Spatial and Temporal Variations in Stable Isotopic Compositions of Precipitation in Southeast Asia

In this project, we’re collecting daily precipitation across Southeast Asia and measuring its stable isotopic composition over time. Our study focuses how stable isotopic compositions of precipitation change in Southeast Asia. Such knowledge will help us to interpret past climate archives and understand regional to global climate dynamics, which can be used to predict future scenarios, particularly water resource sustainability. We’ve installed a network of rain stations within Singapore and are collaborating with universities and academic organizations in neighboring countries to install rain collectors at their institutes.

In FY 16, through collective efforts, we have successfully established a network of rain stations in Southeast Asia, recording temperature, rainfall amount and relative humidity while collecting rainwater. The rainwater is being filled in small bottles and sent to us for isotope analysis.

Climate station which we have installed at University of Bengkulu, Indonesia, measuring temperature, rainfall and relative humidity while collecting rain water for isotope analysis. (Source: Dominik Jackisch)

We will continue the campaign for daily precipitation collection in this region between 2017 and 2019, and measure the stable isotope compositions of precipitation. Our study focuses on spatial and temporal variations in stable isotopic compositions. These data record the processes driving the isotopic compositions of precipitation, providing information about the atmospheric and climate processes that control the regional climate. The results will help to improve the physical and chemical components of predictive global and regional climate models.

One of our two climate stations located in Vietnam. The one shown above is installed at the Institute of Oceanography in Nah Trang City since 2015. (Source: Shaoneng He)

Simultaneous measurements of stable isotopes in rain and vapor; analysis results for one particular rainfall event. The rainfall event on 5th January 2017 is characterized by a v-shape pattern of isotope values, while isotope values of vapor show a steady decrease with the start of the rain event. Vapor is more depleted in D18O than rainfall of more than 10 ‰. Additional climate information such as temperature, rainfall amount and relative humidity is provided through our climate station installed on the rooftop of EOS. (Source: Dominik Jackisch)