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At least 757 records · Page 42
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Anthropogenic Influences on Tornadic Storms

The impact of climate change on severe storms and tornadoes remains uncertain, largely owing to inconsistencies in observational data and limitations of climate models. Here, we performed ensembles of convection-permitting climate model simulations to examine how three tornadic storms would change if similar events were to occur in pre-industrial and future climates. The choice of events includes winter, nocturnal, and spring tornadic storms to provide insight into how the timing and seasonality of storms may affect their response to climate change. Updraft helicity (UH), convective available potential energy (CAPE), storm relative helicity (SRH), and convective inhibition (CIN) were used to determine the favorability for the three tornadic storm events in the different climate states. We found that from the pre-industrial to present, the potential for tornadic storms decreased in the winter event and increased in the nocturnal and spring events. With future climate change, the potential for tornadic storms increased in the winter and nocturnal events in association with increased CAPE, and decreased in the spring event despite greater CAPE.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2024

Changes in the SST Seasonal Cycle in a Warmer North Pacific without Ocean Dynamical Feedbacks

Climate models project a significant intensification of the sea surface temperature (SST) seasonal cycle over the subpolar North Pacific due to global warming, with the shallower mixed layer widely recognized as the dominant factor. However, employing slab ocean experiments with only ocean–atmosphere thermal coupling, we find a substantial contribution from changes in surface heat flux to this seasonal cycle intensification. In particular, the stronger Newtonian cooling effect in winter acts as a more potent damping than in summer. This differential damping inhibits the warming in colder seasons, significantly contributing to the intensified SST seasonal cycle in the subpolar North Pacific. In addition, consistent phase shifts in the North Pacific are identified across CMIP6 models. In the northwest North Pacific, a phase advance is associated with anomalous heating in early spring, driven by enhanced warm atmospheric advection from lower latitudes and sea ice melting in marginal seas. In contrast, the southeast North Pacific exhibits a phase delay attributed to the anomalous cooling in spring relative to autumn. This cooling is due to weakened trade winds and increased presence of high clouds. In conclusion, the former leads to stronger evaporative cooling in spring, while the latter impedes shortwave radiation from reaching the ocean.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

Impacts of the Large Seasonal Cycle of Upwelling Zone Sea Surface Temperatures on the Atmosphere

Abstract The amplitude of the annual cycle of sea surface temperatures (SSTs) within the tropics is the largest in the eastern Atlantic and Pacific Oceans. Upwelling activity in these regions is maximum during late boreal summer and autumn, resulting in cool SSTs, and minimum in spring, leading to warm SSTs. The fundamental question of how this large seasonal cycle affects the atmosphere has received relatively little scientific attention. In this study, we use perturbed-SST experiments in an atmosphere model to identify the effects of the seasonal cycle of upwelling zone SSTs on the atmospheric state. Although annual-mean upwelling zone SSTs are cool, preventing their convective coupling with the free troposphere for much of the year, their boreal spring warmth can activate precipitating convection. We find that in this season, upwelling zone SSTs affect the atmosphere by 1) altering the intensity and position of the local intertropical convergence zone and 2) inducing a thermally forced Matsuno–Gill response, altering subtropical winds. On the seasonal time scale, the Atlantic upwelling zone is more effective than the Pacific in inducing this response. We also find that, consistent with prior work, the Pacific upwelling zone excites extratropical modes of internal atmospheric variability. Upwelling zone SSTs have remained poorly simulated through generations of climate models; our experiments allow us to diagnose the atmospheric biases that arise in response to upwelling zone SST biases. Our experiments show that upwelling zone SST biases are most impactful in boreal spring, particularly over the Atlantic.

Ramesh, Nandini↗
DOE OSTI2014

Coupling Genetic and Chemical Microbiome Profiling Reveals Heterogeneity of Archaeome and Bacteriome in Subsurface Biofilms That Are Dominated by the Same Archaeal Species

Earth harbors an enormous portion of subsurface microbial life, whose microbiome flux across geographical locations remains mainly unexplored due to difficult access to samples. Here, we investigated the microbiome relatedness of subsurface biofilms of two sulfidic springs in southeast Germany that have similar physical and chemical parameters and are fed by one deep groundwater current. Due to their unique hydrogeological setting these springs provide accessible windows to subsurface biofilms dominated by the same uncultivated archaeal species, called SM1 Euryarchaeon. Comparative analysis of infrared imaging spectra demonstrated great variations in archaeal membrane composition between biofilms of the two springs, suggesting different SM1 euryarchaeal strains of the same species at both aquifer outlets. This strain variation was supported by ultrastructural and metagenomic analyses of the archaeal biofilms, which included intergenic spacer region sequencing of the rRNA gene operon. At 16S rRNA gene level, PhyloChip G3 DNA microarray detected similar biofilm communities for archaea, but site-specific communities for bacteria. Both biofilms showed an enrichment of different deltaproteobacterial operational taxonomic units, whose families were, however, congruent as were their lipid spectra. Consequently, the function of the major proportion of the bacteriome appeared to be conserved across the geographic locations studied, which was confirmed by dsrB-directed quantitative PCR. Consequently, microbiome differences of these subsurface biofilms exist at subtle nuances for archaea (strain level variation) and at higher taxonomic levels for predominant bacteria without a substantial perturbation in bacteriome function. The results of this communication provide deep insight into the dynamics of subsurface microbial life and warrant its future investigation with regard to metabolic and genomic analyses.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2013

Hot Pot Field Observations

Map of field observations including depressions, springs, evidence of former springs, travertine terraces and vegetation patterns. Map also contains interpretation of possible spring alignments.

15 GEOTHERMAL ENERGY↗
DOE OSTI2019

AmeriFlux US-RC4 Moscow Mountain on-farm site

This is the AmeriFlux version of the carbon flux data for the site US-RC4 Moscow Mountain on-farm site. Site Description - The Moscow Mountain On-farm site operated 2012-2016 as part of a cluster of 5 towers (RC1 to RC5) operated for the Regional Approaches to Climate Change (REACCH) USDA-supported research project. The site is located in the high precipitation agroecological zone of the Columbia Plateau’s dryland cropping region, near Moscow, Idaho. The site was managed with conventional (reduced) tillage. The crop rotation was spring barley, spring field peas, winter wheat, and spring wheat. Soils are silt loam mollisols including the Latahco, Thatuna, Southwick, and Larkin soil series. The site topography is sloping and is situated within the rolling hills of the Palouse region.

Chi, Jinshu↗
DOE OSTI2026

AmeriFlux FLUXNET-1F US-RC4 Moscow Mountain on-farm site

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-RC4 Moscow Mountain on-farm site. This is the FLUXNET version of the carbon flux data for the site US-RC4 Moscow Mountain on-farm site produced by applying the standard ONEFlux (1F) software. Site Description - The Moscow Mountain On-farm site operated 2012-2016 as part of a cluster of 5 towers (RC1 to RC5) operated for the Regional Approaches to Climate Change (REACCH) USDA-supported research project. The site is located in the high precipitation agroecological zone of the Columbia Plateau’s dryland cropping region, near Moscow, Idaho. The site was managed with conventional (reduced) tillage. The crop rotation was spring barley, spring field peas, winter wheat, and spring wheat. Soils are silt loam mollisols including the Latahco, Thatuna, Southwick, and Larkin soil series. The site topography is sloping and is situated within the rolling hills of the Palouse region.

Chi, Jinshu [The Hong Kong University of Science a↗
DOE OSTI2024

Site Characterization of the Highest-Priority Geologic Formations for CO2 Storage in Wyoming

The project Site Characterization of the Highest-Priority Geologic Formations for CO2 Storage in Wyoming is one of 9 site characterization projects that were implemented as part of ARRA (American Recovery and Reinvestment Act). Data from this project was used to improve resolution of data in NATCARB in the area of study. Data related to this study has already been incorporated in NATCARB Atlas. The Wyoming Carbon Underground Storage Project (WY-CUSP) consisted of CO2 storage site characterization and evaluation, focusing on Wyoming’s most promising CO2 storage reservoirs (the Pennsylvanian Weber/Tensleep Sandstone and Mississippian Madison Limestone) and premier CO2 storage site (Rock Springs Uplift). Results from the WY-CUSP project suggest the two reservoirs could store up to 17,000 million tons of CO2. The WY-CUSP team drilled a stratigraphic test well and acquired a 3-D seismic survey covering 25 square miles of the Rock Springs Uplift site. The team retrieved 916 feet of core from the 12,810-foot-deep well, along with a complete log suite, borehole images, fluid samples, and other data. Project partners (1) provided continuous visual documentation of the core, including grain size, mineralogy, facies distribution, and porosity; (2) performed continuous permeability and velocity scans of selected reservoir intervals; and (3) chemically analyzed the fluid samples. WY-CUSP scientists integrated seismic attributes with observations from log suites, a VSP survey, core, fluid samples, and laboratory analyses, including continuous permeability scans. From these integrations, researchers constructed 3-D spatial distribution volumes of reservoir and seal properties that represent geological heterogeneity at the targeted CO2 storage site. The WY-CUSP team used this data to perform new CO2 plume migration simulations. Baker Hughes, Inc., completed a series of small-scale, in-situ water injectivity measurements. A database was formed when observations, analyses, and experiments from the stratigraphic test well were integrated. Correlation of these data allowed petrophysical parameters to be extrapolated from the test well out into the storage domain (5x5 mile 3-D seismic survey volume). This resulted in an improved, realistic understanding of performance assessments for potential CO2 storage scenarios. The WY-CUSP team worked on (1) improving CO2 storage resource estimates, (2) establishing long-term integrity and permanence of confining layers, (3) designing a profitable strategy for pressure management, and (4) evaluating the utilization of stored CO2 at the Rock Spring Uplift. Finally, Baker Hughes developed a microseismic baseline for the test site using in-bore geophones to complete field operations.

3-D seismic↗
DOE OSTI2023

Finchite, Sr(UO 2 ) 2 (V 2 O 8 )·5H 2 O, a new uranyl sorovanadate with the francevillite anion topology

Finchite (IMA2017-052), Sr(UO 2 ) 2 (V 2 O 8 )·5H 2 O, is the first uranium mineral known to contain essential Sr. The new mineral occurs as yellow-green blades up to ~10 µm in length in surface outcrops of the calcrete-type uranium deposit at Sulfur Springs Draw, Martin County, Texas, U.S.A. Crystals of finchite were subsequently discovered underground in the Pandora mine, La Sal, San Juan County, Utah, U.S.A., as diamond-shaped golden-yellow crystals reaching up to 1 mm. In this work, the crystal structure of finchite from both localities was determined using single-crystal X-ray diffraction and is orthorhombic, Pcan, with a = 10.363(6) Å, b = 8.498(5) Å, c = 16.250(9) Å, V = 1431.0(13) Å 3 , Z = 4 (R 1 = 0.0555) from Sulfur Springs Draw; and a = 10.3898(16), b = 8.5326(14), c = 16.3765(3) Å, V = 1451.8(4) Å 3 , Z = 4 (R 1 = 0.0600) from the Pandora mine. Electron-probe microanalysis provided the empirical formula (Sr 0.88 K 0.17 Ca 0.10 Mg 0.07 Al 0.03 Fe 0.02 ) Σ1.20 (UO 2 ) 2 (V 2.08 O 8 )·5H 2 O for crystals from Sulfur Springs Draw, and (Sr 0.50 Ca 0.28 Ba 0.22 K 0.05 ) Σ0.94 (U 0.99 O 2 ) 2 (V 2.01 O 8 )·5H 2 O for crystals from the Pandora mine, based on 17 O atoms per formula unit. The structure of finchite contains uranyl vanadate sheets based upon the francevillite topology. Finchite is a possible immobilization species for both uranium and the dangerous radionuclide 90 Sr because of the relative insolubility of uranyl vanadate minerals in water.

58 GEOSCIENCES↗
DOE OSTI2012

Hydroacoustic Evaluation of Juvenile Salmonid Passage and Distribution at Lookout Point Dam, 2010

Pacific Northwest National Laboratory evaluated juvenile salmonid passage and distribution at Lookout Point Dam (LOP) on the Middle Fork Willamette River for the U.S. Army Corps of Engineers, Portland District (USACE), to provide data to support decisions on long-term measures to enhance downstream passage at LOP and others dams in USACE's Willamette Valley Project. This study was conducted in response to the listing of Upper Willamette River Spring Chinook salmon (Oncorhynchus tshawytscha) and Upper Willamette River steelhead (O. mykiss) as threatened under the Endangered Species Act. We conducted a hydroacoustic evaluation of juvenile salmonid passage and distribution at LOP during February 2010 through January 2011. Findings from this 1 year of study should be applied carefully because annual variation can be expected due to variability in adult salmon escapement, egg-to-fry and fry-to-smolt survival rates, reservoir rearing and predation, dam operations, and weather. Fish passage rates for smolt-size fish (> ~90 mm and < 300 mm) were highest during December-January and lowest in mid-summer through early fall. Passage peaks were also evident in early spring, early summer, and late fall. During the entire study period, an estimated total of 142,463 fish ± 4,444 (95% confidence interval) smolt-size fish passed through turbine penstock intakes. Of this total, 84% passed during December-January. Run timing for small-size fish (~65-90 mm) peaked (702 fish) on December 18. Diel periodicity of smolt-size fish showing crepuscular peaks was evident in fish passage into turbine penstock intakes. Relatively few fish passed into the Regulating Outlets (ROs) when they were open in summer (2 fish/d) and winter (8 fish/d). Overall, when the ROs were open, RO efficiency (RO passage divided by total project passage) was 0.004. In linear regression analyses, daily fish passage (turbines and ROs combined) for smolt-size fish was significantly related to project discharge (P<0.001). This relationship was positive, but there was no relationship between total project passage and forebay elevation (P=0.48) or forebay elevation delta, i.e., day-to-day change in forebay elevation (P=0.16). In multiple regression analyses, a relatively parsimonious model was selected that predicted the observed data well. The multiple regression model indicates a positive trend between expected daily fish passage and each of the three variables in the model-Julian day, log(discharge), and log(abs(forebay delta)); i.e., as any of the environmental variables increase, expected daily fish passage increases. For vertical distribution of fish at the face of the dam, fish were surface-oriented with 62%-80% occurring above 10 m deep. The highest percentage of fish (30%-60%) was found between 5-10-m-deep. During spring and summer, mean target strengths for the analysis periods ranged from -44.2 to -42.1 dB. These values are indicative of yearling-sized juvenile salmon. In contrast, mean target strengths in fall and winter were about -49.0 dB, which are representative of subyearling-sized fish. The high-resolution spatial and temporal data reported herein provide detailed information about vertical, horizontal, diel, daily, and seasonal fish passage rates and distributions at LOP from March 2010 through January 2011. This information will support management decisions on design and development of surface passage and collection devices to help restore Chinook salmon populations in the Middle Fork Willamette River watershed above LOP.

13 HYDRO ENERGY↗
DOE OSTI2012

Annual Report of Monitoring at Morrill, Kansas, in 2011

Carbon tetrachloride contamination in groundwater at Morrill, Kansas, was initially identified in 1985 during statewide testing of public water supply wells for volatile organic compounds (VOCs). High levels of nitrate were also present in the wells. The city of Morrill is located in Brown County in the northeastern corner of the state, about 7 mi east of Sabetha (Figure 1.1). The population of Morrill as of the 2010 Census was approximately 230 (down from 277 in 2000). All residents of Morrill now obtain their drinking water from the Sabetha municipal water system via a pipeline constructed in 1991. The findings of the April 2011 and October 2011 monitoring events at Morrill support the following conclusions: (1) Groundwater flow during the 2011 review period (as in prior years) was predominantly to the south, from the vicinity of the former CCC/USDA facility toward Terrapin Creek. Automatic water level monitoring data suggest that spring precipitation and recharge represent the predominant factors affecting the local groundwater level patterns. (2) No significant changes were observed in the concentration or distribution of carbon tetrachloride in groundwater during the spring and fall 2011 monitoring events versus the spring and fall 2010 monitoring events. In October 2011, a maximum carbon tetrachloride concentration of 49 μg/L was identified in groundwater at well MW3S on the former CCC/USDA facility, with concentrations decreasing downgradient toward Terrapin Creek. (3) Since 2004, the accumulated results of 15 sampling events have demonstrated a significant decline in the maximum detected concentration of carbon tetrachloride in groundwater. In 1995, the contaminant was detected at the former CCC/USDA facility at 390 μg/L, while the current maximum levels are < 50 μg/L. The residual contaminant plume extending from the former CCC/USDA facility southward toward Terrapin Creek is well-defined and slowly declining in concentration naturally. (4) No carbon tetrachloride contamination was detected in 2011 in surface waters or shallow streambed sediments sampled at five locations along Terrapin Creek, downgradient from the former CCC/USDA facility. These results indicate that Terrapin Creek remains unaffected by the carbon tetrachloride plume. (5) Since 2007, the accumulated results of 10 monitoring events for surface water and sediment in Terrapin Creek have demonstrated no impact to the sediment and surface waters of the creek by carbon tetrachloride and no imminent risk for further degradation of the creek. (6) Terrapin Creek (tributary segment 308 to Walnut Creek) receives discharge from the Morrill wastewater treatment plant and several confined animal feeding operations regulated by the KDHE. The Walnut Creek watershed is designated by the KDHE as impaired by fecal coliform bacteria. Terrapin Creek is classified by the KDHE as not open to or accessible by the public for contact recreation and does not support the food procurement designated use (KDHE 2010b). (7) In July 2011, trace concentrations of carbon tetrachloride were detected in vegetation samples collected from trees at 2 of the 42 sampled locations south (downgradient) of the former CCC/USDA facility. (8) Sampling of indoor air in August 2010 to evaluate the potential for vapor intrusion into homes overlying and within 100 ft laterally of the identified carbon tetrachloride plume resulted in no detections of carbon tetrachloride. Low concentrations of chloroform, indicative of indoor air sources, were detected. Low radon levels were also detected. The results indicate no evidence of upward migration of vapors from the low-level carbon tetrachloride contamination in groundwater to indoor air.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2012

Hydroacoustic Evaluation of Juvenile Salmonid Passage and Distribution at Detroit Dam, 2011

Pacific Northwest National Laboratory evaluated juvenile salmonid passage and distribution at Detroit Dam (DET) on the North Santiam River, Oregon for the U.S. Army Corps of Engineers (USACE) to provide data to support decisions on long-term measures to enhance downstream passage at DET and others dams in USACE’s Willamette Valley Project. This study was conducted in response to regulatory requirements necessitated by the listing of Upper Willamette River Spring Chinook salmon (Oncorhynchus tshawytscha) and Upper Willamette River steelhead (O. mykiss) as threatened under the Endangered Species Act. The goal of the study was to provide information of juvenile salmonid passage and distribution at DET from February 2011 through February 2012. The results of the hydroacoustic study provide new and, in some cases, first-ever data on passage estimates, run timing, distributions, and relationships between fish passage and environmental variables at the dam. This information will inform management decisions on the design and development of surface passage and collection devices to help restore Chinook salmon populations in the North Santiam River watershed above DET. During the entire study period, an estimated total of 182,526 smolt-size fish (±4,660 fish, 95% CI) passed through turbine penstock intakes. Run timing peaked in winter and early spring months. Passage rates were highest during late fall, winter and early spring months and low during summer. Horizontal distribution for hours when both turbine units were operated simultaneously indicated Unit 2 passed almost twice as much fish as Unit 1. Diel distribution for smolt-size fish during the study period was fairly uniform, indicating fish were passing the turbines at all times of the day. A total of 5,083 smolt-size fish (± 312 fish, 95% CI) were estimated passed via the spillway when it was open between June 23 and September 27, 2011. Daily passage was low at the spillway during the June-August period, and increased somewhat in September 2011. When the spillway was operated simultaneously with the turbines, spillway efficiency (efficiency is estimated as spillway passage divided by total project passage) was 0.72 and effectiveness (fish:flow ratio—proportion fish passage at a route (e.g., spillway) divided by proportion water through that route out of the total project) was 2.69. That is, when the spillway was open, 72% of the fish passing the dam used the spillway and 28% passed into the turbine penstocks. Diel distribution for smolt-size fish at the spillway shows a distinct peak in passage between mid-morning and mid-afternoon and low passage at night. We estimated that 23,339 smolt-size fish (± 572 fish, 95% CI) passed via the Regulating Outlet (RO) when it was open from October 29 through November 12, 2011, January 2-6, and January 20 through February 3, 2012. During the October–November period, RO passage peaked at 1,086 fish on November 5, with a second peak on November 7 (1,075 fish). When the RO was operated simultaneously with the turbines, RO efficiency was 0.33 and effectiveness was 0.89. In multiple regression analyses, a relatively parsimonious model was selected that predicted the observed fish passage data well. The best model included forebay temperature at depth, forebay elevation, total discharge, hours of daylight, and the operation period. The vertical distribution of fish in the forebay near the face of the dam where the transducers sampled showed fish were generally distributed throughout the water column during all four operational periods. During the refill and full pool periods, vertical distribution was bi-modal with surface-layer and mid-water modes. Patterns for day and night distributions were variable. Fish were distributed above and below the thermocline when it was present (full pool and drawdown periods).

Hydroacoustics↗
DOE OSTI2013

Geoscience Perspectives in Carbon Sequestration - Educational Training and Research Through Classroom, Field, and Laboratory Investigations

The most effective mechanism to limit CO 2 release from underground Geologic Carbon Sequestration (GCS) sites over multi-century time scales will be to convert the CO 2 into solid carbonate minerals. This report describes the results from four independent research investigations on carbonate mineralization: 1) Colloidal calcite particles forming in Maramec Spring, Missouri, provide a natural analog to evaluate reactions that may occur in a leaking GCS site. The calcite crystals form as a result of physiochemical changes that occur as the spring water rises from a depth of more than 190'. The resultant pressure decrease induces a loss of CO 2 from the water, rise in pH, lowering of the solubility of Ca 2+ and CO 3 2- , and calcite precipitation. Equilibrium modelling of the spring water resulted in a calculated undersaturated state with respect to calcite. The discontinuity between the observed occurrence of calcite and the model result predicting undersaturated conditions can be explained if bicarbonate ions (HCO 3 - ) are directly involved in precipitation process rather than just carbonate ions (CO 3 2- ). 2) Sedimentary rocks in the Oronto Group of the Midcontinent Rift (MCR) system contain an abundance of labile Ca-, Mg-, and Fe-silicate minerals that will neutralize carbonic acid and provide alkaline earth ions for carbonate mineralization. One of the challenges in using MCR rocks for GCS results from their low porosity and permeability. Oronto Group samples were reacted with both CO 2 -saturated deionized water at 90°C, and a mildly acidic leachant solution in flow-through core-flooding reactor vessels at room temperature. Resulting leachate solutions often exceeded the saturation limit for calcite. Carbonate crystals were also detected in as little as six days of reaction with Oronto Group rocks at 90oC, as well as experiments with forsterite-olivine and augite, both being common minerals this sequence. The Oronto Group samples have poor reservoir rock characteristics, none ever exceeded a permeability value of 2.0 mD even after extensive dissolution of calcite cement during the experiments. The overlying Bayfield Group – Jacobsville Formation sandstones averaged 13.4 ± 4.3% porosity and a single sample tested by core-flooding revealed a permeability of ~340 mD. The high porosity-permeability characteristics of these sandstones will allow them to be used for GCS as a continuous aquifer unit with the overlying Mt. Simon Formation. 3) Anaerobic sulfate reducing bacteria (SRB) can enhance the conversion rate of CO 2 into solid minerals and thereby improve long-term storage. SRB accelerated carbonate mineralization reactions between pCO 2 values of 0.0059 and 14.7 psi. Hydrogen, lactate and formate served as suitable electron donors for SRB metabolism. The use of a 13 CO 2 spiked gas source also produced carbonate minerals with ~53% of the carbon being derived from the gas phase. The sulfate reducing activity of the microbial community was limited, however, at 20 psi pCO 2 and carbonate mineralization did not occur. Inhibition of bacterial metabolism may have resulted from the acidic conditions or CO 2 toxicity. 4) Microbialite communities forming in the high turbidity and hypersaline water of Storrs’ Lake, San Salvador Island, The Bahamas, were investigated for their distribution, mineralogy and microbial diversity. Molecular analysis of the organic mats on the microbialites indicate only a trace amount of cyanobacteria, while anaerobic and photosynthetic non-sulfur bacteria of the phyla Chloroflexi and purple sulfur bacteria of class Gammaproteobacteria were abundant.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2014

Measurements of 222 Rn, 220 Rn, and CO 2 Emissions in Natural CO 2 Fields in Wyoming: MVA Techniques for Determining Gas Transport and Caprock Integrity

An integrated field-laboratory program evaluated the use of radon and CO 2 flux measurements to constrain source and timescale of CO 2 fluxes in environments proximate to CO 2 storage reservoirs. By understanding the type and depth of the gas source, the integrity of a CO 2 storage reservoir can be assessed and monitored. The concept is based on correlations of radon and CO 2 fluxes observed in volcanic systems. This fundamental research is designed to advance the science of Monitoring, Verification, and Accounting (MVA) and to address the Carbon Storage Program goal of developing and validating technologies to ensure 99 percent storage performance. Graduate and undergraduate students conducted the research under the guidance of the Principal Investigators; in doing so they were provided with training opportunities in skills required for implementing and deploying CCS technologies. Although a final method or “tool” was not developed, significant progress was made. The field program identified issues with measuring radon in environments rich in CO 2 . Laboratory experiments determined a correction factor to apply to radon measurements made in CO 2 -bearing environments. The field program also identified issues with radon and CO 2 -flux measurements in soil gases at a natural CO 2 analog. A systematic survey of radon and CO 2 flux in soil gases at the LaBarge CO 2 Field in Southwest Wyoming indicates that measurements of 222 Rn (radon), 220 Rn (thoron), and CO 2 flux may not be a robust method for monitoring the integrity of a CO 2 storage reservoir. The field program was also not able to correlate radon and CO 2 flux in the CO 2 -charged springs of the Thermopolis hydrothermal system. However, this part of the program helped to motivate the aforementioned laboratory experiments that determined correction factors for measuring radon in CO 2 -rich environments. A graduate student earned a Master of Science degree for this part of the field program; she is currently employed with a geologic consulting company. Measurement of radon in springs has improved significantly since the field program first began; however, in situ measurement of 222 Rn and particularly 220 Rn in springs is problematic. Future refinements include simultaneous salinity measurements and systematic corrections, or adjustments to the partition coefficient as needed for more accurate radon concentration determination. A graduate student earned a Master of Science degree for this part of the field program; he is currently employed with a geologic consulting company. Both graduate students are poised to begin work in a CCS technology area. Laboratory experiments evaluated important process-level fundamentals that effect measurements of radon and CO 2 . Laboratory tests established that fine-grained source minerals yield higher radon emissivity compared to coarser-sized source minerals; subtleties in the dataset suggest that grain size alone is not fully representative of all the processes controlling the ability of radon to escape its mineral host. Emissivity for both 222 Rn and 220Rn increases linearly with temperature due to reaction of rocks with water, consistent with faster diffusion and enhanced mineral dissolution at higher temperatures. The presence of CO 2 changes the relative importance of the factors that control release of radon. Emissivity for both 222 Rn and 220 Rn in CO 2 -bearing experiments is greater at all temperatures compared to the experiments without CO 2 , but emissivity does not increase as a simple function of temperature. Governing processes may include a balance between enhanced dissolution versus carbonate mineral formation in CO 2 -rich waters.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Field Testing of an Unvented Roof with Fibrous Insulation, Tiles and Vapor Diffusion Venting

This research is a test implementation of an unvented tile roof assembly in a hot-humid climate (Orlando, FL; Zone 2A), insulated with air permeable insulation (netted and blown fiberglass). Given the localized moisture accumulation and failures seen in previous unvented roof field work, it was theorized that a 'diffusion vent' (water vapor open, but air barrier 'closed') at the highest points in the roof assembly might allow for the wintertime release of moisture, to safe levels. The 'diffusion vent' is an open slot at the ridge and hips, covered with a water-resistant but vapor open (500+ perm) air barrier membrane. As a control comparison, one portion of the roof was constructed as a typical unvented roof (self-adhered membrane at ridge). The data collected to date indicate that the diffusion vent roof shows greater moisture safety than the conventional, unvented roof design. The unvented roof had extended winter periods of 95-100% RH, and wafer (wood surrogate RH sensor) measurements indicating possible condensation; high moisture levels were concentrated at the roof ridge. In contrast, the diffusion vent roofs had drier conditions, with most peak MCs (sheathing) below 20%. In the spring, as outdoor temperatures warmed, all roofs dried well into the safe range (10% MC or less). Some roof-wall interfaces showed moderately high MCs; this might be due to moisture accumulation at the highest point in the lower attic, and/or shading of the roof by the adjacent second story. Monitoring will be continued at least through spring 2016 (another winter and spring).

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2016

Norwegian Young Sea Ice Experiment (N-ICE) Field Campaign Report

The Norwegian Young Sea Ice (N-ICE) experiment was conducted aboard the R/V Lance research vessel from January through June 2015. The primary purpose of the experiment was to better understand thin, first-year sea ice. This includes understanding of how different components of the Arctic system affect sea ice, but also how changing sea ice affects the system. A major part of this effort is to characterize the atmospheric conditions throughout the experiment. A micropulse lidar (MPL) (S/N: 108) was deployed from the U.S. Department of Energy’s (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility as part of the atmospheric suite of instruments. The MPL operated successfully throughout the entire experiment, acquiring data from 21 January 2015 through 23 June 2015. The MPL was the essential instrument for determining the phase (water, ice or mixed) of the lower-level clouds over the sea ice. Data obtained from the MPL during the N-ICE experiment show large cloud fractions over young, thin Arctic sea ice from January through June 2015 (north of Svalbard). The winter season was characterized by frequent synoptic storms and large fluctuations in the near-surface temperature. There was much less synoptic activity in spring and summer as the near-surface temperature rose to 0 C. The cloud fraction was lower in winter (60%) than in the spring and summer (80%). Supercooled liquid clouds were observed for most of the deployment, appearing first in mid-February. Spring and summer clouds were characterized by low, thick, uniform clouds.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Seismic Fracture Characterization Methodologies for Enhanced Geothermal Systems

Executive Summary The overall objective of this work was the development of surface and borehole seismic methodologies using both compressional and shear waves for characterizing faults and fractures in Enhanced Geothermal Systems. We used both surface seismic and vertical seismic profile (VSP) methods. We adapted these methods to the unique conditions encountered in Enhanced Geothermal Systems (EGS) creation. These conditions include geological environments with volcanic cover, highly altered rocks, severe structure, extreme near surface velocity contrasts and lack of distinct velocity contrasts at depth. One of the objectives was the development of methods for identifying more appropriate seismic acquisition parameters for overcoming problems associated with these geological factors. Because temperatures up to 300º C are often encountered in these systems, another objective was the testing of VSP borehole tools capable of operating at depths in excess of 1,000 m and at temperatures in excess of 200º C. A final objective was the development of new processing and interpretation techniques based on scattering and time-frequency analysis, as well as the application of modern seismic migration imaging algorithms to seismic data acquired over geothermal areas. The use of surface seismic reflection data at Brady's Hot Springs was found useful in building a geological model, but only when combined with other extensive geological and geophysical data. The use of fine source and geophone spacing was critical in producing useful images. The surface seismic reflection data gave no information about the internal structure (extent, thickness and filling) of faults and fractures, and modeling suggests that they are unlikely to do so. Time-frequency analysis was applied to these data, but was not found to be significantly useful in their interpretation. Modeling does indicate that VSP and other seismic methods with sensors located at depth in wells will be the most effective seismic tools for getting information on the internal structure of faults and fractures in support of fluid flow pathway management and EGS treatment. Scattered events similar to those expected from faults and fractures are seen in the VSP reported here. Unfortunately, the source offset and well depth coverage do not allow for detailed analysis of these events. This limited coverage also precluded the use of advanced migration and imaging algorithms. More extensive acquisition is needed to support fault and fracture characterization in the geothermal reservoir at Brady's Hot Springs. The VSP was effective in generating interval velocity estimates over the depths covered by the array. Upgoing reflection events are also visible in the VSP results at locations corresponding to reflection events in the surface seismic. Overall, the high temperature rated fiber optic sensors used in the VSP produced useful results. Modeling has been found useful in the interpretation of both surface reflection seismic and VSP data. It has helped identify possible near surface scattering in the surface seismic data. It has highlighted potential scattering events from deeper faults in the VSP data. Inclusion of more detailed fault and fracture specific stiffness parameters are needed to fully interpret fault and fracture scattered events for flow properties (Pyrak-Nolte and Morris, 2000, Zhu and Snieder, 2002). Shear wave methods were applied in both the surface seismic reflection and VSP work. They were not found to be effective in the Brady's Hot Springs area. This was due to the extreme attenuation of shear waves in the near surface at Brady's. This does not imply that they will be ineffective in general. In geothermal areas where good shear waves can be recorded, modeling suggests they should be very useful for characterizing faults and fractures.

15 GEOTHERMAL ENERGY↗
DOE OSTI2016

Final DOE-ASR Report for the Project “Advancing our Understanding and the Remote Sensing of Ice Clouds”

This project has evolved during its execution, and what follows are the key project findings. This project has arguably provided the first global view of how cirrus cloud (defined as having cloud base temperature T < 235 K) nucleation physics (evaluated through satellite retrievals of ice particle number concentration Ni, effective diameter De and ice water content IWC) evolves with the seasons for a given temperature, latitude zone and surface type (e.g. ocean vs. land), based on a new satellite remote sensing method developed for this project. The retrieval method is unique in that it is very sensitive to the small ice crystals that govern the number concentration Ni, allowing Ni to be retrieved. The method currently samples single-layer cirrus clouds having visible optical depth ranging from about 0.3 to 3.0, using co-located observations from the Infrared Imaging Radiometer (IIR) and from the CALIOP (Cloud and Aerosol Lidar with Orthogonal Polarization) lidar aboard the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) polar orbiting satellite, employing IIR channels at 10.6 μm and 12.05 μm. Retrievals of Ni are primarily used to estimate the cirrus cloud formation mechanism; that is, either homo- or heterogeneous ice nucleation (henceforth hom and het). This is possible since, in general, hom produces more than an order of magnitude more ice crystals than does het. Thus the retrievals provide insight on how these mechanisms change with the seasons for a given latitude zone or region, based on the years 2008 and 2013. Using a conservative criterion for hom cirrus, on average, the sampled cirrus clouds formed through hom occur about 43% of the time in the Arctic and 50% of the time in the Antarctic, and during winter at mid-latitudes in the Northern Hemisphere, hom cirrus occur 37% of the time. Elsewhere (and during other seasons in the Northern Hemisphere mid-latitudes), this hom cirrus fraction is lower, and it is lowest in the tropics. Thus, the microphysical properties of cirrus clouds in the Polar Regions are much different than they are in the tropics; something unknown prior to this study. Moreover, the frequency of cirrus cloud occurrence in the Polar Regions varies strongly with season, peaking during winter in the Arctic and during spring in the Antarctic. Considering these seasonal changes in microphysics and inferred cloud coverage, this leads us to speculate that the buildup of Arctic cirrus during winter may significantly contribute to tropospheric heating in that region, possibly affecting winter jet-stream dynamics and mid-latitude weather patterns through the thermal-wind balance relationship. This cirrus cloud research provides essential guidance for realistically representing cirrus clouds in climate models; guidance previously unavailable. For example, mid-latitude hom cirrus were widespread during winter over or nearby mountainous terrain, evidently due to mountain-induced waves that produce strong updrafts at cirrus cloud levels. The treatment of turbulent mountain stress and gravity waves will likely need to be improved in climate models in order to adequately represent cirrus clouds outside the tropics. Another goal of this project was to develop a ground-based 94-GHz radar retrieval for winter snowstorms, based on (1) an improved analytical framework describing the interaction of radiation from radar with snowfall and (2) the development of a steady-state snow growth model that predicts the height-evolution of the ice particle size distribution through ice particle growth by vapor diffusion, aggregation and riming (i.e. the growth of snow through collisions with supercooled cloud droplets). Although activities (1) and (2) were completed, there was insufficient time to test and finalize the radar retrieval scheme. However, activity (2) provided a new method for relating ice particle mass “m” and projected area “A” to the ice particle maximum dimension “D”. The ice cloud microphysical processes (which determine ice cloud radiative properties) in climate models are parameterized in terms of these m-D and A-D relationships. By improving these relationships, the ice cloud radiative properties in Community Atmosphere Model version 5, or CAM5 (an atmosphere global climate model, or GCM) were improved. Student funding from the University of Nevada, Reno, was combined with funds from this project to conduct some basic research on the mechanism of the North American monsoon, or NAM. Federal research on the NAM has dwindled since 2006, but atmospheric soundings taken during research vessel cruises in the Gulf of California (GC) during the North American Monsoon Experiment (NAME) were used to reveal a likely mechanism that explains the relationship between an intrusion of tropical warm water into the GC during late spring-early summer and the onset of relatively heavy NAM rainfall in northwest Mexico and the southwestern United States. These soundings, combined with reanalysis data, satellite sea surface temperatures and satellite measurements of outgoing longwave radiation were used to develop and provide evidence for a planetary-scale NAM mechanism. As far as we know, no other physical explanation has been offered for the spring-summer evolution of the NAM system.

54 ENVIRONMENTAL SCIENCES↗