Article,
ERA-20C: An atmospheric reanalysis of the 20th century
J. Climate, (2016)
DOI: 10.1175/jcli-d-15-0556.1
Abstract
AbstractThe ERA-20C reanalysis (1900-2010) assimilates surface pressure and marine wind observations. The reanalysis is single-member, and the background errors are spatio-temporally varying, derived from an ensemble. The atmospheric general circulation model uses the same configuration as the control member of the ERA-20CM ensemble, forced by observationally-based analyses of sea-surface temperature, sea-ice cover, atmospheric composition changes and solar forcing. The resulting climate trend estimations resemble ERA-20CM for temperature and the water cycle. The ERA-20C water cycle features stable precipitation minus evaporation global averages, and no spurious jumps or trends. The assimilation of observations adds realism on synoptic time-scales as compared to ERA-20CM in regions that are sufficiently well observed. Comparing to night-time ship observations, ERA-20C air temperatures are 1 K colder. Generally, the synoptic quality of the product and the agreement in terms of climate indices with other products improve with the availability of observations. The MJO mean amplitude in ERA-20C is larger than in 20CRv2c throughout the century, and in agreement with other reanalyses such as JRA-55. A novelty in ERA-20C is the availability of observation feedback information. As shown, this information can help assess the product?s quality on selected time-scales and regions.
