Climate Research Group








































































































Taylor Hughlett

Education
B.S. in Geology, Environmental Option
University of Texas at Arlington, Dec. 2010

Currently enrolled at UTA in the Earth and Environmental Science B.S. to PhD Fast Track program

Awards
2011 - Enhanced Graduate Teaching Award Recipient
2012 – Travel Grant Recipient to the 2012 Community Earth System Modeling Tutorial at the National Center for Atmospheric Research in Boulder, CO

Office: Geoscience, Room 117

My primary area of focus for my Ph.D. research is the Younger Dryas (YD) cooling event, which occurred approximately 12,900 years before present (1). The YD event is considered to be the last event of its kind in the geological record and is famous for its considerably short time span on a geological time scale. The cause of this event is still unknown, though several hypotheses have been issued as probable causes for the event. The most widely accepted involves the input of meltwater discharge from Lake Agassiz via one of three different routes into the Northern Atlantic, brought on by the melting of the Laurentide Ice Sheet during the Bolling-Allerod event, which occurred just prior to the YD onset (2, 3). This input into the Northern Atlantic causes a decrease in North Atlantic Deep Water (NADW) formation and shut down of the Atlantic meridional overturning circulation (AMOC). A second theory involves the reduction of the Laurentide Ice Sheet, which allows for changes in atmospheric circulation. This causes an increased amount of precipitation to fall over the Northern Atlantic, inducing the same reduction of oceanic circulation (4). Currently, this theory has only been applied to a present day climate. A third popular hypothesis involves the impact of an Extra-Terrestrial object, presumably onto the Laurentide Ice Sheet, which allowed for a sudden pulse of melt water into the Northern Atlantic (5, 6). This theory was debunked quickly after it was proposed (7), but an independent study revealed that it is in fact a viable theory and all evidence reported in the initial study is present (8). Using the National Center for Atmospheric Research’s Community Climate System Model version 3.0 (NCAR CCSM3), I plan to investigate (i) the effects of the implementation of a carbon cycle model (OCMIP-2) into a previous simulation by Feng He (9) by comparing stable carbon isotope tracers provided as output from the model with those observed from the Greenland Ice Sheet Project (GISP) ice core data, (ii) the effects of varying the amount of melt water discharged into the North Atlantic, the orbital parameters and the amount of greenhouse gases in the atmosphere on the YD climate, and (iii) whether the reduction of ice sheets could lead to an increased amount of precipitation over the Northern Atlantic given a YD climate. By investigating the Younger Dryas, I hope to gain a better understanding of oceanic and atmospheric circulation processes, as well as come to a conclusion of a possible future climate scenario for the Earth. With the increasing temperatures of the Earth due to the anthropogenic input of greenhouse gases (10), the melting of the Greenland Ice Sheet is becoming a real and present threat. Should the melt water discharge into the Northern Atlantic, it could be possible that we could see another event similar to the Younger Dryas in the future.

Literature

  1. 1. Bakke, J, Lie, Ø, Heegaard, E, et al. (2009). Rapid oceanic and atmospheric changes during the Younger Dryas cold period. Nature Geoscience 2(3):202-205.
  2. Broecker, WS., et al. (1989). Routing of Meltwater from the Laurentide Ice Sheet During the Younger Dryas Cold Episode. Nature 341: 318-321.
  3. Liu, Z, Otto-Bliesner, BL, He, F, et al. (2009). Transient simulation of last deglaciation with a new mechanism for Bolling-Allerod warming. Science (New York, N.Y.) 325(5938):310-4.
  4. Eisenman, I, Bitz, C, Tziperman, E. (2009). Rain driven by receding ice sheets as a cause of past climate change. Paleoceanography 24(4):1-12.
  5. Firestone, RB, West, A, Kennett, JP, et al. (2007) Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling. Proceedings of the National Academy of Sciences of the United States of America 104(41):16016-21.
  6. Kennett, DJ, Kennett, JP, West, A, et al. (2009). Nanodiamonds in the Younger Dryas boundary sediment layer. Science (New York, N.Y.) 323(5910):94.
  7. Surovell, TA, Holliday, VT, Gingerich, J, et al. (2009). An independent evaluation of the Younger Dryas extraterrestrial impact hypothesis. Proceedings of the National Academy of Sciences of the United States of America 106(43):18155-8.
  8. LeCompte, MA, Goodyear, AC, Demitroff, MN, et al. (2012). Independent evaluation of conflicting microspherules results from different investigations of the Younger Dryas impact hypothesis. Proceedings of the National Academy of Sciences of the United States of America. 1-10.
  9. He, F. (2011). Simulating Transient Climate Evolution of the Last Deglaciation with CCSM3. University of Wisconsin – Madison. 1-185.
  10. Cox, P.M., Bettis, R.A., Jones, C.D., Spall, S.A., Totterdell, I.J. (2000). Acceleration of global warming due to carbon-cycle feedbacks in a coupled climate model. Nature. 408: 184-187.

Memberships

  • Golden Key International Honor Society
  • Sigma Gamma Epsilon, Geology Honor Society
  • American Meteorological Society (AMS)
  • Geological Society of America (GSA)
  • American Association of Petroleum Geologists (AAPG)
  • American Geophysical Union (AGU)

Activities

  • April 2013 – Poster presentation at the Geological Society of America South-Central Sectional Meeting in Austin, TX (GSA)
  • March 2013 – Oral Presentation at the Annual Celebration of Excellence by Students Symposium (ACES; UTA)
  • July 2012 – Attended the 2012 Community Earth System Modeling Tutorial Workshop at the National Center for Atmospheric Research in Boulder, CO
  • April 2012 – Presented at the Earth Day Speaker Event (UTA)