I am a paleoclimatologist. My research focuses on reconstructing and assessing the impact of climate variability on human societies, especially in semi-arid regions over the past 1000 years.
I am trained in geochemical applications within the broad discipline of earth sciences. My research focuses on paleoclimate applications to understand how climate variability affects the interaction between human societies and environments. I am fascinated by timescales e.g. how long does it take for climate variability to impact a human-environment system; once you perturb or stress such a system, how does the system respond, long does it take for the system to respond and how does that response evolve. As such, my research has encompassed timescale of human interest (tens to hundred years), natural systems (hundreds of years) and in the recent past of geological systems (millions of years). I enjoy working with students - undergraduates and graduates alike- and find collaborative research approaches (cross-cutting disciplines) most invigorating, intriguing and important, especially given the global nature of the challenges we face. Below are some of the topics that I am working on (as you will see that I am quite immersed in questions about timescales!)
[i] Exploring coral as archives of historical environmental (sediment runoff) change (100 - 400 years). I study the abundance of metals and detrital (earth derived materials) content in reef-building corals to reconstruct the history of environmental, climatological and human impact over the last few centuries. This approach also helps me characterize the response of the coral reefs to both local and remote stressors.
[ii] Historical climate variability in arid regions during the Common Era (past 1000 years). This time period, when human history evolved under more or less current climactic conditions, hold information about how climate affects human societies and therefore, is of tremendous value to our survival in the near and far future. In particular, I am fascinated by how human societies evolved, adapted to and in many instances vanished from, naturally water-stressed environments. Arid and semi-arid regions are prone to dramatic climate variability and abrupt changes. To understand climate variability and its impact on environments, ecosystems, and landscape in such regions, I use a suite of approaches that hinges on exploiting 'proxy observations' in high-resolution natural archives (e.g. corals, well-dated lacustrine materials) in relation to archival and archeological information that help inform agriculture and trade decisions. Combining the two provides critical information on how climate variability influences collective human response to their physical environment
[ii] Historical climate impacts and climate adaptation south-east Asia during the Common Era (past 1000 years): Climate variability is only one part of the information about human-climate interaction. It is often very difficult to assess the impact of climate variability on human civilization. We cannot just rely on information from natural archives. We have to delve into the world, where records of daily lives of people affected and who coped (and how they coped) with changing climate. I am currently working with students to constrain climate impacts during the historical time periods in central India. History is truly fascinating. But history can be useful too: much can be achieved if we can quantify and use the information about how human societies survived through, changed and adapted to climate variability! I am engaged in applying paleoclimate methods to extracting climate information from a range of historical and archeological texts.
I have worked on geological systems that helped shape my understanding of thresholds in systems and linked processes that lead to dramatic shifts in human-environment systems!
[iv] Geochemical oceanography on geological timescales (500 million years!). I use high-precision techniques (such as ion probe, electron probe, clumped isotope and trace elements) in well-preserved fossils and carbonate veins to look for remnants of ancient ocean compositions, mostly by constraining the effects of diagenesis that often affects these old materials.
[v] Subduction zones and process associated with the accretion of the Gondwanaland (1-3 billion years!!): I used high precision techniques (such as ion probe and electron probe) to date detrital mineral grains in ancient Indian cratonic rocks in order to understand plate accretionary processes and impacts on global climate and environment (this is a work that I am pursuing with my father, a well-known geologist and learning much in that way!)
I am passionate about including undergraduate students in research
[vi] Undergraduate research education (URE): I am keen on exploring how we can incorporate and assess the efficacy of discipline-based education research (DBER) approaches to improve undergraduate research education (URE).
Finally, I teach upper-division undergraduate courses that explore how human societies interact with climate and the environment. I also write. Both professionally and also for the sheer pleasure of it.
If you are interested in these questions or would like to collaborate, I'd love to hear from you!!
Faculty and Research Affiliate, Environmental Studies & Institute of Arctic and Alpine Research (INSTAAR), University of Colorado, Boulder (2015-)
Postdoctoral Scholar, Dept. of Earth, Planetary and Space Sciences, University of California-Los Angeles (2014-2015)
Research Scholar and Faculty, Dept. of Marine Earth and Atmospheric Sciences & Environmental Studies Program, North Carolina State University (2013-2014)
Ph.D, Earth and Planetary Sciences, Harvard University (2005-2012)
M.Sc, Applied Geosciences, Indian Institute of Technology-Kharagpur, India (2003-2005)
B.Sc, Geology, Presidency College, Calcutta University, India (2000-2003)
Science animation videos- artifacts will be posted soon!