Balance characteristics of multivariate background error covariances and their impact on analyses and forecasts in tropical and Arctic regions
For variational data assimilation, the background error covariance matrix plays a crucial role because it is strongly linked with the local meteorological features, and is especially dominated by error correlations between different analysis variables. Multivariate background error (MBE) statistics...
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ftncar:oai:drupal-site.org:articles_12729 2023-07-30T04:01:18+02:00 Balance characteristics of multivariate background error covariances and their impact on analyses and forecasts in tropical and Arctic regions Chen, Yaodeng (author) Rizvi, Syed (author) Huang, Xiang-yu (author) Min, Jinzhong (author) Zhang, Xin (author) 2013-07-01 application/pdf http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-018-988 https://doi.org/10.1007/s00703-013-0251-y en eng Springer Meteorology and Atmospheric Physics http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-018-988 doi:10.1007/s00703-013-0251-y ark:/85065/d7xs5w8p Copyright 2013 The Author(s). This article is published with open access at Springer.com Text article 2013 ftncar https://doi.org/10.1007/s00703-013-0251-y 2023-07-17T18:27:59Z For variational data assimilation, the background error covariance matrix plays a crucial role because it is strongly linked with the local meteorological features, and is especially dominated by error correlations between different analysis variables. Multivariate background error (MBE) statistics have been generated for two regions, namely the Tropics (covering Indonesia and its neighborhood) and the Arctic (covering high latitudes). Detailed investigation has been carried out for these MBE statistics to understand the physical processes leading to the balance (defined by the forecasts error correlations) characteristics between mass and wind fields for the low and high latitudes represented by these two regions. It is found that in tropical regions, the unbalanced (full balanced) part of the velocity potential (divergent part of wind) contributes more to the balanced part of the temperature, relative humidity, and surface pressure fields as compared with the stream function (rotational part of wind). However, the exact opposite happens in the Arctic. For both regions, the unbalanced part of the temperature field is the main contributor to the balanced part of the relative humidity field. Results of single observation tests and six-hourly data assimilation cycling experiments are consistent with the respective balance part contributions of different fields in the two regions. This study provides an understanding of the contrasting dynamical balance relationship that exists between the mass and wind fields in high- and low-latitude regions. The study also examines the impact of MBE on Weather Research and Forecasting model forecasts for the two regions. Article in Journal/Newspaper Arctic OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Arctic Meteorology and Atmospheric Physics 121 1-2 79 98 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
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ftncar |
language |
English |
description |
For variational data assimilation, the background error covariance matrix plays a crucial role because it is strongly linked with the local meteorological features, and is especially dominated by error correlations between different analysis variables. Multivariate background error (MBE) statistics have been generated for two regions, namely the Tropics (covering Indonesia and its neighborhood) and the Arctic (covering high latitudes). Detailed investigation has been carried out for these MBE statistics to understand the physical processes leading to the balance (defined by the forecasts error correlations) characteristics between mass and wind fields for the low and high latitudes represented by these two regions. It is found that in tropical regions, the unbalanced (full balanced) part of the velocity potential (divergent part of wind) contributes more to the balanced part of the temperature, relative humidity, and surface pressure fields as compared with the stream function (rotational part of wind). However, the exact opposite happens in the Arctic. For both regions, the unbalanced part of the temperature field is the main contributor to the balanced part of the relative humidity field. Results of single observation tests and six-hourly data assimilation cycling experiments are consistent with the respective balance part contributions of different fields in the two regions. This study provides an understanding of the contrasting dynamical balance relationship that exists between the mass and wind fields in high- and low-latitude regions. The study also examines the impact of MBE on Weather Research and Forecasting model forecasts for the two regions. |
author2 |
Chen, Yaodeng (author) Rizvi, Syed (author) Huang, Xiang-yu (author) Min, Jinzhong (author) Zhang, Xin (author) |
format |
Article in Journal/Newspaper |
title |
Balance characteristics of multivariate background error covariances and their impact on analyses and forecasts in tropical and Arctic regions |
spellingShingle |
Balance characteristics of multivariate background error covariances and their impact on analyses and forecasts in tropical and Arctic regions |
title_short |
Balance characteristics of multivariate background error covariances and their impact on analyses and forecasts in tropical and Arctic regions |
title_full |
Balance characteristics of multivariate background error covariances and their impact on analyses and forecasts in tropical and Arctic regions |
title_fullStr |
Balance characteristics of multivariate background error covariances and their impact on analyses and forecasts in tropical and Arctic regions |
title_full_unstemmed |
Balance characteristics of multivariate background error covariances and their impact on analyses and forecasts in tropical and Arctic regions |
title_sort |
balance characteristics of multivariate background error covariances and their impact on analyses and forecasts in tropical and arctic regions |
publisher |
Springer |
publishDate |
2013 |
url |
http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-018-988 https://doi.org/10.1007/s00703-013-0251-y |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_relation |
Meteorology and Atmospheric Physics http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-018-988 doi:10.1007/s00703-013-0251-y ark:/85065/d7xs5w8p |
op_rights |
Copyright 2013 The Author(s). This article is published with open access at Springer.com |
op_doi |
https://doi.org/10.1007/s00703-013-0251-y |
container_title |
Meteorology and Atmospheric Physics |
container_volume |
121 |
container_issue |
1-2 |
container_start_page |
79 |
op_container_end_page |
98 |
_version_ |
1772812043867389952 |