{"id":880,"date":"2009-09-06T04:02:25","date_gmt":"2009-09-06T08:02:25","guid":{"rendered":"http:\/\/mseas.net16.net\/?p=880"},"modified":"2021-08-16T20:23:20","modified_gmt":"2021-08-17T00:23:20","slug":"many-task-computing-for-multidisciplinary-ocean-sciences-real-time-uncertainty-prediction-and-data-assimilation","status":"publish","type":"post","link":"https:\/\/mseas.mit.edu\/?p=880","title":{"rendered":"Many Task Computing for Multidisciplinary Ocean Sciences: Real-Time Uncertainty Prediction and Data Assimilation"},"content":{"rendered":"Error Subspace Statistical Estimation (ESSE), an uncertainty\r\nprediction and data assimilation methodology employed\r\nfor real-time ocean forecasts, is based on a characterization\r\nand prediction of the largest uncertainties. This\r\nis carried out by evolving an error subspace of variable size.\r\nWe use an ensemble of stochastic model simulations, initialized\r\nbased on an estimate of the dominant initial uncertainties,\r\nto predict the error subspace of the model fields.\r\nThe dominant error covariance (generated via an SVD of\r\nthe ensemble-generated error covariance matrix) is used for\r\ndata assimilation. The resulting ocean fields are provided\r\nas the input to acoustic modeling, allowing for the prediction\r\nand study of the spatiotemporal variations in acoustic\r\npropagation and their uncertainties.\r\nThe ESSE procedure is a classic case of Many Task Computing:\r\nThese codes are managed based on dynamic workflows\r\nfor the: (i) perturbation of the initial mean state, (ii)\r\nsubsequent ensemble of stochastic PE model runs, (iii) continuous\r\ngeneration of the covariance matrix, (iv) successive\r\ncomputations of the SVD of the ensemble spread until a\r\nconvergence criterion is satisfied, and (v) data assimilation.\r\nIts ensemble nature makes it a many task data intensive application\r\nand its dynamic workflow gives it heterogeneity.\r\nSubsequent acoustics propagation modeling involves a very\r\nlarge ensemble of short-in-duration acoustics runs.","protected":false},"excerpt":{"rendered":"<p>Error Subspace Statistical Estimation (ESSE), an uncertainty prediction and data assimilation methodology employed for real-time ocean forecasts, is based on a characterization and prediction of the largest uncertainties. This is carried out by evolving an error subspace of variable size. We use an ensemble of stochastic model simulations, initialized based on an estimate of the [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[32,182,37,34,29,38,5,67,69,73],"tags":[],"class_list":["post-880","post","type-post","status-publish","format-standard","hentry","category-numerical-ocean-modeling","category-learning-and-data-assimilation","category-applications-to-ocean-dynamics","category-data-assimilation","category-computer-science","category-physical-oceanography","category-publications","category-proceedings-of-refereed-conferences-physical-oceanography","category-proceedings-of-refereed-conferences-data-assimilation","category-proceedings-of-refereed-conferences-computer-science"],"_links":{"self":[{"href":"https:\/\/mseas.mit.edu\/index.php?rest_route=\/wp\/v2\/posts\/880","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mseas.mit.edu\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mseas.mit.edu\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mseas.mit.edu\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mseas.mit.edu\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=880"}],"version-history":[{"count":2,"href":"https:\/\/mseas.mit.edu\/index.php?rest_route=\/wp\/v2\/posts\/880\/revisions"}],"predecessor-version":[{"id":1190,"href":"https:\/\/mseas.mit.edu\/index.php?rest_route=\/wp\/v2\/posts\/880\/revisions\/1190"}],"wp:attachment":[{"href":"https:\/\/mseas.mit.edu\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=880"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mseas.mit.edu\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=880"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mseas.mit.edu\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=880"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}