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Coast Guard Polar Icebreaker Modernization: Background and Issues for Congress

Description: This report provides background information and issues for Congress on the sustainment and modernization of the Coast Guard's polar icebreaker fleet. The Coast Guard's proposed FY2018 budget requests $19 million in acquisition funding for a new polar icebreaker that the Coast Guard wants to begin building in FY2019.
Date: September 14, 2017
Creator: O'Rourke, Ronald
Partner: UNT Libraries Government Documents Department

The polar regions and the USGCRP

Description: The US Global Change Research Program provides interagency coordination for the ten federal agencies supporting research on global environmental change. Program activities are described annually in Our Changing Planet, which is a report submitted to Congress each year in support of the President`s budget request. The USGCRP also periodically prepares a multiyear research overview (referred to officially as a multiyear research plan even though it is more of a strategy) to provide a framework for organizing research over the next ten years. Consideration of the polar regions is of particular interest in pursuit of the goals of the USGCRP in each of the major environmental issue areas. Especially with the increased emphasis of the USGCRP on the regional aspects of global environmental change and the regional differentiation of consequences for the environment, the polar regions will be receiving intense attention in future research activities.
Date: June 1, 1997
Creator: MacCracken, M. C.,
Partner: UNT Libraries Government Documents Department

Effects of an RTG power source on neutron spectroscopy measurements on the martian surface.

Description: A continuing goal of Mars science is to identify the exact locations of near-surface water and/or hydrated minerals using in situ measurements. Recent data from the Mars Odyssey mission has used both neutron and gamma-ray spectroscopy to measure large amounts of water ice near both polar regions . Furthermore, these data have also determined that in the mid-latitude regions, there likely exist relatively large amounts of hydrogen (-4-7 equivalent H2O wt.%), although it is not certain in which form this hydrogen exists . While these are exciting results, one drawback of these measurements is that they are averaged over a large (-400 km) footp ri nt and do not reflect any small (<1 km) inhomogenieties in hydrogen abundance that likely exist on the Martian surface. For any future in situ mission (e g, Mars Smart Lander (MSL)) that seeks to measure and characterize nearsurface H 2O, especially in the mid-latitude regions, is will be necessary to know th e locati ons of the H20.
Date: January 1, 2003
Creator: Lawrence, David J. (David Jeffery),; Elphic, R. C. (Richard C.) & Wiens, R. C. (Roger C.)
Partner: UNT Libraries Government Documents Department

Climate response to projected changes in short-lived species under an A1B scenario from 2000-2050 in the GISS climate model

Description: We investigate the climate forcing from and response to projected changes in short-lived species and methane under the A1B scenario from 2000-2050 in the GISS climate model. We present a meta-analysis of new simulations of the full evolution of gas and aerosol species and other existing experiments with variations of the same model. The comparison highlights the importance of several physical processes in determining radiative forcing, especially the effect of climate change on stratosphere-troposphere exchange, heterogeneous sulfate-nitrate-dust chemistry, and changes in methane oxidation and natural emissions. However, the impact of these fairly uncertain physical effects is substantially less than the difference between alternative emission scenarios for all short-lived species. The net global mean annual average direct radiative forcing from the short-lived species is .02 W/m{sup 2} or less in our projections, as substantial positive ozone forcing is largely offset by negative aerosol direct forcing. Since aerosol reductions also lead to a reduced indirect effect, the global mean surface temperature warms by {approx}0.07 C by 2030 and {approx}0.13 C by 2050, adding 19% and 17%, respectively, to the warming induced by long-lived greenhouse gases. Regional direct forcings are large, up to 3.8 W/m{sup 2}. The ensemble-mean climate response shows little regional correlation with the spatial pattern of the forcing, however, suggesting that oceanic and atmospheric mixing generally overwhelms the effect of even large localized forcings. Exceptions are the polar regions, where ozone and aerosols may induce substantial seasonal climate changes.
Date: March 26, 2007
Creator: Menon, Surabi; Shindell, Drew T.; Faluvegi, Greg; Bauer, Susanne E.; Koch, Dorothy M.; Unger, Nadine et al.
Partner: UNT Libraries Government Documents Department

Coast Guard Polar Icebreaker Modernization: Background and Issues for Congress

Description: Report that is written in response to the Coast Guard's budget request for a new polar ice breaker, of which the Coast Guard currently has none in operation. Polar icebreakers perform a variety of missions supporting U.S. interests in polar regions. Issues for Congress include what to do with decommissioned ice breakers, the impact of having no ice breakers, how to budget for new ice breakers, and how future ice breakers should be obtained.
Date: July 24, 2013
Creator: O'Rourke, Ronald
Partner: UNT Libraries Government Documents Department

Requirements assessment and operational demands for a resource mapping rover mission to the lunar polar regions

Description: A preliminary set of requirements for a robotic rover mission to the lunar polar region are described and assessed. Tasks to be performed by the rover include core drill sample acquisition, mineral and volatile soil content assay, and significant wide area traversals. Assessment of the postulated requirements is performed using first order estimates of energy, power, and communications throughput issues. Two potential rover system configurations are considered, a smaller rover envisioned as part of a group of multiple rovers, and a larger single rover envisioned along more traditional planetary surface rover concept lines.
Date: January 26, 2000
Creator: KLARER,PAUL R.; BINDER,ALAN B. & LENARD,ROGER X.
Partner: UNT Libraries Government Documents Department

Coast Guard Polar Icebreaker Modernization: Background and Issues for Congress

Description: This report provides background information and issues for Congress on the sustainment and modernization of the Coast Guard's polar icebreaker fleet, which performs a variety of missions supporting U.S. interests in polar regions. The report is written in response to the Coast Guard's budget request for a new polar ice breaker (none are currently in operation).
Date: March 28, 2014
Creator: O'Rourke, Ronald
Partner: UNT Libraries Government Documents Department

Coast Guard Polar Icebreaker Modernization: Background and Issues for Congress

Description: This report provides background information and issues for Congress on the sustainment and modernization of the Coast Guard's polar icebreaker fleet, which performs a variety of missions supporting U.S. interests in polar regions. The report is written in response to the Coast Guard's budget request for a new polar ice breaker (none are currently in operation).
Date: February 11, 2014
Creator: O'Rourke, Ronald
Partner: UNT Libraries Government Documents Department

Bacteria in Permafrost

Description: Significant numbers of viable ancient microorganisms are known to be present within the permafrost. They have been isolated in both polar regions from the cores up to 400 m deep and ground temperatures of -27 C. The age of the cells corresponds to the longevity of the permanently frozen state of the soils, with the oldest cells dating back to {approx}3 million years in the Arctic, and {approx}5 million years in the Antarctic. They are the only life forms known to have retained viability over geological time. Thawing of the permafrost renews their physiological activity and exposes ancient life to modern ecosystems. Thus, the permafrost represents a stable and unique physicochemical complex, which maintains life incomparably longer than any other known habitats. If we take into account the depth of the permafrost layers, it is easy to conclude that they contain a total microbial biomass many times higher than that of the soil cover. This great mass of viable matter is peculiar to permafrost only.
Date: January 1, 2008
Creator: Gilichinsky, David A.; Vishnivetskaya, Tatiana A.; Petrova, Maya A.; Spirina, Elena V.; Mamikin, Vladimir & Rivkina, Elizaveta
Partner: UNT Libraries Government Documents Department

[Multifractal cloud properties data assessment]

Description: Our group has been very active over the last year, analyzing a number of data sets to characterize multifractal cloud properties and assess the effects of clouds on surface radiation properties (spectral and broadband). The data sets analyzed include: AVHRR observations of clouds over the ocean, SPOT observations of clouds over the ocean, SSM/I observations of clouds over the ocean, pyranometer data with all-sky photographs, pyrgeometer data all-sky photographs, and spectral surface irradiance all-sky photographs. A number of radiative transfer computations have been performed to help in the interpretation of these observations or provide theoretical guidance for their analysis. Finally 4 number of radiative transfer models have been acquired and tested to prepare for the interpretation of ARM/CART data.
Date: May 6, 1992
Creator: Gautier, C.; Ricchiazzi, P.; Peterson, P.; Lavallee, D. (California Univ., Santa Barbara, CA (United States)); Frouin, R.; Lubin, D. (California Univ., San Diego, CA (United States)) et al.
Partner: UNT Libraries Government Documents Department

Black carbon aerosols and the third polar ice cap

Description: Recent thinning of glaciers over the Himalayas (sometimes referred to as the third polar region) have raised concern on future water supplies since these glaciers supply water to large river systems that support millions of people inhabiting the surrounding areas. Black carbon (BC) aerosols, released from incomplete combustion, have been increasingly implicated as causing large changes in the hydrology and radiative forcing over Asia and its deposition on snow is thought to increase snow melt. In India BC emissions from biofuel combustion is highly prevalent and compared to other regions, BC aerosol amounts are high. Here, we quantify the impact of BC aerosols on snow cover and precipitation from 1990 to 2010 over the Indian subcontinental region using two different BC emission inventories. New estimates indicate that Indian BC emissions from coal and biofuel are large and transport is expected to expand rapidly in coming years. We show that over the Himalayas, from 1990 to 2000, simulated snow/ice cover decreases by {approx}0.9% due to aerosols. The contribution of the enhanced Indian BC to this decline is {approx}36%, similar to that simulated for 2000 to 2010. Spatial patterns of modeled changes in snow cover and precipitation are similar to observations (from 1990 to 2000), and are mainly obtained with the newer BC estimates.
Date: April 15, 2010
Creator: Menon, Surabi; Koch, Dorothy; Beig, Gufran; Sahu, Saroj; Fasullo, John & Orlikowski, Daniel
Partner: UNT Libraries Government Documents Department

WET MARS: plentiful, readily-available martian water and its implications

Description: Water and its major constituent, oxygen, in large specific quantities are essential for maintenance of human life. Providing them in adequate quantities is widely believed to be a major challenge for human Mars exploration and settlement. The Martian regolith isn't known to bear either water or hydrogen, the ice-rich Martian polar regions are thermally inhospitable, and the measured water content of Mars' thin atmosphere represents a layer of liquid water of average thickness only about 1% that of the Moon: {approximately}0.001 cm. Crucially, however, the atmospheric Martian water inventory is advected to everyplace on Mars by meteorological phenomena, so that the few cubic kilometers of liquid water-equivalent in the atmosphere are available most anywhere when, merely for the effort of condensing it. Well-engineered apparatus deployed essentially anywhere on Mars can condense water from the atmosphere in daily quantities not much smaller than its own mass, rejecting into space from radiators deployed over the local terrain the water's heat-of-condensation and the heat from non-ideality of the equipment's operation. Thus, an optimized, photovoltaically-powered 0.3 ton water-condensing system could strip 40 tons of water each year from {approximately}10{sup 4} times this mass of thin, dry Martian air. Given a 480 set I{sub sp} of H{sub 2}-O{sub 2} propulsion systems exhausting into the 6 millibar Mars-surface atmosphere and the 5.0 km/s Martian gravity well, {ge}40 tons of water two-thirds converted into 5:1 O{sub 2}/H{sub 2} cryogenic fuel could support exploration and loft a crew-of-four and their 8-ton ascent vehicle into Earth-return trajectory. The remaining water and excess oxygen would suffice for half-open-cycle life support for a year's stay on Mars. A Mars Expedition thus needs to land only explorers, dehydrated food, habitation gear and unfueled exploration I Earth-return equipment - and a water/oxygen/fuel plant with embedded power supply which operates on Martian atmospheric water. ...
Date: August 12, 1999
Creator: Hyde, R; Ishikawa, M; Nuckolls, J; Whitehead, J & Wood, L
Partner: UNT Libraries Government Documents Department

Coast Guard Polar Icebreaker Modernization: Background, Issues, and Options for Congress

Description: Coast Guard polar icebreakers perform a variety of missions supporting U.S. interests in polar regions. The Coast Guard's two heavy polar icebreakers - Polar Star and Polar Sea - have exceeded their intended 30-year service lives. Following a decision to design and build one or more new polar icebreakers, the first replacement polar icebreaker might enter service in eight to 10 years, by which time Polar Star and Polar Sea could be more than 40 years old. The issue for Congress is whether to approve, reject, or modify Coast Guard plans for modernizing its polar icebreakers. Congressional decisions on this issue could affect the Coast Guard's ability to perform its polar missions, Coast Guard funding requirements, and the U.S. shipbuilding industrial base.
Date: September 29, 2010
Creator: O'Rourke, Ronald
Partner: UNT Libraries Government Documents Department