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Beck, S. M.

Publications and source records attributed to Beck, S. M..

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2014

A Global Upper Atmosphere Observatory Using of Lidar on the International Space Station

A concept for hosting a lidar facility for the upper atmosphere on the International Space Station (ISS) is presented and discussed. The concept is based on utilizing an existing Large Space Optics mirror having a 2.37-m aperture as the primary mirror in its receiver. This large aperture provides for hosting several transmitter systems to retrieve density, temperature, and wind measurements for several upper atmospheric species. Thus the concept provides for measurements over a wide altitude range (80-600 km), at various time and spatial resolutions, and hosting on the ISS provides nearly global coverage. The baseline concept includes transmitters and receivers for atomic oxygen (80-500 km), metastable helium (400-600 km), and sodium (80-110 km). The facility is conceived as being flexible such that other transmitter/receiver systems could be added to allow the possibility of other species to be studied, such as iron. The presentation discusses the transformative science that would be gained by such an observatory by combining the nearly global coverage afforded by the ISS orbit with the extension of powerful lidar techniques to high altitudes. The challenges in realizing such an observatory are discussed, as are current plans and partnerships to meet those challenges. The presentation also reports on the development status of several components, primarily various independent transmitter/receiver systems, that are under consideration for the baseline observatory. Several institutions are performing these developments.

Clemmons, J. H.↗
NASA NTRS1990

The Amazon Boundary Layer Experiment - Wet season 1987

This paper describes the overall experimental design for the Amazon Boundary Layer Experiment (ABLE 2B), which used data from aircraft, ground-based, and satellite platforms to characterize the chemistry and dynamics of the lower atmosphere over the Amazon Basin during wet season conditions in April-May 1987. The ABLE 2B focused on determining the spatial and temporal scales of variability in trace gases and aerosols in the lower and midtroposphere over the Amazonian rain forest during wet season conditions, and assessing the role of local-to-regional atmospheric scales of motion on determining the distribution of atmospheric chemical species and their photochemical environment. A summary of the results from the combined ABLE 2A and ABLE 2B are presented.

Harriss, R. C.↗
NASA NTRS1990

Peroxyacetyl nitrate measurements during CITE 2 - Atmospheric distribution and precursor relationships

Results are reported from airborne PAN measurements obtained at altitudes 0-6 km over the continental U.S. and the eastern Pacific during the NASA Global Tropospheric Experiment Chemical Instrumentation Test and Evaluation 2 (CITE 2) in summer 1986. The CITE 2 flights and instrumentation are described, and the results are presented in extensive graphs and characterized in detail. It is shown that PAN is an important reactive N-containing species in the troposphere. Although the PAN mixing ratios were highly variable, in general high mixing ratios of 100-300 parts per trillion by volume (pptv) were found at 4-6 km, and very low ratios (5-20 pptv) were detected in the marine boundary layer. Good correlation was seen between the CITE 2 PAN values and those for O3, NO(y), NO(x), HNO3, C2H6, CO, and CFCl3.

Singh, H. B.↗
NASA NTRS1990

Aircraft measurements of NO(x) over the eastern Pacific and continental United States and implications for ozone production

Results are reported from airborne measurements of NO, NO2, O3, and CO obtained in the free troposphere (FT) and boundary layer (BL) over the western U.S. and eastern Pacific during the NASA Global Tropospheric Experiment Chemical Instrumentation Test and Evaluation 2 (CITE 2) in summer 1986. The aircraft instrumentation and the CITE 2 flight protocols are described, and the results are presented in extensive tables and graphs. Over the ocean the median mixing ratios for NO and NO2 were found to be 4.0 and 10.4 parts per trillion by volume (pptv), respectively, in the BL and 12.4 and 18.0 pptv in the FT; the corresponding values over land were 34.5 and 75.0 pptv in the BL and 13.0 and 36.0 pptv in the FT. in continental air masses. NO(x) is shown to be positively correlated with O3 and CO and negatively correlated with dewpoint over the ocean, whereas over land NO(x) was positively correlated with O3, CO, and dewpoint.

Carroll, M. A.↗
NASA NTRS1988

The Amazon Boundary Layer Experiment (ABLE 2A) - Dry season 1985

The Amazon Boundary Layer Experiment (ABLE 2A) used data from aircraft, ground-based, and satellite platforms to characterize the chemistry and dynamics of the lower atmosphere over the Amazon Basin during the early-to-middle dry season, July and August 1985. This paper reports the conceptual framework and experimental approach used in ABLE 2A and serves as an introduction to the detailed papers which follow in this issue. The results of ABLE 2A demonstrate that isoprene, methane, carbon dioxide, nitric oxide, dimethylsulfide, and organic aerosol emissions from soils and vegetation play a major role in determining the chemical composition of the atmospheric mixed layer over undisturbed forest and wetland environments. As the dry season progresses, emissions from both local and distant biomass burning become an important source of carbon monoxide, nitric oxide and ozone in the atmosphere over the central Amazon Basin.

Harriss, R. C.↗
NASA NTRS1987

Tropopause fold structure determined from airborne lidar and in situ measurements

Airborne differential absorption lidar and in situ data obtained during the April 20, 1984 flight experiment conducted over Nevada and California are analyzed. The O3 and aerosols profiles and in situ measurements reveal a 2.0-km-deep layer (with high O3 concentrations and enhanced aerosol backscattering) and a correlation of 0.8 between O3 and aerosol backscatter (with both values decreasing about 25 percent along the central axis of the fold). It is observed that the cold boundary of the fold has weaker gradients, larger-scale undulations, and more irregularity than the warm boundary. The potential vorticity distribution along the flight path was derived from radiosonde data. A positive correlation between the O3 mixing ratio and the potential vorticity values in the fold is detected; the average ratio between O3 and potential vorticity is 50.2 ppbv/10 to the -5th sq cm deg per g s.

Browell, E. V.↗
NASA NTRS1986

Air chemistry over the tropical forest of Guyana

A comparison is made of the atmospheric chemistry within and above the atmospheric boundary layer over the tropical forest of Guyana. The data were gathered by NASA during the Global Tropospheric Experiment program in 1984, with an instrumented aircraft being used to collect data at altitudes of 3.5 km and between 150-450 m. The synoptic data covered concentrations of O3, CO, dimethylsulfide (DMS), halocarbons and isoprene and three different aerosol particulate measurements (DIAL system). The forest boundary layer proved to be a significant sink for O3, and a source for substantial emissions of DMS. Isoprene emitted by the forest was photochemically oxidized and became a source of CO.

Gregory, G. L.↗
NASA NTRS1986

Distribution and geochemistry of aerosols in the tropical North Atlantic troposphere - Relationship to Saharan dust

Estimates of global aerosol production suggest that mobilization of natural eolian material greatly exceeds anthropogenic-related emissions, and it appears that soil material transported from arid regions by wind might be mainly responsible for the distribution of certain clay materials in oceanic sediments. In connection with studies related to an investigation of these possibilities, the present paper provides a discussion of the aerosol spatial distribution and its water-soluble chemical composition in the tropical North Atlantic troposphere during the ABLE-Barbados mission. Particular attention is given to the composition of the water-soluble fraction, since its chemical reactivity is important with respect to various atmospheric and biogeochemical processes. On the basis of the obtained results, it is suggested that Saharan dust has also a significant impact on the aerosol chemistry over the tropical North Atlantic.

Talbot, R. W.↗
NASA NTRS1985

Operational overview of Wallops Island instrument intercomparison - Carbon monoxide, nitric oxide, and hydroxyl instrumentation

NASA has initiated the Global Tropospheric Experiment (GTE) for the study of the chemistry of the global troposphere. One phase of GTE, Chemical Instrumentation Test and Evaluation (CITE), is concerned with the development and validation of measurement techniques for trace species which play important roles in the tropospheric chemical cycles. In connection with CITE 1 an intercomparison of instruments is conducted for the measurement of CO, NO, and OH. These species have been identified as critical for an understanding of homogeneous gas-phase chemistry in the troposphere. The present paper provides an operational overview of the first of three instrument intercomparison field missions conducted as part of GTE/CITE 1. The missions include one ground-based and two airborne missions, and were designed to characterize current capability of measuring ambient levels of CO, NO, and OH.

Gregory, G. L.↗
NASA NTRS1984

Observations of atmospheric ozone - 38 to 76 deg north latitude at altitudes from 8 km to the surface

Ozone data were obtained from 8 km to the surface and at latitudes from 38 to 76 deg N during January and February 1983. Flight lines covered northeastern U.S., Canada, and Greenland. The results of the latitudinal survey at 5- to 8-km altitude showed O3 mixing ratios to be about 40 ppbv with little variation in latitude. One region of elevated O3 was observed and extended from 54 N to 57 deg N latitude. Ozone reached 150 ppbv at 6.4-km altitude. This sampling was stratospheric air as the tropopause height was 5.6-km altitude. Profiles at 76, 67, and 53 deg N showed O3 to be be well mixed from about 5 km to the surface. In some cases, profiles identified a layer of 1 km to 100 m vertical dimension at the surface, in which O3 destruction had occurred.

Gregory, G. L.↗
NASA NTRS1984

Measurements of free tropospheric ozone - An aircraft survey from 44 degrees north to 46 south latitude

Ozone data were obtained in the free troposphere at altitudes of 5 to 7.5 km and at latitudes from 44 degrees N to 46 degrees S during a 3-week period from October 19 to November 4, 1982. Flight trajectories included the continental U.S., Central America, and the western coast of South America. Maximum observed ozone was 110 ppb at about 41 degrees S latitude and at an altitude of 7.3 km (msl). Analysis of the data as a function of latitude showed a region of elevated ozone in the southern latitudes extending from about 2 degrees to 30 degrees in which latitudinal ozone averages (2 degree bands) peaked at about 80 ppb. Ozone concentrations, measured at northern latitudes, were lower, averaging about 35 ppb. A discussion of the data, including comparison with other ozone data sets, is presented.

Gregory, G. L.↗
NASA NTRS1984

Atmospheric transport of pollutants from North America to the North Atlantic Ocean

Ground-based measurements strongly support the hypothesis that pollutant materials of anthropogenic origin are being transported over long distances in the midtroposphere and are a significant source of acid rain, acid snow, trace metal deposition, ozone and visibility-reducing aerosols in remote oceanic and polar regions of the Norhern Hemisphere. Atmospheric sulphur budget calculations and studies of acid rain on Bermuda indicate that a large fraction of pollutant materials emitted into the atmosphere in eastern North America are advected eastwards over the North Atlantic Ocean. The first direct airborne measurements of the vertical distribution of tropospheric aerosols over the western North Atlantic is reported here. A newly developed airborne differential adsorption lidar system was used to obtain continuous, remotely sensed aerosol distributions along its flight path. The data document two episodes of long-distance transport of pollutant materials from North America over the North Atlantic Ocean.

Harriss, R. C.↗
NASA NTRS1982

Carbon monoxide measurements in the troposphere

Approximately 35 hours of radiometric measurements were obtained of the CO mixing ratio in the middle troposphere, upper troposphere, and lower stratosphere, by means of the Measurement of Air Pollution from Satellites (MAPS) experiment carried in the OSTA-1 payload of the second Space Shuttle flight. In view of gas filter radiometer data in the 4.67-micron band, gathered over the 38 N-38 S latitude region during both daytime and nighttime, the performance of MAPS was excellent. Significant gradients have been found in the middle tropospheric CO mixing ratio with both latitude and longitude over the North Atlantic, the Mediterranean Sea, and the Middle East.

Reichle, H. G., Jr.↗
NASA NTRS1981

In situ correlative measurements for the ultraviolet differential absorption lidar and the high spectral resolution lidar air quality remote sensors: 1980 PEPE/NEROS program

In situ correlative measurements were obtained with a NASA aircraft in support of two NASA airborne remote sensors participating in the Environmental Protection Agency's 1980persistent elevated pollution episode (PEPE) and Northeast regional oxidant study (NEROS) field program in order to provide data for evaluating the capability of two remote sensors for measuring mixing layer height, and ozone and aerosol concentrations in the troposphere during the 1980 PEPE/NEROS program. The in situ aircraft was instrumented to measure temperature, dewpoint temperature, ozone concentrations, and light scattering coefficient. In situ measurements for ten correlative missions are given and discussed. Each data set is presented in graphical and tabular format aircraft flight plans are included.

Gregory, G. L.↗
NASA NTRS1978

Aircraft instrumentation system for the remote sensing of carbon monoxide

A light twin-engine aircraft has been instrumented with a carbon monoxide remote gas sensor system and test flown over the Southern Lake Michigan basin during August, 1976. The remote sensor is based on the gas filter correlation technique. The radiance levels from the sensor along with the data on the surface temperature, air temperature, dewpoint, and altitude were digitized and recorded on seven-track magnetic tape. Air samples were collected at various altitudes over selected sites for later analysis of carbon monoxide concentration and comparison with the inferred concentration from the remote sensor. The values of carbon monoxide obtained from the air samples and the values inferred from the remote sensor for data collected over water are in good agreement.

Beck, S. M.↗
NASA NTRS1976

Proton and deuteron double differential cross sections at angles from 10 deg to 60 deg from Be, C, Al, Fe, Cu, Ge, W, and Pb under 558-MeV-proton irradiation

The double differential cross sections for the production of protons and deuterons from targets of Be, C, Al, Fe, Cu, Ge, W, and Pb were obtained at laboratory angles of scatter of 10, 20, 30, 40, 50, and 60 degrees for 558-MeV incident protons. The position of the quasi-elastic peak, discernible in the cross sections up to approximately 40 degrees, corresponded closely to the theoretical predictions for proton-proton elastic scattering at 558 MeV. The mean ratio of deuteron to proton energy-integrated cross sections was 0.056 + or - 0.008. The dependence of energy-integrated cross sections for both protons and deuterons on target mass number A varied from A to the 1/3 power at 10 degrees to A to the 2/3 power above approximately 30 degrees. The ratio of energy-integrated deuteron cross sections for quasielastic processes to that for reactions yielding a deuteron-pi-meson pair was approximately 10 percent.

Beck, S. M.↗
NASA NTRS1975

A two-parameter scintillation spectrometer system for measurement of secondary proton, deuteron, and triton distributions from materials under 558-MeV-proton irradiation

A two-parameter scintillation spectrometer system developed and used to obtain proton, deuteron, and triton double differential cross sections from materials under 558-MeV-proton irradiation is described. The system measures both the time of flight of secondary particles over a 488-cm flight path and the energy deposited in a scintillator, 12.7 cm in diameter and 30.48 cm long. The time resolution of the system is 0.39 nsec. The calculated energy resolution based on this time resolution varies with energy from 1.6 precent to 7.75 percent for 50- and 558-MeV protons. Various systematic and statistical errors are evaluated, and the double differential cross sections for secondary proton and deutron production at 20 deg from a 2.35 g/sq cm thick beryllium target are shown as an example of the results obtainable with this system. The uncertainly in the cross sections for secondary protons varies with particle energy from approximately + or - 9 percent at 50 MeV to approximately + or - 11 percent at 558 MeV.

Beck, S. M.↗