1In the early 1970s, the great West African drought raised concerns among the scientific community regarding the stability of the environment and climate in the tropical belt. In the years that followed, this concern became a research priority. Observatories were designed to determine long-term trends in the different physical and biogeochemical variables which control the “critical zone”, i.e. the thin layer between the lower atmosphere and the subsoil, which accounts for 99% of terrestrial life.

Mission on the Zongo glacier, Bolivia.

••• Over the past 30 years, national observation services have monitored the impact of global shifts in the tropical belt and the Mediterranean Basin •••

Flow measurement on Rio Marañon, Peru.

2The sites selected to host these observatories are representative of the major tropical systems. The best structured sites were designated as “National Observation Services” by IRD and CNRS. They were designed to reflect the specific features of the environments they monitor. A number of observatories were created over the years:  AMMA-Catch in Niger, Benin and Mali, which documents West Africa; Hybam in Brazil and Andean countries, to observe the Amazon Basin; Glacioclim in Bolivia and Ecuador, which monitors changes in tropical glaciers; Pirata in the tropical Atlantic; and Omère in Morocco and Tunisia, dedicated to the Mediterranean region.

AMMA, impending rain on IRD’s measurement site, Niger.

3These observatories are critical to understanding the mechanics and impact of global shifts. Field data collected provides input so that the models can be validated and upgraded. It is also used to test and calibrate new measurement techniques such as radar, infrared or microwave sensors, or proton magnetic resonance (PMR), making it possible to qualify groundwater. In situ data from the observatories is also valuable when calibrating satellite data, such as recently with the GRACE satellite which uses gravitational field fluctuations to infer continental water storage variations over very large areas.

“The Hybam and Glacioclim observatories provide the scientific community of tropical Andean countries with a robust tool for addressing the needs of decision-makers in light of global shifts, by effectively documenting changes in the region’s hydroclimatic regimes.” 
Juan Carlo Espinoza, Geophysical Institute of Peru, Lima