Review Article The Twentieth Century Reanalysis Project
The Twentieth Century Reanalysis (20CR) project is an international effort to produce a comprehensive global atmospheric circulation dataset spanning the twentieth century, assimilating only surface pressure reports and using observed monthly sea-surface temperature and sea-ice distributions as boun...
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ftunivnebraskali:oai:digitalcommons.unl.edu:usdeptcommercepub-1253 2023-11-12T04:22:43+01:00 Review Article The Twentieth Century Reanalysis Project Compo, G. P. Whitaker, J. S. Sardeshmukh, P. D. Matsui, N. Allan, R. J. Yin, X. Gleason, B. E., Jr. Vose, R. S. Rutledge, G. Bessemoulin, P. Brönnimann, S. Brunet, M. Crouthamel, R. I. Grant, A. N. Groisman, P. Y. Jones, P. D. Kruk, M. C. Kruger, A. C. Marshall, G. J. Maugeri, M. Mok, H. Y. Nordli, Ø. Ross, T. F. Trigo, R. M. Wang, X. L. Woodruff, S. D. Worley, S. J. 2011-01-01T08:00:00Z application/pdf https://digitalcommons.unl.edu/usdeptcommercepub/254 https://digitalcommons.unl.edu/context/usdeptcommercepub/article/1253/viewcontent/Compo_QJRMS_2011_Reviw_article_Twentieth_century.pdf unknown DigitalCommons@University of Nebraska - Lincoln https://digitalcommons.unl.edu/usdeptcommercepub/254 https://digitalcommons.unl.edu/context/usdeptcommercepub/article/1253/viewcontent/Compo_QJRMS_2011_Reviw_article_Twentieth_century.pdf Publications, Agencies and Staff of the U.S. Department of Commerce data assimilation Ensemble Kalman Filter state estimation surface pressure sea-level pressure Environmental Sciences text 2011 ftunivnebraskali 2023-10-30T09:45:13Z The Twentieth Century Reanalysis (20CR) project is an international effort to produce a comprehensive global atmospheric circulation dataset spanning the twentieth century, assimilating only surface pressure reports and using observed monthly sea-surface temperature and sea-ice distributions as boundary conditions. It is chiefly motivated by a need to provide an observational dataset with quantified uncertainties for validations of climate model simulations of the twentieth century onall time-scales,with emphasisonthe statistics of daily weather. It uses an Ensemble Kalman Filter data assimilation method with background ‘first guess’ fields supplied by an ensemble of forecasts from a global numerical weather prediction model. This directly yields a global analysis every 6 hours as the most likely state of the atmosphere, and also an uncertainty estimate of that analysis. The 20CR dataset provides the first estimates of global tropospheric variability, and of the dataset’s time-varying quality, from 1871 to the present at 6-hourly temporal and 2° spatial resolutions. Intercomparisons with independent radiosonde data indicate that the reanalyses are generally of high quality. The quality in the extratropical Northern Hemisphere throughout the century is similar to that of current three-day operational NWP forecasts. Intercomparisons over the second half-century of these surface-based reanalyses with other reanalyses that also make use of upper-air and satellite data are equally encouraging. It is anticipated that the 20CR dataset will be a valuable resource to the climate research community for both model validations and diagnostic studies. Some surprising results are already evident. For instance, the long-term trends of indices representing the North Atlantic Oscillation, the tropical Pacific Walker Circulation, and the Pacific–North American pattern are weak or non-existent over the full period of record. The long-term trends of zonally averaged precipitation minus evaporation also differ in character from ... Text North Atlantic North Atlantic oscillation Sea ice University of Nebraska-Lincoln: DigitalCommons@UNL Pacific |
institution |
Open Polar |
collection |
University of Nebraska-Lincoln: DigitalCommons@UNL |
op_collection_id |
ftunivnebraskali |
language |
unknown |
topic |
data assimilation Ensemble Kalman Filter state estimation surface pressure sea-level pressure Environmental Sciences |
spellingShingle |
data assimilation Ensemble Kalman Filter state estimation surface pressure sea-level pressure Environmental Sciences Compo, G. P. Whitaker, J. S. Sardeshmukh, P. D. Matsui, N. Allan, R. J. Yin, X. Gleason, B. E., Jr. Vose, R. S. Rutledge, G. Bessemoulin, P. Brönnimann, S. Brunet, M. Crouthamel, R. I. Grant, A. N. Groisman, P. Y. Jones, P. D. Kruk, M. C. Kruger, A. C. Marshall, G. J. Maugeri, M. Mok, H. Y. Nordli, Ø. Ross, T. F. Trigo, R. M. Wang, X. L. Woodruff, S. D. Worley, S. J. Review Article The Twentieth Century Reanalysis Project |
topic_facet |
data assimilation Ensemble Kalman Filter state estimation surface pressure sea-level pressure Environmental Sciences |
description |
The Twentieth Century Reanalysis (20CR) project is an international effort to produce a comprehensive global atmospheric circulation dataset spanning the twentieth century, assimilating only surface pressure reports and using observed monthly sea-surface temperature and sea-ice distributions as boundary conditions. It is chiefly motivated by a need to provide an observational dataset with quantified uncertainties for validations of climate model simulations of the twentieth century onall time-scales,with emphasisonthe statistics of daily weather. It uses an Ensemble Kalman Filter data assimilation method with background ‘first guess’ fields supplied by an ensemble of forecasts from a global numerical weather prediction model. This directly yields a global analysis every 6 hours as the most likely state of the atmosphere, and also an uncertainty estimate of that analysis. The 20CR dataset provides the first estimates of global tropospheric variability, and of the dataset’s time-varying quality, from 1871 to the present at 6-hourly temporal and 2° spatial resolutions. Intercomparisons with independent radiosonde data indicate that the reanalyses are generally of high quality. The quality in the extratropical Northern Hemisphere throughout the century is similar to that of current three-day operational NWP forecasts. Intercomparisons over the second half-century of these surface-based reanalyses with other reanalyses that also make use of upper-air and satellite data are equally encouraging. It is anticipated that the 20CR dataset will be a valuable resource to the climate research community for both model validations and diagnostic studies. Some surprising results are already evident. For instance, the long-term trends of indices representing the North Atlantic Oscillation, the tropical Pacific Walker Circulation, and the Pacific–North American pattern are weak or non-existent over the full period of record. The long-term trends of zonally averaged precipitation minus evaporation also differ in character from ... |
format |
Text |
author |
Compo, G. P. Whitaker, J. S. Sardeshmukh, P. D. Matsui, N. Allan, R. J. Yin, X. Gleason, B. E., Jr. Vose, R. S. Rutledge, G. Bessemoulin, P. Brönnimann, S. Brunet, M. Crouthamel, R. I. Grant, A. N. Groisman, P. Y. Jones, P. D. Kruk, M. C. Kruger, A. C. Marshall, G. J. Maugeri, M. Mok, H. Y. Nordli, Ø. Ross, T. F. Trigo, R. M. Wang, X. L. Woodruff, S. D. Worley, S. J. |
author_facet |
Compo, G. P. Whitaker, J. S. Sardeshmukh, P. D. Matsui, N. Allan, R. J. Yin, X. Gleason, B. E., Jr. Vose, R. S. Rutledge, G. Bessemoulin, P. Brönnimann, S. Brunet, M. Crouthamel, R. I. Grant, A. N. Groisman, P. Y. Jones, P. D. Kruk, M. C. Kruger, A. C. Marshall, G. J. Maugeri, M. Mok, H. Y. Nordli, Ø. Ross, T. F. Trigo, R. M. Wang, X. L. Woodruff, S. D. Worley, S. J. |
author_sort |
Compo, G. P. |
title |
Review Article The Twentieth Century Reanalysis Project |
title_short |
Review Article The Twentieth Century Reanalysis Project |
title_full |
Review Article The Twentieth Century Reanalysis Project |
title_fullStr |
Review Article The Twentieth Century Reanalysis Project |
title_full_unstemmed |
Review Article The Twentieth Century Reanalysis Project |
title_sort |
review article the twentieth century reanalysis project |
publisher |
DigitalCommons@University of Nebraska - Lincoln |
publishDate |
2011 |
url |
https://digitalcommons.unl.edu/usdeptcommercepub/254 https://digitalcommons.unl.edu/context/usdeptcommercepub/article/1253/viewcontent/Compo_QJRMS_2011_Reviw_article_Twentieth_century.pdf |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
North Atlantic North Atlantic oscillation Sea ice |
genre_facet |
North Atlantic North Atlantic oscillation Sea ice |
op_source |
Publications, Agencies and Staff of the U.S. Department of Commerce |
op_relation |
https://digitalcommons.unl.edu/usdeptcommercepub/254 https://digitalcommons.unl.edu/context/usdeptcommercepub/article/1253/viewcontent/Compo_QJRMS_2011_Reviw_article_Twentieth_century.pdf |
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