{"id":1215,"date":"2023-07-03T02:43:38","date_gmt":"2023-07-03T01:43:38","guid":{"rendered":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/?page_id=1215"},"modified":"2023-07-03T02:43:38","modified_gmt":"2023-07-03T01:43:38","slug":"abstract253","status":"publish","type":"page","link":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/programme\/abstract253\/","title":{"rendered":"Abstract 253"},"content":{"rendered":"

[vc_row][vc_column][vc_column_text]Abstract ID:<\/strong> 253<\/p>\n

The tropical influence on sub-seasonal predictability of wintertime stratosphere and stratosphere-troposphere coupling<\/h2>\n

Lead Author:<\/strong> Alexey Karpechko
\nFMI, Finland
\n<\/span><\/p>\n

Keywords:<\/strong> Stratosphere, Madden-Julian Oscillation, Stratosphere-troposphere coupling, Relaxation experiments, Subseasonal forecasts<\/p>\n

Abstract:<\/strong> A unique set of relaxation experiments with a forecast model initialized during December-January 1999-2019 is used to explore tropical influence on the Northern Hemisphere polar stratosphere and stratosphere-troposphere coupling, to quantify predictability benefits due to the perfect knowledge of the tropical variability. On average, predictability of the polar stratosphere, as represented by the 50-hPa geopotential height anomalies (Z50), increases from 17 days in freely running (control) forecasts to 21 days in the tropical relaxation experiments. At sub-seasonal timescales, a statistically significant improvement in weekly mean skill scores can be demonstrated in 14-20% of individual forecast ensembles, mostly in cases when the skill of the corresponding control forecast is worse than average. In these forecasts, root mean square errors and forecast spread of Z50 during forecast weeks 3-5 are decreased by 10-15%. Stratospheric improvements are detected during periods of both vortex strengthening and vortex weakening, including most major Sudden Stratospheric Warmings that occurred during the study period, via modulation of the upward wave activity fluxes. An active Madden-Julian Oscillation is found in most of these events with MJO phase 5-7 preceding vortex weakening and MJO phase 3-4 preceding vortex strengthening. Forecasts with improved stratospheric circulation also have improved tropospheric circulation during and after the periods when improvements are detected in the stratosphere. However, stratosphere-troposphere coupling is limited to the Atlantic sector and overall plays only a secondary role in these tropospheric improvements. More likely, these improvements are due to tropospheric tropical teleconnections.<\/p>\n

Co-authors:
\n<\/strong>Frederic Vitart (European Centre for Medium-range Weather Forecasts),
\nIrina Statnaia (Finnish Meteorological Institute)
\nInna Polistchouk (European Centre for Medium-range Weather Forecasts)
\nMagdalena Balmaseda-Alonso (European Centre for Medium-range Weather Forecasts)[\/vc_column_text][vc_separator][\/vc_column][\/vc_row][vc_row][vc_column width=”1\/6″][vc_single_image image=”344″ img_size=”full” onclick=”custom_link” link=”http:\/\/s2sprediction.net\/”][\/vc_column][vc_column width=”1\/6″][vc_single_image image=”345″ img_size=”full” onclick=”custom_link” link=”https:\/\/public.wmo.int\/en”][\/vc_column][vc_column width=”1\/6″][vc_single_image image=”346″ img_size=”full” onclick=”custom_link” link=”https:\/\/community.wmo.int\/activity-areas\/wwrp”][\/vc_column][vc_column width=”1\/6″][vc_single_image image=”347″ img_size=”full” onclick=”custom_link” link=”https:\/\/www.wcrp-climate.org\/”][\/vc_column][vc_column width=”1\/6″][vc_single_image image=”348″ img_size=”full”][\/vc_column][vc_column width=”1\/6″][vc_single_image image=”349″ img_size=”full” onclick=”custom_link” link=”https:\/\/www.reading.ac.uk\/”][\/vc_column][\/vc_row]<\/p>\n","protected":false},"excerpt":{"rendered":"

[vc_row][vc_column][vc_column_text]Abstract ID: 253 The tropical influence on sub-seasonal predictability of wintertime stratosphere and stratosphere-troposphere coupling Lead Author: Alexey Karpechko FMI, Finland Keywords: Stratosphere, Madden-Julian Oscillation, Stratosphere-troposphere coupling, Relaxation experiments, Subseasonal…Read More ><\/a><\/p>\n","protected":false},"author":145,"featured_media":0,"parent":528,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"__cvm_playback_settings":[],"__cvm_video_id":"","footnotes":""},"coauthors":[13],"class_list":["post-1215","page","type-page","status-publish","hentry"],"acf":[],"yoast_head":"\nAbstract 253 - WWRP\/WCRP S2S Summit 2023<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/research.reading.ac.uk\/s2s-summit2023\/programme\/abstract253\/\" \/>\n<meta property=\"og:locale\" content=\"en_GB\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Abstract 253 - WWRP\/WCRP S2S Summit 2023\" \/>\n<meta property=\"og:description\" content=\"[vc_row][vc_column][vc_column_text]Abstract ID: 253 The tropical influence on sub-seasonal predictability of wintertime stratosphere and stratosphere-troposphere coupling Lead Author: Alexey Karpechko FMI, Finland Keywords: Stratosphere, Madden-Julian Oscillation, Stratosphere-troposphere coupling, Relaxation experiments, Subseasonal...Read More >\" \/>\n<meta property=\"og:url\" content=\"https:\/\/research.reading.ac.uk\/s2s-summit2023\/programme\/abstract253\/\" \/>\n<meta property=\"og:site_name\" content=\"WWRP\/WCRP S2S Summit 2023\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Estimated reading time\" \/>\n\t<meta name=\"twitter:data1\" content=\"2 minutes\" \/>\n\t<meta name=\"twitter:label2\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data2\" content=\"Robert Lee\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/research.reading.ac.uk\/s2s-summit2023\/programme\/abstract253\/\",\"url\":\"https:\/\/research.reading.ac.uk\/s2s-summit2023\/programme\/abstract253\/\",\"name\":\"Abstract 253 - WWRP\/WCRP S2S Summit 2023\",\"isPartOf\":{\"@id\":\"https:\/\/research.reading.ac.uk\/s2s-summit2023\/#website\"},\"datePublished\":\"2023-07-03T01:43:38+00:00\",\"dateModified\":\"2023-07-03T01:43:38+00:00\",\"breadcrumb\":{\"@id\":\"https:\/\/research.reading.ac.uk\/s2s-summit2023\/programme\/abstract253\/#breadcrumb\"},\"inLanguage\":\"en-GB\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/research.reading.ac.uk\/s2s-summit2023\/programme\/abstract253\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/research.reading.ac.uk\/s2s-summit2023\/programme\/abstract253\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/research.reading.ac.uk\/s2s-summit2023\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Programme\",\"item\":\"https:\/\/research.reading.ac.uk\/s2s-summit2023\/programme\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Abstract 253\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/research.reading.ac.uk\/s2s-summit2023\/#website\",\"url\":\"https:\/\/research.reading.ac.uk\/s2s-summit2023\/\",\"name\":\"WWRP\/WCRP S2S Summit 2023\",\"description\":\"Advancing Sub-seasonal to Seasonal Predictions and their Applications\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/research.reading.ac.uk\/s2s-summit2023\/?s={search_term_string}\"},\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"en-GB\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Abstract 253 - WWRP\/WCRP S2S Summit 2023","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/programme\/abstract253\/","og_locale":"en_GB","og_type":"article","og_title":"Abstract 253 - WWRP\/WCRP S2S Summit 2023","og_description":"[vc_row][vc_column][vc_column_text]Abstract ID: 253 The tropical influence on sub-seasonal predictability of wintertime stratosphere and stratosphere-troposphere coupling Lead Author: Alexey Karpechko FMI, Finland Keywords: Stratosphere, Madden-Julian Oscillation, Stratosphere-troposphere coupling, Relaxation experiments, Subseasonal...Read More >","og_url":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/programme\/abstract253\/","og_site_name":"WWRP\/WCRP S2S Summit 2023","twitter_card":"summary_large_image","twitter_misc":{"Estimated reading time":"2 minutes","Written by":"Robert Lee"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/programme\/abstract253\/","url":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/programme\/abstract253\/","name":"Abstract 253 - WWRP\/WCRP S2S Summit 2023","isPartOf":{"@id":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/#website"},"datePublished":"2023-07-03T01:43:38+00:00","dateModified":"2023-07-03T01:43:38+00:00","breadcrumb":{"@id":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/programme\/abstract253\/#breadcrumb"},"inLanguage":"en-GB","potentialAction":[{"@type":"ReadAction","target":["https:\/\/research.reading.ac.uk\/s2s-summit2023\/programme\/abstract253\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/programme\/abstract253\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/"},{"@type":"ListItem","position":2,"name":"Programme","item":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/programme\/"},{"@type":"ListItem","position":3,"name":"Abstract 253"}]},{"@type":"WebSite","@id":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/#website","url":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/","name":"WWRP\/WCRP S2S Summit 2023","description":"Advancing Sub-seasonal to Seasonal Predictions and their Applications","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"en-GB"}]}},"_links":{"self":[{"href":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/wp-json\/wp\/v2\/pages\/1215","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/wp-json\/wp\/v2\/users\/145"}],"replies":[{"embeddable":true,"href":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/wp-json\/wp\/v2\/comments?post=1215"}],"version-history":[{"count":2,"href":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/wp-json\/wp\/v2\/pages\/1215\/revisions"}],"predecessor-version":[{"id":1236,"href":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/wp-json\/wp\/v2\/pages\/1215\/revisions\/1236"}],"up":[{"embeddable":true,"href":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/wp-json\/wp\/v2\/pages\/528"}],"wp:attachment":[{"href":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/wp-json\/wp\/v2\/media?parent=1215"}],"wp:term":[{"taxonomy":"author","embeddable":true,"href":"https:\/\/research.reading.ac.uk\/s2s-summit2023\/wp-json\/wp\/v2\/coauthors?post=1215"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}