Jean-Noël Thépaut

TL;DR: ERA-Interim as discussed by the authors is the latest global atmospheric reanalysis produced by the European Centre for Medium-Range Weather Forecasts (ECMWF), which will extend back to the early part of the twentieth century.

TL;DR: In this paper, an approximation to 4D-Var, namely the incremental approach, is considered and is shown to produce the same result at the end of the assimilation window as an extended Kalman filter in which no approximations are made in the assimilating model but in which instead a simplitied evolution of the forecast error is introduced.

TL;DR: The ERA-20C water cycle features stable precipitation minus evaporation global averages and no spurious jumps or trends as mentioned in this paper, and the assimilation of observations adds realism on synoptic time scales.

TL;DR: In this article, Mesoscale model simulations suggest that an increase in surface roughness is contributing to the stilling trend in the mid-latitude Northern Hemisphere over the past few decades.