CAREER: CLUMPMAP - Glacial Climate from Clumped Isotope Thermometry

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As a scientist and educator, the PI's lifelong career goals are to (i) develop, calibrate, and apply geochemical tools for use in paleoclimate, and better understand the diagenetic processes that can overprint proxies, (ii) improve public awareness of climate change, and the basic and social relevance of the geosciences, (iii) enhance diversity in the geosciences, and (iv) establish and maintain a leading paleoclimate program. This project seeks to further all of these objectives with an innovative program that capitalizes on her experience with one of the most exciting new tools in geology: "clumped" isotopes. Specifically the project will (i) reconstruct terrestrial climates during the Last Glacial Maximum (LGM; ~23,000-19,000 years ago), and (ii) work to educate, recruit, and retain a diverse population to the geosciences.Intellectual Merit: The project builds on the PI's recent work and describes a program termed CLUMPMAP that uses sedimentary archives to study LGM environmental change and promotes diversity in the geosciences. Changes in temperature from the LGM to recent have been studied to constrain how climate can respond to relative well-constrained forcings and as a result geologic data from LGM deposits provides valuable benchmarks for climate models. Over the next five years, the team will apply clumped isotope thermometry to carbonates and study LGM paleoclimate. This powerful new geothermometer uses the latest technology in gas-source mass spectrometry and is based on measuring the temperature-dependent 'clumping of 13C and 18O bonds in carbonate minerals. Temperature estimates also allow us to unravel the longstanding Gordian knot of carbonate 18O/16O (d18O) signatures and isolate fluid d18O. Reconstructions will be compared to climate model simulations in a manner analogous to what the PI has previously done in published studies. Thus results will provide insights into past climate variations and the processes driving them, and will be used to test the accuracy of physical representations of climate in models. Hypotheses from her recent work will be tested, focusing on role of tropospheric structure and planetary-scale atmospheric dynamics in determining the sensitivity of tropical and monsoonal climates to LGM forcings. An important aspect of this work will be assessing the reliability of model predictions of climate states that are substantially different than present.Broader impacts include: 1. Supporting the PI in expanding an integrated program of research and education, developing CLUMPMAP into a community effort and resource; 2. furthering the training and educational/career development of student and early career scientists from under-represented groups, strengthening their qualifications to continue on in higher education; 3. providing these groups with resources to conduct research with a cutting-edge technique; 4. engaging and training early career scientists and students in outreach; 5. enhancing the recruitment and retention of bright people from diverse backgrounds through the provision of role models and mentorship; 6. advancing knowledge and appreciation of geosciences amongst young people, their parents, and their teachers; 7. establishing more role models that can and should improve the present culture for under-represented groups in many institutions; 8. furthering scientific understanding of deep-time (pre-Holocene) Earth systems in areas that are relevant to improving climate models; 9. developing new collaborations with international experts and promoting the engagement and training of U.S. students and junior researchers in research, through fieldwork and collaborative visits; 10. support of a NSF- and state-funded analytical facility the PI has built; and 11. facilitating the dissemination of this technique in the fields of sedimentary geology and paleoclimate.