Fig. 3: Mean sea level pressure (MSLP) bias (hPa) as an ensemble mean over the 5 historical realizations for 1985–2014 compared to ERA5 climatology (Copernicus Climate Change Service (C3S), 2017; Hersbach et al., 2020) from 1985–2014. (a) DJF, (b) MAM, (c) JJA, (d) SON, (e) annual mean
Fig. 4 shows zonal means of temperature and zonal wind biases averaged over the period 1985-2014. In large areas of the troposphere, temperature biases are smaller than 1 °C. Exceptions are the high latitudes with larger positive biases in the north and larger negative biases in the south. Furthermore, in the mid- and high-latitudes there are negative temperature biases of up to around 3 °C in the lower stratosphere around 200 hPa. Not surprisingly, the bias pattern looks very similar to the one from MPIM shown in Müller et al. (2018), their Fig. 9e. The zonal mean zonal wind is generally well represented compared to the ERA5 reanalysis data. Biases are mostly smaller than 2 m/s. Exceptions are the tropical stratosphere, the tropical upper troposphere and the subtropical / mid-latitude stratosphere around 100 hPa and 40-50°N and S. Compared to Müller et al. (2018), their Fig. 9d, biases are generally similar although the subtropical / mid-latitude stratosphere areas of strong biases of more than 2 m/s are smaller in AWI-CM. Furthermore, the negative bias around 60°S extending from 700 to 200 hPa in Müller et al. (2018) does not exist in AWI-CM.
(a) (b)