Monthly Archives: March 2021

Reanalysis Comparison Update

This post provides a quick comparison update of two different reanalysis daily global mean surface air temperature anomaly (GMSATA) time series for 2014 through 2021 March 11. The graph in Figure 1 shows the daily GMSATA time series for the Climate Forecast System Reanalysis (CFSR) output based on the Global Forecast System (GFS) initialization output four times each day. The temperature output is for the atmosphere at 10 meters above ground level. The CFSR model uses a 0.5 degree latitude by 0.5 degree longitude grid.

Figure 1. CFSR GMSATA 2014-2022 (click to enlarge)

The graph in Figure 2 shows the daily GMSATA time series for the Sigma 0.995 level output from the National Centers for Environmental Prediction and National Center for Atmospheric Research Reanalysis 1 (NCAR R1) cooperative effort. The Sigma 0.995 level corresponds to the pressure altitude at 99.5 % of the surface air pressure, which is roughly about 50 meters above ground level. The actual height above ground level varies somewhat depending on atmospheric conditions. The NCAR R1 model uses a 2.5 degree latitude by 2.5 degree longitude grid.

Figure 2. NCAR R1 GMSATA 2014-2022 (click to enlarge)

Figure 3 provides the NCAR R1 daily GMSATA time series for the current century beginning in 2001.

Figure 3. NCAR R1 GMSATA 2001-2022 (click to enlarge)

For a broader perspective, Figure 4 provides the NCAR R1 daily GMSATA time series for its entire period of record, beginning in 1948.

Figure 4. NCAR R1 GMSATA 1948-2022 (click to enlarge)