Importance of high resolution precipitation isotope datasets for climate change studies
Climate change has an unprecedented effect on the hydrologic cycle and could impact water resources. However, the link between climate patterns, atmospherics processes and water availability is poorly known. This is largely the case in a drought sensitive region of the world where direct observations of climate are limited. As conservative dual tracer, stable isotopes of oxygen (18O) and deuterium (2H) in precipitation can provide an integrated view of the hydroclimate. In Ethiopia, there is one long-term (1961-2016) monthly precipitation isotope monitoring station in Addis Ababa. However, the data from this station deviates from expectations given its inland location and high altitude, making the generalized framework usually used to interpret isotopic data in hydrology and paleoclimate studies difficult. Moreover, the reasons for these anomalously high values are poorly understood. To understand what drives these anomalously high isotope values in Addis Ababa, we analyzed 50 daily precipitation samples collected in the main rainy season (June-September 2018). Our result shows that the daily amount weighted monthly averages from this study are similar to the long-term data in Addis Ababa. The two data sets also show a similar trend throughout the rainy season with the lowest isotopic values in August. Despite theses similarities, the daily isotope measurements exhibit larger range that the long-term monthly data in Addis Ababa. Our high-resolution daily isotope dataset could provide new insights into the climatic controls on the isotopic composition of rainfall in Ethiopia and understand hydroclimate variability today and in the past.
Zelalem K Bedaso, Shuang-Ye Wu
Primary Advisor's Department
Stander Symposium poster
"Importance of high resolution precipitation isotope datasets for climate change studies" (2019). Stander Symposium Posters. 1753.