Thejna Tharammal

Thejna Tharammal
Indian Institute of Science | IISC · Centre for Atmospheric and Oceanic Sciences (CAOS)

Doctor of Philosophy

About

14
Publications
3,137
Reads
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301
Citations
Additional affiliations
February 2019 - March 2020
Indian Institute of Science
Position
  • Researcher
Description
  • Paleoclimate modeling, Future climate change projections, Modeling of Land Carbon cycle
January 2015 - January 2019
Indian Institute of Science
Position
  • PostDoc Position
Description
  • Modeling of: water isotope effects, Global carbon cycle, future climate change scenarios
July 2013 - November 2014
MARUM Center for Marine Environmental Sciences
Position
  • PostDoc Position
Description
  • Modeling paleoclimate changes
Education
January 2009 - July 2013
Universität Bremen
Field of study
  • Climate modeling, Water isotopes, paleoclimatology

Publications

Publications (14)
Article
Full-text available
To understand the validity of δ18O proxy records as indicators of past temperature change, a series of experiments was conducted using an atmospheric general circulation model fitted with water isotope tracers (Community Atmosphere Model version 3.0, IsoCAM). A pre-industrial simulation was performed as the control experiment, as well as a simulati...
Article
Full-text available
The empirical "amount effect" observed in the distribution of stable water isotope ratios in tropical precipitation is used in several studies to reconstruct past precipitation. Recent observations suggest the importance of large-scale organized convection systems on amount effect. With a series of experiments with Community Atmospheric Model versi...
Article
Full-text available
Terrestrial and oceanic carbon sinks together sequester >50% of the anthropogenic emissions, and the major uncertainty in the global carbon budget is related to the terrestrial carbon cycle. Hence, it is important to understand the major drivers of the land carbon uptake to make informed decisions on climate change mitigation policies. In this pape...
Article
The variation of stable water isotopes (δ18O, δD) in climate archives is an important proxy to understand the evolution of South Asian monsoon (SA) precipitation over the Holocene. In this study, using an isotope-enabled climate-model, we examine the responses of water isotopes in precipitation over the SA region to orbital changes in the early to...
Article
Full-text available
Anthropogenic influences and global climate change are expected to alter the land carbon stocks in the future. In this modeling study, using the NCAR Community Earth System Model (CESM), we assess the relative importance of CO2 fertilization, nitrogen deposition, climate change, and land use and land cover changes (LULCC) on the land carbon uptake...
Data
The Indian Summer Monsoon (ISM) is a major global climatic phenomenon. Long-term precipitation proxy records of the ISM, however, are often fragmented and discontinuous, impeding an estimation of the magnitude of precipitation variability from the Last Glacial to the present. To improve our understanding of past ISM variability, we provide a contin...
Article
Carbon and water isotopes are included as passive tracers in the MIT general circulation model (MITgcm). The implementation of the carbon isotopes is based on the existing MITgcm carbon cycle component and involves the fractionation processes during photosynthesis and air-sea gas exchange. Special care is given to the use of a real freshwater flux...
Article
Stable isotopes of water recorded in polar ice cores are used to reconstruct past temperatures and the fractionation during phase changes make them a useful tracer of the hydrological cycle. This study focuses on the global and regional variations in the distribution of water isotopes with changes in the climate. Sensitivity experiments and time-sl...
Data
To understand the validity of d18O proxy records as indicators of past temperature change, a series of experiments was conducted using an atmospheric general circulation model fitted with water isotope tracers (Community Atmosphere Model version 3.0, IsoCAM). A pre-industrial simulation was performed as the control experiment, as well as a simulati...
Data
The hydrogen isotopic composition of plant leaf-wax n-alkanes (dDwax) is a novel proxy for estimating dD of past precipitation (dDp). However, vegetation life-form and relative humidity exert secondary effects on dDwax, preventing quantitative estimates of past dDp. Here, we present an approach for removing the effect of vegetation-type and relativ...
Article
Full-text available
A series of experiments was conducted using a water isotope tracers-enabled atmospheric general circulation model (Community Atmosphere Model version 3.0, CAM3.0-Iso), by changing the individual boundary conditions (greenhouse gases, ice sheet albedo and topography, sea-surface temperature) each at a time to Last Glacial Maximum (LGM) values. In ad...
Article
Full-text available
Arabian sea is one of the highly productive seas in the Indian ocean region due to its long boundaries and the open ocean processes which manifest as upwelling during summer monsoon (June-September) and cooling during winter especially in the northern regions. The present study is aimed at applying ocean color satellite imagery to understand the se...

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Cited By

Projects

Project (1)
Archived project
The project aims at a better understanding of monsoon dynamics at timescales of societal relevance. Joint project in the frame of the programme CAME (Central Asia – Monsoon Dynamics and Geo-Ecosystems), coordinated by MARUM at the University of Bremen. Funded by the German Federal Ministry of Education and Research (BMBF).