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Nitric oxide (NO) measurements from the Solar Occultation for Ice Experiment (SOFIE) are validated through detailed uncertainty analysis and comparisons with independent observations. SOFIE was compared with coincident satellite measurements from the Atmospheric Chemistry Experiment (ACE) - Fourier Transform Spectrometer (FTS) instrument and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument. The comparisons indicate mean differences of less than ĝ1/450 % for altitudes from roughly 50 to 105 km for SOFIE spacecraft sunrise and 50 to 140 km for SOFIE sunsets. Comparisons of NO time series show a high degree of correlation between SOFIE and both ACE and MIPAS for altitudes below ĝ1/4130 km, indicating that measured NO variability in time is robust. SOFIE uncertainties increase below ĝ1/480 km due to interfering H2O absorption and signal correction uncertainties, which are larger for spacecraft sunrise compared to sunset. These errors are sufficiently large in sunrises that reliable NO measurements are infrequent below 80 km.© Author(s) 2019., This research has been supported by NASA (grant no. NAS5-03132, Heliophysics Guest Investigator project 80NSSC19K0281).

Wind is the process that connects Mars’ climate system. Measurements of Mars atmospheric winds from orbit would dramatically advance our understanding of Mars and help prepare for human exploration. Multiple instruments in development will be ready for flight in the next decade. We urge the Decadal Survey to make these measurements a priority.

Nitric oxide (NO) measurements from the Solar Occultation for Ice Experiment (SOFIE) are validated through detailed uncertainty analysis and comparisons with independent observations. SOFIE was compared with coincident satellite measurements from the Atmospheric Chemistry Experiment (ACE) – Fourier Transform Spectrometer (FTS) instrument, and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument. The comparisons indicate mean differences of less than ~ 50 % for altitudes from roughly 50 to 105 km for SOFIE spacecraft sunrise, and 50 to 140 km for SOFIE sunsets. Comparisons of NO time series show a high degree of correlation between SOFIE and both ACE and MIPAS for altitudes below ~ 130 km, indicating that measured NO variability in time is robust. SOFIE uncertainties increase below ~ 80 km due to interfering H2O absorption, and from signal correction uncertainties which are larger for spacecraft sunrise compared to sunset. These errors are sufficiently large in sunrises that reliable NO measurements are infrequent below ~ 80 km.

The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) measured water vapor (H2O) had errors of unknown origin that were recently identified and corrected. The cause of the errors was determined to be unaccounted for spectral out-of-band (OOB) radiance in the H2O channel centered at 6.8 μm arising from ozone emission in the 9.6 μm band. The corrected SABER radiance profiles have been used to produce a long-term H2O data base labeled as version 2.07 (v2.07). Water vapor volume mixing ratio (VMR) vertical profiles are available in the SABER data archive covering the stratosphere and mesosphere extending from near the tropopause at ~100 hPa (~16 km) to the mesopause region at ~ 0.006 hPa (~83 km), and over the time period from 25 January 2002 to the present day. The random error of the v2.07 product is smaller than 4% at 60 km and below, while above this altitude it rapidly increases to 30% (at 80 km), mainly due to low signal-to-noise. The estimated systematic error of SABER v2.07 H2O is about 10–20%. Coincidence analysis between SABER v2.07, MLS v4.2, ACE v3.5-3.6, MIPAS ESA reprocessed v6, and SOFIE v1.3 shows overall excellent agreement in the mean profile with the mean difference being within ±10% in most cases. In the stratopause region SABER H2O tends to be biased high relative to each of the other data sets used for comparisons especially in the SH polar winter where the mean difference reaches 20% or greater. In polar summer above 80 km, SABER H2O is biased low by ~20% compared to the other measurements. SABER H2O therefore reflects the polar winter and spring descent very well but in the summer PMC region the enhancement is weaker than expected. SABER H2O long-term series in the latitude range 50°S-50°N shows close agreement with MLS on a series of pressure levels throughout the stratosphere and mesosphere on inter-annual to decadal time scales. On these time scales also, throughout the years 2002–2005, SABER and MIPAS long-term time series agree well in the equatorial region which serves as an unprecedented validation for this time period. SABER H2O also captures the “tape recorder” phenomenon in the tropical tropopause region very well.

This presentation introduces a High Altitude Thermal Sensor (HATS) that has the potential to resolve the thermal structure of the upper atmosphere (cloud top to 100km) with both horizontal and vertical resolution of 5-7 km or better. This would allow the complete characterization of the wave structures that carry weather signature from the underlying atmosphere. Using a novel gas correlation technique, an extremely high-resolution spectral scan is accomplished by measuring a Doppler modulated signal as the atmospheric thermal scene passes through the HATS 2D FOV. This high spectral resolution, difficult to impossible to achieve with any other passive technique, enables the separation of radiation emanating at high altitudes from that emanating at low altitudes. A principal component analysis of these modulation signals then exposes the complete thermal structure of the upper atmosphere. We show that nadir sounding from low earth orbit, using various branches of CO2 emission in the 17 to 15 micron region, with sufficient spectral resolution and spectral measurement range, can distinguish thermal energy that peaks at various altitudes. By observing the up-welling atmospheric emission through a low pressure (Doppler broadened) gas cell, as the scene passes through our FOV, a modulation signal is created as the atmospheric emission lines are shifted through the spectral position of the gas cell absorption lines. The modulation signal is shown to be highly correlated to the emission coming from the spectral location of the gas cell lines relative to the atmospheric emission lines. This effectively produces a scan of the atmospheric emission with a Doppler line resolution. Similar to thermal sounding of the troposphere, a principal component analysis of the modulation signal can be used to produce an altitude resolved profile, given a reasonable a priori temperature profile. It is then shown that with the addition of a limb observation with one CO2 broadband channel (similar to methods employed with sensors like LIMS on Nimbus 7, HIRDLS on Aura, and SABER on TIMED), a limb temperature profile can be retrieved and used as the a priori profile, nearly eliminating uncertainty due to a priori inaccuracy. Feasibility studies and proposed instrument designs are presented. A tutorial for a similar technique proposed for measuring winds and temperature with limb observations can be found at http://www.gats-inc.com/future_missions.html

This paper describes a methodology for water vapor retrieval in the mesosphere-lower thermosphere (MLT) using 6.6 μm daytime broadband emissions measured by SABER, the limb scanning infrared radiometer on board the TIMED satellite. Particular attention is given to accounting for the non-local thermodynamic equilibrium (non-LTE) nature of the H2O 6.6 μm emission in the MLT. The non-LTE H2O(ν2) vibrational level populations responsible for this emission depend on energy exchange processes within the H2O vibrational system as well as on interactions with vibrationally excited states of the O2, N2, and CO2 molecules. The rate coefficients of these processes are known with large uncertainties that undermines the reliability of the H2O retrieval procedure. We developed a methodology of finding the optimal set of rate coefficients using the nearly coincidental solar occultation H2O density measurements by the ACE-FTS satellite and relying on the better signal-to-noise ratio of SABER daytime 6.6 μm measurements. From this comparison we derived an update to the rate coefficients of the three most important processes that affect the H2O(ν2) populations in the MLT: a) the vibrational-vibrational (V–V) exchange between the H2O and O2 molecules; b) the vibrational-translational (V–T) process of the O2(1) level quenching by collisions with atomic oxygen, and c) the V–T process of the H2O(010) level quenching by collisions with N2, O2, and O. Using the advantages of the daytime retrievals in the MLT, which are more stable and less susceptible to uncertainties of the radiance coming from below, we demonstrate that applying the updated H2O non-LTE model to the SABER daytime radiances makes the retrieved H2O vertical profiles in 50–85 km region consistent with climatological data and model predictions. The H2O retrieval uncertainties in this approach are about 10% at and below 70 km, 20% at 80 km, and 30% at 85 km altitude.

The objective of this study was to evaluate the performance of growing cattle when intensively grazing stockpiled endophyte-infected (E+), endophyte-free (E-), and nontoxic endophyte-infected (EN) tall fescue during the winter. The experiment was conducted over 5 consecutive winters. In each year, plots (1 ha each, 4 per treatment) were harvested for hay in August, fertilized in September, and forage was allowed to accumulate until grazing was initiated in early December. Each year, 48 Angus-cross tester cattle (4 per plot) were given a daily allotment of forage, under strip-grazing (frontal grazing) management, with a target residual height of 5 cm. Steers were used the first year, and heifers were used in subsequent years. The grazing periods for determination of pasture ADG were 86 d (yr 1), 70 d (yr 2), 86 d (yr 3), 72 d (yr 4), and 56 d (yr 5). Pasture ADG of cattle did not differ among treatments (P = 0.13) and were 0.51, 0.59, and 0.56 kg/d (SEM 0.03) for E+, E-, and EN, respectively. Serum prolactin concentrations of heifers grazing E+ were less (P 0.20) except in yr 4. During yr 4, serum prolactin of heifers grazing E- was greater (P = 0.05) than that of heifers grazing EN. Serum urea-N concentrations (SUN) tended to differ among treatments (P = 0.10) and there was a treatment x year interaction (P = 0.05). During yr 1 through 3, SUN did not differ (P > 0.15) among treatments. However, as the stands aged, E- had a greater invasion of other plant species, which increased the CP content of the sward, thus causing heifers grazing E- during yr 5 to have greater (P 0.20) among treatments. The use of stockpiled E+ as a source of low-cost winter feed is a viable option for producers, whereas grazing of EN may be more beneficial during the spring and fall, when more severe negative effects of ergot alkaloids have been observed.

© Author(s) 2014. We present vM21 MIPAS temperatures from the lower stratosphere to the lower thermosphere, which cover all optimized resolution measurements performed by MIPAS in the middle-atmosphere, upper-atmosphere and noctilucent-cloud modes during its lifetime, i.e., from January 2005 to April 2012. The main upgrades with respect to the previous version of MIPAS temperatures (vM11) are the update of the spectroscopic database, the use of a different climatology of atomic oxygen and carbon dioxide, and the improvement in important technical aspects of the retrieval setup (temperature gradient along the line of sight and offset regularizations, apodization accuracy). Additionally, an updated version of ESA-calibrated L1b spectra (5.02/5.06) is used. The vM21 temperatures correct the main systematic errors of the previous version because they provide on average a 1-2 K warmer stratopause and middle mesosphere, and a 6-10 K colder mesopause (except in high-latitude summers) and lower thermosphere. These lead to a remarkable improvement in MIPAS comparisons with ACE-FTS, MLS, OSIRIS, SABER, SOFIE and the two Rayleigh lidars at Mauna Loa and Table Mountain, which, with a few specific exceptions, typically exhibit differences smaller than 1 K below 50 km and than 2 K at 50-80 km in spring, autumn and winter at all latitudes, and summer at low to midlatitudes. Differences in the high-latitude summers are typically smaller than 1 K below 50 km, smaller than 2 K at 50-65 km and 5 K at 65-80 km. Differences between MIPAS and the other instruments in the mid-mesosphere are generally negative. MIPAS mesopause is within 4 K of the other instruments measurements, except in the high-latitude summers, when it is within 5-10 K, being warmer there than SABER, MLS and OSIRIS and colder than ACE-FTS and SOFIE. The agreement in the lower thermosphere is typically better than 5 K, except for high latitudes during spring and summer, when MIPAS usually exhibits larger vertical gradients., M. Garcia-Comas was financially supported by the Ministry of Economy and Competitiveness (MINECO) through its >Ramon y Cajal> subprogram. The IAA team was supported by the Spanish MINECO, through project AYA2011-23552, the CONSOLIDER program CSD2009-00038, and EC FEDER funds. Funding for ACE comes primarily from the Canadian Space Agency. We thank ESA for providing MIPAS level-1b data.

We present vM21 MIPAS temperatures from the lower stratosphere to the lower thermosphere, which cover all optimized resolution measurements performed by MIPAS in the Middle Atmosphere, Upper Atmosphere and NoctiLucent Cloud modes during its lifetime. i.e., from January 2005 to March 2012. The main upgrades with respect to the previous version of MIPAS temperatures (vM11) are the update of the spectroscopic database, the use of a different climatology of atomic oxygen and carbon dioxide, and the improvement of important technical aspects of the retrieval setup (temperature gradient along the line of sight and offset regularizations, apodization accuracy). Additionally, an updated version of ESA calibrated L1b spectra (5.02/5.06) is used. The vM21 temperatures correct the main systematic errors of the previous version because they on average provide a 1–2 K warmer stratopause and middle mesosphere, and a 6–10 K colder mesopause (except in high latitude summers) and lower thermosphere. These lead to a remarkable improvement of MIPAS comparisons with ACE-FTS, MLS, OSIRIS, SABER, SOFIE and the two Rayleigh lidars at Mauna Loa and Table Mountain, that, with few specific exceptions, typically exhibit differences smaller than 1 K below 50 km and than 2 K at 50–80 km in spring, autumn, winter at all latitudes, and summer at low to mid-latitudes. Differences in the high latitude summers are typically smaller than 1 K below 50 km, smaller than 2 K at 50–65 km and 5 K at 65–80 km. Differences with the other instruments in the mid-mesosphere are generally negative. MIPAS mesopause is within 4 K of the other instruments measurements, except in the high latitude summers, where it is within 5–10 K of the other instruments, being warmer than SABER, MLS and OSIRIS and colder than ACE-FTS and SOFIE. The agreement in the lower thermosphere is typically better than 5 K, except for high latitudes during spring and summer, where MIPAS usually exhibits larger vertical gradients.

Climate change and air quality are the most pressing environmental issues of the 21st century. Despite decades of research, the sources and sinks of key greenhous e gases remain highly uncertain [IPCC 1 ] making quantitative predictions of atmospheric composition and their impacts. The Geostationary Remote Infrared Pollution Sounder (GRIPS) is a multi-purpose instrument designed to reduce uncertainty associated with atmospheric radiative forcing. GRIPS will measure will measure greenhouse gases and aerosols – two of the mo st important elements in the earth’s radiation budget. GRIPS will observe carbon dioxide (CO 2 ), carbon monoxide (CO), methane (CH4), - the carbon gases, nitrous oxide (N 2 O), water vapor and aerosols with unprecedented precision through the atmosphere. The GRIPS instrument uses gas filter correlation radiometry (GFCR) to detect reflected and thermal IR radiation to detect the gases and the reflec ted solar radiation in the visible and short-wave infrared bands for aerosols. GRIPS is designed to have sensitivity down to the Earth’s surface at ~2-8km nadir resolution. GRIPS can resolve CO

A new approach to measuring wind and temperature is under development that could revolutionize our ability to monitor wind and neutral temperature in the upper atmosphere. Using a Doppler modulated gas filter correlation technique, wind and temperature can be measured simultaneously from low Earth orbit, continuously from 15 km to over 200 km, on one second time intervals, both day and night. A constellation of six of these dual-sided Doppler Wind and Temperature Sensors (DWTS) on small-sat platforms could provide nearly real time global temperature and wind fields. The DWTS technique, measurements and weather forecast benefits are discussed.

Over the last decade it has been established that medium- to long-range weather patterns are significantly affected by stratospheric events, and it is well known that the severe storms are critically dependent on the winds aloft. However, existing observations of the dynamical atmosphere above the cloud tops are sparse and irregular, and remote measurements of upper atmospheric winds have historically proved challenging. Current numerical models must rely on data from widely separated land-based instruments and satellite observations with modest precision and coverage. Even less plentiful are observations of the neutral atmosphere above 100 km, despite the high potential impact of space weather on global navigational and electrical systems. We present here a new instrument concept, the Doppler Wind and Temperature Sounder (DWTS) that will enable global daily measurements of winds and temperature from 15 to 250 km with fine vertical and horizontal sampling. The measurement concept leverages the high spectral resolution inherently available with gas-filter correlation radiometry. By exploiting the Doppler shifts resulting from a limbviewing low Earth orbit satellite, DWTS spectrally resolves large ensembles of atmospheric emission features. From this, we are able to extract horizontal wind vectors and kinetic temperature with unprecedented precision. Here we review the DWTS measurement concept, present simulation results, and conclude by describing a low-cost operational system that would quantify atmospheric dynamics from the lower stratosphere into the mid thermosphere for the first time.

The role of heating due to absorption of solar radiation by molecular oxygen (O2) in the A, B, and γ atmospheric bands and in the infrared atmospheric band is reviewed. Prior studies have demonstrated the importance of heating by these O2 bands in the vicinity of the tropopause. In the middle mesosphere, the heating associated with O2 atmospheric bands is shown to rival that of the numerous individual solar and chemical heat sources. We show that heating in the O2 atmospheric bands increases the total diabatic (i.e., solar plus exothermic chemical reaction) heating by 5 to 15 percent between 60 and 80 km.

Climate change and air quality are the most pressing environmental issues of the 21st century. Despite decades of research, the sources and sinks of key greenhouse gases remain highly uncertain [IPCC, 2007] making atmospheric composition predictions difficult. The Geostationary Remote Infrared Pollution Sounder (GRIPS) will measure carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), and nitrous oxide (N2O) with unprecedented precision to reduce substantially this uncertainty. The GRIPS instrument uses gas filter correlation radiometry (GFCR) to detect reflected and thermal IR radiation from geostationary orbit. GRIPS is designed to haves sensitivity down to the Earth’s surface at ~8 km nadir resolution. GRIPS can also resolve CO2, CO, and CH4 anomalies in the planetary boundary layer and the free troposphere to quantify lofting, diurnal variations and long-range transport. With repeated measurements throughout the day GRIPS can maximize the number of cloud free measurements determining biogenic and anthropogenic sources, sinks, and fluxes. Finally, the GFCR technique is, to first order, insensitive to aerosols interference. GRIPS is highly complementary to the Orbiting Carbon Observatory, OCO-2, and other existing and planned missions.

A set of subroutines has been written for use in developing spectral models, with emphasis on the Earth's atmosphere. Features include rapid calculation of absorption cross section, radiance and transmission spectra for multiple gases and multiple paths. The routines are designed to allow user control of model geometry, line shape functions, band models, atmospheric layering, and spectral resolution. Numerical techniques and applications are described with examples that include a simulated limb scan retrieval and comparison to other codes.

A library of subroutines has been written for rapid modeling of broadband atmospheric emission and transmission. Features include multiple gases, multiple bandpasses, multiple atmospheric paths, accurate line overlap correction, ability to model any observation geometry, and complete control of atmospheric layering and state definitions. Numerical procedures and examples of use are described.

Measurement of atmospheric temperature as a function of pressure, T(P), is key to understanding many atmospheric processes and a prerequisite for retrieving gas mixing ratios and other parameters from solar occultation measurements. This paper gives a brief overview of the solar occultation measurement technique followed by a detailed discussion of the mechanisms that make the measurement sensitive to temperature. Methods for retrieving T(P) using both broadband transmittance and refraction are discussed. Investigations using measurements of broadband transmittance in two CO2 absorption bands (the 4.3 and 2.7 μm bands) and refractive bending are then presented. These investigations include sensitivity studies, simulated retrieval studies, and examples from SOFIE.

The Digital Array Gas Radiometer (DAGR) concept is based on traditional and reliable Gas Filter Correlation Radiometry (GFCR) for remote trace gas detection and monitoring. GFCR sensors have been successful in many infrared remote sensing applications. Historically however, solar backscatter measurements have not been as successful because instrument designs have been susceptible to natural variations in surface albedo, which induce clutter and degrade the sensitivity. DAGR overcomes this limitation with several key innovations. First, a pupil imaging system scrambles the received light, removing nearly all spatial clutter and permitting a small calibration source to be easily inserted. Then, by using focal plane arrays rather than single detectors to collect the light, dramatic advances in dynamic range can be achieved. Finally, when used with the calibration source, data processing approaches can further mitigate detector non-uniformity effects. DAGR sensors can be made as small as digital cameras and are well suited for downlooking detection of gases in the boundary layer, where solar backscatter measurements are needed to overcome the lack of thermal contrast in the IR. Easily integrated into a satellite platform, a space-based DAGR would provide near-global sensing of climatically important species such as such as CO, CH 4 , and N 2 O. Aircraft and UAV measurements with a DAGR could be used to monitor agricultural and industrial emissions. Ground-based or portable DAGRs could augment early warning systems for chemical weapons or toxic materials. Finally, planetary science applications include detection and mapping of biomarkers such as CH 4 in the Martian atmosphere.

[1] The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument operating onboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite since 2002 has provided day and nighttime measurements of ozone on a daily basis in the middle to upper atmosphere (15–100 km) using limb scanning in the 9.6-μm band. The focus of this paper is on validation of v1.07 O3 in the stratosphere and mesosphere region below 70 km. SABER v1.07 O3 measurements have a precision of ∼1–2% in the stratosphere and ∼3–5% in the lower mesosphere. A SABER positive bias exists in all regions other than the lower stratosphere. The positive biases in the stratosphere are within ∼5–12% in most cases except in the equatorial to middle latitudes in the altitude range ∼30–50 km, where they reach ∼15–17% and exceed the combined systematic error by ∼5–6%. The comparisons in the lower mesosphere indicate that SABER O3 captures the diurnal variability very well. The best agreement of ∼5–7% occurs for daytime comparisons with solar occultation measurements in the lower mesosphere. As with most large satellite data sets, a small portion of the O3 profiles show unrealistically large values. The occurrences of these profiles were revealed using a probability approach, which enabled the identification of the time frames and spatial regions where these anomalies occur.

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.

The objective of this study was to evaluate the performance of growing cattle when intensively grazing stockpiled endophyte-infected (E+), endophyte-free (E-), and nontoxic endophyte-infected (EN) tall fescue during the winter. The experiment was conducted over 5 consecutive winters. In each year, plots (1 ha each, 4 per treatment) were harvested for hay in August, fertilized in September, and forage was allowed to accumulate until grazing was initiated in early December. Each year, 48 Angus-cross tester cattle (4 per plot) were given a daily allotment of forage, under strip-grazing (frontal grazing) management, with a target residual height of 5 cm. Steers were used the first year, and heifers were used in subsequent years. The grazing periods for determination of pasture ADG were 86 d (yr 1), 70 d (yr 2), 86 d (yr 3), 72 d (yr 4), and 56 d (yr 5). Pasture ADG of cattle did not differ among treatments (P = 0.13) and were 0.51, 0.59, and 0.56 kg/d (SEM 0.03) for E+, E-, and EN, respectively. Serum prolactin concentrations of heifers grazing E+ were less (P0.05) than those grazing E- and EN during all years except yr 2. In yr 2, E+ and E- did not differ (P = 0.11). Serum prolactin of heifers grazing E- and EN did not differ (P0.20) except in yr 4. During yr 4, serum prolactin of heifers grazing E- was greater (P = 0.05) than that of heifers grazing EN. Serum urea-N concentrations (SUN) tended to differ among treatments (P = 0.10) and there was a treatment x year interaction (P = 0.05). During yr 1 through 3, SUN did not differ (P0.15) among treatments. However, as the stands aged, E- had a greater invasion of other plant species, which increased the CP content of the sward, thus causing heifers grazing E- during yr 5 to have greater (P0.01) SUN than heifers grazing E+ and EN, which did not differ (P = 0.89). Forage disappearance (DM basis) did not differ (P = 0.75) among treatments and was 4.7, 4.7, and 5.0 kg/animal daily (SEM 0.27) for E+, E-, and EN, respectively. Body weight gain per hectare was greater (P = 0.04) for E+ (257 kg) than for E- (220 kg) or EN (228 kg). In most years, animal grazing days on E+ were greater than those on E- or EN. However, in yr 5, animal grazing days did not differ (P0.20) among treatments. The use of stockpiled E+ as a source of low-cost winter feed is a viable option for producers, whereas grazing of EN may be more beneficial during the spring and fall, when more severe negative effects of ergot alkaloids have been observed.

The quality of the retrieved temperature-versus-pressure (or T(p)) profiles is described for the middle atmosphere for the publicly available Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) Version 1.07 (V1.07) data set. The primary sources of systematic error for the SABER results below about 70 km are (1) errors in the measured radiances, (2) biases in the forward model, and (3) uncertainties in the corrections for ozone and in the determination of the reference pressure for the retrieved profiles. Comparisons with other correlative data sets indicate that SABER T(p) is too high by 1-3 K in the lower stratosphere but then too low by 1 K near the stratopause and by 2 K in the middle mesosphere. There is little difference between the local thermodynamic equilibrium (LTE) algorithm results below about 70 km from V1.07 and V1.06, but there are substantial improvements/differences for the non-LTE results of V1.07 for the upper mesosphere and lower thermosphere (UMLT) region. In particular, the V1.07 algorithm uses monthly, diurnally averaged CO2 profiles versus latitude from the Whole Atmosphere Community Climate Model. This change has improved the consistency of the character of the tides in its kinetic temperature (T(sub k)). The T(sub k) profiles agree with UMLT values obtained from ground-based measurements of column-averaged OH and O2 emissions and of the Na lidar returns, at least within their mutual uncertainties. SABER T(sub k) values obtained near the mesopause with its daytime algorithm also agree well with the falling sphere climatology at high northern latitudes in summer. It is concluded that the SABER data set can be the basis for improved, diurnal-to-interannual-scale temperatures for the middle atmosphere and especially for its UMLT region.

This paper presents extensive validation analyses of ozone observations from the Atmospheric Chemistry Experiment (ACE) satellite instruments: the ACE Fourier Transform Spectrometer (ACE-FTS) and the Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation (ACE-MAESTRO) instrument. The ACE satellite instruments operate in the mid-infrared and ultraviolet-visible-near-infrared spectral regions using the solar occultation technique. In order to continue the long-standing record of solar occultation measurements from space, a detailed quality assessment is required to evaluate the ACE data and validate their use for scientific purposes. Here we compare the latest ozone data products from ACE-FTS and ACE-MAESTRO with coincident observations from satellite-borne, airborne, balloon-borne and ground-based instruments, by analysing volume mixing ratio profiles and partial column densities. The ACE-FTS version 2.2 Ozone Update product reports more ozone than most correlative measurements from the upper troposphere to the lower mesosphere. At altitude levels from 16 to 44 km, the mean differences range generally between 0 and +10% with a slight but systematic positive bias (typically +5%). At higher altitudes (45–60 km), the ACE-FTS ozone amounts are significantly larger than those of the comparison instruments by up to ~40% (typically +20%). For the ACE-MAESTRO version 1.2 ozone data product, agreement within ±10% (generally better than ±5%) is found between 18 and 40 km for the sunrise and sunset measurements. At higher altitudes (45–55 km), systematic biases of opposite sign are found between the ACE-MAESTRO sunrise and sunset observations. While ozone amounts derived from the ACE-MAESTRO sunrise occultation data are often smaller than the coincident observations (by as much as −10%), the sunset occultation profiles for ACE-MAESTRO show results that are qualitatively similar to ACE-FTS and indicate a large positive bias (+10 to +30%) in this altitude range. In contrast, there is no significant difference in bias found for the ACE-FTS sunrise and sunset measurements. These systematic effects in the ozone profiles retrieved from the measurements of ACE-FTS and ACE-MAESTRO are being investigated. This work shows that the ACE instruments provide reliable, high quality measurements from the tropopause to the upper stratosphere and can be used with confidence in this vertical domain.

[1] The polar summer thermal structure, with its cold mesopause and steep temperature gradients, both below and above the mesopause, produces the largest non-LTE effects in the CO2ν2 mode manifold states. In this paper we focus on validating the non-LTE model applied for operational temperature retrievals from the SABER 15 μm limb radiance observations for these extreme conditions. We demonstrate that accounting for the redistribution of ν2 quanta among various CO2 isotopes shifts the retrieved summer 2002 polar mesopause altitude upwards by 2 to 4 km. It brings the SABER temperature measurements into a better agreement with those of falling sphere experiments, lidar observations, as well as with climatological data.

Accurate temperature and pressure profiles are the key to high quality retrievals from solar occultation measurements. For best results these profiles should be retrieved from measurements that have an identical field-of-view and are simultaneous, with companion measurements. We explore three general methods, corresponding implementation strategies and their major error sources. These methods include: 1) one or more channels sensing CO 2 extinction, 2) a single channel using the oxygen A band, and 3) use of refraction angle measurements to infer temperature from density derivatives (limited to the stratosphere). It is shown that extraordinary results can be achieved if high precision solar tracking, and solar pointing knowledge, are accomplished.

The SABER instrument aboard the TIMED satellite is providing highly resolved and precise broadband limb emission measurements. Inverting these measurements to temperature profiles that extend into the lower thermosphere (90+ kilometers) is a complicated and often unstable process. Non-Local Thermodynamic Equilibrium models must be employed to model the upper atmosphere physics that thwarts the normal limb measurement advantages available to lower atmosphere retrievals. Maintaining hydrostatic pressure constraints while accurately modeling the effects of upwelling radiation can induce instabilities in attempts at iterative relaxation. We show that the limb geometry can be used to apply boundary conditions during “bottom-up” procedures that stabilize the process and allow rapid convergence by minimizing the required calculations of upwelling flux.

[1] The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) experiment on the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics satellite has delivered over 1 year of radiance profile data from which middle atmosphere temperature profiles have been retrieved. Version 1.01 temperatures are precise and sufficiently accurate, such that one can obtain estimates of their synoptic distributions on pressure surfaces. A sequential estimation algorithm was used to generate daily, zonal Fourier coefficients of temperature (through zonal wave number 6), and maps on constant pressure surfaces were generated using those coefficients. Maps of temperature, geopotential height, and geostrophic winds are compared with products from the Met Office analyses. Stratospheric differences are within about 2 K for temperature and 160 m for geopotential height. The respective wind fields indicate flow patterns that are similar. Examples of the fields are shown for a period in February 2002 during a sudden stratospheric warming event that occurred in the Northern Hemisphere. A cooling of the middle mesosphere accompanies the warming. It is anticipated that large-scale, middle atmospheric dynamics and transport studies can be undertaken and that data assimilation products can be extended to near the mesopause using the SABER profiles.

A new approach for measuring high-altitude winds and temperatures has been developed that employs gas filter correlation radiometry from low Earth orbit. This approach would provide unprecedented observations of atmospheric dynamics from the lower stratosphere into the middle thermosphere. Our objective was to test the Doppler wind and temperature sounder (DWTS) retrievals (including uncertainties) using realistic middle atmosphere virtual input. We present several sampling scenarios for DWTS, and demonstrate its capability to retrieve planetary-scale variations in global temperature and vector winds.

Cosmic material enters the Earth's atmosphere daily. These incoming meteoroids are vaporized during atmospheric entry, and the resulting vapor condenses into "smoke" particles which accumulate near 85 km altitude. Cosmic particles are thought to be important in the formation of polar mesospheric clouds, which have been identified as the "miner's canary" of climate change. This work addresses some issues associated with remote measurements of the smoke layer. Signals expected from cosmic particles were modeled and these results indicate that the recently proposed Solar Occultation for Ice (SOFIE) instrument may have the capability to provide the first remote measurements of the smoke layer.

Solar occultation measurements from satellite have been very successful at sounding the upper atmosphere from cloud-top to well into the mesosphere (e.g. HALOE, ATMOS, SAGE, POAM). The HALOE instrument achieves transmission precision of 4 X10-6 at 2 arcminute resolution (1.6 Km at the Earth limb) with the differential gas correlation technique. With modern detectors, high precision tracking, better throughput and differential broadband radiometry, achievable precision should approach 10-7 (~10-9 km-1 extinction) or better. We show that this will allow accurate sounding of CO2, O3, H2O and NO mixing ratios simultaneously with temperature and pressure well into the lower thermosphere. In addition, such precision could provide the first mapping of the Earth's cosmic dust layer.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Remote sensing of atmospheric trace gases form geostationary orbit has unique scientific value and unique measurement interpretation advantages. This paper describes a proposed measurement method and analysis strategy for inferring CO concentration in the troposphere. Gas filter correlation radiometry is found to be very well suited for remote sensing using full globe images from geostationary orbit. Strengths of the gas correlation technique include measurement efficiency, effective high spectral resolution, excellent spectral calibration, manageable data rate, and measurements over the full spectral bandpass simultaneously.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Attitude and absolute response of broadband IR radiometers can be inferred directly from atmospheric limb measurements. The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) experiment will demonstrate such techniques.

Microbolometer array technology is making rapid progress in the commercial and tactical military world. An array was used for uncooled IR imaging in a very successful Shuttle flight and more is planned. Applications for long missions with microbolometers are on the drawing board. A recent study concluded that an uncooled staring array, when applied to Mid IR atmospheric ozone limb profile measurement could dramatically improve earth coverage, vertical precision and mixing ratio accuracy. Imaging by a staring array also alleviates some of the problems of non-imaging approach. This paper describes the technique and strategy of ozone profiling with an uncooled microbolometer array, the derived key instrument requirements and a brief discussion on the instrument implementation approach.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The stray light analysis of the sounding of the atmosphere using broadband emission radiometry (SABER) instrument on the thermosphere-ionosphere-mesosphere energetics and dynamics (TIMED) mission is discussed. Relevant mission objectives and operating conditions are stated to define the stray light problem. Since SABER is an earth limb viewing sensor, the telescope must be designed for large off-axis rejection. Described are the key design features which make the instrument well suited for its mission. Representative point source transmittance (PST) curves computed using the commercial stray light program APART are presented. Nonrejected radiance (NRR) values computed using APART generated PST curves and LINEPACK generated curves for the total radiance from the earth and the atmosphere are given. A method for computing NRR from the earth and the atmosphere using line-of-sight radiance profiles versus tangent height is described. Computed NRR values demonstrate that the effect of stray light on SABER's measurement capability is negligible.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

We present a new approach for measuring high-altitude winds and temperatures. We describe how gas filter correlation radiometry can be employed from low Earth orbit to simultaneously measure the Doppler shift and linewidth of emission spectra to infer both wind and kinetic temperature. Measurements are performed with a simple radiometer that images the limb emission of nitric oxide near 5.3 μm (to sense altitudes of >90 km and

A new method for measuring atmospheric refraction angles is presented, with in-orbit measurements demonstrating a precision of +/-0.02 arcsec (+/-0.1 microrad). Key advantages of the method are the following: (1) Simultaneous observation of two celestial points during occultation (i.e., top and bottom edges of the solar image) eliminates error from instrument attitude uncertainty. (2) The refraction angle is primarily a normalized difference measurement, causing only scale error, not absolute error. (3) A large number of detector pixels are used in the edge location by fitting to a known edge shape. The resulting refraction angle measurements allow temperature sounding up to the lower mesosphere.

Aerosol absorption measurements using diffuse reflectance and transmission techniques were made as part of the First International Workshop on light absorption by aerosol particles during July and August 1980. Our diffuse reflectance measurements were used to determine the imaginary component of the refractive index and the mass absorption coefficient for the aerosols and for the bulk material from which the aerosols were generated. Mass absorption coefficients measured by these techniques appear to be lower than those determined by diffuse transmission techniques. Our diffuse transmission measurements of sigma(A), the volume absorption coefficient, show that the measured response for this technique will be dependent on filter orientation and on the type of filter. Our data suggest that there may also be a dependence on the physical properties of the aerosol. Average omega values calculated on the basis of these diffuse transmission measurements range from 0.18 for soots to 0.98 for ammonium sulfate.