400\" \/><br \/>\n                   <input src=\"http:\/\/nwp-saf.eumetsat.int\/monitoring\/amv\/amvusage\/ukplots\/stats4_1912_m11wv73_AllLat.gif\" type=\"image\" width=\"400\" \/><\/td>\n<\/tr>\n<tr>\n<td align=\"center\">Himawari-8<\/td>\n<td align=\"center\"><input src=\"http:\/\/nwp-saf.eumetsat.int\/monitoring\/amv\/amvusage\/ukplots\/stats4_1912_him8ir_AllLat.gif\" type=\"image\" width=\"400\" \/><br \/>\n                   <input src=\"http:\/\/nwp-saf.eumetsat.int\/monitoring\/amv\/amvusage\/ukplots\/stats4_1912_him8vis_AllLat.gif\" type=\"image\" width=\"400\" \/><br \/>\n                   <input src=\"http:\/\/nwp-saf.eumetsat.int\/monitoring\/amv\/amvusage\/ukplots\/stats4_1912_him8wv_AllLat.gif\" type=\"image\" width=\"400\" \/><\/td>\n<\/tr>\n<tr>\n<td align=\"center\">GOES-16<\/td>\n<td align=\"center\"><input src=\"http:\/\/nwp-saf.eumetsat.int\/monitoring\/amv\/amvusage\/ukplots\/stats4_1912_g16ir_AllLat.gif\" type=\"image\" width=\"400\" \/><\/td>\n<\/tr>\n<tr>\n<td align=\"center\">MODIS<\/td>\n<td align=\"center\"><input src=\"http:\/\/nwp-saf.eumetsat.int\/monitoring\/amv\/amvusage\/ukplots\/stats4_1912_naquair_AllLat.gif\" type=\"image\" width=\"400\" \/><br \/>\n                   <input src=\"http:\/\/nwp-saf.eumetsat.int\/monitoring\/amv\/amvusage\/ukplots\/stats4_1912_naquawv_AllLat.gif\" type=\"image\" width=\"400\" \/><br \/>\n                   <input src=\"http:\/\/nwp-saf.eumetsat.int\/monitoring\/amv\/amvusage\/ukplots\/stats4_1912_naquacswv_AllLat.gif\" type=\"image\" width=\"400\" \/><\/td>\n<\/tr>\n<tr>\n<td align=\"center\">AVHRR<\/td>\n<td align=\"center\"><input src=\"http:\/\/nwp-saf.eumetsat.int\/monitoring\/amv\/amvusage\/ukplots\/stats4_1912_n18ir_AllLat.gif\" type=\"image\" width=\"400\" \/><br \/>\n                   <input src=\"http:\/\/nwp-saf.eumetsat.int\/monitoring\/amv\/amvusage\/ukplots\/stats4_1912_n19ir_AllLat.gif\" type=\"image\" width=\"400\" \/><br \/>\n                   <input src=\"http:\/\/nwp-saf.eumetsat.int\/monitoring\/amv\/amvusage\/ukplots\/stats4_1912_cmetopbir_AllLat.gif\" type=\"image\" width=\"400\" \/><br \/>\n                   <input src=\"http:\/\/nwp-saf.eumetsat.int\/monitoring\/amv\/amvusage\/ukplots\/stats4_1912_eumetopbir108_AllLat.gif\" type=\"image\" width=\"400\" \/><\/td>\n<\/tr>\n<td align=\"center\">VIIRS<\/td>\n<td align=\"center\"><input src=\"http:\/\/nwp-saf.eumetsat.int\/monitoring\/amv\/amvusage\/ukplots\/stats4_1912_nppir_AllLat.gif\" type=\"image\" width=\"400\" \/><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n<h3>References<\/h3>\n<p>Lorenc, A.C. (2017), Improving ensemble covariances in hybrid variational data assimilation without increasing ensemble size. Q.J.R. Meteorol. Soc., 143: 1062-1072.\u00a0<a href=\"https:\/\/doi.org\/10.1002\/qj.2990\">https:\/\/doi.org\/10.1002\/qj.2990<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Use of AMVs in the Met Office model Physical characteristics Global Model (coupled atmosphere-ocean) GC4 global coupled atmosphere-land-ocean-seaice GA8 atmospheric configuration Grid-point model: 2560&#215;1920 grid points Horizontal resolution: Forecast N1280 (~10 km in mid-latitudes) Vertical resolution: 70 vertical levels, hybrid-eta configuration, lid ~80 km Forecast range: out to T+168 (7 days) GL9 land configuration GO6 ocean (with GSI8 sea ice) configuration at ORCA025 tri-polar grid 1\/4 deg resolution UKV Model Grid-point model: 622&#215;810 grid points (inner), 950&#215;1025 grid (total) Horizontal resolution: variable stretching from ~1.5 km (outer domain) to ~4 km (inner) Vertical resolution: 70 vertical levels, lid ~40 km [&hellip;]<\/p>\n","protected":false},"author":25,"featured_media":0,"parent":1312,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_bbp_topic_count":0,"_bbp_reply_count":0,"_bbp_total_topic_count":0,"_bbp_total_reply_count":0,"_bbp_voice_count":0,"_bbp_anonymous_reply_count":0,"_bbp_topic_count_hidden":0,"_bbp_reply_count_hidden":0,"_bbp_forum_subforum_count":0,"footnotes":""},"class_list":["post-12851","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/nwp-saf.eumetsat.int\/site\/wp-json\/wp\/v2\/pages\/12851","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nwp-saf.eumetsat.int\/site\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/nwp-saf.eumetsat.int\/site\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/nwp-saf.eumetsat.int\/site\/wp-json\/wp\/v2\/users\/25"}],"replies":[{"embeddable":true,"href":"https:\/\/nwp-saf.eumetsat.int\/site\/wp-json\/wp\/v2\/comments?post=12851"}],"version-history":[{"count":1,"href":"https:\/\/nwp-saf.eumetsat.int\/site\/wp-json\/wp\/v2\/pages\/12851\/revisions"}],"predecessor-version":[{"id":51905,"href":"https:\/\/nwp-saf.eumetsat.int\/site\/wp-json\/wp\/v2\/pages\/12851\/revisions\/51905"}],"up":[{"embeddable":true,"href":"https:\/\/nwp-saf.eumetsat.int\/site\/wp-json\/wp\/v2\/pages\/1312"}],"wp:attachment":[{"href":"https:\/\/nwp-saf.eumetsat.int\/site\/wp-json\/wp\/v2\/media?parent=12851"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}