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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.

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At least 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

The covariance of temperature and ozone due to planetary-wave forcing

The cross-spectra of temperature and ozone mass mixing ratio at 42 km and 28 km has been determined for spring (1971) and summer (1971-2) over Christchurch, New Zealand (44 S, 172 E). The sources of data are the SCR and BUV experiments on Nimbus 4. The observed covariances are compared with a model in which the temperature and ozone perturbations are forced by an upward propagating planetary wave. The agreement between the observations and the model is reasonable. It is suggested that this cross-spectral method permits an estimate of the meridional gradient of ozone mass mixing ratio from measurements of the vertical profile of ozone mass mixing ratio at one location, supported by temperature profiles from at least two locations.

Fraser, G. J.↗
NASA NTRS1975

Measurement of line widths of CO of planetary interest at low temperatures

Self-broadened, air-broadened and CO2-broadened half-widths of lines R(0) through R(16) in the CO fundamental have been measured at 100 K (self-broadening only), 200 K, 250 K and 300 K using the Ladenburg-Reiche curve-of-growth. The relation which we found previously for the nitrogen-broadened half-widths of R(0), R(8), and R(16), is shown to be valid for all of the line widths measured in the present study.

Varanasi, P.↗
NASA NTRS1980

Spectroscopic studies of water and water/regolith mixtures on planetary surfaces at low temperatures

New reflectance spectra of Ganymede, Europe, Callisto, Io, Saturn's rings, and Mars were obtained. The new data is combined with data covering other spectral regions for compositional interpretation. The spectral properties of water and mixtures of water plus other minerals were studied in the laboratory at the low temperatures typical of Mars, the Galilean satellites, and Saturn's rings. High precision reflectance spectra of water ice were studied.

Clark, R. N.↗
NASA NTRS1966

The planet Venus.

Venus atmosphere, surface temperature and radiation characteristics

PLANETARY TEMPERATURE↗
NASA NTRS1972

On the exospheric temperature of hydrogen-dominated planetary atmospheres.

Results of studies of hydrogen-dominated atmospheres in which exospheric temperatures were calculated to estimate the evaporative loss rates of the constituents. Expressions are given for the exospheric temperature of a two-component diffusive equilibrium model which consists of a lighter molecule dominating the thermosphere and absorbing solar EUV, and a heavier constituent providing radiative cooling in the vicinity of the mesopause. The model approximates well the assumed atmospheres, but the resulting expressions may have wider application. The dynamics of an expanding atmosphere are discussed. A three-dimensional outflow against the back pressure of the solar wind may be configured like a comet's tail.

Gross, S. H.↗
DOE OSTI2011

ON THE ANOMALOUS RADII OF THE TRANSITING EXTRASOLAR PLANETS

We present a systematic evaluation of the agreement between the observed radii of 90 well-characterized transiting extrasolar giant planets and their corresponding model radii. Our model radii are drawn from previously published calculations of coreless giant planets that have attained their asymptotic radii, and which have been tabulated for a range of planet masses and equilibrium temperatures. (We report a two-dimensional polynomial fitting function that accurately represents the models.) As expected, the model radii provide a statistically significant improvement over a null hypothesis that the sizes of giant planets are completely independent of mass and effective temperature. As is well known, however, fiducial models provide an insufficient explanation; the planetary radius anomalies, R{identical_to}R{sub obs}-R{sub pred}, are strongly correlated with planetary equilibrium temperature. We find that the radius anomalies have a best-fit dependence, R{proportional_to}T{sub eff}{sup {alpha}}, with {alpha} = 1.4 {+-} 0.6. Incorporating this relation into the model radii leads to substantially less scatter in the radius correlation. The extra temperature dependence represents an important constraint on theoretical models for hot Jupiters. Using simple scaling arguments, we find support for the hypothesis of Batygin and Stevenson that this correlation can be attributed to a planetary heating mechanism that is mediated by magnetohydrodynamic coupling between the planetary magnetic field and near-surface flow that is accompanied by ohmic dissipation at adiabatic depth. Additionally, we find that the temperature dependence is likely too strong to admit kinetic heating as the primary source of anomalous energy generation within the majority of the observed transiting planets.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS1990

Upcoming planetary missions and the applicability of high temperature superconductor bolometers

Past and present planetary exploration is briefly reviewed, and the planned 1996 Cassini mission to Saturn and Titan is examined. The CIRS experiment aboard Cassini, which will retrieve information on the atmospheres of Titan and Saturn, is discussed. Ongoing efforts to build a high-sensitivity, high-Tc bolometer that would greatly improve detection in Titan's atmosphere are addressed.

Brasunas, J.↗
DOE OSTI2015

Modeling the surface temperature of earth-like planets

We introduce a novel Earth-like planet surface temperature model (ESTM) for habitability studies based on the spatial–temporal distribution of planetary surface temperatures. The ESTM adopts a surface energy balance model (EBM) complemented by: radiative–convective atmospheric column calculations, a set of physically based parameterizations of meridional transport, and descriptions of surface and cloud properties more refined than in standard EBMs. The parameterization is valid for rotating terrestrial planets with shallow atmospheres and moderate values of axis obliquity (ϵ≲45{sup ∘}). Comparison with a 3D model of atmospheric dynamics from the literature shows that the equator-to-pole temperature differences predicted by the two models agree within ≈5 K when the rotation rate, insolation, surface pressure and planet radius are varied in the intervals 0.5≲Ω/Ω{sub ⊕}≲2, 0.75≲S/S{sub ∘}≲1.25, 0.3≲p/(1 bar)≲10, and 0.5≲R/R{sub ⊕}≲2, respectively. The ESTM has an extremely low computational cost and can be used when the planetary parameters are scarcely known (as for most exoplanets) and/or whenever many runs for different parameter configurations are needed. Model simulations of a test-case exoplanet (Kepler-62e) indicate that an uncertainty in surface pressure within the range expected for terrestrial planets may impact the mean temperature by ∼60 K. Within the limits of validity of the ESTM, the impact of surface pressure is larger than that predicted by uncertainties in rotation rate, axis obliquity, and ocean fractions. We discuss the possibility of performing a statistical ranking of planetary habitability taking advantage of the flexibility of the ESTM.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS1989

Assessment of surface turbulent fluxes using geostationary satellite surface skin temperatures and a mixed layer planetary boundary layer scheme

A method is presented for evaluating the fluxes of sensible and latent heating at the land surface, using satellite-measured surface temperature changes in a composite surface layer-mixed layer representation of the planetary boundary layer. The basic prognostic model is tested by comparison with synoptic station information at sites where surface evaporation climatology is well known. The remote sensing version of the model, using satellite-measured surface temperature changes, is then used to quantify the sharp spatial gradient in surface heating/evaporation across the central United States. An error analysis indicates that perhaps five levels of evaporation are recognizable by these methods and that the chief cause of error is the interaction of errors in the measurement of surface temperature change with errors in the assigment of surface roughness character. Finally, two new potential methods for remote sensing of the land-surface energy balance are suggested which will relay on space-borne instrumentation planned for the 1990s.

Diak, George R.↗
NASA NTRS1984

Intercomparison of planetary-scale diagnostics derived from separate satellite and radiosonde time-mean temperature fields

The planetary-scale components of the extratropical Northern Hemisphere troposphere-stratosphere 1973-74 winter circulation are diagnosed using separate time-mean temperature fields based on radiosonde and satellite observations. Meridional cross-sections of zonal wind together with, for zonal wavenumbers 1, 2 and 3, the streamfunction amplitude, phase and Eliassen-Palm flux are displayed, with the relative accuracy of the satellite-derived diagnostics assessed through comparison with the 'ground-truth' radiosonde information. The satellite and radiosonde diagnostics compare most favourably in terms of zonal wind speed and shear, direction of wave propagation and meridional wave structure - all of which are closely related to the differential properties of the atmospheric temperature field. The intensity of the satellite-derived patterns of tropospheric wave propagation is underestimated due to the effects of spatial smoothing and residual cloud contamination present in the satellite radiance measurements.

Miles, T.↗