scholarly journals Interannual variability of H218O in precipitation over the Asian monsoon region

2012 ◽  
Vol 117 (D16) ◽  
pp. n/a-n/a ◽  
Author(s):  
Yasuhiro Ishizaki ◽  
Kei Yoshimura ◽  
Shinjiro Kanae ◽  
Masahide Kimoto ◽  
Naoyuki Kurita ◽  
...  
Keyword(s):  
Interannual Variability ◽  
Asian Monsoon ◽  
Monsoon Region ◽  
Asian Monsoon Region

scholarly journals What controls the stable isotope composition of precipitation in the Asian monsoon region?

2017 ◽  
Author(s):  
Le Duy Nguyen ◽  
Ingo Heidbüchel ◽  
Hanno Meyer ◽  
Bruno Merz ◽  
Heiko Apel
Keyword(s):  
Isotopic Composition ◽  
Asian Monsoon ◽  
Precipitation Amount ◽  
Climatic Conditions ◽  
Monsoon Region ◽  
Asian Monsoon Region ◽  
Air Mass ◽  
Local Factors ◽  
Regional Factors ◽  
Isotopic Records

Abstract. This study analyzes the influence of local and regional climatic factors on the stable isotopic composition of rainfall in the Vietnamese Mekong Delta as part of the Asian monsoon region. It is based on 1.5 years of weekly rainfall samples. Their isotopic content is analyzed by Local Meteoric Water Lines (LMWL) and single-factor regressions. Additionally, the contribution of several regional and local factors is quantified by multiple linear regressions (MLR) of all possible factor combinations and by relative importance analysis, a novel approach for the interpretation of isotopic records. The local factors are extracted from local climate records, while the regional factors are derived from atmospheric backward trajectories of water particles. The regional factors, i.e. precipitation, temperature, relative humidity and moving distance of the backward trajectories, are combined with equivalent local climatic parameters to predict the response variables δ18O, δ2H, and d-excess of precipitation at the station of measurement. The results indicate that (i) MLR can much better explain the isotopic variation of precipitation (R2 = 0.8) compared to single-factor linear regression (R2 = 0.3); (ii) the isotopic variation in precipitation is controlled dominantly by regional moisture regimes (~ 70 %) compared to local climatic conditions (~ 30 %); (iii) the most important climatic parameter during the early rainy season is the precipitation amount along the trajectories of air mass movements; (iv) the influence of local precipitation amount and temperature is not significant during the early rainy season, unlike the regional precipitation amount effect; (v) secondary fractionation processes (e.g. sub-cloud evaporation) take place mainly in the dry season, either locally for δ18O and δ2H, or along the air mass trajectories for d-excess. The analysis shows that regional and local factors vary in importance over the seasons, and that the source regions and transport pathways, and in particular the climatic conditions along the pathways, have a large influence on the isotopic composition of rainfall. The proposed methods thus proved to be valuable for the interpretation of the isotopic records in rainfall and the factors controlling it. The results illustrate that the interpretation of the isotopic composition in precipitation as a recorder of local climatic conditions, as for example performed for paleo records of water isotopes, may not be adequate in the Southern part of the Indochinese Peninsula, and likely also not in other regions affected by monsoon processes. However, the presented approach could open a pathway towards better and seasonally differentiated reconstruction of paleoclimates based on isotopic records.

Temperature signals of ice core and speleothem isotopic records from Asian monsoon region as indicated by precipitation δ18O

2021 ◽  
Vol 554 ◽  
pp. 116665
Author(s):  
Wusheng Yu ◽  
Tandong Yao ◽  
Lonnie G. Thompson ◽  
Jean Jouzel ◽  
Huabiao Zhao ◽  
...  
Keyword(s):  
Asian Monsoon ◽  
Ice Core ◽  
Monsoon Region ◽  
Asian Monsoon Region ◽  
Isotopic Records ◽  
Precipitation Δ18o

scholarly journals Interpreting Precession-Driven δ18O Variability in the South Asian Monsoon Region

2018 ◽  
Vol 123 (11) ◽  
pp. 5927-5946 ◽  
Author(s):  
Clay R. Tabor ◽  
Bette L. Otto-Bliesner ◽  
Esther C. Brady ◽  
Jesse Nusbaumer ◽  
Jiang Zhu ◽  
...  
Keyword(s):  
South Asian ◽  
Asian Monsoon ◽  
South Asian Monsoon ◽  
Monsoon Region ◽  
The South ◽  
Asian Monsoon Region

scholarly journals Water vapor increase in the lower stratosphere of the Northern Hemisphere due to the Asian monsoon anticyclone observed during the TACTS/ESMVal campaigns

2018 ◽  
Vol 18 (4) ◽  
pp. 2973-2983 ◽  
Author(s):  
Christian Rolf ◽  
Bärbel Vogel ◽  
Peter Hoor ◽  
Armin Afchine ◽  
Gebhard Günther ◽  
...  
Keyword(s):  
Water Vapor ◽  
Northern Hemisphere ◽  
Asian Monsoon ◽  
Eastern China ◽  
Potential Temperature ◽  
Monsoon Region ◽  
Asian Monsoon Region ◽  
Air Mass ◽  
Air Masses ◽  
The Impact

Abstract. The impact of air masses originating in Asia and influenced by the Asian monsoon anticyclone on the Northern Hemisphere stratosphere is investigated based on in situ measurements. A statistically significant increase in water vapor (H2O) of about 0.5 ppmv (11 %) and methane (CH4) of up to 20 ppbv (1.2 %) in the extratropical stratosphere above a potential temperature of 380 K was detected between August and September 2012 during the HALO aircraft missions Transport and Composition in the UT/LMS (TACTS) and Earth System Model Validation (ESMVal). We investigate the origin of the increased water vapor and methane using the three-dimensional Chemical Lagrangian Model of the Stratosphere (CLaMS). We assign the source of the moist air masses in the Asian region (northern and southern India, eastern China, southeast Asia, and the tropical Pacific) based on tracers of air mass origin used in CLaMS. The water vapor increase is correlated with an increase of the simulated Asian monsoon air mass contribution from about 10 % in August to about 20 % in September, which corresponds to a doubling of the influence from the Asian monsoon region. Additionally, back trajectories starting at the aircraft flight paths are used to differentiate transport from the Asian monsoon anticyclone and other source regions by calculating the Lagrangian cold point (LCP). The geographic location of the LCPs, which indicates the region where the set point of water vapor mixing ratio along these trajectories occurs, can be predominantly attributed to the Asian monsoon region.

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