Coverage, spatial and temporal resolution
Period and temporal resolution:
- 1983-01 to 2018-12
- Monthly and 10-Daily
Missing months: 1983-01 & -11; 1984-11; 1985-02, -03, & -11;1986-08; 1988-11 & -12; 1989-01, -02, -05 & -09; 1990-01 & -02; 1992-02; 1993-05; 1996-10; 1999-01; 2006-09; main reason for these missing months usually is a missing 10-day period.
Coverage and spatial resolution:
- Africa, over land
- Spatial resolution: 0.0375° x 0.0375°, cartesian grid
- Geographic longitude: -19.0125°E to 51.975°E
- Geographic latitude: -35.9625°N to 38.025°N
- Dimension: 1974 rows x 1894 columns
- Altitude: following terrain
The data set does not include any explicit uncertainty estimates.
A number of issues need to be kept in mind to understand potential uncertainties.
1) The TAMSAT algorithm works best for convective precipitation. Version 3.0 has reduced tendency to underestimate precipitation amount compared to version 2.0. Orographically induced precipitation from comparably warm clouds remains problematic in general and is under-estimated when rooting the retrieval on infrared observations solely, as is the case for this data set.
2) The (changing) spatial distribution of rain gauges impacts the calibration of the TAMSAT rainfall estimates - particularly when extending the estimates over the entire continent. This also impacts the near-real-time validation.
3) The (changing) temporal distribution of rain gauges does also impact both the calibration and extension as well as the validation.
4) The calibration requires to use regions of different extent and with different rain gauge densities because of the various climatic zones encountered across Africa; this may lead to spatial inconsistencies. Compared to version 2.0, version 3.0 has much less inconsistencies due to gaps in the calibration and validation data.
5) A relatively dense network of rain gauges in some areas does not guarantee a large enough number of data for the near-real-time validation; often only 20-25% of the stations report in due time.
More information about data quality can be found in the references - particularly the two from 2014. In addition the TAMSAT team regularly issues validation reports which can be found on www.met.reading.ac.uk/~tamsat
TAMSAT Research Group
Meteorology Department, University of Reading, UK
email: tamsat (at) reading.ac.uk
ICDC / CEN / University of Hamburg
email: stefan.kern (at) uni-hamburg.de
When using this data set please cite the following two papers:
Maidment, R., et al., 2014, The 30 year TAMSAT African Rainfall Climatology And Time series (TARCAT) data set. J. Geophys. Res., 119, 10,619-10,644, doi:10.1002/2014JD021927
Tarnavsky, E., et al., 2014, Extension of the TAMSAT Satellite-Based Rainfall Monitoring over Africa and from 1983 to present. J. Appl. Meteorol. Climatol., 53, 2805-2822, doi:10.1175/JAMC-D-14-0016.1