Search NASA⌕ Search

SEARCH · Search NASA

Results for “water elevation”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

The ICESat-2 Mission: Land, Ocean, and Inland Water Data Products for Middle and Low Latitude Science and Applications

NASA’s Ice, Cloud, and Land Elevation Satellite (ICESat-2) is a polar orbiting mission, launched on September 15, 2018, with over two years of nearly continuous observations. The sole instrument onboard is the Advanced Topographic Laser Altimeter System (ATLAS), a micropulse, high repetition rate, six-beam, 532 nm Lidar with photon-counting technology. Although designed primarily for detecting height changes in ice caps and sea ice in the high latitudes, it continuously observes all terrain in its track including middle and low latitude regions as well, during approximately 15 orbits per day. The official ICESat-2 products include not only cryosphere data but also global high resolution parameters associated with tree canopies, land surface, oceans, and over 1.5 million inland water bodies consisting of lakes, rivers and coastal waters. This presentation provides an overview and the status of the ICESat-2 mission including: i) a summary of the salient technological features and orbit design, ii) the official ICESat-2 science data products for ice, vegetation canopy, ocean sea level, and inland water including several examples in the middle and low latitudes, iii) a list of NASA sponsored software tools for globally browsing the two year archive and for processing both the raw data and the official ICESat-2 geophysical data products, and iv) avenues for interested users to connect with the ICESat-2 Applications Program for answering questions and assistance in possibly using ICESat-2 data in your particular science or application. The overall goal is to facilitate the use of ICESat-2 data not only for science investigations but also for improved decision support applications with societal benefit. Additional ICESat-2 information, documentation and data products are publicly available at https://nsidc.org/data/icesat-2

ICESat-2↗
NASA NTRS1977

ATS-6 ascending - Near horizon measurements over water at 30 GHz

The return of the ATS-6 satellite to a western longitude during the fall of 1976 presented a unique opportunity to perform low-angle-of-elevation measurements at 30 GHz. For this purpose a receiver using a 1.5 m antenna was set up at Port Aransas, Texas, resulting in a propagation path entirely over water. The 30 GHz beacon was monitored daily for at least one hour from 8 September to 21 September 1976. During the time the elevation angle changed from 1.5 to 17.3 deg, the mean attenuation decreased from 20 to 2 dB and the standard deviation from over 6 dB to less than .2 dB. The deep fades at angles below 4 deg show significantly sharper nulls than peaks on a log scale. Spectra of the log amplitude fluctuations vary as the (-8/3) power of the spectral frequency in the limit. A flattening is noticeable at the low frequencies. A precipitation even at 8.5 deg elevation produced a 16 dB fade and significantly increased the variance.

Vogel, W. J.↗
NASA NTRSDate not supplied

Worswick Hot Springs: A Radioactive Hydrothermal Field Site

We report on a systematic characterization of the radiation environment and water temperatures of Worswick Hot Springs, which is in support of companion biochemical and microbial investigations of iron respiration in the ‘extreme’ microbial systems found at the field site. We have discovered localized areas of elevated radioactivity that are approximately four to five times greater than background radiation. Additionally, we have observed that both the radiation environment and the temperature of the spring waters vary over time. Because localized “hot spots” of elevated radiation and biofilms are easily accessible, various biological studies of radiation resistance and biosignature formation are possible, making this field site relevant for analog field studies that consider microbiology, geochemistry, and ionizing radiation. In addition to Worswick being a natural radiation biology laboratory that may also be relevant for space biology applications, we assert that these unusual environmental conditions may inform us about locations on Mars that are also enriched in radioactive elements and their potential for hosting biosignatures.

Jon C. Rask↗
NASA NTRS2015

Aram Chaos: a Long Lived Subsurface Aqueous Environment with Strong Water Resources Potential for Human Missions on Mars

Aram Chaos, Mars is a crater 280 kilometers in diameter with elevations circa. minus 2 to minus 3 kilometers below datum that provides a compelling landing site for future human explorers as it features multiple scientific regions of interest (ROI) paired with a rich extensible Resource ROI that features poly-hydrated sulfates [1]. The geologic history of Aram Chaos suggests several past episodes of groundwater recharge and infilling by liquid water, ice, and other materials [1-3]. The creation of the fractured region with no known terrestrial equivalent may have been caused by melting of deep ice reservoirs that triggered the collapse of terrain followed by catastrophic water outflows over the region. Aram Chaos is of particular scientific interest because it is hypothesized that the chaotic terrain may be the source of water that contributed to the creation of nearby valleys such as Ares Vallis flowing toward Chryse Planitia. The liquid water was likely sourced as groundwater and therefore represents water derived from a protected subsurface environment making it a compelling astrobiological site [2]. The past history of water is also represented by high concentrations of hematite, Fe-oxyhydroxides, mono-hydrated and poly-hydrated sulfates [1, 2]. Poly-hydrated sulfates are likely to contain abundant water that evolves at temperatures below 500 degrees Centigrade thus conferring Aram Chaos a potentially high value for early in-situ resource utilization (ISRU) [4]. The geologic history also calls for future prospecting of deep ice deposits and possibly liquid water via deep drilling. The most recent stratigraphic units in the central part of Aram Chaos are not fractured, and are part of a dome-shaped formation that features bright, poorly-consolidated material that contains both hydrated sulfates and ferric oxides according to OMEGA (Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité) data [5]. These surface material characteristics are preliminary indications of their potential use in civil engineering activities that involve regolith moving and hauling, while further study is needed to assess traverse-ability challenges. The widespread distribution of sulfates is also of interest as a resource for the use of sulfur as a binding compound in regolith-based concrete for constructions. The terrain depressions caused by the rock fracturing events may challenge surface mobility but also suggest the possibility of using such natural features for additional shielding from space radiation and as emplacement of nuclear surface power reactors for the same reason. The high concentration of hematite (up to 16 percent) in some of the smoother recent terrains of the central part of Aram Chaos [2] is a favorable attribute for metal extraction ISRU to create iron-based feedstock for in-situ fabrication of replacement parts or their repairs. Preliminary data on Aram Chaos indicate that it offers a combination of many critical criteria for human missions to the surface of Mars: equatorial region at low Mars Orbiter Laser Altimeter (MOLA), evidence of hydrated minerals over large areas and at high concentrations tied to historic evidence of liquid water over long periods.

Sibille, L.↗
NASA NTRS1972

Feasibility demonstration of a hyperfiltration technique to reclaim shower wastewater at elevated temperatures

A feasibility demonstration of a hyperfiltration technique to determine its capability to reclaim shower wastewater at elevated temperature was conducted. Approximately twenty (20) gallons of typical shower water were processed through a dynamically formed membrane at a temperature of 167 F. Chemical and bacterial analyses of the product water are presented which show compliance with all potable water requirements established for extended manned space missions. In addition, subsystem characteristics and capabilities are discussed.

Hester, J. C.↗
NASA NTRS1986

The vertical structure of limb hazes in the Martian atmosphere

Vertical distribution and reflectance properties of aerosols in the Martian atmosphere are presented, based on Viking Orbiter images containing the planetary limb. Profiles of scattered light above the limb are used to constrain the temporal and spatial behavior of the aerosols. The data cover a wide range of seasons, locations, and viewing geometries. The typical atmospheric column contains one or more discrete, optically thin, ice-like haze layers between 30 and 90 km elevation, depending on the season, whose composition is inferred to be water ice. Below the detached hazes there is a continuous haze extending to the surface. The continuous haze is rarely above 50 km and is much redder in color than the detached hazes above, implying a composition that has a strong dust component. The aerosol distribution exhibits solid seasonal control inferred to be driven by the variable solar flux around the orbit of Mars.

Jaquin, Fred↗
NASA NTRS1987

The effect of wave breaking on wave spectrum in water of finite depth

An approximate method is devised to compute the energy-containing portion of the spectrum of waves in water of finite depth, taking into account the effect of wave breaking. It is assumed that there exists a linear and Gaussian ideal wave train whose spectrum is first calculated using the wave energy flux balance equation without considering wave breaking. The Miche wave-breaking criterion for waves in water of finite depth is then applied to limit the wave elevation and establish an expression for the breaking wave elevation in terms of the elevation and elevation's second time derivative of the ideal waves. Simple expressions for the mean value, the mean square value, and the spectrum of the breaking waves are then obtained, and numerical results are presented graphically.

Tung, C. C.↗
NASA NTRS2006

Promoted-Combustion Chamber with Induction Heating Coil

An improved promoted-combustion system has been developed for studying the effects of elevated temperatures on the flammability of metals in pure oxygen. In prior promoted-combustion chambers, initial temperatures of metal specimens in experiments have been limited to the temperatures of gas supplies, usually near room temperature. Although limited elevated temperature promoted-combustion chambers have been developed using water-cooled induction coils for preheating specimens, these designs have been limited to low-pressure operation due to the hollow induction coil. In contrast, the improved promoted-combustion chamber can sustain a pressure up to 10 kpsi (69 MPa) and, through utilization of a solid induction coil, is capable of preheating a metal specimen up to its melting point [potentially in excess of 2,000 F (approximately equal to 1,100 C)]. Hence, the improved promoted combustion chamber makes a greater range of physical conditions and material properties accessible for experimentation. The chamber consists of a vertical cylindrical housing with an inner diameter of 8 in. (20.32 cm) and an inner height of 20.4 in. (51.81 cm). A threaded, sealing cover at one end of the housing can be unscrewed to gain access for installing a specimen. Inlet and outlet ports for gases are provided. Six openings arranged in a helical pattern in the chamber wall contain sealed sapphire windows for viewing an experiment in progress. The base of the chamber contains pressure-sealed electrical connectors for supplying power to the induction coil. The connectors feature a unique design that prevents induction heating of the housing and the pressure sealing surfaces; this is important because if such spurious induction heating were allowed to occur, chamber pressure could be lost. The induction coil is 10 in. (25.4 cm) long and is fitted with a specimen holder at its upper end. At its lower end, the induction coil is mounted on a ceramic base, which affords thermal insulation to prevent heating of the base of the chamber during use. A sapphire cylinder protects the coil against slag generated during an experiment. The induction coil is energized by a 6-kW water-cooled power supply operating at a frequency of 400 kHz. The induction coil is part of a parallel-tuned circuit, the tuning of which is used to adjust the coupling of power to the specimen. The chamber is mounted on a test stand along with pumps, valves, and plumbing for transferring pressurized gas into and out of the chamber. In addition to multiple video cameras aimed through the windows encircling the chamber, the chamber is instrumented with gauges for monitoring the progress of an experiment. One of the gauges is a dual-frequency infrared temperature transducer aimed at the specimen through one window. Chamber operation is achieved via a console that contains a computer running apparatus-specific software, a video recorder, and real-time video monitors. For safety, a blast wall separates the console from the test stand.

Richardson, Erin↗
NASA NTRS2022

Identifying Meteorologic and Oceanic Conditions Contributing to a Unique Phytoplankton Bloom Occurrence in Micronesia during October 2013

On the first several days of October 2013, daily chlorophyll a (chl a) data acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the National Aeronautics and Space Administration (NASA) Aqua satellite detected a marked increase in chlorophyll a concentrations (chl a) in the vicinity of Chuuk Lagoon and the Federated States of Micronesia. Such an increase, likely indicative of a phytoplankton bloom, has not been observed in this location at any other time during the MODIS-Aqua mission, which commenced in 2002 and continues to present. Examination of sea surface wind data from the Modern Era Retrospective analysis for Research and Applications Version 2 (MERRA-2) reanalysis dataset indicated that the region experienced a sequence of alternating elevated and very low wind speed events prior to the observation of the bloom. The influence of the winds can be seen in MERRA-2 sea surface skin temperature data. Elevated windspeeds for several days likely induced a mixing of deeper waters with higher nutrient levels to the surface, which was followed by stratification and phytoplankton growth during low wind intervals and finally transport induced by a brief high windspeed event. Analysis of hourly MERRA-2 maximum windspeed data over a 40-year period indicated that this sequence was climatologically rare.

Remote Sensing↗
NASA NTRS1993

Thermal and hydraulic considerations regarding the fate of water discharged by the outflow channels to the Martian northern plains

The identification of possible shorelines in the Martian northern plains suggests that the water discharged by the circum-Chryse outflow channels may have led to the formation of transient seas, or possibly even an ocean, covering as much as one-third of the planet. Speculations regarding the possible fate of this water have included local ponding and reinfiltration into the crust; freezing, sublimation, and eventual cold-trapping at higher latitudes; or the in situ survival of this now frozen water to the present day -- perhaps aided by burial beneath a protective cover of eolian sediment or lavas. Although neither cold-trapping at higher latitudes nor the subsequent freezing and burial of flood waters can be ruled out, thermal and hydraulic considerations effectively eliminate the possibility that any significant reassimilation of this water by local infiltration has occurred given climatic conditions resembling those of today. The arguments against the local infiltration of flood water into the northern plains are two-fold. First, given the climatic and geothermal conditions that are thought to have prevailed on Mars during the Late Hesperian (the period of peak outflow channel activity in the northern plains), the thickness of the cryosphere in Chryse Planitia is likely to have exceeded 1 km. A necessary precondition for the widespread occurrence of groundwater is that the thermodynamic sink represented by the cryosphere must already be saturated with ice. For this reason, the ice-saturated cryosphere acts as an impermeable barrier that effectively precludes the local resupply of subpermafrost groundwater by the infiltration of water discharged to the surface by catastraphic floods. Note that the problem of local infiltration is not significantly improved even if the cryosphere were initially dry, for as water attempts to infiltrate the cold, dry crust, it will quickly freeze, creating a seal that prevents any further infiltration from the ponded water above. The second argument against the local infiltration of flood water in the northern plains is based on hydraulic considerations. Repeated impacts have likely brecciated the Martian crust down to a depth of roughly 10 km. Given a value of permeability no greater than that inferred for the top 10 km of the Earth's crust (approximately 10(exp -2) darcies), a timescale as much as a billion years or more for the Martian groundwater system to achieve hydrostatic equilibrium, and the approximately 2-4 km elevation difference between the outflow channel source regions and the northern plains, the water confined beneath the frozen crust of the northern plains should have been under a significant hydraulic head. Thus, the existence of a hydraulic pathway between the ponded flood waters above the northern plains and the confined aquifer lying beneath it would not have led to the infiltration of flood water back into the crust, but rather the additional expulsion of groundwater onto the surface.

Clifford, S. M.↗
NASA NTRS2006

Assessment of Satellite Surface Radiation Products in Highland Regions with Tibet Instrumental Data

This study presents results of comparisons between instrumental radiation data in the elevated Tibetan Plateau and two global satellite products: the Global Energy and Water Cycle Experiment - Surface Radiation Budget (GEWEX-SRB) and International Satellite Cloud Climatology Project - Flux Data (ISCCP-FD). In general, shortwave radiation (SW) is estimated better by ISCCP-FD while longwave radiation (LW) is estimated better by GEWEX-SRB, but all the radiation components in both products are under-estimated. Severe and systematic errors were found in monthly-mean SRB SW (on plateau-average, -48 W/sq m for downward SW and -18 W/sq m for upward SW) and FD LW (on plateau-average, -37 W/sq m for downward LW and -62 W/sq m for upward LW) for radiation. Errors in monthly-mean diurnal variations are even larger than the monthly mean errors. Though the LW errors can be reduced about 10 W/sq m after a correction for altitude difference between the site and SRB and FD grids, these errors are still higher than that for other regions. The large errors in SRB SW was mainly due to a processing mistake for elevation effect, but the errors in SRB LW was mainly due to significant errors in input data. We suggest reprocessing satellite surface radiation budget data, at least for highland areas like Tibet.

Yang, Kun↗
NASA NTRS1986

Development of a water recovery subsystem based on Vapor Phase Catalytic Ammonia Removal (VPCAR)

An integrated engineering breadboard subsystem for the recovery of potable water from untreated urine was designed, fabricated and tested. It was fabricated from commercially available components without emphasis on weight, volume and power requirement optimization. Optimizing these parameters would make this process competitive with other spacecraft water recovery systems. Unlike other phase change systems, this process is based on the catalytic oxidation at elevated temperatures of ammonia and volatile hydrocarbons to innocuous products; therefore, no urine pretreatment is required. The testing program consisted of parametric tests, one month of daily tests, and a continuous run of 165 hours. The recovered water is low in ammonia, hydrocarbons and conductivity and requires only adjustment of its pH to meet drinking water standards.

Budininkas, P.↗
NASA NTRS1986

A two-scale Bragg scattering model for microwave backscatter from wind generated waves

A model for the wavenumber spectrum for fully developed seas is derived as a function of the mean wind gradient. The high wavenumber part of the spectrum, which defines the Bragg wavenumbers, is an equilibrium spectrum in balance by a wind forcing term determined by viscous dissipation, which is a strong function of water temperature, and dissipation by breaking and microbreaking. The low wavenumber spectrum, constructed from surface elevation observations of gravity waves, is merged with the high wavenumber spectrum. Parameters are adjusted to fit circle flight data for Ku-band. The full spectrum is used in the two-scale Bragg scattering theory, plus specular reflection, to compute backscatter as a function of wind speed, direction, incidence angle, and water temperature (which determines viscosity) for Ku-band.

Donelan, M. A.↗
NASA NTRS2008

Progress on the Use of Combined Analog and Photon Counting Detection for Raman Lidar

The Atmospheric Radiation Measurement (ARM) program Raman Lidar (CARL) was upgraded in 2004 with a new data system that provides simultaneous measurements of both the photomultiplier analog output voltage and photon counts. The so-called merge value added procedure (VAP) was developed to combine the analog and count-rate signals into a single signal with improved dynamic range. Earlier versions of this VAP tended to cause unacceptably large biases in the water vapor mixing ratio during the daytime as a result of improper matching between the analog and count-rate signals in the presence of elevated solar background levels. We recently identified several problems and tested a modified version of the merge VAP by comparing profiles of water vapor mixing ratio derived from CARL with simultaneous sonde data over a six month period. We show that the modified merge VAP significantly reduces the daytime bias, and results in mean differences that are within approximately 1% for both nighttime and daytime measurements.

Newsom, Rob↗
NASA NTRS1992

Temperature/pressure and water vapor sounding with microwave spectroscopy

Two intense microwave spectra lines exist in the martian atmosphere that allow unique sounding capabilities: water vapor at 183 GHz and the (2-1) rotational line of CO at 230 GHz. Microwave spectra line sounding is a well-developed technique for the Earth's atmosphere for sounding from above from spacecraft and airplanes, and from below from fixed surface sites. Two simple instruments for temperature sounding on Mars (the CO line) and water vapor measurements are described. The surface sounder proposed for the MESUR sites is designed to study the boundary layer water vapor distribution and the temperature/pressure profiles with vertical resolution of 0.25 km up to 1 km with reduced resolution above approaching a scale height. The water channel will be sensitive to a few tenths of a micrometer of water and the temperature profile will be retrieved to an accuracy between 1 and 2 K. The latter is routinely done on the Earth using oxygen lines near 60 GHz. The measurements are done with a single-channel heterodyne receiver looking into a 10-cm mirror that is canned through a range of elevation angles plus a target load. The frequency of the receiver is sweep across the water and CO lines generating the two spectra at about 1-hr intervals throughout the mission. The mass and power for the proposed instrument are 2 kg and 5-8 W continuously. The measurements are completely immune to the atmospheric dust and ice particle loads. It was felt that these measurements are the ultimate ones to properly study the martian boundary layer from the surface to a few kilometers. Sounding from above requires an orbiting spacecraft with multichannel microwave spectrometers such as the instrument proposed for MO by a subset of the authors, a putative MESUR orbiter, and a proposed Discovery mission called MOES. Such an instrument can be built with less than 10 kg and use less than 15 W. The obvious advantage of this approach is that the entire atmosphere can be sounded for temperature and water vapor in a few hours with somewhat better than a scale height resolution. If a bigger mirror is used (greater than 30 cm) limb sounding geometry can be employed and half scale height resolution achieved to altitudes up to at least 60 km. Again, the measurements are immune to dust and ice loads. Water vapor sensitivity of 0.1 micrometer can be achieved (even with a nadir instrument) and temperature profiles retrieved to an accuracy of better than 2 K from the surface to about 60 km. Winds can be measured from the doppler shifts of CO lines in the limb sounding mode.

Muhleman, D. O.↗
NASA NTRS1994

Effects of Increased CO2 Level on the Well-Being, Growth and Renal Function of Rats

On the Space Shuttle the mean CO2 levels have been 0.3% which is ten times normal air, while there have been extended periods with mean levels of 0.7% and peak concentrations of 2%. On the Space Station the projected mean concentration of CO2 is 0.7% and not to exceed 1.0%. To ensure that high level of CO2 does not compromise the integrity of the science on the Space Station, the effects of chronic exposure to high levels of CO2 were investigated. Following 7 days of cage adaptation animals exposed to 2% CO2 for 30 days were compared to control (ambient air) animals and the effects on the well-being, growth and renal function analyzed. Ten male rats per group were placed in individual metabolic cages which allowed monitoring of daily food and water consumption, as well as feces and urine to be collected. Cages were placed in a plexiglass chamber with internal environment controlled by a computer in conjunction with gas sensors. The elevated CO2 was held constant at 2.0 +/- 0.03% and the O2 at 20.9 +/- 0.15%. Body weight and food and water intake were measured daily for the first ten days of exposure and then every three to four days for the remaining three weeks. Urine was measured for pH, CO2 (as an indicator for bicarbonate) and ammonia (as an indicator for ammonium). During 2% CO2 exposure, animal growth, weight, food and water consumption were within normal ranges suggesting that their well-being was not affected. Urine pH decreased from 7.12 to 6.77 over the first 6 days of exposure and increased the following 24 days returning to pre-exposure levels. Urine NH4+ increased 68% the first 6 days then dropped to and remained at 29% higher than pre-exposure level. Urine bicarbonate concentration did not change the first 6 days, but significantly increased by day 30. These results of chronic exposure to 2% C02 are consistent with renal compensation for respiratory acidosis which may impact science conducted on the Space Shuttle or the Space Station if CO2 levels reach 2%.

Lang, C.↗
NASA NTRS1993

Presenting the Rain-Sea Interaction Facility

The new Rain-Sea Interaction Facility (RSIF) was established at GSFC/WFF and the first finds are presented. The unique feature of this laboratory is the ability to systematically study microwave scattering from a water surface roughened by artificial rain, for which the droplets are at terminal velocity. The fundamental instruments and systems (e.g., the rain simulator, scatterometers, and surface elevation probes) were installed and evaluated during these first experiments - so the majority of the data were obtained with the rain simulator at 1 m above the water tank. From these initial experiments, three new models were proposed: the square-root function for NCS vs. R, the log Gaussian model for ring-wave elevation frequency spectrum, and the Erland probability density distribution for back scattered power. Rain rate is the main input for these models, although the coefficients may be dependent upon other factors (drop-size distribution, fall velocity, radar configuration, etc.). The facility is functional and we foresee collaborative studies with investigators who are engaged in measuring and modeling rain-sea interaction processes.

Bliven, Larry F.↗
NASA NTRS1991

The magnesium sulfate-water system at pressures to 4 kilobars

Hydrated magnesium sulfate constitutes up to 1/6 of the mass of carbonaceous chondrites, and probably is important in many icy asteroids and satellites. It occurs naturally in meteorites mostly as epsomite. MgSO4, considered anhydrously, comprises nearly 3/4 of the highly soluble fraction of C1 chondrites. Thus, MgSO4 is probably an important solute in cryovolcanic brines erupted on certain icy objects in the outer solar system. While the physiochemical properties of the water-magnesium sulfate system are well known at low pressures, planetological applications of these data are hindered by a dearth of useful published data at elevated pressures. Accordingly, solid-liquid phase equilibria was recently explored in this chemical system at pressures extending to about 4 kilobars. The water magnesium sulfate system in the region of the eutectic exhibits qualitatively constant behavior between pressures of 1 atm and 2 kbar. The eutectic melting curve closely follows that for water ice, with a freezing point depression of about 4 K at 1 atm decreasing to around 3.3 K at 2 kbars. The eutectic shifts from 17 pct. MgSO4 at 1 atm to about 15.3 pct at 2 kbars. Above 2 kbars, the eutectic melting curve again tends to follow ice.

Hogenboom, D. L.↗