Observational Research on Stable Isotopes in Precipitation over Indonesian Maritime Continent

Abstract

The Indonesian Maritime Continent (IMC) is located in the tropics and consists of a number of islands and seas. This particular arrangement of land masses and seas produces unique weather and climate characteristics. Various hydrometeorology studies have been conducted exploring the variability of stable isotopes in precipitation over the IMC. Stable isotopes (δ 18 O and δD) in precipitation can be used to obtain information about atmospheric processes (e.g., precipitation, temperature and hydrological cycle). The Global Network of Isotopes in Precipitation, operated by the International Atomic Energy Agency, has been conducting worldwide monthly surveys of isotope levels in precipitation since 1961. To better understand the isotopic variability in the IMC, the Japan Agency for Marine-Earth Science and Technology began operating in the IMC region in 2001. There are three types of seasonal variation of stable isotopes in precipitation, depending on the level of precipitation amount and also stable isotopic value, namely, semiannual, anti-monsoonal and monsoonal. Negative correlations between the precipitation amount and stable isotope value (amount effect) were identified when using the monthly averages. The interannual variability of stable isotopes in precipitation was mainly because of El Niño Southern Oscillation activity, whereas intraseasonal variability was closely related to the Madden-Julian Oscillation. Stable isotope variability in short periods was found to be due to precipitation cloud types and post-condensation processes.

Temporal Variation in the Stable Isotopes In

“…The slope was close to 8, which was near equilibrium. The slope for Pasoh FR was very similar to several continental stations in Indonesia, although other Indonesian stations located near the coast and small islands showed slopes near 7 (Rozanski et al 1993, Clark & Fritz 1997, Belgaman et al 2016. With a slope near 8, Pasoh FR corresponded to the theoretical results obtained under isotopic equilibrium conditions (Belgaman et al 2016).…”

Meridional march of diurnal rainfall over Jakarta, Indonesia, observed with a C-band Doppler radar: an overview of the HARIMAU2010 campaign

“…, 26 m AMSL) every 3 or 6 h for stable isotope analyses (e.g., Fudeyasu et al 2011;Belgaman et al 2016), though these data are not examined in this paper.…”

Continuous real‐time analysis of the isotopic composition of precipitation during tropical rain events: Insights into tropical convection

“…For years, the temperature effect has been used to interpret precipitation isotopes at mid to high latitudes, and the amount effect has been used to interpret precipitation isotopes in tropical regions (Aggarwal et al, ; Bowen, ). Precipitation isotopes in tropical regions, however, have very weak correlation to temperature, and the amount effect is only observed in monthly and yearly precipitation and not in daily or event precipitation (Belgaman, Ichiyanagi, Tanoue, & Suwarman, ; Kurita, Ichiyanagi, Matsumoto, Yamanaka, & Ohata, ; Marryanna et al, ; Permana, Thompson, & Setyadi, ). In addition, these famous isotope–climate relationships fail to explain isotopic data obtained from palaeoclimate records in the tropics (Hoffmann et al, ; Pausata, Battisti, Nisancioglu, & Bitz, ; Ramirez et al, ).…”