EARS develops the Energy and Water Balance Monitoring System (EWBMS). EWBMS is a Meteosat-based system which provides daily continental-scale data fields (evapotranspiration, radiation, precipitation, etc.) from 1982–date. We use these products for climate monitoring, drought index insurance, river flow forecasting, and crop yield forecasting.
Climatic data products based on the EWBMS are generated using hourly Meteosat imagery and aggregated by EARS to data products with the following characteristics:
The rainfall processing is based on cloud presence observed by satellite. Clouds are continuously identifed and classified based on their cloud top temperatures. Because hourly data is used as inputs for the rainfall algorithm, we can also detect how long certain clouds linger in an area during a one to ten day period. These qualitative rainfall indicators are used in combination with rain gauge data from the World Meteorological Organization to create the rainfall data products.
The energy balance processing is based on the physics of energy and mass exchange at the Earth's surface. Solving the energy balance equation gives an indication of what the incoming energy from the sun is used for: whether it is reflected by clouds, used for heating the surface, or if it is used by plants for producing biomass through evapotranspiration and photosynthesis. The evapotranspiration component of the energy balance is especially important for studies related to crop yields and for monitoring the effects of drought on crop production.
The data used for EARS index insurance products is the Relative Evapotranspiration (RE) index. The RE index has a strong relation to crop yields because biomass and yield (produced using CO2 entering the plant) are proportional to evapotranspiration (water exiting the plant). The opening and closing of the plant stomata as a result of drought affects these both equally, therefore making the RE index highly suitable for estimating drought related crop yield losses.
During product design, the RE index is used to understand historical drought risk, such as the frequency and severity of drought in the insured areas. Index monitoring by satellite then detects when a drought occurs, what the impact on the crop yield is, and how much the farmer should be paid at the end of the season. Relative evapotranspiration is an important data product of the EWBMS system.
In addition to rainfall and energy balance products, EARS also produces a variety of other data products derived from Meteosat imagery. These are products such as the Normalized Difference Vegetation Index (NDVI), Soil Moisture Index (SMI), Hydrological Drought Index (HDI), Meteorological Drought Index (MDI). We also deliver data aggregated over longer time periods, or difference products where we compare the current situation to long term averages from the past.