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Newman, P.

Publications and source records attributed to Newman, P..

16 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2005

The CRYSTAL-FACE Mission

The Cirrus Regional Study of Tropical Anvils and Cirrus Layers - Florida Area Cirrus Experiment (CRYSTAL-FACE) was a measurement campaign designed to investigate tropical cirrus cloud physical properties and formation processes. Understanding the production of upper tropospheric cirrus clouds is essential for the successful modeling of the Earth's climate. The mission was staged in July 2002 with flights of 6 aircraft from Key West, Florida. Several aircraft were used for in situ and remote sensing of aerosols, ice crystals, meteorological fields, radiative fluxes, and gas concentrations. The NASA ER-2 and WB-57, the Proteus aircraft, owned by Northrop Grumman and operated by Scaled Composites, CIRPAS provided the DeHavilland UV-l8A, "Twin Otter" aircraft, the University of North Dakota provided a Cessna Citation II aircraft , and NSF supported the ELDORA radar onboard the Naval Research Laboratory P-3 aircraft. In this presentation, I will describe some of the flights, the conditions, and some of the results from the mission.

Newman, P.↗
NASA NTRS2004

The Antarctic Ozone Hole: Initial Results from Aura / OMI Compared with TOMS

A series of TOMS instruments (on November 7 , Meteor 3, and Earth Probe) has been monitoring the annual development of the Antarctic ozone hole since the 1980s. The ozone mapping instrument on Aura, OMI, is expected to take over this record of observation from the aging Earth Probe TOMS instrument. The area of the ozone hole can be taken as a sensitive indicator of the magnitude of ozone destruction each year. The timing of initial formation of the ozone hole and its duration are sensitive to the atmospheric dynamics of the southern polar regions. The entire TOMS data record (1978 - 2004) has recently been reprocessed with the new version 8 algorithm, which includes a revised calibration. The effect has been to slightly increase ozone hole area over earlier estimates, but only by 23%. OMI (ozone monitoring instrument) on Aura is a hyperspectral imaging instrument that operates in a pushbroom mode to measure solar backscattered radiation in the ultraviolet and visible. OMI has higher spatial resolution than TOMS - 14 x 24 km versus 38 km x 38 km from TOMS. OMI has now begin mapping total column ozone on a global basis in a measurement similar to TOMS. The ozone hole measurements for 2003 are compared with those from Earth Probe TOMS.

McPeters, R.↗
NASA NTRS2004

UAVs: Current and Future Use

Uninhabited Aerial Vehicles (UAVs) provide ideal sampling platforms for atmospheric missions. In this presentation, I will: 1) review the atmospheric science missions that have used UAVs, 2) review and describe UAVs, 3) discuss the future of UAVs in atmospheric science missions.

Newman, P.↗
NASA NTRS2004

Comparison of Measurements: Cal/Val

Calibration and validation of satellite instruments is vital to long-term trend estimates of ozone and other trace species. A satellite instrument is calibrated by comparing it against a particular standard on the ground prior to launch or against know standards in flight. An instrument is validated by making a comparison of the same measurable or measurement. Validation is performed in a number of ways. In particular, measurements by ground, balloon, aircraft, and other satellite instruments are used to provide validation.

Newman, P.↗
NASA NTRS2004

Sensitivity of the FVGCM to Changes in Ozone

We have carried out an experiment with the finite volume general circulation model (FVGCM). This experiment consisted of two different imposed changes in the climatological ozone fields assumed in the radiation code. for conditions with no significant ozone hole. This distribution was obtained from a 50-year simulation of the full stratospheric ozone chemistry, with a time-dependent chlorine loading, done with our off-line chemical transport model (CTM). Three years (1978-1980) of this simulation were averaged to form a monthly, zonal-mean ozone distribution that was used in the 20-year integration of the FVGCM for "unperturbed" conditions. The second 20-year GCM integration included a fully-developed ozone hole. This ozone distribution was from three years, 1998-2000, from the same CTM simulation. The goal of this work is to determine the coupled response of the chemistry and dynamics of the stratosphere. These experiments are the first step in understanding the coupled response. An important initial question concerns the significance of the signals: if 20-year integrations turn out to be too short, the runs will be extended.

Stolarski↗
NASA NTRS2001

Chemistry-Climate Models of the Stratosphere

Over the last decade, improved computer power has allowed three-dimensional models of the stratosphere to be developed that can be used to simulate polar ozone levels over long periods. This paper compares the meteorology between these models, and discusses the future of polar ozone levels over the next 50 years.

Austin, J.↗
NASA NTRS1998

Lidar temperature measurements at NY-Alesund (79N) during winter, 1998

During January and February, 1998, a measurements campaign was held at the Network for the Detection of Stratospheric Change (NDSC) Arctic site at Ny-Alesund (78.9N). Lidar measurements of ozone, temperature and aerosol parameters were made along with balloon sonde and microwave measurements of ozone. Atmospheric temperatures were measured between 10 and 70 km. During the time of the campaign an strong warming occurred at the stratopause, elevating the measured temperature by as much as 80 K. The height of the stratopause descended at this time to below 40 km.

McGee, T. J.↗
NASA NTRS1993

Chlorine chemistry on polar stratospheric cloud particles in the Arctic winter

Simultaneous in situ measurements of hydrochloric acid (HCl) and chlorine monoxide (ClO) in the Arctic winter vortex showed large HCl losses of up to 1 ppbv, which were correlated with high ClO levels of up to 1.4 ppbv. Air parcel trajectory analysis identified that this conversion of inorganic chlorine occurred at air temperatures of less than 196 -/+ 4 kelvin. High ClO was always accompanied by loss of HCl mixing ratios equal to 1/2(ClO+ 2Cl2O2). These data indicate that the heterogeneous reaction HCl + ClONO2 - Cl2 + HNO3 on particles of polar stratospheric clouds establishes the chlorine partitioning, which, contrary to earlier notions, begins with an excess of ClONO2, not HCl.

Webster, C. R.↗
NASA NTRS1993

Heterogeneous reaction probabilities, solubilities, and the physical state of cold volcanic aerosols

On 19 January 1992, heterogeneous loss of HNO3, ClNO3, and HCl was observed in part of the Mount Pinatubo volcanic cloud that had cooled as a result of forced ascent. Portions of the volcanic cloud froze near 191 kelvin. The reaction probability of ClNO3 and the solubility of HNO3 were close to laboratory measurements on liquid sulfuric acid. The magnitude of the observed loss of HCl suggests that it underwent a heterogeneous reaction. Such reactions could lead to substantial loss of HCl on background sulfuric acid particles and so be important for polar ozone loss.

Toon, O.↗
NASA NTRS1993

Stratospheric meteorological conditions in the Arctic polar vortex, 1991 to 1992

Stratospheric meteorological conditions during the Airborne Arctic Stratospheric Expedition II (AASE II) presented excellent observational opportunities from Bangor, Maine, because the polar vortex was located over southeastern Canada for significant periods during the 1991-1992 winter. Temperature analyses showed that nitric acid trihydrates (NAT temperatures below 195 K) should have formed over small regions in early December. The temperatures in the polar vortex warmed beyond NAT temperatures by late January (earlier than normal). Perturbed chemistry was found to be associated with these cold temperatures.

Newman, P.↗
NASA NTRS1993

Record low global ozone in 1992

The 1992 global average total ozone, measured by the Total Ozone Mapping Spectrometer (TOMS) on the Nimbus-7 satellite, was 2 to 3 percent lower than any earlier year observed by TOMS (1979 to 1991). Ozone amounts were low in a wide range of latitudes in both the Northern and Southern Hemispheres, and the largest decreases were in the regions from 10 to 20 deg S and 10 to 60 deg N. Global ozone in 1992 is at least 1.5 percent lower than would be predicted by a statistical model that includes a linear trend and accounts for solar cycle variation and the quasi-biennial oscillation. These results are confirmed by comparisons with data from other ozone monitoring instruments: the SBUV/2 instrument on the NOAA-11 satellite, the TOMS instrument on the Russian Meteor-3 satellite, the World Standard Dobson Instrument 83, and a collection of 22 ground-based Dobson instruments.

Gleason, J. F.↗
NASA NTRS1992

Automatic differentiation of advanced CFD codes for multidisciplinary design

Automated multidisciplinary design of aircraft and other flight vehicles requires the optimization of complex performance objectives with respect to a number of design parameters and constraints. The effect of these independent design variables on the system performance criteria can be quantified in terms of sensitivity derivatives which must be calculated and propagated by the individual discipline simulation codes. Typical advanced CFD analysis codes do not provide such derivatives as part of a flow solution; these derivatives are very expensive to obtain by divided (finite) differences from perturbed solutions. It is shown that sensitivity derivatives can be obtained accurately and efficiently using the ADIFOR source translator for automatic differentiation. In particular, it is demonstrated that the 3-D, thin-layer Navier-Stokes, multigrid flow solver called TLNS3D is amenable to automatic differentiation in the forward mode even with its implicit iterative solution algorithm and complex turbulence modeling. It is significant that by using computational differentiation, consistent discrete nongeometric sensitivity derivatives have been obtained from an aerodynamic 3-D CFD code in a relatively short time, e.g., O(man-week) not O(man-year).

Bischof, C.↗
NASA NTRS1990

Comparison of ozone profiles from ground-based lidar, electrochemical concentration cell balloon sonde, ROCOZ-A rocket ozonesonde, and Stratospheric Aerosol and Gas Experiment satellite measurements

A series of coordinated atmospheric ozone profile measurements was made during October and November 1988. Only SAGE II measurements made within 1000 km of both of the ground, sites were considered for this intercomparison study. It was found that, at least for the time of year of the study, SAGE II measurements agreed only when they were made much closer than 1000 km (less than 500 km) from the other sites, and this is explained in terms of the large latitudinal gradient observed in the ozone concentration profile. Agreement to 5 percent was seen between the instruments, over the altitude range from 20 to 50 km, when the measurements were made close together in both time and space.

Mcdermid, I. S.↗
NASA NTRS1985

Post flight analysis of NASA standard star trackers recovered from the solar maximum mission

The flight hardware returned after the Solar Maximum Mission Repair Mission was analyzed to determine the effects of 4 years in space. The NASA Standard Star Tracker would be a good candidate for such analysis because it is moderately complex and had a very elaborate calibration during the acceptance procedure. However, the recovery process extensively damaged the cathode of the image dissector detector making proper operation of the tracker and a comparison with preflight characteristics impossible. Otherwise, the tracker functioned nominally during testing.

Newman, P.↗
NASA NTRS1981

Applications systems verification and transfer project. Volume 7: Cost/benefit analysis for the ASVT on operational applications of satellite snow-cover observations

The results of the OASSO ASVT's were used to estimate the benefits accruing from the added information available from satellite snowcover area measurement. Estimates of the improvement in runoff prediction due to addition of SATSCAM were made by the Colorado ASVT personnel. The improvement estimate is 6-10%. Data were applied to subregions covering the Western States snow area amended by information from the ASVT and other watershed experts to exclude areas which are not impacted by snowmelt runoff. Benefit models were developed for irrigation and hydroenergy uses. The benefit/cost ratio is 72:1. Since only two major benefit contributors were used and since the forecast improvement estimate does not take into account future satellite capabilities these estimates are considered to be conservative. The large magnitude of the benefit/cost ratio supports the utility and applicability of SATSCAM.

Castruccio, P.↗