TY - JOUR
T1 - Towards a more reliable historical reanalysis
T2 - Improvements for version 3 of the Twentieth Century Reanalysis system
AU - Slivinski, Laura C.
AU - Compo, Gilbert P.
AU - Whitaker, Jeffrey S.
AU - Sardeshmukh, Prashant D.
AU - Giese, Benjamin S.
AU - McColl, Chesley
AU - Allan, Rob
AU - Yin, Xungang
AU - Vose, Russell
AU - Titchner, Holly
AU - Kennedy, John
AU - Spencer, Lawrence J.
AU - Ashcroft, Linden
AU - Brönnimann, Stefan
AU - Brunet, Manola
AU - Camuffo, Dario
AU - Cornes, Richard
AU - Cram, Thomas A.
AU - Crouthamel, Richard
AU - Domínguez-Castro, Fernando
AU - Freeman, J. Eric
AU - Gergis, Joëlle
AU - Hawkins, Ed
AU - Jones, Philip D.
AU - Jourdain, Sylvie
AU - Kaplan, Alexey
AU - Kubota, Hisayuki
AU - Blancq, Frank Le
AU - Lee, Tsz Cheung
AU - Lorrey, Andrew
AU - Luterbacher, Jürg
AU - Maugeri, Maurizio
AU - Mock, Cary J.
AU - Moore, G. W.Kent
AU - Przybylak, Rajmund
AU - Pudmenzky, Christa
AU - Reason, Chris
AU - Slonosky, Victoria C.
AU - Smith, Catherine A.
AU - Tinz, Birger
AU - Trewin, Blair
AU - Valente, Maria Antónia
AU - Wang, Xiaolan L.
AU - Wilkinson, Clive
AU - Wood, Kevin
AU - Wyszyński, Przemysław
N1 - Publisher Copyright:
© 2019 Royal Meteorological Society
PY - 2019/10/1
Y1 - 2019/10/1
N2 - Historical reanalyses that span more than a century are needed for a wide range of studies, from understanding large-scale climate trends to diagnosing the impacts of individual historical extreme weather events. The Twentieth Century Reanalysis (20CR) Project is an effort to fill this need. It is supported by the National Oceanic and Atmospheric Administration (NOAA), the Cooperative Institute for Research in Environmental Sciences (CIRES), and the U.S. Department of Energy (DOE), and is facilitated by collaboration with the international Atmospheric Circulation Reconstructions over the Earth initiative. 20CR is the first ensemble of sub-daily global atmospheric conditions spanning over 100 years. This provides a best estimate of the weather at any given place and time as well as an estimate of its confidence and uncertainty. While extremely useful, version 2c of this dataset (20CRv2c) has several significant issues, including inaccurate estimates of confidence and a global sea level pressure bias in the mid-19th century. These and other issues can reduce its effectiveness for studies at many spatial and temporal scales. Therefore, the 20CR system underwent a series of developments to generate a significant new version of the reanalysis. The version 3 system (NOAA-CIRES-DOE 20CRv3) uses upgraded data assimilation methods including an adaptive inflation algorithm; has a newer, higher-resolution forecast model that specifies dry air mass; and assimilates a larger set of pressure observations. These changes have improved the ensemble-based estimates of confidence, removed spin-up effects in the precipitation fields, and diminished the sea-level pressure bias. Other improvements include more accurate representations of storm intensity, smaller errors, and large-scale reductions in model bias. The 20CRv3 system is comprehensively reviewed, focusing on the aspects that have ameliorated issues in 20CRv2c. Despite the many improvements, some challenges remain, including a systematic bias in tropical precipitation and time-varying biases in southern high-latitude pressure fields.
AB - Historical reanalyses that span more than a century are needed for a wide range of studies, from understanding large-scale climate trends to diagnosing the impacts of individual historical extreme weather events. The Twentieth Century Reanalysis (20CR) Project is an effort to fill this need. It is supported by the National Oceanic and Atmospheric Administration (NOAA), the Cooperative Institute for Research in Environmental Sciences (CIRES), and the U.S. Department of Energy (DOE), and is facilitated by collaboration with the international Atmospheric Circulation Reconstructions over the Earth initiative. 20CR is the first ensemble of sub-daily global atmospheric conditions spanning over 100 years. This provides a best estimate of the weather at any given place and time as well as an estimate of its confidence and uncertainty. While extremely useful, version 2c of this dataset (20CRv2c) has several significant issues, including inaccurate estimates of confidence and a global sea level pressure bias in the mid-19th century. These and other issues can reduce its effectiveness for studies at many spatial and temporal scales. Therefore, the 20CR system underwent a series of developments to generate a significant new version of the reanalysis. The version 3 system (NOAA-CIRES-DOE 20CRv3) uses upgraded data assimilation methods including an adaptive inflation algorithm; has a newer, higher-resolution forecast model that specifies dry air mass; and assimilates a larger set of pressure observations. These changes have improved the ensemble-based estimates of confidence, removed spin-up effects in the precipitation fields, and diminished the sea-level pressure bias. Other improvements include more accurate representations of storm intensity, smaller errors, and large-scale reductions in model bias. The 20CRv3 system is comprehensively reviewed, focusing on the aspects that have ameliorated issues in 20CRv2c. Despite the many improvements, some challenges remain, including a systematic bias in tropical precipitation and time-varying biases in southern high-latitude pressure fields.
KW - 20CRv3
KW - data assimilation
KW - reanalysis
KW - surface pressure
UR - http://www.scopus.com/inward/record.url?scp=85071142011&partnerID=8YFLogxK
U2 - 10.1002/qj.3598
DO - 10.1002/qj.3598
M3 - Article
SN - 0035-9009
VL - 145
SP - 2876
EP - 2908
JO - Quarterly Journal of the Royal Meteorological Society
JF - Quarterly Journal of the Royal Meteorological Society
IS - 724
ER -