Engineering topics

Russell, J. M., III

Publications and source records attributed to Russell, J. M., III.

At least 37 records · Page 2

NASA NTRS1996

The Effects of Tropical Cirrus Clouds on the Abundance of Lower Stratospheric Ozone

The distribution of many chemical constituents of the atmosphere (e.g., ozone) is at least partially determined by the, distribution of net radiative heating in the atmosphere. In this paper, we demonstrate the significant effect of high cirrus clouds on the net radiative heating of the tropical lower stratosphere. A model of tropical lower stratospheric ozone is then used to demonstrate the sensitivity of calculated ozone to the varying cloud cover used in the model. We conclude that calculated ozone is sensitive to the inclusion of clouds in models and that models of the atmosphere should include a realistic description of tropical cirrus clouds in order to accurately simulate the chemical composition of the atmosphere.

Dessler, A. E.↗

NASA NTRS1996

The Effects of Tropical Cirrus Clouds on the Abundance of Lower Stratospheric Ozone

The distribution of many chemical constituents of the atmosphere (e.g., ozone) is at least partially determined by the distribution of net radiative heating in the atmosphere. In this paper, we demonstrate the significant effect of high cirrus clouds on the net radiative heating of the tropical lower stratosphere. A model of tropical lower stratospheric ozone is then used to demonstrate the sensitivity of calculated ozone to the varying cloud cover used in the model. We conclude that calculated ozone is sensitive to the inclusion of clouds in models and that models of the atmosphere should include a realistic description of tropical cirrus clouds in order to accurately simulate the chemical composition of the atmosphere.

Dessler, A. E.↗

NASA NTRS1994

Hydrochloric acid and the chlorine budget of the lower statosphere

Concentrations of HCl measurements in the lower stratosphere in 1993 by the ALIAS instrument on the ER-2 aircraft reveal that only 40% of inorganic chlorine (Cl(y), inferred from in situ measurements of organic chlorinated sources gases) is present as HCl, significantly lower than model predictions. Although the sum of measured HCl, ClO and ClONO2, the latter inferred from measurements of ClO and NO2 equals Cl(y) to within the incertainty of measurement, it is systematically less than Cl(y) by 30-50%. This discrepancy suggests that concentrations of ClONO2 may exceed those of HC; near 20 km altitude, consistent with a slower photolysis rate for ClONO2 than calculated using recommended cross sections. Comparison of profiles of HCl measured during 1992 and 1193 at mid-latitudes by balloon (BLISS and MARKIV), space shuttle (ATMOS), and satellite (HALOE) instruments with the aircraft data reveal an apparent pressure dependence to the HCl to Cl(y) ratio, consistent with a factor of 3-10 reduction in the photolysis rate for ClONO2 at ER-2 altitudes. However, the diurnal variation of ClO is well-simulated by models using the recommended photolysis rate, and simulations measurements of ClONO2 and HCl at mid-latitudes by ATMOS and MARKIV report HCl (HCL+ ClONO2) ratios greater than or equal to 50%. Premliminary measurements by ALIAS in the southern hemisphere report HCl/Cl(y) values of about 75%.

Webster, C. R.↗

NASA NTRS1994

Synoptic interpretation of measurements from HALOE

The degree to which the Southern Hemisphere polar vortex is isolated against horizontal (isentropic) mixing is investigated using data from the Halogen Occultation Experiment (HALOE), U.K. Meteorological Office (UKMO) potential vorticity (PV), and contour advection diagnostics. Measurements of methane and water vapor taken by HALOE during a disturbed period in the Southern Hemisphere springtime (21 September - 15 October 1992) are interpreted in light of the prevailing synoptic meteorology. Daily fields of winds and PV are shown to be essential in the interpretation of the data. A climatological high pressure region is responsible for a distorted vortex, and a substantial 'vortex stripping' event is present, associated with the early stages of vortex breakdown. This leads to significant temporal, zonal, and altitudinal variations in the distribution of tracers. The authors point out the difficulties this presents for the interpretation of solar occultation data, especially with regard to the use of zonal average time series. Longitude-height methane distributions from two days during the period are examined. Both days show substantial variations in abundance around a latitude circle. In particular, the authors investigate HALOE measurements at 77 deg S on 15 October 1992, which indicate an abundance of methane in the height region 600-2000 K (approximately 30-1 mb) that is more typical of midlatitude air. Similar distributions, observed in the 1991 HALOE data, have previously been interpreted as evidence for the penetration of midlatitude air into the vortex. Gradients of potential vorticity and contour advection diagnositcs are employed to examine whether the UKMO winds are consistent with this hypothesis in 1992. Although midlatitude air is able to penetrate poleward of the main jet core by advection processes alone, an essentially intact inner core of vortex air remains, which does not mix to any great extent with air from lower latitudes. The authors show that the high-latitude HALOE abundances that are typical of midlatitude air were observed in a region of extensive filamentation and mixing, rather than within the inner, more isolated, core.

Bithell, M.↗

NASA NTRS1994

An overview of the Halogen Occultation Experiment (HALOE) and preliminary results

The Halogen Occultation Experiment (HALOE) experiment has observed vertical profiles and pressure versus latitude cross sections of temperature HCl, HF, CH4, H2O, NO, NO2, O3, and aerosols over the range from 80 deg S to 80 deg N. An in-orbit precision of better than 0.3 ppbv has been demonstrated for HCl, HF, NO, NO2 and less than 0.6 ppmv for the other channels. Comparisons with correlative measurements at this early stage are encouraging. Nitric oxide has been observed over the range from the upper troposphere to 130-km. Latitudinal cross sections of the long-lived tracers CH4 and HF show clear indications of the effect of the general circulation.

Russell, J. M., III↗

NASA NTRS1993

Intercomparison of haloe and ER-2 aircraft H2O and CH4 observations collected during the second Airborne Arctic Stratospheric Experiment (AASE-II)

HALOE observations of H2O and CH4 are compared with in situ techniques aboard the ER-2 aircraft during the northern winter of 1991/92, in particular for the dates 911208, 920108, 920217, 920222, and 920320 when the spatial coincidences are close, within +/- 1 deg latitude and +/- 12 deg longitude. The results reveal the limitations of comparing high resolution in situ aircraft data with a remote sounding limb scanner. Of the five comparison dates, three had HALOE/ER-2 coincidences which occurred near the edge of the Arctic vortex; the vertical variability in the HALOE results and the horizontal variability in the ER-2 observations on these days show that the vortex edge is not a region where exact agreement can be expected except by chance. On a 4th comparison date, there was substantial overlap away from the vortex edge, although for some species the aircraft data show considerable variability near the coincidence point. On the 5th comparison date, the ER-2 had no overlap in altitude with the lowest HALOE observations; however, a short linear interpolation over about 1 km altitude results in smooth composite profiles. Generally speaking the agreement between HALOE and the ER-2 at overlap altitudes is about 12 percent in the case of water vapor, which shows low horizontal and vertical variability. The agreement for methane, with limited data having altitude overlap, is better than 6 percent.

Tuck, A. F.↗

NASA NTRS1992

The spectroscopy of the atmosphere using far-infrared emission experiment (SAFIRE)

The goal of the SAFIRE experiment is to improve understanding of the middle-atmospher ozone distribution by conducting and analyzing global-scale measurements of important chemical, radiative and dynamical processes, including coupling among these processes and atmospheric regions. This will be accomplished by observing vertical profiles of temperature and key gases in the main chemical families. A detailed listing of SAFIRE measurements, including sepctral ranges, altitude ranges, IFOV, spatial and temporal resolution, latitude coverage and estimated precision is provided. The temperature, O3, CH4, and H2O observations will be useful for deriving and studying dynamical quantities such as geopotential height, potential vorticity, balanced winds and Eliassen-Palm fluxes. The SAFIRE observations will provide important data for study of chemistry, dynamics and transport processes. This experiment was conceived in response to a need for simultaneous measurements of odd hydrogen gases. These include gases such as OH, HO2, and atomic oxygen, which have not been observed by past satellite experiments and which will not be measured by any of teh Upper Atmosophere Reserach Satellite (UARS) experiments to be launched in 1991.

Russell, J. M., III↗

NASA NTRS1990

An interim reference model for the variability of the middle atmosphere water vapor distribution

A reference model for the middle atmosphere water vapor distribution for some latitudes and seasons was developed using two data sets. One is the seven months of Nimbus LIMS data obtained during November 1978 to May 1979 over the range 64 deg S - 84 deg N latitude and from about 100-mb to 1-mb altitude, and the other is represented by water vapor profiles from 0.2 mb to 0.01 mb in the mid-mesosphere, measured on ground at several fixed mid-latitude sites in the Northern Hemisphere, using microwave-emission techniques. This model provides an interim water vapor profile for the entire vertical range of the middle atmosphere, with accuracies of better than 25 percent. The daily variability of stratospheric water vapor profiles about the monthly mean is demonstrated, and information is provided on the longitudinal variability of LIMS water vapor profiles about the daily, weekly, and monthly zonal means.

Remsberg, E. E.↗

NASA NTRS1989

An interim reference model for the variability of the middle atmosphere H2O vapor distribution

Water vapor is an important minor constituent in the studies of the middle atmosphere for a variety of reasons, including its role as a source for active HO(y) chemicals and its use in analysis of transport processes. A number of in situ and remote techniques were employed in the determination of water vapor distributions. Two of the more complete data sets were used to develop an interim reference profile. First, there are the seven months of Nimbus 7 limb infrared monitor of the stratosphere (LIMS) data obtained during Nov. 1978 to May 1979 over the range 64S to 84N latitude and from about 100 to 1 mb in the mid-mesosphere at several fixed Northern Hemisphere mid-latitude sites. These two data sets were combined to give a mid-lattitude, interim reference water vapor profile for the entire vertical range of the middle atmosphere and with accuracies of better than 25 percent. The daily variability of stratospheric water vapor profiles about the monthly mean was also established from these data sets for selected months. Information is also provided on the longitudinal variability of LIMS water vapor profiles about the daily, weekly, and monthly zonal means. Generally, the interim reference water vapor profile and its variability are consistent with prevailing ideas about chemistry and transport.

Remsberg, E. E.↗

NASA NTRS1988

Concentrations of carbonyl sulfide and hydrogen cyanide in the free upper troposphere and lower stratosphere deduced from ATMOS/Spacelab 3 infrared solar occultation spectra

This paper presents the results on the volume mixing ratio profiles of carbonyl sulfide and hydrogen cyanide, deduced from the spectroscopic analysis of IR solar absorption spectra obtained in the occultation mode with the Atmospheric Trace Molecule Spectroscopy (ATMOS) instrument during its mission aboard Spacelab 3. A comparison of the ATMOS measurements for both northern and southern latitudes with previous field investigations at low midlatitudes shows a relatively good agreement. Southern Hemisphere volume mixing ratio profiles for both molecules were obtained for the first time, as were the profiles for the Northern Hemisphere covering the upper troposphere and the lower stratosphere simultaneously.

Zander, R.↗

NASA NTRS1988

Measurements of odd nitrogen compounds in the stratosphere by the ATMOS experiment on Spacelab 3

Spacelab 3's Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment has obtained 30 deg N and 48 deg S vertical profiles of reservoir gases, source gases, and other trace molecules that are important in the middle atmosphere's odd nitrogen, odd chlorine, and odd hydrogen chemical families. The abundances of individual gases and total odd nitrogen levels measured by ATMOS have been compared with prior results obtained from balloon and satellite platforms. The lower-limit profile agrees with ATMOS data to within 16 percent up to 42 km altitude.

Russell, J. M., III↗

NASA NTRS1987

Concentrations of ethane (C2H6) in the lower stratosphere and upper troposphere and acetylene (C2H2) in the upper troposphere deduced from Atmospheric Trace Molecule Spectroscopy/Spacelab 3 spectra

This paper reports the results of the spectroscopic analysis of C2H6 and C2H2 absorption spectra obtained by the Atmospheric Trace Molecule Spectroscopy (ATMOS) instrument flown on the Shuttle as part of the Spacelab 3 mission. The spectra were recorded during sunset occultations occurring between 25 deg N and 31 deg N latitudes, yielding volume-mixing ratio profiles of C2H6 in the lower stratosphere and the upper troposphere, and an upper tropospheric profile of C2H2. These results compare well with previous in situ and remote sounding data obtained at similar latitudes and with model calculations. The results demonstrate the feasibility of the ATMOS instrument to sound the lower atmosphere from space.

Rinsland, C. P.↗

NASA NTRS1987

SAFIRE - A novel high resolution cooled spectrometer for atmospheric research

The SAFIRE (Spectroscopy of Atmospheric Far Infra-Red Emissions) experiment is discussed with particular reference to the scientific aims and the conceptual instrument design of the project. The principal requirements of the experiment are reviewed, and it is shown how these requirements are met in the instrument concept. In particular, measurements of hydrogen oxides and other important species in the stratosphere require a far infrared limb sounder. Some problems involved in the optical and thermal design of the instrument are examined.

Harries, J. E.↗

NASA NTRS1987

Comparison of Southern Hemisphere radiosonde and LIMS temperatures at 100 mb

Radiosonde (RS)and satellite-derived (Nimbus-7 LIMS) 100-mb temperatures over New Zealand at 12 GMT are compared for the 1978-79 summer. The colocated LIMS temperature information consists of synoptically mapped values (for 12 GMT), as well as the primary nighttime orbital retrievals valid at about 1030 GMT. The RS time series of temperature is dominated by temporal fluctuations associated mainly with the eastward passage of waves which have characteristic periods of 4-5 and 11-12 days and peak-to-peak amplitudes of 10-15 K. The LIMS temperatures and the corresponding temperature time series are also found to exhibit quite close agreement (in terms of temporal phase for the latter) with the RS data. However, the LIMS-mapped temperature fluctuations suffer from a noticeable attenuation in amplitude (approaching 50 percent for higher-frequency fluctuations), which will affect the accuracy of LIMS-derived estimates of dynamical quantities such as wind velocity and relative vorticity in the lower stratosphere.

Miles, T.↗

NASA NTRS1987

Retrieval of upper atmosphere pressure-temperature profiles from high resolution solar occultation spectra

Pressure-temperature profiles over the 18 to 75 km altitude range were retrieved from 0.01 cm(-1) resolution infrared solar absorption spectra recorded with the Atmospheric Trace Molecule Spectroscopy (ATMOS) Fourier transform spectrometer operating in the solar occultation mode during the Spacelab 3 shuttle mission (April 30 to May 1, 1985). The analysis method is described and preliminary results deduced for five occultation events are compared to correlative pressure-temperature measurments.

Rinsland, C. P.↗

NASA NTRS1987

An interim reference model for the middle atmosphere water vapor distribution

Nimbus 7 LIMS data are used to determine monthly and seasonal zonal mean reference stratospheric profiles over selected latitude bands, and other ground and airborne microwave data are combined with the LIMS data to construct an interim reference profile from the tropopause to 80 km for the midlatitude region averaged over the winter and spring periods. The present profiles indicate the presence of a hygropause near 50 mb pressure in the tropics, a relatively constant mixing ratio distribution with a height of 4.7-5 ppmv in the midlatitude and high latitude stratosphere, and a decrease in the midlatitude mesosphere to 1 ppmv at about 80 km.

Russell, J. M., III↗

NASA NTRS1987

About a possible reference model for stratospheric NO2

After a brief review of observations of the global distribution of stratospheric NO2, the possibiliy of combining different data sets to construct a NO2 reference model is discussed. It is shown that difficulties mainly arise from the diversity of techniques and variability of NO2 in the stratosphere. The diurnal variation and possibly a long term trend present special problems.

Naudet, J. P.↗

NASA NTRS1986

Description of data on the Nimbus 7 LIMS map archive tape: Ozone and nitric acid

The Nimbus 7 Limb Infrared Monitor of the Stratosphere (LIMS) data set has been processed into a Fourier coefficient representation with a Kalman filter algorithm applied to profile data at individual latitudes and pressure levels. The algorithm produces synoptic data at noon Greenwich Mean Time (GMT) from the asynoptic orbital profiles. This form of the data set is easy to use and is appropriate for time series analysis and further data manipulation and display. Ozone and nitric acid results are grouped together in this report because the LIMS vertical field of views (FOV's) and analysis characteristics for these species are similar. A comparison of the orbital input data with mixing ratios derived from Kalman filter coefficients indicates errors in mixing ratio of generally less than 5 percent, with 15 percent being a maximum error. The high quality of the mapped data was indicated by coherence of both the phases and the amplitudes of waves with latitude and pressure. Examples of the mapped fields are presented, and details are given concerning the importance of diurnal variations, the removal of polar stratospheric cloud signatures, and the interpretation of bias effects in the data near the tops of profiles.

Remsberg, E. E.↗