Research

My CV

The not-so-sciency version: I am currently a PhD candidate at Stanford working in Dr. Page Chamberlain’s terrestrial paleoclimate group. My research focuses on changes in climate, topography and vegetation over the last 65 million years in western North America and central Asia. Our group produces these paleoclimate records by collecting minerals in sedimentary rocks and analyzing their isotopic composition, which reflects the climatic conditions from the time of their formation. These records are our essential to our understanding of Earth system history, climate dynamics, and provide context for modern anthropogenic climate change. In particular, my research examines, hot, high-CO₂ times in the past. Current global temperatures and atmospheric CO₂ concentrations are higher than any point in the past several million years, and the most recent analogs for the coming decades are tens of millions of years ago.

Here’s a San Francisco Chronicle article profiling this work.

 

Read at your peril: Here’s some more on my current projects:

Cenozoic climatic and topographic evolution of western North America

Topowave

Oxygen and hydrogen isotope records from calcium carbonate, smectite and other minerals provide critical constraints to changes in the hydrologic cycle. As a portion of my PhD research, I have both compiled published records and produced my own to improve understanding of topographic evolution and climate change in Cenozoic western North America. I am also involved in an isotope-tracking general circulation modeling of the uplift of the North American Cordillera with researchers at the University of Michigan. I have contributed to several paleoaltimetry and paleoclimate publications:

Chamberlain, C.P., Mix, H.T., Mulch, A., Hren, M.T., Kent-Corson, M.L., Davis, S.J., Horton, T.W., Graham, S.A. (2012) The Cenozoic Climatic and Topographic Evolution of the Western North American Cordillera. American Journal of Science.

Mix, H.T., Mulch, A., Kent-Corson, M.L., Chamberlain, C.P. (2011). Cenozoic migration of topography in the North American Cordillera. Geology, v. 39, p. 87-90. PDF

Davis, S.J., Mix, H.T., Wiegand, B.A., Carroll, A.R. and Chamberlain, C.P. (2009) Synorogenic evolution of large-scale drainage patterns: Isotope paleohydrology of sequential Laramide basins. American Journal of Science, v. 309, p. 549-602. PDF

Interactions between Neogene grassland expansion and climatic evolution

Grassland

Evapotranspiration is one of the most significant inputs in the terrestrial hydrologic budget.  ET rates, however, vary greatly between vegetation types. Paleoenvironmental changes, such as the rise of grass-dominated ecosystems during the Neogene, would dramatically affect vapor recycling and ultimately drive changes in the hydrologic regime. I am applying several techniques to examining the relationship between changes in vegetation cover and concurrent climate change: 1) Stable isotopic paleoclimate records from sedimentary basins around the world. 2) Simple moisture transport models to assess the isotopic effects of changing vegetation. 3) Isotope-tracking general circulation modeling with Dr. Chris Poulsen’s group at the University of Michigan to improve our understanding of these interactions between the biosphere and the climate system.

Water isotope records of hydrologic change and paleotemperature from smectite in Cenozoic western North America

I have produced oxygen and hydrogen isotope records from several Neogene basins in the Basin and Range, Rocky Mountains and Great Plains. With both δ18O and δD, it is possible to reconstruct the ancient local meteoric water line, which can constrain and distinguish between changes in moisture source, evaporation, and temperature.

Cenozoic paleoclimate of central Asia and topographic development of the Hangay Dome, Mongolia

Our group is involved with an interdisciplinary research project in Mongolia. We are producing stable isotope records from several Cenozoic basins in southern, central and western Mongolia. I will return to Mongolia this summer for our second field season.

Science Communication and Outreach

I am passionate about communicating climate science, particularly the perspective of modern climate change that paleoclimatology provides, to K-12 students, teachers and the public. I have taught climate science through the Geoscape Bay Area Teacher Professional Development Project and the NASA-Stanford Climate Change Education Project.

One thought on “Research

  1. Vojtech Holubec

    Hi Hari,
    while googling possible sources climatic maps of Tien Shan I came to your site and pictures of Khan Tengri. I wonder if you can help me. I need to make simplified maps of TS climate – precipitation, temperatures, and geology for my future book on Tien Shan flowers.
    Maybe I would welcome 1 or 2 pictures of Khan Tengri from Chapaev if you are willing to share.
    We published a book The Caucasus and its flowers in 2006.
    Best wishes
    Vojtech

    Reply

Leave a Reply

Your email address will not be published.