Title: The potential value of early (1939-1967) upper-air data in atmospheric climate reanalysis

Abstract

In recent years a number of reanalysis datasets have been published that cover the past century or more, including the ‘Twentieth Century Reanalysis’ 20CRv2 and the European Reanalysis of the twentieth century ERA‐20C . These datasets are widely used, showing the need for, and possible benefit of, reanalysis data products designed for climate applications. The twentieth‐century reanalyses so far have assimilated only surface observations, and rely on independent estimates of monthly averaged sea‐surface temperatures and sea ice concentrations as boundary conditions. While 20CRv2 uses only observations of surface and sea‐level pressure, ERA‐20C additionally assimilates marine winds. Here we describe an experimental reanalysis, referred to as ERA‐PreSAT , which covers the period 1939–1967 and also assimilates historical upper‐air data. Assessments of this dataset including comparisons with independent data show that (i) temperature biases in the Northern Hemisphere are largely reduced compared to reanalyses that assimilate surface data only, (ii) concentration of 1940s upper‐air data in the northern extratropics created a strong interhemispheric asymmetry which is likely not realistic, (iii) the forecast skill in the Northern Hemisphere has increased substantially compared to reanalyses that assimilate surface data only, (iv) day‐to‐day and (in the northern extratropics) month‐to‐month correlations with independent observations (of totalmore » column ozone, upper‐air data) increase over time, (v) interannual variability is well captured in the reanalysis, (vi) a signature of the stratospheric Quasi‐Biennial Oscillation is present as far back as the 1940s, and (vii) tropical cyclones are not well represented. The generally encouraging results from the experimental ERA‐PreSAT reanalysis underline that early upper‐air data greatly contribute to our knowledge on the troposphere and lower stratosphere over the twentieth century.« less

Authors:

Hersbach, Hans ^[1]; Bronnimann, Stefan ^[2]; Haimberger, Leopold ^[3]; Mayer, Michael ^[3]; Villiger, Leonie ^[2]; Comeaux, Joey ^[4]; Simmons, Adrian ^[1]; Dee, Dick ^[1]; Jourdain, Sylvie ^[5]; Peubey, Carole ^[1]; Poli, Paul ^[6]; Rayner, Nick ^[7]; Sterin, Alexander M. ^[8]; Stickler, Alexander ^[9]; Valente, Maria A. ^[10]; Worley, Steven J. ^[4]

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+ Show Author Affiliations

1. European Centre for Medium-Range Weather Forecasts (ECMWF), Reading (United Kingdom)
2. Univ. of Bern (Switzerland). Oeschger Centre for Climate Change Research and Institute of Geography
3. Univ. of Vienna (Austria). Dept. of Meteorology and Geophysics
4. National Center for Atmospheric Research (NCAR), Boulder, CO (United States)
5. Météo-France, Toulouse (France). Direction de la Climatologie et des Service Climatiques
6. Météo-France, Brest (France). Direction des Systèmes d'Observation (DSO), Centre de Météorologie Marine (CMM)
7. Met Office Hadley Centre, Exeter (United Kingdom)
8. Russian Research Institute for Hydrometeorological Information - World Data Center (RIHMI-WDC), Obninsk (Russia)
9. Univ. of Bern, (Switzerland). Oeschger Centre for Climate Change Research and Institute of Geography
10. Faculdade de Ciências da Universidade de Lisboa (Portugal). Instituto Dom Luiz

Publication Date:

Fri Mar 24 00:00:00 EDT 2017

Research Org.:

Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF); Lawrence Berkeley National Laboratory, Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)

Sponsoring Org.:

USDOE Office of Science (SC), Biological and Environmental Research (BER); USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR)

OSTI Identifier:

1461670

Alternate Identifier(s):

OSTI ID: 1464543

Grant/Contract Number:  

AC02-05CH11231; AC05-00OR22725

Resource Type:

Accepted Manuscript

Journal Name:

Quarterly Journal of the Royal Meteorological Society

Additional Journal Information:

Journal Volume: 143; Journal Issue: 704; Journal ID: ISSN 0035-9009

Publisher:

Royal Meteorological Society

Country of Publication:

United States

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES; climate reanalysis; upper‐air data; historical observations