A New 34-Year Satellite-Based Monthly Tmax Climate Data Record, the Climate Hazards Infrared/MERRA2 Tmax with Stations: CHIMERRAS Tmax

This is the first long term satellite based surface air temperature climate data record. Many parts of the developing world are sparsely sampled and the number of observations has been declining in recent years. As climate continues to change good temperature data compliments precipitation as essential for monitoring droughts.

CHIRTSmax is based of three main inputs (similar to our CHIRPS product): 1) a high resolution 0.05 degree monthly climatology (CHTclim_max) capturing spatial variability, 2) GeoSat IR data that captures the temporal variability and 3) available ground observations of Tmax.

Methodology overview:

1) Filter Geostationary IR data to screen out clouds

2) Calculate monthly averages of geostationary cloud-screened IR data (IRT_max)

3) Create high resolution 0.05 degree Tmax climatology (CHTclim_max)

4) Translate IR brightness temperature anomalies into estimates of 2m Tmax anomalies

5) Add these anomalies to the CHTclim to create satellite-based estimates of Tmax air temperatures (CHIRT_max)

6) Blend in station anomalies with CHIRT_max to make CHIRTS_max

The resulting CHIRTSmax is a 0.05x0.05 degree land Tmax product from 70N to 60S, from 1983 to 2016.

Future products will use the CPC IR data to produce a CHIRTSmax with latency of about 3-7 weeks.

We expect to produce a Tmin climate data record later this year.

The methodology, results and validations will be presented.