I am looking for gridded/raster estimates of daily mean temperature (ideally ambient/at 2 meter) for a public health analysis. Specifically, I want to correlate daily mortality counts with daily mean ambient temperature (globally, between the years 1990-2016). I want to use gridded data rather than nearby temperature stations to allow for some extrapolation to areas without stations with long time series (e.g. large swaths of sub-Saharan Africa).
The accuracy of temperature in terms of degrees is somewhat less important relative to the accuracy of day-to-day variability for this project.
It seems like the GEFS Reforcast and NCEP Reanalysis products both provide daily mean temperature at a global extent, albeit at different spatial resolutions. I've looked at the documentation and underlying papers, but my earth science background is weak and I can't really suss out the difference between the two products.
Is one product substantially better than the other for global mean ambient temperature estimates? Is there a simple difference between the two products that I've missed?
Parameters I care about (roughly in order):
- Daily measurement of mean temperature with global coverage
- High spatial resolution
- Accuracy of day to day variation (e.g. if day 1 was X degrees hotter than day 2, is that reflected?)
- Accuracy of daily mean estimate