Isotopic characteristics of Indian precipitation

Abstract

2003-2006 (12 locations in 2003 and 18 locations in 2004-2006). The amount of rainfall along with air temperature and humidity were also measured. The meteoric water line developed for India using isotopic data of precipitation samples, namely, d 2 H = 7.93 (±0.06) × d18 O + 9.94(±0.51) (n = 272, r 2 = 0.98), differs slightly from the global meteoric water line. Regional meteoric water lines were developed for several Indian regions (i.e., northern and southern regions of India, western Himalayas) and found to be different from each other (southern Indian meteoric water line, slope is 7.82, intercept or D excess is 10.23; northern Indian meteoric water line, slope is 8.15, intercept is 9.55) which is attributed to differences in their geographic and meteorological conditions and their associated atmospheric processes (i.e., ambient temperature, humidity, organ, and source of vapor masses). The local meteoric water lines developed for a number of locations show wide variations in the slope and intercept. These variations are due to different vapor sources such as the northeast (NE) monsoon that originates in the Bay of Bengal; the southwest monsoon (SW) that originates in the Arabian Sea; a mixture of NE and SW monsoons; retreat of NE and SW monsoons and western disturbances that originate in the Mediterranean Sea. The altitude effect in the isotopic composition of precipitation estimated for western Himalayan region also varies from month to month.

Controls on Deuterium Excess across Asia

“…That said, recycling may increase d-excess values of precipitation downwind, if accompanied by a progressive increase in the amount of recycled moisture and a decrease in relative humidity, as seen on the Tibetan Plateau [17]. [20,[29][30][31][32], and are shown in Supplementary Materials, Table S1. Interpolation was done using a spherical kriging algorithm in ArcGIS (Esri, Redlands, CA, USA).…”

Isotopic composition of daily precipitation along the southern foothills of the Himalayas: impact of marine and continental sources of atmospheric moisture

“…Consequently, the well-established isotope effects such as the amount effect, the temperature effect and the altitude effect are not clearly visible in the precipitation isotope data sets available for the Indian subcontinent (Jeelani and Deshpande, 2017;Deshpande and Gupta, 2012;Deshpande et al, 2010;Warrier et al, 2010;Yavada, 2007). However, at local or watershed scales, stable water isotopes of precipitation showed a good relationship with altitude and temperature (Jeelani et al, 2017a(Jeelani et al, , 2015(Jeelani et al, , 2013Kumar et al, 2010). The abrupt change in stable water isotopic values and the d-excess of precipitation during summer has been attributed to the reversal/change in the source of precipitation from western disturbances to southwest monsoons (Jeelani et al, 2017b;Breitenbach et al, 2010).…”

Geochemical and isotopic signatures for the identification of seawater intrusion in an alluvial aquifer

“…Different studies were carried out in the isotopic characterization of precipitation pattern for India's major geographic regions like northern, southern India and Himalayas (Chidambaram et al 2009;Kumar et al 2010). The local meteoric water line (LMWL) for south India given by Kumar et al (2010) has been used in this study. enrichment, which indicates the effect of recharge of evaporation enriched water.…”