Steven Hostetler, Ph.D. (Former Employee)
Science and Products
Filter Total Items: 82
Ages, distributions, and origins of upland coastal dune sheets in Oregon, USA
A total of ten upland dune sheets, totaling 245??km in combined length, have been investigated for their origin(s) along the Oregon coast (500??km in length). The ages of dune emplacement range from 0.1 to 103??ka based on radiocarbon (36 samples) and luminescence (46 samples) dating techniques. The majority of the emplacement dates fall into two periods of late-Pleistocene age (11-103??ka) and mi
Authors
C. D. Peterson, E. Stock, D.M. Price, R. Hart, F. Reckendorf, J.M. Erlandson, S. W. Hostetler
Large fluctuations of dissolved oxygen in the Indian and Pacific oceans during Dansgaard-Oeschger oscillations caused by variations of North Atlantic Deep Water subduction
Paleoclimate records from glacial Indian and Pacific oceans sediments document millennial-scale fluctuations of subsurface dissolved oxygen levels and denitrification coherent with North Atlantic temperature oscillations. Yet the mechanism of this teleconnection between the remote ocean basins remains elusive. Here we present model simulations of the oxygen and nitrogen cycles that explain how cha
Authors
A. Schmittner, E.D. Galbraith, S. W. Hostetler, Thomas F. Pedersen, R. Zhang
Atlas of climatic controls of wildfire in the western United States
Wildfire behavior depends on several factors including ecologic characteristics, near-term and antecedent climatic conditions,fuel availability and moisture level, weather, and sources of ignition (lightning or human). The variability and interplay of these factors over many spatial and temporal scales present an ongoing challenge to our ability to forecast a given wildfire season. Here we focus o
Authors
S. W. Hostetler, P. J. Bartlein, J.O. Holman
Radiolaria and pollen records from 0 to 50 ka at ODP Site 1233: Continental and marine climate records from the Southeast Pacific
Site 1233 drilled during Leg 202 of the Ocean Drilling Program provides a detailed record of marine and continental climate change in the Southeast Pacific and South American continent. Splits from over 500 samples taken at 20 cm intervals for quantitative analysis of radiolarian and pollen populations yield a temporal resolution of 200-400 years. In each sample, 39 pollen taxa and 40 radiolarian
Authors
N. G. Pisias, L. Heusser, C. Heusser, S. W. Hostetler, A.C. Mix, M. Weber
Sensitivity of Last Glacial Maximum climate to uncertainties in tropical and subtropical ocean temperatures
The faunal and floral gradients that underlie the CLIMAP (1981) sea-surface temperature (SST) reconstructions for the Last Glacial Maximum (LGM) reflect ocean temperature gradients and frontal positions. The transfer functions used to reconstruct SSTs from biologic gradients are biased, however, because at the warmest sites they display inherently low sensitivity in translating fauna to SST and th
Authors
S. Hostetler, N. Pisias, A. Mix
Modeling paleoclimates
Paleoclimatic data and climate models play a complimentary role in understanding climate change. This chapter provides an overview of the process of climate-system modeling, presents the taxonomy of the models recently applied in the study of Quaternary climate change and variation, and discusses the development of climate modeling since the 1965 International Union for Quaternary Science (INQUA)
Authors
Patrick J Bartlein, Steven W. Hostetler
Coupling ice-sheet and climate models for simulation of former ice sheets
This chapter explores the development of coupled climate and ice-sheet models over the past two decades, discusses the current technical and physical capabilities of models, and identifies future work for developing a better understanding of ice-climate events that have punctuated Earth history. The chapter also illustrates the complex behavior of the climate system and the modeling challenges pos
Authors
Shawn J. Marshall, David Pollard, Steven W. Hostetler, Peter U. Clark
Freshwater forcing of abrupt climate change during the last glaciation
Large millennial-scale fluctuations of the southern margin of the North American Laurentide Ice Sheet occurred during the last deglaciation, when the margin was located between about 43° and 49°N. Fluctuations of the ice margin triggered episodic increases in the flux of freshwater to the North Atlantic by rerouting continental runoff from the Mississippi River drainage to the Hudson or St. Lawren
Authors
Peter U. Clark, Shawn J. Marshall, Garry K. C. Clarke, Steven W. Hostetler, Joseph M. Licciardi, James T. Teller
Evaporation from groundwater discharge playas, Estancia Basin, central New Mexico
Bowen ratio meteorological stations have been deployed to measure rates of evaporation from groundwater discharge playas and from an adjacent vegetated bench in the Estancia Basin, in central New Mexico. The playas are remnants of late Pleistocene pluvial Lake Estancia and are discharge areas for groundwater originating as precipitation in the adjacent Manzano Mts. They also accumulate water durin
Authors
Kirsten M. Menking, Roger Y. Anderson, Nathaniel A. Brunsell, Bruce D. Allen, Amy L. Ellwein, Thomas A. Loveland, Steven W. Hostetler
Tropical climate at the last glacial maximum inferred from glacier mass-balance modeling
Model-derived equilibrium line altitudes (ELAs) of former tropical glaciers support arguments, based on other paleoclimate data, for both the magnitude and spatial pattern of terrestrial cooling in the tropics at the last glacial maximum (LGM). Relative to the present, LGM ELAs were maintained by air temperatures that were 3.5??to 6.6 ??C lower and precipitation that ranged from 63% wetter in Hawa
Authors
S. W. Hostetler, P.U. Clark
Simulated influences of Lake Agassiz on the climate of central North America 11,000 years ago
Eleven thousand years ago, large lakes existed in central and eastern North America along the margin of the Laurentide Ice Sheet. The large-scale North American climate at this time has been simulated with atmospheric general circulation models, but these relatively coarse global models do not resolve potentially important features of the mesoscale circulation that arise from interactions among th
Authors
S. W. Hostetler, P. J. Bartlein, P.U. Clark, E.E. Small, A.M. Solomon
Simulation of the potential responses of regional climate and surface processes in western North America to a canonical Heinrich event
No abstract available.
Authors
S. W. Hostetler, P. J. Bartlein
Science and Products
Filter Total Items: 82
Ages, distributions, and origins of upland coastal dune sheets in Oregon, USA
A total of ten upland dune sheets, totaling 245??km in combined length, have been investigated for their origin(s) along the Oregon coast (500??km in length). The ages of dune emplacement range from 0.1 to 103??ka based on radiocarbon (36 samples) and luminescence (46 samples) dating techniques. The majority of the emplacement dates fall into two periods of late-Pleistocene age (11-103??ka) and mi
Authors
C. D. Peterson, E. Stock, D.M. Price, R. Hart, F. Reckendorf, J.M. Erlandson, S. W. Hostetler
Large fluctuations of dissolved oxygen in the Indian and Pacific oceans during Dansgaard-Oeschger oscillations caused by variations of North Atlantic Deep Water subduction
Paleoclimate records from glacial Indian and Pacific oceans sediments document millennial-scale fluctuations of subsurface dissolved oxygen levels and denitrification coherent with North Atlantic temperature oscillations. Yet the mechanism of this teleconnection between the remote ocean basins remains elusive. Here we present model simulations of the oxygen and nitrogen cycles that explain how cha
Authors
A. Schmittner, E.D. Galbraith, S. W. Hostetler, Thomas F. Pedersen, R. Zhang
Atlas of climatic controls of wildfire in the western United States
Wildfire behavior depends on several factors including ecologic characteristics, near-term and antecedent climatic conditions,fuel availability and moisture level, weather, and sources of ignition (lightning or human). The variability and interplay of these factors over many spatial and temporal scales present an ongoing challenge to our ability to forecast a given wildfire season. Here we focus o
Authors
S. W. Hostetler, P. J. Bartlein, J.O. Holman
Radiolaria and pollen records from 0 to 50 ka at ODP Site 1233: Continental and marine climate records from the Southeast Pacific
Site 1233 drilled during Leg 202 of the Ocean Drilling Program provides a detailed record of marine and continental climate change in the Southeast Pacific and South American continent. Splits from over 500 samples taken at 20 cm intervals for quantitative analysis of radiolarian and pollen populations yield a temporal resolution of 200-400 years. In each sample, 39 pollen taxa and 40 radiolarian
Authors
N. G. Pisias, L. Heusser, C. Heusser, S. W. Hostetler, A.C. Mix, M. Weber
Sensitivity of Last Glacial Maximum climate to uncertainties in tropical and subtropical ocean temperatures
The faunal and floral gradients that underlie the CLIMAP (1981) sea-surface temperature (SST) reconstructions for the Last Glacial Maximum (LGM) reflect ocean temperature gradients and frontal positions. The transfer functions used to reconstruct SSTs from biologic gradients are biased, however, because at the warmest sites they display inherently low sensitivity in translating fauna to SST and th
Authors
S. Hostetler, N. Pisias, A. Mix
Modeling paleoclimates
Paleoclimatic data and climate models play a complimentary role in understanding climate change. This chapter provides an overview of the process of climate-system modeling, presents the taxonomy of the models recently applied in the study of Quaternary climate change and variation, and discusses the development of climate modeling since the 1965 International Union for Quaternary Science (INQUA)
Authors
Patrick J Bartlein, Steven W. Hostetler
Coupling ice-sheet and climate models for simulation of former ice sheets
This chapter explores the development of coupled climate and ice-sheet models over the past two decades, discusses the current technical and physical capabilities of models, and identifies future work for developing a better understanding of ice-climate events that have punctuated Earth history. The chapter also illustrates the complex behavior of the climate system and the modeling challenges pos
Authors
Shawn J. Marshall, David Pollard, Steven W. Hostetler, Peter U. Clark
Freshwater forcing of abrupt climate change during the last glaciation
Large millennial-scale fluctuations of the southern margin of the North American Laurentide Ice Sheet occurred during the last deglaciation, when the margin was located between about 43° and 49°N. Fluctuations of the ice margin triggered episodic increases in the flux of freshwater to the North Atlantic by rerouting continental runoff from the Mississippi River drainage to the Hudson or St. Lawren
Authors
Peter U. Clark, Shawn J. Marshall, Garry K. C. Clarke, Steven W. Hostetler, Joseph M. Licciardi, James T. Teller
Evaporation from groundwater discharge playas, Estancia Basin, central New Mexico
Bowen ratio meteorological stations have been deployed to measure rates of evaporation from groundwater discharge playas and from an adjacent vegetated bench in the Estancia Basin, in central New Mexico. The playas are remnants of late Pleistocene pluvial Lake Estancia and are discharge areas for groundwater originating as precipitation in the adjacent Manzano Mts. They also accumulate water durin
Authors
Kirsten M. Menking, Roger Y. Anderson, Nathaniel A. Brunsell, Bruce D. Allen, Amy L. Ellwein, Thomas A. Loveland, Steven W. Hostetler
Tropical climate at the last glacial maximum inferred from glacier mass-balance modeling
Model-derived equilibrium line altitudes (ELAs) of former tropical glaciers support arguments, based on other paleoclimate data, for both the magnitude and spatial pattern of terrestrial cooling in the tropics at the last glacial maximum (LGM). Relative to the present, LGM ELAs were maintained by air temperatures that were 3.5??to 6.6 ??C lower and precipitation that ranged from 63% wetter in Hawa
Authors
S. W. Hostetler, P.U. Clark
Simulated influences of Lake Agassiz on the climate of central North America 11,000 years ago
Eleven thousand years ago, large lakes existed in central and eastern North America along the margin of the Laurentide Ice Sheet. The large-scale North American climate at this time has been simulated with atmospheric general circulation models, but these relatively coarse global models do not resolve potentially important features of the mesoscale circulation that arise from interactions among th
Authors
S. W. Hostetler, P. J. Bartlein, P.U. Clark, E.E. Small, A.M. Solomon
Simulation of the potential responses of regional climate and surface processes in western North America to a canonical Heinrich event
No abstract available.
Authors
S. W. Hostetler, P. J. Bartlein