Monitoring The State Of Global Rainfall And Drought

April Flowers for – Your Universe Online

Despite the fact that it has become a widely accepted practice to use modern weather satellites to monitor terrestrial rainfall, establishing a reliable context for relating space-based rainfall observations to current and historical ground-based rainfall data has been difficult.

A team of researchers from UC Santa Barbara and the United States Geological Survey (USGS) has developed a new dataset that can be used for environmental monitoring and drought early warning. The dataset is called CHIRPS, or Climate Hazards Group Infrared Precipitation with Stations, and it is the result of a collaboration between UCSB’s Climate Hazards Group and USGS’s Earth Resources Observation and Science (EROS). CHIRPS combines space observed rainfall data with more than three decades of ground station data collected worldwide.

“This dataset seeks to blend the best qualities of rainfall station observations, satellite temperature data and rainfall’s unique spatial characteristics to create the best available rainfall information for climate and agricultural monitoring,” said Gregory J. Husak, an assistant researcher with the Climate Hazards Group in UCSB’s Department of Geography, in a recent statement.

Experts who specialize in early warning for drought and famine will be able to use CHIRPS to monitor rainfall in near real-time, at high resolution, over most of the planet. The data can be imported into existing climate models, where combining it with other environmental and meteorological data will allow scientists to project future agricultural and vegetation conditions.

The research team designed CHIRPS specifically for drought monitoring, and it is already in use identifying hot spots of food insecurity. For example, because of a series of poor rainy seasons in 2008, 2009, 2011 and 2012, much of East Africa is still suffering because of high food prices. This is especially true in South Sudan where over one million refugees have been displaced by a civil war.

Near Lake Victoria, Kenya, is the Rift Valley, which is full of highly productive farms that make up the bulk of Kenya’s food supply. Typically, millions of people are fed from the high crop yields brought about by abundant spring rains. CHIRPS has identified a very poor start to the growing season in the Rift Valley this year. Using the long historical record set incorporated as part of CHIRPS, researchers know that this April’s rainfall (approximately 2 inches) was the lowest in 34 years. This information has already been transmitted to the Famine Early Warning Systems Network of the U.S. Agency for International Development (USAID), prompting on-the-ground assessments of potential crop failure.

CHIRPS is also being used to investigate recent trends in rainfall, such as the long-term decline across both the southwestern United States and easternmost part of East Africa. UCSB and USGS scientists are working with USAIID to create development and adaptation strategies in Africa.

“Our most recent research suggests that these declines are likely linked to warming in the western Pacific and eastern Indian oceans,” said Chris Funk, a research scientist with the USGS’ EROS.

The development team would like to see the CHIRPS dataset being used to guide climate-smart development, as well as water managers, hydroelectric power companies, natural resource managers and disaster relief agencies prepare for a changing climate.

CHIRPS is being hosted by both the UCSB Climate Hazard Group and USGS’ EROS, and is available to the public.