Monday, May 8, 2023

April global surface TempLS down 0.158°C from March.

The TempLS FEM anomaly (1961-90 base) was 0.859°C in April, down from 1.017°C in March. It was still the fourth warmest April in the record, and the second warmest month since October 2021. The NCEP/NCAR reanalysis base index fell even more by 0.332°C.

Almost all the world was warm, with cold spots just in Alaska, central Siberia down to India, and some of mid west USA. Nowhere was very warm, except a patch in Antarctica.

Here is the temperature map, using now the FEM-based map of anomalies.

As always, the 3D globe map gives better detail. There are more graphs and a station map in the ongoing report which is updated daily.

This post is part of a series that has now run since 2011. The TempLS mesh data is reported here, and the recent history of monthly readings is here. Unadjusted GHCN is normally used, but if you click the TempLS button there, it will show data with adjusted, and also with different integration methods. There is an interactive graph using 1981-2010 base period here which you can use to show different periods, or compare with other indices. There is a general guide to TempLS here.

The reporting cycle starts with a report of the daily reanalysis index on about the 4th of the month. The next post is this, the TempLS report, usually about the 8th. Then when the GISS result comes out, usually about the 15th, I discuss it and compare with TempLS. The TempLS graph uses a spherical harmonics to the TempLS mesh residuals; the residuals are displayed more directly using a triangular grid in a better resolved WebGL plot here.

A list of earlier monthly reports of each series in date order is here:

  1. NCEP/NCAR Reanalysis report
  2. TempLS report
  3. GISS report and comparison with TempLS


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