Link to the University of Pittsburgh Homepage
Link to the University Library System Homepage Link to the Contact Us Form

QUANTITATIVE DROUGHT RECONSTRUCTION IN THE PACIFIC NORTHWEST FROM LAKE SEDIMENT RECORDS AND PREDICTIVE MODELS

Steinman, Byron Anthony (2011) QUANTITATIVE DROUGHT RECONSTRUCTION IN THE PACIFIC NORTHWEST FROM LAKE SEDIMENT RECORDS AND PREDICTIVE MODELS. Doctoral Dissertation, University of Pittsburgh. (Unpublished)

[img]
Preview
PDF
Primary Text

Download (12MB) | Preview

Abstract

Water resources in the American west are under mounting stress due to increasing demand, receding glaciers, and diminishing winter snowpack amounts. By understanding past aridity patterns, we can improve the ability of global climate models to predict regional hydroclimatic conditions in the coming decades and centuries. Such forecasting is critical to the development of sound water allocation policies. To produce accurate forecasts, global climate models rely on paleo-proxy evidence to constrain climate parameters that govern, for example, important potential changes in the El Niño Southern Oscillation and its associated impacts on extratropical precipitation and drought patterns in response to future anthropogenic climate forcing. Lake sediment oxygen isotope records are one such form of paleo-proxy evidence, providing valuable information about past climatic conditions on time scales ranging from years to millennia. Here a numerical lake-catchment model defined by a system of twelve ordinary differential equations is developed and used to describe the physical processes controlling lake-catchment hydrology and oxygen isotope dynamics. This model is applied to Castor Lake and Scanlon Lake, central Washington, and used to conduct simulations designed to characterize lake hydrologic and isotopic responses to mean state and stochastic hydroclimatic variability. Ultimately, the Castor Lake sediment oxygen isotope record is interpreted using an ensemble of Monte Carlo lake model simulations to produce a probabilistic, quantitative reconstruction of precipitation amounts over the past 1500 years. This reconstruction indicates that the Medieval Climate Anomaly (MCA) (950-1250 BP) was a relatively wet period and that the Little Ice Age (LIA) (1450-1850 BP) was relatively dry, suggesting that the MCA was characterized by a La Niña like state of the tropical Pacific and the LIA was characterized by El Niño like conditions. These results are the first quantitative, probabilistic estimate of paleo-precipitation using lake sediment oxygen isotope records from the interior Pacific Northwest, and will provide a resource for the parameterization of climate models designed to investigate future Pacific Ocean responses to anthropogenic forcing and the associated influence on aridity patterns in the American west.


Share

Citation/Export:
Social Networking:
Share |

Details

Item Type: University of Pittsburgh ETD
Status: Unpublished
Creators/Authors:
CreatorsEmailPitt UsernameORCID
Steinman, Byron Anthonybas68@pitt.edubas68@pitt.edu
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairAbbott, Mark Bmabbott1@pitt.edumabbott1@pitt.edu
Committee MemberBain, Daniel Jdbain@pitt.edudbain@pitt.edu
Committee MemberRosenmeier, Michael Fmrosenme@pitt.edumrosenme@pitt.edu
Committee MemberLevine, Staceysel@mathcs.duq.edusel@mathcs.duq.edu
Committee MemberHarbert, WilliamHARBERT@pitt.eduHARBERT@pitt.edu
Date: 30 June 2011
Date Type: Completion
Defense Date: 1 April 2011
Approval Date: 30 June 2011
Submission Date: 21 April 2011
Access Restriction: 5 year -- Restrict access to University of Pittsburgh for a period of 5 years.
Institution: University of Pittsburgh
Schools and Programs: Dietrich School of Arts and Sciences > Geology and Planetary Science
Degree: PhD - Doctor of Philosophy
Thesis Type: Doctoral Dissertation
Refereed: Yes
Uncontrolled Keywords: isotopes; lakes; modeling; Pacific Northwest; paleoclimatology; precipitation
Other ID: http://etd.library.pitt.edu/ETD/available/etd-04212011-202522/, etd-04212011-202522
Date Deposited: 10 Nov 2011 19:40
Last Modified: 30 Jun 2016 05:15
URI: http://d-scholarship.pitt.edu/id/eprint/7465

Metrics

Monthly Views for the past 3 years

Plum Analytics


Actions (login required)

View Item View Item