Statistical Analysis of the Precipitation Isotope Data with Reference to the Indian Subcontinent

The isotopic analysis of precipitation provides useful information on a variety of hydrological and atmospheric processes. The dynamical characteristics of precipitation isotopes have been well investigated, but a systematic study of their statistical behavior seems to be lacking. We have performed the statistical analysis, basically the distribution characteristics of precipitation isotopes vis-a-vis rainfall data for specific regions. The probability distribution functions of precipitation isotopes have been calculated from local to global scales. It has been observed that the isotopic values, in general, followed a pattern that is similar to the normal distribution, though the rainfall distribution patterns are very different. Under certain circumstances, the isotopic distribution patterns closely resemble the normal distribution, implying a well-constrained moisture source contributing to precipitation. The distribution patterns of oxygen and hydrogen isotopes on continental and global scales show similar behavior. It was observed that the distribution patterns of primary isotopic variables (δ18O and δD) are not very sensitive to the outliers. On the contrary, the secondary parameter, d-excess, is very sensitive to outliers, which offers an effective means to quality control of the precipitation isotopic values

Stable isotopic investigation of <i>Porites</i> coral from the Minicoy Island

1465-1470Stable isotope analysis has been performed on a coral collected from the Minicoy Island to investigate its potential as a proxy for southwest monsoonal variability. The X-Ray picture of the porites coral collected revealed about 24 annual bands (1989-2013). The mean annual extension over this period is ca. 7.7mm/year. Stable carbon (δ13C) and oxygen isotope (δ18O) analysis of these bands reveal that the isotopic composition is controlled by kinetic fractionation. There is a drop of δ18O, ca 1‰ relative to the mean value -during -1998 indicating anomalous warming of the sea surface warming

chapter 16. Application of precipitation isotopes in pursuit of paleomonsoon reconstruction: an indian perspective

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What controls the atmospheric methane seasonal variability over India?

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Linkage between precipitation isotopes and biosphere-atmosphere interaction observed in northeast India

© 2022, The Author(s).The intra-seasonal variation in precipitation isotopes shows a characteristic declining trend over northeast India. As of now, no mechanism offers a consistent explanation of this trend. We have performed the isotopic analysis of precipitation (rain) and estimated net ecosystem exchange and latent heat fluxes using an eddy-covariance system in northeast India. Additionally, we have used a diagnostic model to determine the recycled rainfall in this region. We find a strong link between the enhanced ecosystem productivity and isotopic enrichment in rainwater during the premonsoon season. Subsequently, on the advent of monsoon, the Bay of Bengal generated moisture enters this region and depletes the isotopic values. Additionally, the regional-scale convective activities produce periodic lows in the precipitation isotopes. Contrary to the general understanding, our study shows that the internal factors, such as the local land-atmosphere interactions, rather than the external influences, play a significant role in governing the precipitation isotopes in northeast India.11Ysciescopu