SEARCH · Engineering Papers

Results for “atmospheric processing”

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.

SourceResearch connectionFrom yearThrough year

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

At least 487 records · Page 27

All sources NASA NTRS DOE OSTI

NASA NTRS1985

A new scheme for the parameterization of the turbulent planetary boundary layer in the GLAS fourth order GCM

Methods being used to increase the horizontal and vertical resolution and to implement more sophisticated parameterization schemes for general circulation models (GCM) run on newer, more powerful computers are described. Attention is focused on the NASA-Goddard Laboratory for Atmospherics fourth order GCM. A new planetary boundary layer (PBL) model has been developed which features explicit resolution of two or more layers. Numerical models are presented for parameterizing the turbulent vertical heat, momentum and moisture fluxes at the earth's surface and between the layers in the PBL model. An extended Monin-Obhukov similarity scheme is applied to express the relationships between the lowest levels of the GCM and the surface fluxes. On-line weather prediction experiments are to be run to test the effects of the higher resolution thereby obtained for dynamic atmospheric processes.

Helfand, H. M.↗

NASA NTRS1986

Molecular oxygen absorption continua at 195-300 nm and O2 radiative lifetimes

With the aid of new calculations on the transition moments between the six lowest states of O2 (Klotz and Peyerimhoff, 1986), absorption cross sections have been calculated for several oxygen continua. Reasonable agreement is achieved with recent experimental results, the comparison indicating an overestimation of the theoretical transition moment for the A-X system of 20-25 percent. With this adjustment, the calculated radiative lifetime for the O2(A) state is 150 ms, in close agreement with the currently used value. The continua cross sections indicate that absorption by O2(a) cannot be a significant atmospheric process.

Saxon, R. P.↗

NASA NTRS1987

Geomagnetic activity and local modulations of cosmic rays circa 1 GV

Solar-sector synchronous modulations of the particulate cosmic radiation reaching the earth's atmosphere have been studied using low altitude satellite and surface data. The flux in the broad maximum of the galactic cosmic ray differential spectrum (near GV rigidity) exhibits an intermittent north-south asymmetry (NSA) in mid and high geomagnetic latitudes. During the 1964 and 1965 years of sunspot minimum, this modulation had a negative rigidity dependence and strong correlations with geomagnetic disturbance index (ap) and interplanetary magnetic field direction. Taken together with other features, this ap dependence is consistent with the hypothesis that reconnection of the interplanetary and geomagnetic fields should produce a local NSA independent of much larger scale NSAs associated with cosmic ray gradients in the heliosphere. This finding is also consistent with suggestions that solar activity influence on atmospheric processes may be mediated by the resulting modulations of upper tropospheric ionization.

Ely, J. T. A.↗

NASA NTRS1987

Remote sensing from space; Proceedings of Symposium 3, Workshop V, and Topical Meeting A2 of the Twenty-sixth COSPAR Plenary Meeting, Toulouse, France, June 30-July 11, 1986

Various papers on remote sensing from space are presented. The use of such remote sensing to study terrestrial patterns and processes is examined, including the relevant processes and theories, observed vegetation and surface climate parameters, derived terrestrial processes, atmospheric effects, and new sensors. Quantitative radar remote sensing of land and oceanic surface features is addressed, including systems, calibration, simulation, data evaluation for vegetational studies, altimetry, sea ice monitoring, and oil slick detection. The use of satellite observations for weather prediction is discussed.

Goward, S. N.↗

NASA NTRS1987

High altitude turbulence for supersonic cruise vehicles

The characteristics of high altitude turbulence and its associated meteorological features are reviewed. Findings based on data from NASA flight research programs with prototype military aircraft, the XB-70 and YF-12A, are emphasized. An example of detailed numerical atmospheric simulations, which may provide greatly increased understanding of these earlier turbulence observations, is presented. Comparisons between observation and numerical simulation should help to delineate the limitations of analysis techniques and improve our understanding of atmospheric processes in the stratosphere.

Ehernberger, L. J.↗

NASA NTRS1988

Wind, current and swell influences on the ice extent and flux in the Grand Banks-Labrador sea area as observed in the LIMEX '87 experiment

This paper presents data collected by airborne and satellite instruments during the Labrador Ice Margin Experiment, that demonstrate the effects of oceanic and atmospheric processes on the ice conditions in the Grand Banks-Labrador sea area. Special consideration is given to the development of algorithms for extracting information from SAR data. It is shown that SAR data can be used to monitor ice extent, determine ice motion, locate shear zones, monitor the penetration of swell into the ice, estimate floe sizes, and establish the dimensions of the ice velocity zones. It is also shown that the complex interaction of the ice cover with winds, currents, swell, and coastlines is similar to the dynamics established for a number of sites in both polar regions.

Argus, Susan Digby↗

NASA NTRS1988

Relations between water vapor imagery, vertical motion, and tropopause folds

The atmospheric processes associated with the movement and development of a pronounced dry feature in a series of 6.7-micron images from March, 1982 are examined. It is found that the dark, warm image bands are due to subsidence. The advective band is produced by descent associated with the entrance region of a polar jet streak. The evolution of the development image component is coincident with a tropopause fold and associated intrusion of dry stratospheric air into the middle troposphere. The increasing brightness temperatures are simulated by altering upwind soundings based on trajectory-determined vertical motion and using both the original and altered profiles as input to a radiative transfer model.

Moore, Steven R.↗

NASA NTRS1989

Atmospheric planetary waves induced by solar rotation

It is known that there are variations in the atmospheric processes with a period close to that of the rotation of the Sun (27 days). The variations are discovered in tropospheric processes, rainfalls, geopotential and in stratosphere. The main theoretical problem is the identification of the physical process by which these heterogeneous solar and meteorological phenomena are connected. Ivanovsky and Krivolutsky proposed that the periodic heating of the ozone layer by the short wave radiation would be the reason of excitation the 27-day oscillations. It was also assumed that excitement takes place in condition of resonance with an excited mode corresponding to the conditions present in the stratospheric circulations. The possibility is discussed of the resonant excitation and presentation is made of the data analysis results which support this idea.

Krivolutsky, A. A.↗

NASA NTRS1991

Clouds and the Earth's Radiant Energy System (CERES) - An Earth Observing System experiment

An overview is presented of the CERES experiment that is designed not only to monitor changes in the earth's radiant energy system and cloud systems but to provide these data with enough accuracy and simultaneity to examine the critical climate/cloud feedback mechanisms which may play a major role in determining future changes in the climate system. CERES will estimate not only the flow of radiation at the top of the atmosphere, but also more complete cloud properties that will permit determination of radiative fluxes within the atmosphere and at the surface. The CERES radiation budget data is also planned for utilization in a wide range of other Earth Observing System interdisciplinary science investigations, including studies of land, biological, ocean and atmospheric processes.

Wielicki, Bruce A.↗

NASA NTRS1991

Earth Radiation Budget Satellite (ERBS): Emergency support

The primary purpose of the Earth Radiation Budget Satellite (ERBS) project is to study the Earth's atmospheric processes and their relationship to the Earth's climate. Following deployment from the Space Shuttle, the satellite was maneuvered into a circular orbit of 610 km x 610 km x 57 degrees, with a period of 99.6 minutes. The Deep Space Network (DSN) will support the ERBS during emergency situations in the event that the standard Tracking and Data Relay Satellite System (TDRSS) to White Sands data link is inoperative. Emergency support will be provided by the DSN's 26-meter antenna subnetwork. Information is given in tabular form for DSN network support, frequency assignments, telemetry, and command.

Williamson, J.↗

NASA NTRS1991

Effects of vegetation on soil moisture distribution and flux with implications for the global hydrologic cycle

Recent climate modeling experiments have identified the critical need for a better understanding of land surface - atmosphere interactions. An important issue in global climate modeling is to be able to relate land surface and atmospheric processes. In the past this link has been inadequately represented due to the lack of understanding of the interaction between the processes and also due to the large spatial variability of the hydrological and soil properties. A project was initiated at the Marshall Space Flight Center (MSFC) in FY-90 under the Center's Directorate Discretionary Fund (CDDF) to study small-scale effects of vegetation on the distribution and fluxes of soil moisture. Installation of a large array of instruments was accomplished during that first year (FY-90). During this second year of the project, the instrumentation and data collection systems were improved and data has begun to be taken. Preliminary analysis of the data show that the equipment has been functioning properly. Some of the preliminary results that have recently been analyzed are given.

Macari, Emir Jose↗

NASA NTRS1991

Meeting Review: Airborne Aerosol Inlet Workshop

Proceedings from the Airborne Aerosol Inlet Workshop are presented. The two central topics of discussion were the role of aerosols in atmospheric processes and the difficulties in characterizing aerosols. The following topics were discussed during the working sessions: airborne observations to date; identification of inlet design issues; inlet modeling needs and directions; objectives for aircraft experiments; and future laboratory and wind tunnel studies.

Baumgardner, Darrel↗

NASA NTRS1991

A Variational Assimilation Method for Satellite and Conventional Data: Development of Basic Model for Diagnosis of Cyclone Systems

A summary is presented of the progress toward the completion of a comprehensive diagnostic objective analysis system based upon the calculus of variations. The approach was to first develop the objective analysis subject to the constraints that the final product satisfies the five basic primitive equations for a dry inviscid atmosphere: the two nonlinear horizontal momentum equations, the continuity equation, the hydrostatic equation, and the thermodynamic equation. Then, having derived the basic model, there would be added to it the equations for moist atmospheric processes and the radiative transfer equation.

Achtemeier, Gary L.↗

NASA NTRS1991

The biosphere as a driver of global atmospheric change

The effects of the biosphere on the evolution of atmospheric oxygen and ozone, and the consequences of that development for global atmospheric change, are discussed. Attention is given to the impact of oxygen and ozone on atmospheric photolysis rates, the effect of oxygen on the biogenic production of nitrous oxide and nitric oxide, and the effects of the evolution of atmospheric oxygen on fires and biomass burning. The influence of the latter on atmospheric processes, particularly the production of methane, carbon dioxide, and carbon monoxide, is considered.

Levine, Joel S.↗

NASA NTRS1992

Natural versus anthropogenic factors affecting low-level cloud albedo over the North Atlantic

Cloud albedo plays a key role in regulating earth's climate. Cloud albedo depends on column-integrated liquid water content and the density of cloud condensation nuclei, which consists primarily of submicrometer-sized aerosol sulfate particles. A comparison of two independent satellite data sets suggests that, although anthropogenic sulfate emissions may enhance cloud albedo immediately adjacent to the east coast of the United States, over the central North Atlantic Ocean the variability in albedo can be largely accounted for by natural marine and atmospheric processes that probably have remained relatively constant since the beginning of the industrial revolution.

Falkowski, Paul G.↗

NASA NTRS1992

Modeling of the partitioning of reactive odd nitrogen in the lower stratosphere using aircraft measurements of NOy, NO, and other trace species

The objective of this research was to gain a more thorough understanding of the atmospheric processes which control the partitioning of species within the reactive nitrogen (NO(y)) reservoir in the lower stratosphere. This understanding is crucial to predicting ozone loss in the stratosphere. NO(y) is defined as NO + NO2 + HNO3 + N2O5 + ClONO2 + HO2NO2 + NO3 + particulate nitrate. The research focuses on deriving the partitioning among these species using the combined set of measurements from the NASA ER-2 aircraft during recent missions designed to study stratospheric ozone depletion.

Kawa, Stephan Randolph↗

NASA NTRS1993

Evolution of the global water cycle on Mars: The geological evidence

The geological evidence for active water cycling early in the history of Mars (Noachian geological system or heavy bombardment) consists almost exclusively of fluvial valley networks in the heavily cratered uplands of the planet. It is commonly assumed that these landforms required explanation by atmospheric processes operating above the freezing point of water and at high pressure to allow rainfall and liquid surface runoff. However, it has also been documented that nearly all valley networks probably formed by subsurface outflow and sapping erosion involving groundwater outflow prior to surface-water flow. The prolonged ground-water flow also requires extensive water cycling to maintain hydraulic gradients, but is this done via rainfall recharge, as in terrestrial environments?

Baker, V. R.↗

NASA NTRS1993

Cirrus cloud development in a mobile upper tropospheric trough: The November 26th FIRE cirrus case study

The period from 18 UTC 26 Nov. 1991 to roughly 23 UTC 26 Nov. 1991 is one of the study periods of the FIRE (First International Satellite Cloud Climatology Regional Experiment) 2 field campaign. The middle and upper tropospheric cloud data that was collected during this time allowed FIRE scientists to learn a great deal about the detailed structure, microphysics, and radiative characteristics of the mid latitude cirrus that occurred during that time. Modeling studies that range from the microphysical to the mesoscale are now underway attempting to piece the detailed knowledge of this cloud system into a coherent picture of the atmospheric processes important to cirrus cloud development and maintenance. An important component of the modeling work, either as an input parameter in the case of cloud-scale models, or as output in the case of meso and larger scale models, is the large scale forcing of the cloud system. By forcing we mean the synoptic scale vertical motions and moisture budget that initially send air parcels ascending and supply the water vapor to allow condensation during ascent. Defining this forcing from the synoptic scale to the cloud scale is one of the stated scientific objectives of the FIRE program. From the standpoint of model validation, it is also necessary that the vertical motions and large scale moisture budget of the case studies be derived from observations. It is considered important that the models used to simulate the observed cloud fields begin with the correct dynamics and that the dynamics be in the right place for the right reasons.

Mace, Gerald G.↗