สถาบันเทคโนโลยีนิวเคลียร์แห่งชาติ ( องค์การมหาชน ) Thailand Institute of Nuclear Technology (TINT) The Application of Stable Isotope on Atmospheric Gas Chemistry in Thailand by the New Approach of off-axis Integrated Cavity Output Spectroscopy (OA-ICOS) นิธิพนธ์ น้อยเผ่า Nitipon Noipow Research and Development Division Ongkarak Nuclear Research Center, Nakorn Nayok

Atmospheric Gas - Increases in the abundance of atmospheric greenhouse gases since the industrial revolution are largely responsible for the observed increases in global temperature [IPCC 2007] The Intergovernmental Panel on Climate Change (IPCC) Greenhouse gases (GHG), in particular carbon dioxide (CO 2 ), methane (CH 4 ), nitrous oxide (N 2 O), water vapor (H 2 O) and halogenated compounds (mainly CFCs)

- Scientific concern / NOAA Annual Greenhouse Gas Index (AGGI) The proportion of Global Radiative Forcing by many species of GHG comparing the year 1990 A. To understand the effect of atmospheric gas to the global and regional climatic change B. and to access their dynamics, the extremely detection precision (in sub ppb) is required. -Also some small amount proportion of Isotope Ratio (Stable)

Brief on Stable Isotopes Non-radioactivity Nuclides Hydrogen 2 stable isotopes, 1 H and 2 H (deuterium), one radioactive isotope, 3 H (tritium)tritium Light Isotope Heavy Isotope

Isotope fractionation fingerprinting were applied as one of the environmental tracers Differential partitioning of isotope species in a physicochemical process - Different molecular kinetic energy - Phase changing - molecular diffusion Isotope Fractionation

6 The convectional Isotope Ratio Mass Spectrometer (IRMS) - Huge/complex system -delicate high vacuum system -complex gas equilibration methods, need chemistry specialist limited an analysis capabilities in only advanced nuclear institutions due to lack of long-term/high frequency stable isotope database

Off-axis Integrated Cavity Output spectroscopy (ICOS) Non-Dispersive Infrared absorbsion in trace gas analysis Beer’s Law Cavity Ring Down Spectroscopy (CRDS); the convectional configuration mixing ratio is functioned to absorbsion intensity

8 Using d-notation, as the difference between the measured ratios of the sample and the standard Water/vapor VSMOW (Vienna Standard Mean Ocean Water) and SLAP (Standard Light Antarctic Precipitation)

Auto injector System Analyzer Bench top Capacity samples/day Liquid Water Isotope Analyzer (LWIA) LGR DLT-100 Fast, inexpensive and less maintenance compared to Conventional IRMS * Easy use can be operated by non-chemist scientist In Thailand, IAEA Technical Cooperation (TC project) Water/vapor Isotope ratio ( 2 H and 18 O)

Stable isotope as fingerprint in water cycles - Enriched and Depleted - Heavy vs. Light isotope composition

- LMWL The Local Meteoric Water Line (Bangkok) and environmental isotopic dispersion of water y = 7.56x BANGKOK LMWL

12 ONRC APRIL 2012 GW recharged from RW GW recharged from RW mix with SW GW recharged from Pond + RW? Pond 75% 25%

13 Mae Tha clastic rocks (C) Lan Sang Gneiss (PЄ)

The Application of Water/Vapor Stable Isotope in Thailand - Thailand is 1 of 101 countries in the 40 years project of Global Network of Isotopes in Precipitation (GNIP) by IAEA and World Meteorological Organization (WMO) - But in few locations of monthly mixed samples y = 7.56x BANGKOK LMWL

15 The isotope data in local precipitations at Ongkarak Nuclear Research Center (ONRC) during September 2008 to recent. - more than 150 samples at daily rain events

16 Higher D-excess by high evaporated vapor source Lower D-excess by amount effect Pre-monsoon & First Monsoon RF 2nd Monsoon RF & Tropical Cyclone

17 Enriched in Pre-monsoon & First Monsoon RF Tropical Cyclone

What’s the next? - Water Vapor direct measured - Rain observation networks (25+ station) - 13 C stable isotope ratio of CO2 in the air and/carbonate rocks

Thank you for your attention!

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Different Physicochemical Characteristics of molecules Differential partitioning of isotope species in a physicochemical process - Different molecular kinetic energy - Phase changing - molecular diffusion - fractionation applied in environmental tracers Isotope Fractionation

In Superb precision Mode (30 unknowns/day) Repeatability 0.1‰ for 18 O/ 16 O and 0.3‰ for D/H Precision and Repeatability

23 where: I v is the intensity through the sample at frequency v; I o is laser intensity before entering the cell; P is gas pressure; S is absorption line strength;  v is the line shape function; L is the optical path length; and  is the mixing ratio of trace gas. Beer’s Law

Nine Isotopic Molecular Species of Water 1.H 2 16 O 2.H 2 17 O 3.H 2 18 O 4.HD 16 O 5.HD 17 O 6.HD 18 O 7.DD 16 O 8.DD 17 O 9.DD 18 O