Distributed energy balance modeling of South Cascade Glacier, Washington and assessment of model uncertainty
Faron S. Anslow, S. Hostetler, W. R. Bidlake, P.U. Clark
2008, Journal of Geophysical Research F: Earth Surface (113)
We have developed a physically based, distributed surface energy balance model to simulate glacier mass balance under meteorological and climatological forcing. Here we apply the model to estimate summer ablation on South Cascade Glacier, Washington, for the 2004 and 2005 mass balance seasons. To arrive at optimal mass balance simulations,...
Surface albedo observations at Gusev Crater and Meridiani Planum, Mars
J.F. Bell III, M.S. Rice, J. R. Johnson, T.M. Hare
2008, Journal of Geophysical Research E: Planets (113)
During the Mars Exploration Rover mission, the Pancam instrument has periodically acquired large-scale panoramic images with its broadband (739??338 nm) filter in order to estimate the Lambert bolometric albedo of the surface along each rover's traverse. In this work we present the full suite of such estimated albedo values measured...
Structure, stratigraphy, and origin of Husband Hill, Columbia Hills, Gusev Crater, Mars
T.J. McCoy, M. Sims, M.E. Schmidt, L. Edwards, L.L. Tornabene, L.S. Crumpler, B. A. Cohen, L.A. Soderblom, D.L. Blaney, S. W. Squyres, R. E. Arvidson, J.W. Rica, E. Treguier, C. d’Uston, J. A. Grant, H.Y. McSween, M.P. Golombek, A. F. C. Haldemann, P.A. de Souza
2008, Journal of Geophysical Research E: Planets (113)
The strike and dip of lithologic units imaged in stereo by the Spirit rover in the Columbia Hills using three-dimensional imaging software shows that measured dips (15-32??) for bedding on the main edifice of the Columbia Hill are steeper than local topography (???8-10??). Outcrops measured on West Spur are conformable...
Population size and relative abundance of adult Alabama shad reaching jim woodruff lock and dam, Apalachicola River, Florida
Patrick C. Ely, S.P. Young, J. Jeffery Isely
2008, North American Journal of Fisheries Management (28) 827-831
We estimated the population size of migrating Alabama shad Alosa alabamae below Jim Woodruff Lock and Dam in the Apalachicola River (located in the central panhandle of northwestern Florida) using mark-recapture and relative abundance techniques. After adjustment for tag loss, emigration, and mortality, the population size was estimated as 25,935...
Satellite-derived aerosol radiative forcing from the 2004 British Columbia wildfires
Song Guo, H. Leighton
2008, Atmosphere - Ocean (46) 203-212
The British Columbia wildfires of 2004 was one of the largest wildfire events in the last ten years in Canada. Both the shortwave and longwave smoke aerosol radiative forcing at the top-of-atmosphere (TOA) are investigated using data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Clouds and the Earth's...
Simulated ground motion in Santa Clara Valley, California, and vicinity from M≥6.7 scenario earthquakes
Stephen C. Harmsen, Stephen H. Hartzell
2008, Bulletin of the Seismological Society of America (98) 1243-1271
Models of the Santa Clara Valley (SCV) 3D velocity structure and 3D finite-difference software are used to predict ground motions from scenario earthquakes on the San Andreas (SAF), Monte Vista/Shannon, South Hayward, and Calaveras faults. Twenty different scenario ruptures are considered that explore different source models with alternative hypocenters, fault...
Low reservoir ages for the surface ocean from mid-Holocene Florida corals
E.R.M. Druffel, L.F. Robinson, S. Griffin, R. B. Halley, J. R. Southon, J.F. Adkins
2008, Paleoceanography (23)
The 14C reservoir age of the surface ocean was determined for two Holocene periods (4908-4955 and 3008-3066 calendar (cal) B.P.) using U/Th-dated corals from Biscayne National Park, Florida, United States. We found that the average reservoir ages for these two time periods (294 ?? 33 and 291 ?? 27 years,...
Evaluating the effects of historical land cover change on summertime weather and climate in New Jersey: Land cover and surface energy budget changes
P. S. Wichansky, L. T. Steyaert, R. L. Walko, C. P. Waever
2008, Journal of Geophysical Research-Atmospheres (113)
The 19th-century agrarian landscape of New Jersey (NJ) and the surrounding region has been extensively transformed to the present-day land cover by urbanization, reforestation, and localized areas of deforestation. This study used a mesoscale atmospheric numerical model to investigate the sensitivity of the warm season climate of NJ to these...
Anticorrelated seismic velocity anomalies from post-perovskite in the lowermost mantle
Alexander R. Hutko, T. Lay, Justin Revenaugh, E.J. Garnero
2008, Science (320) 1070-1074
Earth's lowermost mantle has thermal, chemical, and mineralogical complexities that require precise seismological characterization. Stacking, migration, and modeling of over 10,000 P and S waves that traverse the deep mantle under the Cocos plate resolve structures above the core-mantle boundary. A small -0.07 ?? 0.15% decrease of P wave velocity...
Method for estimating spatially variable seepage loss and hydraulic conductivity in intermittent and ephemeral streams
R.G. Niswonger, David E. Prudic, G.E. Fogg, David A. Stonestrom, E.M. Buckland
2008, Water Resources Research (44)
A method is presented for estimating seepage loss and streambed hydraulic conductivity along intermittent and ephemeral streams using streamflow front velocities in initially dry channels. The method uses the kinematic wave equation for routing streamflow in channels coupled to Philip's equation for infiltration. The coupled model considers variations in seepage...
Rock magnetic characterization of faulted sediments with associated magnetic anomalies in the Albuquerque Basin, Rio Grande rift, New Mexico
M.R. Hudson, V. J. S. Grauch, S.A. Minor
2008, Geological Society of America Bulletin (120) 641-658
Variations in rock magnetic properties are responsible for the many linear, short-wavelength, low-amplitude magnetic anomalies that are spatially associated with faults that cut Neogene basin sediments in the Rio Grande rift, including the San Ysidro normal fault, which is well exposed in the northern part of the Albuquerque Basin. Magnetic-susceptibility...
Paleoclimatic significance of chemical weathering in loess-derived paleosols of subarctic central Alaska
D.R. Muhs, T. A. Ager, G. Skipp, J. Beann, J. Budahn, J. P. McGeehin
2008, Arctic, Antarctic, and Alpine Research (40) 396-411
Chemical weathering in soils has not been studied extensively in high-latitude regions. Loess sequences with modern soils and paleosols are present in much of subarctic Alaska, and allow an assessment of present and past chemical weathering. Five sections were studied in detail in the Fairbanks, Alaska, area. Paleosols likely date...
Using bioenergetics modeling to estimate consumption of native juvenile salmonids by nonnative northern pike in the Upper Flathead River System, Montana
C.C. Muhlfeld, D.H. Bennett, Steinhorst R. Kirk, B. Marotz, M. Boyer
2008, North American Journal of Fisheries Management (28) 636-648
Introductions of nonnative northern pike Esox lucius have created recreational fisheries in many waters in the United States and Canada, yet many studies have shown that introduced northern pike may alter the composition and structure of fish communities through predation. We estimated the abundance of nonnative northern pike (2002-2003) and...
Flow unit modeling and fine-scale predicted permeability validation in Atokan sandstones: Norcan East Kansas
S. Bhattacharya, A.P. Byrnes, W.L. Watney, J.H. Doveton
2008, American Association of Petroleum Geologists Bulletin (92) 709-732
Characterizing the reservoir interval into flow units is an effective way to subdivide the net-pay zone into layers for reservoir simulation. Commonly used flow unit identification techniques require a reliable estimate of permeability in the net pay on a foot-by-foot basis. Most of the wells do not have cores, and...
Use of landsat ETM+ SLC-off segment-based gap-filled imagery for crop type mapping
S.K. Maxwell, M.E. Craig
2008, Geocarto International (23) 169-179
Failure of the Scan Line Corrector (SLC) on the Landsat ETM+ sensor has had a major impact on many applications that rely on continuous medium resolution imagery to meet their objectives. The United States Department of Agriculture (USDA) Cropland Data Layer (CDL) program uses Landsat imagery as the primary source...
Analytical and numerical analyses of an unconfined aquifer test considering unsaturated zone characteristics
A.F. Moench
2008, Water Resources Research (44)
A 7-d, constant rate aquifer test conducted by University of Waterloo researchers at Canadian Forces Base Borden in Ontario, Canada, is useful for advancing understanding of fluid flow processes in response to pumping from an unconfined aquifer. Measured data include not only drawdown in the saturated zone but also volumetric...
Induced dynamic nonlinear ground response at Gamer Valley, California
Z. Lawrence, P. Bodin, C.A. Langston, F. Pearce, J. Gomberg, P.A. Johnson, F.-Y. Menq, T. Brackman
2008, Bulletin of the Seismological Society of America (98) 1412-1428
We present results from a prototype experiment in which we actively induce, observe, and quantify in situ nonlinear sediment response in the near surface. This experiment was part of a suite of experiments conducted during August 2004 in Garner Valley, California, using a large mobile shaker truck from the Network...
A reference data set of hillslope rainfall-runoff response, Panola Mountain Research Watershed, United States
Meerveld H. J. Tromp-van H. J., A.L. James, Jeffery J. McDonnell, N.E. Peters
2008, Water Resources Research (44)
Although many hillslope hydrologic investigations have been conducted in different climate, topographic, and geologic settings, subsurface stormflow remains a poorly characterized runoff process. Few, if any, of the existing data sets from these hillslope investigations are available for use by the scientific community for model development and validation or conceptualization...
The formation conditions of chondrules and chondrites
C. M. O’D. Alexander, Jeffrey N. Grossman, D.S. Ebel, F.J. Ciesla
2008, Science (320) 1617-1619
Chondrules, which are roughly millimeter-sized silicate-rich spherules, dominate the most primitive meteorites, the chondrites. They formed as molten droplets and, judging from their abundances in chondrites, are the products of one of the most energetic processes that operated in the early inner solar system. The conditions and mechanism of chondrule...
MGS-TES thermal inertia study of the Arsia Mons Caldera
Glen E. Cushing, Timothy N. Titus
2008, Journal of Geophysical Research E: Planets (113)
Temperatures of the Arsia Mons caldera floor and two nearby control areas were obtained by the Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES). These observations revealed that the Arsia Mons caldera floor exhibits thermal behavior different from the surrounding Tharsis region when compared with thermal models. Our technique compares...
Mars Exploration Rover Navigation Camera in-flight calibration
J.M. Soderblom, J.F. Bell III, J. R. Johnson, J. Joseph, M.J. Wolff
2008, Journal of Geophysical Research E: Planets (113)
The Navigation Camera (Navcam) instruments on the Mars Exploration Rover (MER) spacecraft provide support for both tactical operations as well as scientific observations where color information is not necessary: large-scale morphology, atmospheric monitoring including cloud observations and dust devil movies, and context imaging for both the thermal emission spectrometer and...
Diurnal and vertical variability of the sensible heat and carbon dioxide budgets in the atmospheric surface layer
P. Casso-Torralba, J. V. -G. de Arellano, F. Bosveld, M.R. Soler, A. Vermeulen, C. Werner, E. Moors
2008, Journal of Geophysical Research D: Atmospheres (113)
The diurnal and vertical variability of heat and carbon dioxide (CO2) in the atmospheric surface layer are studied by analyzing measurements from a 213 in tower in Cabauw (Netherlands). Observations of thermodynamic variables and CO2 mixing ratio as well as vertical profiles of the turbulent fluxes are used to retrieve...
Deep drilling into the Chesapeake Bay impact structure
G. S. Gohn, C. Koeberl, K.G. Miller, W.U. Reimold, J.V. Browning, C.S. Cockell, J. Wright Horton Jr., T. Kenkmann, A.A. Kulpecz, D.S. Powars, W. E. Sanford, M.A. Voytek
2008, Science (320) 1740-1745
Samples from a 1.76-kilometer-deep corehole drilled near the center of the late Eocene Chesapeake Bay impact structure (Virginia, USA) reveal its geologic, hydrologic, and biologic history. We conducted stratigraphic and petrologic analyses of the cores to elucidate the timing and results of impact-melt creation and distribution, transient-cavity collapse, and ocean-water...
Oceanic loading of wildfire-derived organic compounds from a small mountainous river
G.B. Hunsinger, Siddhartha Mitra, J.A. Warrick, C. R. Alexander
2008, Journal of Geophysical Research G: Biogeosciences (113)
Small mountainous rivers (SMRs) export substantial amounts of sediment into the world's oceans. The concomitant yield of organic carbon (OC) associated with this class of rivers has also been shown to be significant and compositionally unique. We report here excessively high loadings of polycyclic aromatic hydrocarbons (PAHs), lignin, and levoglucosan,...
Microbial and chemical factors influencing methane production in laboratory incubations of low-rank subsurface coals
Stephen H. Harris, Richard L. Smith, Charles E. Barker
2008, International Journal of Coal Geology (76) 46-51
Lignite and subbituminous coals were investigated for their ability to support microbial methane production in laboratory incubations. Results show that naturally-occurring microorganisms associated with the coals produced substantial quantities of methane, although the factors influencing this process were variable among different samples tested. Methanogenic microbes in two coals from the...
