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Reading the weather where it is

That Africa will bear the brunt of climate change is cruelly ironic. Widespread poverty deprives Africans of the more costly options for adapting to climate change that are available to wealthier regions. And Africans' low per capita use of fossil fuels places them among the least responsible for human-induced climate change and the least able to mitigate climate change by reforming energy policies.

"Sub-Saharan Africa accounts for 6-7 per cent of global greenhouse gas emissions," observed Dr. Tony Nyong of the University of Jos in Nigeria. "So we can't significantly reduce global emissions. The option for Africa is to adapt. We can facilitate adaptation by capacity building, which requires long-term commitment and collaboration."

Sudanese meteorologists analyse weather-data (TAMSAT)
Sudanese meteorologists analyse weather-data

Tony C. Anuforom, director of Applied Meteorological Services of the Nigerian Meteorological Agency (NIMET), bemoaned conditions hampering his country's 50-plus weather stations. "Nigeria is reported as blank - no data," he said. "Not because we don't collect weather data, but because of obsolete equipment. We need funding to upgrade the infrastructure and human capacity so we can resume uploading our data." Anuforom hopes that the Satellite Agrometeorological Information System (SAMIS) for NIMET, a proposed joint project with the Tropical Applications of Meteorology Using Satellite Data (TAMSAT) group at the University of Reading in the UK, will enable NIMET to become a more efficient and modern provider of the information required for famine early warning and assessment of vulnerability to drought.

SAMIS in Sudan

The Nigerian system follows an earlier Sudanese SAMIS, which was designed and produced by TAMSAT in collaboration with the Sudan Meteorological Authority (SMA) in Khartoum. Funding the project was the World Food Program (Sudan) Vulnerability Assessment and Mapping Unit. The SAMIS assembles and presents in a user-friendly format information about past and recent rainfall as well as vegetation coverage.

"It evolved from a three-way conversation with the SMA and end-users, who told us how they wanted the information presented to them," explained Dr David Grimes of the Department of Meteorology at the University of Reading. "An important feature of the SAMIS system is its flexibility, so it can be tailored to local conditions and end-user requirements. This means that local scientists take ownership of the project and develop it in their own way, allowing them to liaise much more effectively with local users. This is essential so that African scientists, and meteorological services in particular, can be seen to be the active providers of vital information within their own countries."

The SAMIS system creates digital data that geographic information system (GIS) software converts into coloured grid maps for easy interpretation. During the rainy season from June to September, these are posted and explained on the SAMIS website in 10-day and monthly bulletins and an annual season report. The information presented includes rainfall estimates over different time scales as well as early season maps indicating where sowing rains have fallen.

System inputs

SAMIS rainfall map of Sudan (TAMSAT)
SAMIS rainfall map of Sudan

"The length of dry spells is a particularly useful parameter for crop monitoring as it allows an evaluation of the rainfall distribution within a given period," noted Grimes. "Two consecutive 10-day rainfall estimates showing respectable rainfall could hide a dry spell of up to 18 days if the rain fell only on the first and last days of the 20-day period."

Data is currently collected from several sources including Meteosat, the European geostationary meteorological satellite (the data currently being provided by Reading until direct availability to SMA is established), and daily reports from Sudan's 28 ground meteorological stations. For now, vegetation index data is downloaded from the Africa Data Dissemination Service, but eventually this too will be generated in Khartoum.

"SAMIS is intended to be compatible with new hardware and software being supplied to all African meteorological services by the EU, so that they can make full use of the new Meteosat Second Generation weather satellites that are now operational," Grimes said. "Following on from success in Sudan, we've also had expressions of interest from Ethiopia, the Gambia, Kenya and Zambia for similar systems."

Improving weather observation in Africa is fundamental to the continent's ability to cope with current weather variability. Meanwhile, filling the "no data" blanks over much of Africa would improve prospects for accurately predicting future climate change worldwide. Expanding SAMIS beyond Sudan would also go some way toward answering one complaint made by the authors of the African Climate Report, which was commissioned by the UK government and published in December 2004: "Funding available in First World countries tends to exclude the funding of Africans. Funding available for Africans normally excludes funding for scientists from First World countries. Collaborative work in this financial environment is challenging."

Date published: July 2005


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