Geographic effects on stable isotopic composition of precipitation across Thailand
Geographic effects on stable isotopic composition of precipitation across Thailand
复制标题
地理对泰国降水稳定同位素组成的影响
DOI：
10.1080/10256016.2020.1714607
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发表时间：
2020
影响因子：
1.3
通讯作者：
Kimpei Ichiyanagi and Kiattipong Kamdee
中科院分区：
文献类型：
--
作者：
Jeerapong Laonamsai;Kimpei Ichiyanagi and Kiattipong Kamdee
本研究调查了泰国降水中同位素的空间变化与地理条件的关系。利用2013-2015年5°37′ ~ 20 ° 27 ′N，98°04′ ~ 105 ° 31 ′E区域降水稳定同位素（δ 2 H和δ 18 O）的月资料，采用最小二乘回归方法分析了纬度和经度对降水δ 18 O和δ-过剩的可能影响。结果表明，降水同位素的空间变异性受大陆效应和总量效应的共同影响，纬度的变异性略大于经度。经度效应和纬度效应均表现为正相关和负相关。负相关，即同位素值随纬度的增加而下降，发现在6月至8月和9月至11月期间。相反，一个积极的关系出现在12月至2月和3月至5月的季节。由于不同的水汽来源和不同季节的降水类型，这些影响具有相反的相关性。此外，弱相关的纬度和经度的影响，揭示了在9月至11月，因为季风的季节内变化。因此，泰国降水的同位素组成不仅受地理条件的控制，而且还受水汽来源和降水模式的控制。
This study investigated the spatial variation of isotopes in precipitation over Thailand in relation to geographic condition. Monthly data (2013–2015) of stable isotopes (δ2H andδ18O) in precipitation within the region 5°37′–20°27′N, 98°04′–105°31′E were analysed using the least squares regression method to determine the possible effects of latitude and longitude onδ18O andd-excess in precipitation. Results showed that the spatial variability of isotopes in precipitation is affected by both continental and amount effects and that the variation is slightly greater in terms of latitude than longitude. Latitude and longitude effects both exhibited negative and positive correlations. Negative correlation, whereby isotopic values decreased with increasing latitude, was found during the June–August and September–November periods. Conversely, a positive relationship appeared in the December–February and March–May seasons. These effects had opposite correlation owing to the various moisture sources and different precipitation patterns between seasons. Furthermore, weak correlation for both latitude and longitude effects was revealed during September–November because of the intraseasonal variation of the monsoon. Consequently, the isotopic composition of precipitation in Thailand is controlled not only by geography but also by moisture source and precipitation pattern.