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Full-Text Articles in Physical Sciences and Mathematics
Trade-Offs Between Three Forest Ecosystem Services Across The State Of New Hampshire, Usa: Timber, Carbon, And Albedo, David A. Lutz, Elizabeth A. Burakowski, Mackenzie B. Murphy, Mark E. Borsuk
Trade-Offs Between Three Forest Ecosystem Services Across The State Of New Hampshire, Usa: Timber, Carbon, And Albedo, David A. Lutz, Elizabeth A. Burakowski, Mackenzie B. Murphy, Mark E. Borsuk
Dartmouth Scholarship
Forests are more frequently being managed to store and sequester carbon for the purposes of climate change mitigation. Generally, this practice involves long-term conservation of intact mature forests and/or reductions in the frequency and intensity of timber harvests. However, incorporating the influence of forest surface albedo often suggests that long rotation lengths may not always be optimal in mitigating climate change in forests characterized by frequent snowfall. To address this, we investigated trade-offs between three ecosystem services: carbon storage, albedo-related radiative forcing, and timber provisioning. We calculated optimal rotation length at 498 diverse Forest Inventory and Analysis forest sites in …
Search For Higgs Shifts In White Dwarfs, Roberto Onofrio, Gary A. Wegner
Search For Higgs Shifts In White Dwarfs, Roberto Onofrio, Gary A. Wegner
Dartmouth Scholarship
We report on a search for differential shifts between electronic and vibronic transitions in carbon-rich white dwarfs BPM 27606 and Procyon B. The absence of differential shifts within the spectral resolution and taking into account systematic effects such as space motion and pressure shifts allows us to set the first upper bound of astrophysical origin on the coupling between the Higgs field and the Kreschmann curvature invariant. Our analysis provides the basis for a more general methodology to derive bounds to the coupling of long-range scalar fields to curvature invariants in an astrophysical setting complementary to the ones available from …
Climate Change And Forest Fires Synergistically Drive Widespread Melt Events Of The Greenland Ice Sheet, Kaitlin M. Keegan, Mary R. Albert, Joseph R. Mcconnell, Ian Baker
Climate Change And Forest Fires Synergistically Drive Widespread Melt Events Of The Greenland Ice Sheet, Kaitlin M. Keegan, Mary R. Albert, Joseph R. Mcconnell, Ian Baker
Dartmouth Scholarship
In July 2012, over 97% of the Greenland Ice Sheet experienced surface melt, the first widespread melt during the era of satellite remote sensing. Analysis of six Greenland shallow firn cores from the dry snow region confirms that the most recent prior widespread melt occurred in 1889. A firn core from the center of the ice sheet demonstrated that exceptionally warm temperatures combined with black carbon sediments from Northern Hemisphere forest fires reduced albedo below a critical threshold in the dry snow region, and caused the melting events in both 1889 and 2012. We use these data to project the …
Variability Of Black Carbon Deposition To The East Antarctic Plateau, 1800-2000 Ad, M. M. Bisiaux, R. Edwards, J. R. Mcconnell, M. R. Albert
Variability Of Black Carbon Deposition To The East Antarctic Plateau, 1800-2000 Ad, M. M. Bisiaux, R. Edwards, J. R. Mcconnell, M. R. Albert
Dartmouth Scholarship
Refractory black carbon aerosols (rBC) from biomass burning and fossil fuel combustion are deposited to the Antarctic ice sheet and preserve a history of emissions and long-range transport from low- and mid-latitudes. Antarctic ice core rBC records may thus provide information with respect to past combustion aerosol emissions and atmospheric circulation. Here, we present six East Antarctic ice core records of rBC concentrations and fluxes covering the last two centuries with approximately annual resolution (cal. yr. 1800 to 2000). The ice cores were drilled in disparate regions of the high East Antarctic ice sheet, at different elevations and net snow …
A Study Of Carbon Features In Type Ia Supernova Spectra, Jerod T. Parrent, R. C. Thomas, Robert A. Fesen, G. H. Marion
A Study Of Carbon Features In Type Ia Supernova Spectra, Jerod T. Parrent, R. C. Thomas, Robert A. Fesen, G. H. Marion
Dartmouth Scholarship
One of the major differences between various explosion scenarios of Type Ia supernovae (SNe Ia) is the remaining amount of unburned (C+O) material and its velocity distribution within the expanding ejecta. While oxygen absorption features are not uncommon in the spectra of SNe Ia before maximum light, the presence of strong carbon absorption has been reported only in a minority of objects, typically during the pre-maximum phase. The reported low frequency of carbon detections may be due to low signal-to-noise data, low abundance of unburned material, line blending between C II 6580 and Si II 6355, ejecta temperature differences, asymmetrical …
Uv Observations Of The Cool Dbqa5 White Dwarf Lds 678a - Limits On The Atmospheric Composition, Pressure Shift, And Gravitational Redshift Derived From C I 2479, Terry D. Oswalt, Edward M. Sion, Gordon Hammond, Gerard Vauclair, James W. Liebert, Gary Wegner
Uv Observations Of The Cool Dbqa5 White Dwarf Lds 678a - Limits On The Atmospheric Composition, Pressure Shift, And Gravitational Redshift Derived From C I 2479, Terry D. Oswalt, Edward M. Sion, Gordon Hammond, Gerard Vauclair, James W. Liebert, Gary Wegner
Dartmouth Scholarship
A high-resolution ultraviolet spectrum of the helium-rich degenerate LDS 678A, obtained with the International Ultraviolet Explorer (IUE) satellite, is presented. LDS 678A is the coolest metallic line degenerate (DQ or DZ) yet observed with the IUE echelle. These observations provide a detailed line profile of the strong C I 2479 absorption line and equivalent width W2479 = 2.35 + or - 0.06 A from which theoretical profile fits yield a carbon abundance of log C/He = (-6.7 + or- 0.2). The presence of carbon in a He-rich atmosphere lends credence to the notion that LDS 678A is a transitional case …