Engineering topics

Remsberg, Ellis E.

Publications and source records attributed to Remsberg, Ellis E..

At least 19 records

NASA NTRS2012

Remote Measurement of Pollution-A 40-Year Langley Retrospective: Aerosols and Clouds - Part 2

A workshop was convened in 1971 by the National Aeronautics and Space Administration (NASA) on the Remote Measurement of Pollution (RMOP), and the findings and recommendations of its participants are in a NASA Special Publication (NASA SP-285). The three primary workshop panels and their chairmen were focused on trace gas species (Will Kellogg), atmospheric particulates or aerosols (Verner Suomi), and water pollution (Gifford Ewing). Many of the workshop participants were specialists in the techniques that might be employed for regional to global-scale, remote measurements of the atmospheric parameters from Earth-orbiting satellites. In 2011 the author published a 40-year retrospective (or Part I) of the instrumental developments that were an outgrowth of the RMOP panel headed by Will Kellogg, i.e., on atmospheric temperature and gaseous species. The current report (or Part II) is an analogous retrospective of the vision of the panel led by Verner Suomi for the measurement of particulates (or aerosols) and clouds and for their effects on Earth s radiation budget. The class of measurement techniques includes laser radar or lidar, solar occultation, limb emission and scattering, nadir-viewing photometry or radiometry, and aerosol polarimetry. In addition, the retrospective refers to the scientific imperatives that led to those instrument developments of 1971-2010. Contributions of the atmospheric technologists at the Langley Research Center are emphasized, and their progress is placed in the context of the parallel and complementary work from within the larger atmospheric science community.

Remsberg, Ellis E.↗

NASA NTRS2012

Ozone Temperature Correlations in the Upper Stratosphere as a Measure of Chlorine Content

We use data from the Nimbus-7 Limb Infrared Monitor of the Stratosphere (LIMS) for the 1978-1979 period together with data from the Upper Atmosphere Research Satellite Microwave Limb Sounder (UARS MLS) for the years 1993 to 1999, the Aura MLS for the years 2004 to 2011, and the Aura High Resolution Infrared Limb Sounder (HIRDLS) for the years 2005 to 2007 to examine ozone-temperature correlations in the upper stratosphere. Our model simulations indicate that the sensitivity coefficient of the ozone response to temperature (Delta ln(O3)/Delta.(l/T)) decreases as chlorine has increased in the stratosphere and should increase in the future as chlorine decreases. The data are in agreement with our simulation of the past. We also find that the sensitivity coefficient does not change in a constant-chlorine simulation. Thus the change in the sensitivity coefficient depends on the change in chlorine, but not on the change in greenhouse gases. We suggest that these and future data can be used to track the impact of chlorine added to the stratosphere and also to track the recovery of the stratosphere as chlorine is removed under the provisions of the Montreal Protocol.

Stolarski, Richard S.↗

NASA NTRS2011

Remote Measurement of Pollution - A 40-Year Langley Retrospective: Temperature and Gaseous Species - Part 1

The National Aeronautics and Space Administration (NASA) phased down its Apollo Moon Program after 1970 in favor of a partly reusable Space Shuttle vehicle that could be used to construct and supply a manned, Earth-orbiting Space Station. Applications programs were emphasized in response to the growing public concern about Earth's finite natural resources and the degradation of its environment. Shortly thereafter, a workshop was convened in Norfolk, Virginia, on Remote Measurement of Pollution (or RMOP), and its findings are in a NASA Special Publication (NASA SP-285). The three primary workshop panels and their chairmen were focused on trace gas species (Will Kellogg), atmospheric particulates or aerosols (Verner Suomi), and water pollution (Gifford Ewing). Many of the workshop participants were specialists in the techniques that might be employed for the regional to global-scale, remote measurements from an Earth-orbiting satellite. The findings and recommendations of the RMOP Report represent the genesis of and a blueprint for the satellite, atmospheric sensing programs within NASA for nearly two decades. This paper is a brief, 40-year retrospective of those instrument developments that were an outgrowth of the RMOP activity. Its focus is on satellite measurement capabilities for temperature and gaseous species that were demonstrated by atmospheric technologists at the Langley Research Center. Limb absorption by solar occultation, limb infrared radiometry, and gas filter correlation radiometry techniques provided significant science data, so they are emphasized in this review.

Remsberg, Ellis E.↗

NASA NTRS2010

LIMS Version 6 Level 3 Dataset

This report describes the Limb Infrared Monitor of the Stratosphere (LIMS) Version 6 (V6) Level 3 data products and the assumptions used for their generation. A sequential estimation algorithm was used to obtain daily, zonal Fourier coefficients of the several parameters of the LIMS dataset for 216 days of 1978-79. The coefficients are available at up to 28 pressure levels and at every two degrees of latitude from 64 S to 84 N and at the synoptic time of 12 UT. Example plots were prepared and archived from the data at 10 hPa of January 1, 1979, to illustrate the overall coherence of the features obtained with the LIMS-retrieved parameters.

Remsberg, Ellis E.↗

NASA NTRS2009

Observations of Infrared Radiative Cooling in the Thermosphere on Daily to Multiyear Timescales from the TIMED/SABER Instrument

We present observations of the infrared radiative cooling by carbon dioxide (CO2) and nitric oxide (NO) in Earth s thermosphere. These data have been taken over a period of 7 years by the SABER instrument on the NASA TIMED satellite and are the dominant radiative cooling mechanisms for the thermosphere. From the SABER observations we derive vertical profiles of radiative cooling rates (W/cu m), radiative fluxes (W/sq m), and radiated power (W). In the period from January 2002 through January 2009 we observe a large decrease in the cooling rates, fluxes, and power consistent with the declining phase of solar cycle. The power radiated by NO during 2008 when the Sun exhibited few sunspots was nearly one order of magnitude smaller than the peak power observed shortly after the mission began. Substantial short-term variability in the infrared emissions is also observed throughout the entire mission duration. Radiative cooling rates and radiative fluxes from NO exhibit fundamentally different latitude dependence than do those from CO2, with the NO fluxes and cooling rates being largest at high latitudes and polar regions. The cooling rates are shown to be derived relatively independent of the collisional and radiative processes that drive the departure from local thermodynamic equilibrium (LTE) in the CO2 15 m and the NO 5.3 m vibration-rotation bands. The observed NO and CO2 cooling rates have been compiled into a separate dataset and represent a climate data record that is available for use in assessments of radiative cooling in upper atmosphere general circulation models.

Mlynczak, Martin G.↗

NASA NTRS2009

Trends and Solar Cycle Effects in Temperature Versus Altitude From the Halogen Occultation Experiment for the Mesosphere and Upper Stratosphere

Fourteen-year time series of mesospheric and upper stratospheric temperatures from the Halogen Occultation Experiment (HALOE) are analyzed and reported. The data have been binned according to ten-degree wide latitude zones from 40S to 40N and at 10 altitudes from 43 to 80 km-a total of 90 separate time series. Multiple linear regression (MLR) analysis techniques have been applied to those time series. This study focuses on resolving their 11-yr solar cycle (or SC-like) responses and their linear trend terms. Findings for T(z) from HALOE are compared directly with published results from ground-based Rayleigh lidar and rocketsonde measurements. SC-like responses from HALOE compare well with those from lidar station data at low latitudes. The cooling trends from HALOE also agree reasonably well with those from the lidar data for the concurrent decade. Cooling trends of the lower mesosphere from HALOE are not as large as those from rocketsondes and from lidar station time series of the previous two decades, presumably because the changes in the upper stratospheric ozone were near zero during the HALOE time period and did not affect those trends.

Remsberg, Ellis E.↗

NASA NTRS2008

Errors in Sounding of the Atmosphere Using Broadband Emission Radiometry (SABER) Kinetic Temperature Caused by Non-Local Thermodynamic Equilibrium Model Parameters

The vast set of near global and continuous atmospheric measurements made by the SABER instrument since 2002, including daytime and nighttime kinetic temperature (T(sub k)) from 20 to 105 km, is available to the scientific community. The temperature is retrieved from SABER measurements of the atmospheric 15 micron CO2 limb emission. This emission separates from local thermodynamic equilibrium (LTE) conditions in the rarefied mesosphere and thermosphere, making it necessary to consider the CO2 vibrational state non-LTE populations in the retrieval algorithm above 70 km. Those populations depend on kinetic parameters describing the rate at which energy exchange between atmospheric molecules take place, but some of these collisional rates are not well known. We consider current uncertainties in the rates of quenching of CO2 (v2 ) by N2 , O2 and O, and the CO2 (v2 ) vibrational-vibrational exchange to estimate their impact on SABER T(sub k) for different atmospheric conditions. The T(sub k) is more sensitive to the uncertainty in the latter two and their effects depend on altitude. The T(sub k) combined systematic error due to non-LTE kinetic parameters does not exceed +/- 1.5 K below 95 km and +/- 4-5 K at 100 km for most latitudes and seasons (except for polar summer) if the Tk profile does not have pronounced vertical structure. The error is +/- 3 K at 80 km, +/- 6 K at 84 km and +/- 18 K at 100 km under the less favourable polar summer conditions. For strong temperature inversion layers, the errors reach +/- 3 K at 82 km and +/- 8 K at 90 km. This particularly affects tide amplitude estimates, with errors of up to +/- 3 K.

Garcia-Comas, Maya↗

NASA NTRS2008

The Evolution of the Stratopause during the 2006 Major Warming: Satellite Data and Assimilated Meteorological Analyses

Microwave Limb Sounder and Sounding of the Atmosphere with Broadband Emission Radiometry data provide the first opportunity to characterize the four-dimensional stratopause evolution throughout the life-cycle of a major stratospheric sudden warming (SSW). The polar stratopause, usually higher than that at midlatitudes, dropped by 30 km and warmed during development of a major "wave 1" SSW in January 2006, with accompanying mesospheric cooling. When the polar vortex broke down, the stratopause cooled and became ill-defined, with a nearly isothermal stratosphere. After the polar vortex started to recover in the upper stratosphere/lower mesosphere (USLM), a cool stratopause reformed above 75 km, then dropped and warmed; both the mesosphere above and the stratosphere below cooled at this time. The polar stratopause remained separated from that at midlatitudes across the core of the polar night jet. In the early stages of the SSW, the strongly tilted (westward with increasing altitude) polar vortex extended into the mesosphere, and enclosed a secondary temperature maximum extending westward and slightly equatorward from the highest altitude part of the polar stratopause over the cool stratopause near the vortex edge. The temperature evolution in the USLM resulted in strongly enhanced radiative cooling in the mesosphere during the recovery from the SSW, but significantly reduced radiative cooling in the upper stratosphere. Assimilated meteorological analyses from the European Centre for Medium-Range weather Forecasts (ECMWF) and Goddard Earth Observing System Version 5.0.1 (GEOS-5), which are not constrained by data at polar stratopause altitudes and have model tops near 80 km, could not capture the secondary temperature maximum or the high stratopause after the SSW; they also misrepresent polar temperature structure during and after the stratopause breakdown, leading to large biases in their radiative heating rates. ECMWF analyses represent the stratospheric temperature structure more accurately, suggesting a better representation of vertical motion; GEOS-5 analyses more faithfully describe stratopause level wind and wave amplitudes. The high-quality satellite temperature data used here provide the first daily, global, multiannual data sets suitable for assessing and, eventually, improving representation of the USLM in models and assimilation systems.

Manney, Gloria L.↗

NASA NTRS2008

Solar-Terrestrial Coupling Evidenced by Periodic Behavior in Geomagnetic Indexes and the Infrared Energy Budget of the Thermosphere

We examine time series of the daily global power (W) radiated by carbon dioxide (at 15 microns) and by nitric oxide (at 5.3 microns) from the Earth s thermosphere between 100 km and 200 km altitude. Also examined is a time series of the daily absorbed solar ultraviolet power in the same altitude region in the wavelength span 0 to 175 nm. The infrared data are derived from the SABER instrument and the solar data are derived from the SEE instrument, both on the NASA TIMED satellite. The time series cover nearly 5 years from 2002 through 2006. The infrared and solar time series exhibit a decrease in radiated and absorbed power consistent with the declining phase of the current 11-year solar cycle. The infrared time series also exhibits high frequency variations that are not evident in the solar power time series. Spectral analysis shows a statistically significant 9-day periodicity in the infrared data but not in the solar data. A very strong 9-day periodicity is also found to exist in the time series of daily A(sub p) and K(sub p) geomagnetic indexes. These 9-day periodicities are linked to the recurrence of coronal holes on the Sun. These results demonstrate a direct coupling between the upper atmosphere of the Sun and the infrared energy budget of the thermosphere.

Mlynczak, Martin G.↗

NASA NTRS2007

The Evolution of the Stratopause During the 2006 Major Warming: Satellite Data and Assimilated Meteorological Analyses

Microwave Limb Sounder and Sounding of the Atmosphere with Broadband Emission Radiometry data show the polar stratopause, usually higher than and separated from that at midlatitudes, dropping from <55-60 to near 30 km, and cooling dramatically in January 2006 during a major stratospheric sudden warming (SSW). After a nearly isothermal period, a cool stratopause reforms near 75 km in early February, then drops to <55 km and warms. The stratopause is separated in longitude as well as latitude, with lowest temperatures in the transition regions between higher and lower stratopauses. Operational assimilated meteorological analyses, which are not constrained by data at stratopause altitude, do not capture a secondary temperature maximum that overlies the stratopause or the very high stratopause that reforms after the SSW; they underestimate the stratopause altitude variation during the SSW. High-quality daily satellite temperature measurements are invaluable in improving our understanding of stratopause evolution and its representation in models and assimilation systems.

Manney, Gloria L.↗

NASA NTRS2007

Solar Occultation Satellite Data and Derived Meteorological Products: Sampling Issues and Comparisons with Aura MLS

Derived Meteorological Products (DMPs, including potential temperature (theta), potential vorticity, equivalent latitude (EqL), horizontal winds and tropopause locations) have been produced for the locations and times of measurements by several solar occultation (SO) instruments and the Aura Microwave Limb Sounder (MLS). DMPs are calculated from several meteorological analyses for the Atmospheric Chemistry Experiment-Fourier Transform Spectrometer, Stratospheric Aerosol and Gas Experiment II and III, Halogen Occultation Experiment, and Polar Ozone and Aerosol Measurement II and III SO instruments and MLS. Time-series comparisons of MLS version 1.5 and SO data using DMPs show good qualitative agreement in time evolution of O3, N2O, H20, CO, HNO3, HCl and temperature; quantitative agreement is good in most cases. EqL-coordinate comparisons of MLS version 2.2 and SO data show good quantitative agreement throughout the stratosphere for most of these species, with significant biases for a few species in localized regions. Comparisons in EqL coordinates of MLS and SO data, and of SO data with geographically coincident MLS data provide insight into where and how sampling effects are important in interpretation of the sparse SO data, thus assisting in fully utilizing the SO data in scientific studies and comparisons with other sparse datasets. The DMPs are valuable for scientific studies and to facilitate validation of non-coincident measurements.

Manney, Gloria↗

NASA NTRS2007

A Reanalysis for the Seasonal and Longer-Period Cycles and the Trends in Middle Atmosphere Temperature from the HALOE

Previously published analyses for the seasonal and longer-period cycles in middle atmosphere temperature versus pressure (or T(p)) from the Halogen Occultation Experiment (HALOE) are extended to just over 14 years and updated to properly account for the effects of autocorrelation in its time series of zonally-averaged data. The updated seasonal terms and annual averages are provided, and they can be used to generate temperature distributions that are representative of the period 1991-2005. QBO-like terms have also been resolved and are provided, and they exhibit good consistency across the range of latitudes and pressure-altitudes. Further, exploratory analyses of the residuals from each of the 221 time series have yielded significant 11-yr solar cycle (or SC-like) and linear trend terms at a number of latitudes and levels. The amplitudes of the SC-like terms for the upper mesosphere agree reasonably with calculations of the direct solar radiative effects for T(p). Those SC amplitudes increase by about a factor of 2 from the lower to the upper mesosphere and are also larger at the middle than at the low latitudes. The diagnosed cooling trends for the subtropical latitudes are in the range, -0.5 to -1.0 K/decade, which is in good agreement with the findings from models of the radiative effects on pressure surfaces due to known increases in atmospheric CO2. The diagnosed trends are somewhat larger than predicted with models for the upper mesosphere of the northern hemisphere middle latitudes.

Remsberg, Ellis E.↗

NASA NTRS2006

On the Observed Changes in Upper Stratospheric and Mesospheric Temperatures from UARS HALOE

Temperature versus pressure or T(p) time series from the Halogen Occultation Experiment (HALOE) on the Upper Atmosphere Research Satellite (UARS) have been extended and re-analyzed for the period of 1991-2005 and for the upper stratosphere and mesosphere in 10-degree wide latitude zones from 60S to 60N. Even though sampling from a solar occultation experiment is somewhat limited, it is shown to be quite adequate for developing both the seasonal and longer-term variations in T(p). Multiple linear regression (MLR) techniques were used in the re-analyses for the seasonal and the significant interannual, solar cycle (SC-like or decadal-scale), and linear trend terms. A simple SC-like term of 11-yr period was fitted to the time series residuals after accounting for the seasonal and interannual terms. Highly significant SC-like responses were found for both the upper mesosphere and the upper stratosphere. The phases of these SC-like terms were checked for their continuity with latitude and pressure-altitude, and in almost all cases they are directly in-phase with that of standard proxies for the solar flux variations. The analyzed, max minus min, responses at low latitudes are of order 1 K, while at middle latitudes they are as large as 3 K in the upper mesosphere. Highly significant, linear cooling trends were found at middle latitudes of the middle to upper mesosphere (about -2 K/decade), at tropical latitudes of the middle mesosphere (about -1 K/decade), and at 2 hPa (or order -1 K/decade).

Remsberg, Ellis E.↗

NASA NTRS2001

Data Comparison: Satellite and Falling Sphere Temperatures

Small meteorological rocketsondes providing temperature data have beam used for comparison with, and validation of measurements from satellite-borne instruments. A significant number of rocket-borne falling spheres were launched in conjunction with the Upper Atmosphere Research Satellite (UARS) for validation of the Halogen Occultation Experiment (HALOE), High Resolution Doppler Interferometer (HRDI), and the Microwave Limb Sounder (MLS) instruments. Upper stratosphere and mesosphere temperatures measured with these instruments on UARS are compared with inflatable spheres launched from Wallops Island (1992-1999), Brazil (1994), Hawaii (1992), Norway (1992), and Sweden (1993 and 1996). Time and space differences varied between the satellite measurement and the rocketsonde launch, for example HALOE overpasses occurred within 5 days and in some cases there were spatial differences of up to 30 degrees longitude. Validation measurements of the HRDI instrument occurred at Wallops Island when it passed within 20 minutes and 330 kilometers of the launch site. Because of discontinuity in the falling sphere drag coefficients when fall speed neared MACH 1 falling sphere temperatures near 70 kilometers attitude are biased toward lower temperatures. Availability of improved software and a new atmospheric model have helped to reduce this bias. The validated remote instrument measurements permit a new perspective of atmospheric structure to be formed, not always possible with the limited number of falling sphere measurements. Features of the remote measurement temperature profiles and their possible use to extend the climatological data base at the rocketsonde sites will be discussed.

Schmidlin, Francis J.↗

NASA NTRS1999

An Evaluation of the Quality of Halogen Occultation Experiment Ozone Profiles in the Lower Stratosphere

The archived ozone profiles from the Halogen Occultation Experiment (HALOE) have already been corrected for the effects of the spectrally varying, interfering absorption due to aerosols composed of aqueous sulfuric acid, and agreement with correlative measurements in the stratosphere is generally excellent. However, comparisons of sets of coincident HALOE and ozonesonde profiles indicate occasional large differences at the lowest levels of the stratosphere. Most of those instances occur at altitudes just below a well-defined minimum in the 5.26 microns channel aerosol extinction profile, whose wavelength dependence is not represented by a sulfuric acid aerosol model. Further, when the aerosol extinction exceeds about 10(exp 3)/ km, the aerosol correction to the ozone channel transmittances is both large and uncertain. After screening out the HALOE ozone profile segments whose corresponding aerosol/cirrus corrections are likely uncertain and after averaging lie ozonesonde profiles into 2.5 km thick layers, we find that the HALOE ozone areas, on average, to within 10% of their coincident ozonesonde measurements down to 100 hPa at tropical/subtropical latitudes and to 200 hPa at extratropical latitudes. A tightening of the coincidence criteria for the comparisons does not improve the mean differences for the sets nearly as much. Part of the variance of the paired differences was also accounted for when the ozonesonde profile values were integrated into those 2.5 km layers, prior to taking differences. This improvement is due mainly to the vertical averaging of the local, higher-resolution ozonesonde data, matching the lower resolution for HALOE ozone in the lower stratosphere. It is concluded that HALOE is providing accurate ozone profiles throughout the lower stratosphere, when its correction for interfering aerosols has been well characterized and when cirrus layers are not indicated.

Bhatt, Praful P.↗

NASA NTRS1994

An assessment of satellite temperature distributions used to derive the net diabatic transport for zonally averaged models of the middle atmosphere

Determinations of the zonally averaged and diabatically derived residual mean circulation (RMC) are particularly sensitive to the assumed zonal mean temperature distribution used as input. Several different middle atmosphere satellite temperature distributions have been employed in models and are compared here: a 4-year (late 1978 to early 1982) National Meteorological Center (NMC) climatology, the Barnett and Corney (or BC) climatology, and the 7 months of Nimbus 7 limb infrared monitor of the stratosphere (LIMS) temperatures. All three climatologies are generally accurate below the 10 hPa level, but there are systematic differences between them of up to +/-5 K in the upper stratosphere and lower mesosphere. The NMC/LIMS differences are evaluated using time series of rocketsonde and reconstructed satellite temperatures at station locations. Much of those biases can be explained by the differing vertical resolutions for the satellite-derived temperatures; the time series of reconstructed LIMS profiles have higher resolution and are more accurate. Because the LIMS temperatures are limited to just two full seasons, one cannot obtain monthly RMCs from them for an annual model calculation. Two alternate monthly climatologies are examined briefly: the 4-year Nimbus 7 stratospheric and mesospheric sounder (SAMS) temperatures and for the mesosphere the distribution from the Solar Mesosphere Explorer (SME), both of which are limb viewers of medium vertical resolution. There are also differences of the order of +/-5 K for those data sets. It is concluded that a major source of error in the determination of diabatic RMCs is a persistent pattern of temperature bias whose characteristics vary according to the vertical resolution of each individual climatology.

Remsberg, Ellis E.↗

NASA NTRS1994

Ground-based microwave observations of ozone in the upper stratosphere and mesosphere

A 9-month-long series of mesurements of ozone in the upper stratosphere and mesosphere is reported. The measurements are presented as monthly averages of profiles in blocks of roughly 20 min local time and as night-to-day ratios. An error analysis predicts accuracies of 5-26% for the monthly profiles and 2.5-9% for the ratios. The data are compared to historical data from Solar Mesosphere Explorer (SME) and limb infrared monitor of the stratosphere (LIMS), and it is shown how to remove the effect of different vertical resolution from the comparisons. The microwave data typically agree to better than 10% with SMF and nighttime LIMS ozone at all altitudes below the 0.1-mbar surface. Comparison of the microwave night-to-day ratio with the corresponding ratio from LIMS suggests that nonlocal thermodynamic equilibrium effects in the LIMS daytime data exceed 10% at all pressures less than or equal to 1 mbar.

Connor, Brian J.↗

NASA NTRS1994

On the determination of biases in satellite-derived temperature profiles

Comparisons are presented between Nimbus 7 LIMS (Limb Infrared Monitor of the Stratosphere) mapped temperatures and both Datasonde and sphere in situ rocketsonde temperature measurements. With this approach up to 666 LIMS/Datasonde pairs were obtained for various pressure levels to look for small biases in LIMS temperatures as a function of altitude, latitude and season. Between 10-1 hPa LIMS and Datasonde agree everywhere to better than +/- 2 K with the exception of a warm bias of about 3 K at 2 hPa at high latitudes. However, LIMS is colder than the Datasonde by about 4 K at 0.4 hPa and by about 8-10 K at 0.1 hPa. When compared with the more accurate sphere temperatures the bias at 0.1 hPa is reduced by nearly one-half. These results indicate that the LIMS zonal mean constituent profiles are nearly free of temperature bias, except perhaps at 0.1 hPa.

Bhatt, Praful P.↗