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Nassau Plantation: The evolution of a Texas-German slave plantation

Access: Use of this item is restricted to the UNT Community
In the 1840s an organization of German noblemen, the Mainzner Adelsverein, attempted to settle thousands of German emigrants on the Texas frontier. Nassau Plantation, located near modern-day Round Top, Texas, in northern Fayette County, was a significant part of this story. James C. Kearney has studied a wealth of original source material (much of it in German) to illuminate the history of the plantation and the larger goals and motivation of the Adelsverein. This new study highlights the problematic relationship of German emigrants to slavery. Few today realize that the society’s original colonization plan included ownership and operation of slave plantations. Ironically, the German settlements the society later established became hotbeds of anti-slavery and anti-secessionist sentiment. Several notable personalities graced the plantation, including Carl Prince of Solms-Braunfels, Johann Otto Freiherr von Meusebach, botanist F. Lindheimer, and the renowned naturalist Dr. Ferdinand Roemer. Dramatic events also occurred at the plantation, including a deadly shootout, a successful escape by two slaves (documented in an unprecedented way), and litigation over ownership that wound its way to both the Texas Supreme Court and the U.S. Supreme Court.
Date: March 15, 2010
Creator: Kearney, James C.
Object Type: Book
System: The UNT Digital Library
Defense Acquisitions: Opportunities Exist to Position Army's Ground Force Modernization Efforts for Success (open access)

Defense Acquisitions: Opportunities Exist to Position Army's Ground Force Modernization Efforts for Success

A letter report issued by the Government Accountability Office with an abstract that begins "Since 2003, the Future Combat System (FCS) program has been the centerpiece of the Army's efforts to transition to a lighter, more agile, and more capable combat force. In 2009, however, concerns over the program's performance led to the Secretary of Defense's decision to significantly restructure and ultimately cancel the program. As a result, the Army has outlined a new approach to ground force modernization. This report (1) outlines the Army's preliminary post-FCS plans and (2) identifies the challenges and opportunities the Department of Defense (DOD) and the Army must address as they proceed with Army ground force modernization efforts. To meet these objectives, GAO reviewed key documents, performed analyses, visited test facilities where the Army evaluated FCS equipment, and interviewed DOD and Army officials."
Date: March 15, 2010
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Oil and Gas Management: Interior's Oil and Gas Production Verification Efforts Do Not Provide Reasonable Assurance of Accurate Measurement of Production Volumes (open access)

Oil and Gas Management: Interior's Oil and Gas Production Verification Efforts Do Not Provide Reasonable Assurance of Accurate Measurement of Production Volumes

A letter report issued by the Government Accountability Office with an abstract that begins "Oil and natural gas produced from federal leases generated over $6.5 billion in royalties in 2009. To verify that royalties are paid on the correct volumes of oil and gas, the Department of the Interior (Interior) verifies the quantity and quality of oil and gas, both onshore, through the Bureau of Land Management, and offshore, through the Offshore Energy and Minerals Management Service. This report assesses (1) the extent to which Interior's production verification regulations and policies provide reasonable assurance that oil and gas are accurately measured; (2) the extent to which Interior's offshore and onshore production accountability inspection programs consistently set and meet program goals and address key factors affecting measurement accuracy; and (3) Interior's management of its production verification programs. To address these questions, GAO analyzed Interior data on oil and gas inspections and human capital, as well as interviewed officials from Interior, states, oil and gas companies, and other countries."
Date: March 15, 2010
Creator: United States. Government Accountability Office.
Object Type: Report
System: The UNT Digital Library
Texas Attorney General Opinion: GA-0761 (open access)

Texas Attorney General Opinion: GA-0761

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Greg Abbott, regarding a legal question submitted for clarification: Authority of a magistrate to award ownership or title of a motor vehicle under chapter 47, Code of Criminal Procedure, or other law (RQ-0811-GA)
Date: March 15, 2010
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: GA-0762 (open access)

Texas Attorney General Opinion: GA-0762

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Greg Abbott, regarding a legal question submitted for clarification; Whether a Type A general-law municipality may impose and enforce a nonpoint source pollution ordinance in its extraterritorial jurisdiction pursuant to section 26.177 of the Water Code (RQ-0822-GA)
Date: March 15, 2010
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Corrective Action Decision Document/Closure Report for Corrective Action Unit 383: Area E-Tunnel Sites, Nevada Test Site (open access)

Corrective Action Decision Document/Closure Report for Corrective Action Unit 383: Area E-Tunnel Sites, Nevada Test Site

This Corrective Action Decision Document/Closure Report (CADD/CR) was prepared by the Defense Threat Reduction Agency (DTRA) for Corrective Action Unit (CAU) 383, Area 12 E-Tunnel Sites, which is the joint responsibility of DTRA and the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO). This CADD/CR is consistent with the requirements of the Federal Facility Agreement and Consent Order (FFACO) agreed to by the State of Nevada, the DOE, and the U.S. Department of Defense. Corrective Action Unit 383 is comprised of three Corrective Action Sites (CASs) and two adjacent areas: • CAS 12-06-06, Muckpile • CAS 12-25-02, Oil Spill • CAS 12-28-02, Radioactive Material • Drainage below the Muckpile • Ponds 1, 2, and 3 The purpose of this CADD/CR is to provide justification and documentation to support the recommendation for closure with no further corrective action, by placing use restrictions at the three CASs and two adjacent areas of CAU 383.
Date: March 15, 2010
Creator: National Security Technologies, LLC
Object Type: Report
System: The UNT Digital Library
Adult Human Pancreatic Islet Beta-Cells Display Limited Turnover and Long Lifespan as Determined by In-Vivo Thymidine Analog Incorporation and Radiocarbon Dating (open access)

Adult Human Pancreatic Islet Beta-Cells Display Limited Turnover and Long Lifespan as Determined by In-Vivo Thymidine Analog Incorporation and Radiocarbon Dating

Diabetes mellitus results from an absolute or relative deficiency of insulin producing pancreatic beta-cells. The adult human beta-cell's turnover rate remains unknown. We employed novel techniques to examine adult human islet beta-cell turnover and longevity in vivo. Subjects enrolled in NIH clinical trials received thymidine analogues [iododeoxyuridine (IdU) or bromodeoxyuridine (BrdU)] 8-days to 4-years prior to death. Archival autopsy samples from ten patients (aged 17-74 years) were employed to assess beta-cell turnover by scoring nuclear analog labeling within insulin staining cells. Human adult beta-cell longevity was determined by estimating the cells genomic DNA integration of atmospheric carbon-14 ({sup 14}C). DNA was purified from pancreatic islets isolated from cadaveric donors; whole islet prep DNA was obtained from a 15 year old donor, and purified beta-cell DNA was obtained from two donors (age 48 and 80 years). {sup 14}C levels were then determined using accelerator mass spectrometry (AMS). Cellular 'birth date' was determined by comparing the subject's DNA {sup 14}C content relative to a well-established {sup 14}C atmospheric prevalence curve. In the two subjects less than age 20 years, 1-2% of the beta-cell nuclei co-stained for BrdU/IdU. No beta-cell nuclei co-stained in the eight patients more than 30 years old. Consistent with …
Date: March 15, 2010
Creator: Perl, S.; Kushner, J. A.; Buchholz, B. A.; Meeker, A. K.; Stein, G. M.; Hsieh, M. et al.
Object Type: Article
System: The UNT Digital Library
Seedless Polyol Synthesis and CO Oxidation Activity of Monodisperse (111) and (100)-Oriented Rhodium Nanocrystals in Sub-10 nm Sizes (open access)

Seedless Polyol Synthesis and CO Oxidation Activity of Monodisperse (111) and (100)-Oriented Rhodium Nanocrystals in Sub-10 nm Sizes

Monodisperse sub-10 nm (6.5 nm) sized Rh nanocrystals with (111) and (100) surface structures were synthesized by a seedless polyol reduction in ethylene glycol, with poly(vinylpyrrolidone) as a capping ligand. When using [Rh(Ac){sub 2}]{sub 2} as the metal precursor, (111)-oriented Rh nanopolyhedra containing 76% (111)-twined hexagons (in 2D projection) were obtained; whereas, when employing RhCl{sub 3} as the metal precursor in the presence of alkylammonium bromide, such as tetramethylammonium bromide and trimethyl(tetradecyl)ammonium bromide, (100)-oriented Rh nanocubes were obtained with 85% selectivity. The {l_brace}100{r_brace} faces of the Rh nanocrystals are stabilized by chemically adsorbed Br{sup -} ions from alkylammonium bromides, which led to (100)-oriented nanocubes. Monolayer films of the (111)-oriented Rh nanopolyhedra and (100)-oriented Rh nanocubes were deposited on silicon wafers in a Langmuir-Blodgett trough to make model 2D nanoarray catalysts. These nanocatalysts were active for CO oxidation by O{sub 2}, and the turnover frequency was independent of nanoparticle shape, consistent with that previously observed for Rh(111) and Rh(100) single crystals.
Date: March 15, 2010
Creator: Zhang, Yawen; Grass, Michael E.; Huang, Wenyu & Somorjai, Gabor A.
Object Type: Article
System: The UNT Digital Library
Corrective Action Decision Document/Closure Report for Corrective Action Unit 476: Area 12 T-Tunnel Muckpile, Nevada Test Site (open access)

Corrective Action Decision Document/Closure Report for Corrective Action Unit 476: Area 12 T-Tunnel Muckpile, Nevada Test Site

This Corrective Action Decision Document (CADD)/Closure Report (CR) was prepared by the Defense Threat Reduction Agency (DTRA) for Corrective Action Unit (CAU) 476, Area 12 T-Tunnel Muckpile. This CADD/CR is consistent with the requirements of the Federal Facility Agreement and Consent Order (FFACO) agreed to by the State of Nevada, the U.S. Department of Energy, and the U.S. Department of Defense. Corrective Action Unit 476 is comprised of one Corrective Action Site (CAS): • 12-06-02, Muckpile The purpose of this CADD/CR is to provide justification and documentation supporting the recommendation for closure in place with use restrictions for CAU 476.
Date: March 15, 2010
Creator: National Security Technologies, LLC
Object Type: Report
System: The UNT Digital Library
Corrective Action Decision Document/Closure Report for Corrective Action Unit 559: T Tunnel Compressor/Blower Pad, Nevada Test Site (open access)

Corrective Action Decision Document/Closure Report for Corrective Action Unit 559: T Tunnel Compressor/Blower Pad, Nevada Test Site

This Corrective Action Decision Document (CADD)/Closure Report (CR) was prepared by the Defense Threat Reduction Agency (DTRA) for Corrective Action Unit (CAU) 559, T-Tunnel Compressor/Blower Pad. This CADD/CR is consistent with the requirements of the Federal Facility Agreement and Consent Order (FFACO) agreed to by the State of Nevada, the U.S. Department of Energy, and the U.S. Department of Defense. Corrective Action Unit 559 is comprised of one Corrective Action Site (CAS): • 12-25-13, Oil Stained Soil and Concrete The purpose of this CADD/CR is to provide justification and documentation supporting the recommendation for closure in place with use restrictions for CAU 559.
Date: March 15, 2010
Creator: National Security Technologies, LLC
Object Type: Report
System: The UNT Digital Library
Corrective Action Decision Document/Closure Report for Corrective Action Unit 504: 16a-Tunnel Muckpile, Nevada Test Site (open access)

Corrective Action Decision Document/Closure Report for Corrective Action Unit 504: 16a-Tunnel Muckpile, Nevada Test Site

This Corrective Action Decision Document (CADD)/Closure Report (CR) was prepared by the Defense Threat Reduction Agency (DTRA) for Corrective Action Unit (CAU) 504, 16a-Tunnel Muckpile. This CADD/CR is consistent with the requirements of the Federal Facility Agreement and Consent Order (FFACO) agreed to by the State of Nevada; U.S. Department of Energy (DOE), Environmental Management; U.S. Department of Defense; and DOE, Legacy Management. Corrective Action Unit 504 is comprised of four Corrective Action Sites (CASs): • 16-06-01, Muckpile • 16-23-01, Contaminated Burial Pit • 16-23-02, Contaminated Area • 16-99-01, Concrete Construction Waste Corrective Action Site 16-23-01 is not a burial pit; it is part of CAS 16-06-01. Therefore, there is not a separate data analysis and assessment for CAS 16-23-01; it is included as part of the assessment for CAS 16-06-01. In addition to these CASs, the channel between CAS 16-23-02 (Contaminated Area) and Mid Valley Road was investigated with walk-over radiological surveys and soil sampling using hand tools. The purpose of this CADD/CR is to provide justification and documentation supporting the recommendation for closure in place with use restrictions for CAU 504. A CADD was originally submitted for CAU 504 and approved by the Nevada Division of Environmental Protection …
Date: March 15, 2010
Creator: National Security Technologies, LLC
Object Type: Report
System: The UNT Digital Library
Corrective Action Decision Document/Closure Report for Corrective Action Unit 477: Area 12 N-Tunnel Muckpile, Nevada Test Site (open access)

Corrective Action Decision Document/Closure Report for Corrective Action Unit 477: Area 12 N-Tunnel Muckpile, Nevada Test Site

This Corrective Action Decision Document (CADD)/Closure Report (CR) was prepared by the Defense Threat Reduction Agency (DTRA) for Corrective Action Unit (CAU) 477, N-Tunnel Muckpile. This CADD/CR is consistent with the requirements of the Federal Facility Agreement and Consent Order (FFACO) agreed to by the State of Nevada, the U.S. Department of Energy, and the U.S. Department of Defense. Corrective Action Unit 477 is comprised of one Corrective Action Site (CAS): • 12-06-03, Muckpile The purpose of this CADD/CR is to provide justification and documentation supporting the recommendation for closure with no further action, by placing use restrictions on CAU 477.
Date: March 15, 2010
Creator: National Security Technologies, LLC
Object Type: Report
System: The UNT Digital Library
Enhanced Attenuation Technologies: Passive Soil Vapor Extraction (open access)

Enhanced Attenuation Technologies: Passive Soil Vapor Extraction

Passive soil vapor extraction (PSVE) is an enhanced attenuation (EA) approach that removes volatile contaminants from soil. The extraction is driven by natural pressure gradients between the subsurface and atmosphere (Barometric Pumping), or by renewable sources of energy such as wind or solar power (Assisted PSVE). The technology is applicable for remediating sites with low levels of contamination and for transitioning sites from active source technologies such as active soil vapor extraction (ASVE) to natural attenuation. PSVE systems are simple to design and operate and are more cost effective than active systems in many scenarios. Thus, PSVE is often appropriate as an interim-remedial or polishing strategy. Over the past decade, PSVE has been demonstrated in the U.S. and in Europe. These demonstrations provide practical information to assist in selecting, designing and implementing the technology. These demonstrations indicate that the technology can be effective in achieving remedial objectives in a timely fashion. The keys to success include: (1) Application at sites where the residual source quantities, and associated fluxes to groundwater, are relatively low; (2) Selection of the appropriate passive energy source - barometric pumping in cases with a deep vadose zone and barrier (e.g., clay) layers that separate the subsurface …
Date: March 15, 2010
Creator: Vangelas, K.; Looney, B.; Kamath, R.; Adamson, D. & Newell, C.
Object Type: Report
System: The UNT Digital Library

Pyrgeometer Calibration for DOE-Atmospheric System Research Program Using NREL Method

Presented at the DOE-Atmospheric System Research Program, Science Team Meeting, 15-19 March 2010, Bethesda, Maryland. The presentation: Pyrgeometer Calibration for DOE-Atmospheric System Research program using NREL Method - was presented by Ibrahim Reda and Tom Stoffel on March 15, 2010 at the 2010 ASR Science Team Meeting. March 15-19, 2010, Bethesda, Maryland.
Date: March 15, 2010
Creator: Reda, I. & Stoffel, T.
Object Type: Presentation
System: The UNT Digital Library
Fast Ferroelectric L-Band Tuner for ILC Cavities (open access)

Fast Ferroelectric L-Band Tuner for ILC Cavities

Design, analysis, and low-power tests are described on a 1.3 GHz ferroelectric tuner that could find application in the International Linear Collider or in Project X at Fermi National Accelerator Laboratory. The tuner configuration utilizes a three-deck sandwich imbedded in a WR-650 waveguide, in which ferroelectric bars are clamped between conducting plates that allow the tuning bias voltage to be applied. Use of a reduced one-third structure allowed tests of critical parameters of the configuration, including phase shift, loss, and switching speed. Issues that were revealed that require improvement include reducing loss tangent in the ferroelectric material, development of a reliable means of brazing ferroelectric elements to copper parts of the tuner, and simplification of the mechanical design of the configuration.
Date: March 15, 2010
Creator: Hirshfield, Jay L
Object Type: Report
System: The UNT Digital Library
Diagnosing causes of cloud parameterization deficiencies using ARM measurements over SGP site (open access)

Diagnosing causes of cloud parameterization deficiencies using ARM measurements over SGP site

Decade-long continuous surface-based measurements at Great Southern Plains (SGP) collected by the US Department of Energy’s Atmospheric Radiation Measurement (ARM) Climate Research Facility are first used to evaluate the three major reanalyses (i.e., ERA-Interim, NCEP/NCAR Reanalysis I and NCEP/DOE Reanalysis II) to identify model biases in simulating surface shortwave cloud forcing and total cloud fraction. The results show large systematic lower biases in the modeled surface shortwave cloud forcing and cloud fraction from all the three reanalysis datasets. Then we focus on diagnosing the causes of these model biases using the Active Remote Sensing of Clouds (ARSCL) products (e.g., vertical distribution of cloud fraction, cloud-base and cloud-top heights, and cloud optical depth) and meteorological measurements (temperature, humidity and stability). Efforts are made to couple cloud properties with boundary processes in the diagnosis.
Date: March 15, 2010
Creator: Wu, W.; Liu, Y. & Betts, A. K.
Object Type: Article
System: The UNT Digital Library
Influence of Arctic cloud thermodynamic phase on surface shortwave flux (open access)

Influence of Arctic cloud thermodynamic phase on surface shortwave flux

As part of the Indirect and Semi-Direct Aerosol Campaign (ISDAC) an Analytical Spectral Devices (ASD, Inc.) spectroradiometer was deployed at the Barrow NSA site during April and May of 2008, and in April-October of 2009. This instrument recorded one-minute averages of surface downwelling spectral flux in the wavelength interval 350-2200 nm, thus sampling the two major near infrared windows (1.6 and 2.2 microns) in which the flux is influenced by cloud microphysical properties including thermodynamic phase and effective particle size. Aircraft in situ measurements of cloud properties show mostly mixed-phase clouds over Barrow during the campaign, but with wide variability in relative liquid versus ice water content. At fixed total optical depth, this variability in phase composition can yield of order 5-10 Watts per square meter in surface flux variability, with greater cloud attenuation of the surface flux usually occurring under higher ice water content. Thus our data show that changes in cloud phase properties, even within the 'mixed-phase' category, can affect the surface energy balance at the same order of magnitude as greenhouse gas increases. Analysis of this spectral radiometric data provides suggestions for testing new mixed-phase parameterizations in climate models.
Date: March 15, 2010
Creator: Lubin, D. & Vogelmann, A.
Object Type: Article
System: The UNT Digital Library
A study of cloud and drizzle properties in the Azores using Doppler Radar spectra (open access)

A study of cloud and drizzle properties in the Azores using Doppler Radar spectra

Understanding the onset of coalescence in warm clouds is key in our effort to improve cloud representation in numerical models. Coalescence acts at small scales, and its study requires detailed high-resolution dynamical and microphysical measurements from a comprehensive suite of instruments over a wide range of environmental conditions (e.g., aerosol loading). The first AMF is currently in its second year of a two-year deployment at Graciosa Island in the Azores, offering the opportunity to collect a long data set from a stable land-based platform in a marine stratocumulus regime. In this study, recorded WACR Doppler spectra are used to characterize the properties of Doppler spectra from warm clouds with and without drizzle, and from drizzle only, in an effort to observe the transition (onset) to precipitation in clouds. A retrieval technique that decomposes observed Doppler spectra into their cloud and/or drizzle components is applied in order to quantify drizzle growth.
Date: March 15, 2010
Creator: Luke, E.; Remillard, J. & Kollias, P.
Object Type: Article
System: The UNT Digital Library
Why hasn't earth warmed as much as expected? (open access)

Why hasn't earth warmed as much as expected?

The observed increase in global mean surface temperature (GMST) over the industrial era is less than 40% of that expected from observed increases in long-lived greenhouse gases together with the best-estimate equilibrium climate sensitivity given by the 2007 Assessment Report of the Intergovernmental Panel on Climate Change. Possible reasons for this warming discrepancy are systematically examined here. The warming discrepancy is found to be due mainly to some combination of two factors: the IPCC best estimate of climate sensitivity being too high and/or the greenhouse gas forcing being partially offset by forcing by increased concentrations of atmospheric aerosols; the increase in global heat content due to thermal disequilibrium accounts for less than 25% of the discrepancy, and cooling by natural temperature variation can account for only about 15%. Current uncertainty in climate sensitivity is shown to preclude determining the amount of future fossil fuel CO2 emissions that would be compatible with any chosen maximum allowable increase in GMST; even the sign of such allowable future emissions is unconstrained. Resolving this situation by empirical determination of Earth’s climate sensitivity from the historical record over the industrial period or through use of climate models whose accuracy is evaluated by their performance over …
Date: March 15, 2010
Creator: Schwartz, S. E.; Charlson, R.; Kahn, R.; Ogren, J. & Rodhe, H.
Object Type: Article
System: The UNT Digital Library
Tracking tropical cloud systems - Observations for the diagnosis of simulations by the Weather Research and Forecasting (WRF) Model (open access)

Tracking tropical cloud systems - Observations for the diagnosis of simulations by the Weather Research and Forecasting (WRF) Model

To aid in improving model parameterizations of clouds and convection, we examine the capability of models, using explicit convection, to simulate the life cycle of tropical cloud systems in the vicinity of the ARM Tropical Western Pacific sites. The cloud life cycle is determined using a satellite cloud tracking algorithm (Boer and Ramanathan, 1997), and the statistics are compared to those of simulations using the Weather Research and Forecasting (WRF) Model. Using New York Blue, a Blue Gene/L supercomputer that is co-operated by Brookhaven and Stony Brook, simulations are run at a resolution comparable to the observations. Initial results suggest a computational paradox where, even though the size of the simulated systems are about half of that observed, their longevities are still similar. The explanation for this seeming incongruity will be explored.
Date: March 15, 2010
Creator: Vogelmann, A.M.; Lin, W.; Cialella, A.; Luke, E.; Jensen, M. & Zhang, M.
Object Type: Article
System: The UNT Digital Library
A comparison of cloud microphysical quantities with forecasts from cloud prediction models (open access)

A comparison of cloud microphysical quantities with forecasts from cloud prediction models

Numerical weather prediction models (ECMWF, NCEP) are evaluated using ARM observational data collected at the Southern Great Plains (SGP) site. Cloud forecasts generated by the models are compared with cloud microphysical quantities, retrieved using a variety of parameterizations. Information gained from this comparison will be utilized during the FASTER project, as models are evaluated for their ability to reproduce fast physical processes detected in the observations. Here the model performance is quantified against the observations through a statistical analysis. Observations from remote sensing instruments (radar, lidar, radiometer and radiosonde) are used to derive the cloud microphysical quantities: ice water content, liquid water content, ice effective radius and liquid effective radius. Unfortunately, discrepancies in the derived quantities arise when different retrieval schemes are applied to the observations. The uncertainty inherent in retrieving the microphysical quantities using various retrievals is estimated from the range of output microphysical values. ARM microphysical retrieval schemes (Microbase, Mace) are examined along with the CloudNet retrieval processing of data from the ARM sites for this purpose. Through the interfacing of CloudNet and “ARM” processing schemes an ARMNET product is produced and employed as accepted observations in the assessment of cloud model predictions.
Date: March 15, 2010
Creator: Dunn, M.; Jensen, M.; Hogan, R.; O’Connor, E. & Huang, D.
Object Type: Article
System: The UNT Digital Library
Fast Physics Testbed for the FASTER Project (open access)

Fast Physics Testbed for the FASTER Project

This poster describes the Fast Physics Testbed for the new FAst-physics System Testbed and Research (FASTER) project. The overall objective is to provide a convenient and comprehensive platform for fast turn-around model evaluation against ARM observations and to facilitate development of parameterizations for cloud-related fast processes represented in global climate models. The testbed features three major components: a single column model (SCM) testbed, an NWP-Testbed, and high-resolution modeling (HRM). The web-based SCM-Testbed features multiple SCMs from major climate modeling centers and aims to maximize the potential of SCM approach to enhance and accelerate the evaluation and improvement of fast physics parameterizations through continuous evaluation of existing and evolving models against historical as well as new/improved ARM and other complementary measurements. The NWP-Testbed aims to capitalize on the large pool of operational numerical weather prediction products. Continuous evaluations of NWP forecasts against observations at ARM sites are carried out to systematically identify the biases and skills of physical parameterizations under all weather conditions. The highresolution modeling (HRM) activities aim to simulate the fast processes at high resolution to aid in the understanding of the fast processes and their parameterizations. A four-tier HRM framework is established to augment the SCM- and NWP-Testbeds …
Date: March 15, 2010
Creator: Lin, W.; Liu, Y.; Hogan, R.; Neggers, R.; Jensen, M.; Fridlind, A. et al.
Object Type: Article
System: The UNT Digital Library
Validation of a radar doppler spectra simulator using measurements from the ARM cloud radars (open access)

Validation of a radar doppler spectra simulator using measurements from the ARM cloud radars

The use of forward models as an alternative approach to compare models with observations contains advantages and challenges. Radar Doppler spectra simulators are not new; their application in high- resolution models with bin microphysics schemes could help to compare model output with the Doppler spectra recorded from the vertically pointing cloud radars at the ARM Climate Research Facility sites. The input parameters to a Doppler spectra simulator are both microphysical (e.g., particle size, shape, phase, and number concentration) and dynamical (e.g., resolved wind components and sub-grid turbulent kinetic energy). Libraries for spherical and non-spherical particles are then used to compute the backscattering cross-section and fall velocities, while the turbulence is parameterized as a Gaussian function with a prescribed width. The Signal-to-Noise Ratio (SNR) is used to determine the amount of noise added throughout the spectrum, and the spectral smoothing due to spectral averages is included to reproduce the averaging realized by cloud radars on successive returns. Thus, realistic Doppler spectra are obtained, and several parameters that relate to the morphological characteristics of the synthetically generated spectra are computed. Here, the results are compared to the new ARM microARSCL data products in an attempt to validate the simulator. Drizzling data obtained …
Date: March 15, 2010
Creator: Remillard, J.; Luke, E. & Kollias, P.
Object Type: Article
System: The UNT Digital Library
The Mid-Latitude Continental Convective Clouds Experiment (MC3E) (open access)

The Mid-Latitude Continental Convective Clouds Experiment (MC3E)

The Midlatitude Continental Convective Cloud Experiment (MC3E) will take place in central Oklahoma during the April-May 2011 period. The experiment is a collaborative effort between the U.S. Department of Energy Atmospheric Radition Measurement Program and the National Aeronautics and Space Administration's (NASA) Global Precipitation Measurement (GPM) mission Ground Validation program. The Intensive Observation Period leverages the unprecedented observing infrastructure currently available in the central United States, combined with an extensive sounding array, remote sensing and in situ aircraft observations, NASA GPM ground validation remote sensors and new ARM instrumentation purchased with American Recovery and Reinvestment Act funding. The overarching goal is to provide the most complete characterization of convective cloud systems, precipitation and the environment that has ever been obtained, providing constraints for model cumulus parameterizations and space-based rainfall observations over land that have never before been available. Several different components of convective processes tangible to the convective parameterization problem are targeted such as, pre-convective environment and convective initiation, updraft / downdraft dynamics, condensate transport and detrainment, precipitation and cloud microphysics, influence on the environment and radiation and a detailed description of the large-scale forcing. MC3E will use a new multi-scale observing strategy with the participation of a network of …
Date: March 15, 2010
Creator: Petersen,W.; Jensen,M.; Genio, A. D.; Giangrande, S.; Heymsfield, A.; Heymsfield, G. et al.
Object Type: Article
System: The UNT Digital Library