Long-term temperature evolution

[nicrie]

Reference

1. Get all six data sets

• ERA5: use CDS
• GISTEMPv4: use CDS
• NOAA GlobalTempv5: link to gridded netCDF
• JRA-55: needs registration (?)
• HadCRUT5: link to gridded netCDF
• Berkeley Earth: use CDS

2. Comparison figure

• compare temperature for four regions (global, global-land, Europe, Arctic)

[nicrie]

Preprocessing

Steps are explained in Simmons et al. (2016) and ECMWF's Technical Memoranda

• area weighting using cosine of latitude
• additional weights based on land fraction

Issues

• cannot reproduce ERA5 mean temperature estimates for reference period (1991-2020); perhaps due to lower resolution? used incorrect spatial definition of Europe (taken from original publication, but one has to take the one defined in the ESOTC section
• ERA5 mean temperature estimate for reference period (1991-2020) is still of about ~0.1, e.g. we get 9.35 although it is 9.2 according to the indicator website