bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiple Scattering Contributions on the Lidar Return from Space
Authors: Flesia C. , Schwendimann P.
Published: February 2023

As long the single scattering is dominant, the distance between the lidar and the scattering volume is well determined, but when the multiple scattering events become significant, the lidar spatial resolution is reduced and only average properties can be analysed from the single scattering measurements. Moreover, all inversion methods relating lidar signal to number densities and particle size distributions must be modified since the multiple scattering affects the direct analysis. The essential requirements of a realistic model for lidar measurements which include the multiple scattering and which can be applied to practical situations are the following: a) Not just correction terms or rough approximations describing certain experimental results, but a general theory tying together the relevant physical parameters we seek to measure. b) Relatively small CPU time for the calculation of high scattering orders. c) A numerically stable and rapidly converging model for the calculation of higher scattering orders, of large cloud depth with relatively high experimental noise.
Pressure and Temperature Retrieval using Oxygen A Band in Solar Occultation Measurement with Improved Limb Atmospheric Spectrometer (ILAS)
Authors: Suzuki M. , Nakajima T. , Sasano Y.
Published: February 2023

It has been well recognized that the temperature and pressure determination is important to the remote sensing of atmosphere. Currently, most limb viewing instruments, such as LIMS, IS AMS, and HALOE, have been using infrared CO2band for the pressure retrieval because of its uniform mixing ratio through troposphere to stratosphere. Molecular oxygen, which has well established spectrum and has extremely uniform mixing ratio in the atmosphere, could give better pressure information compared with the CO2. Matsuzaki et al.[1] have reported the rocket experiment to observe the oxygen A band, where they showed that the rotational spectrum could give the mean temperature of a slant path in a precision as low as 1.5 K. Considering the size of visible spectrometer, it is very valuable to build the IR solar occultation instrument with a visible spectrometer for the temperature and pressure retrieval, because the better pressure and temperature give more accurate vertical profilde of the target gases in the IR channel. This paper presents the pressure and temperature retrieval using Oxygen A band for a solar occultation measurement by Improved Limb Atmospheric Spectrometer(ILAS) aboard ADEOS spacecraft which will be launched in early 1995.
Large-Scale Retrieval of Atmospheric Parameters from Remote Sounding Data
Authors: Sparks L. , Lyster P. , Patterson J. E. , Fanselow J. L.
Published: February 2023

The remote sounding instruments that fly as part of NASA's Earth Observing System (EOS) will generate vast quantities of observational data. The analysis of these data will permit nearly continuous monitoring of the global distributions of temperature, pressure, and molecular abundances over a fifteen year period. The EOS program requires that the analysis of each data set be performed rapidly and the results conveyed quickly to the scientific community. Within the context of existing models for atmospheric radiation, these goals may be achieved only by developing retrieval methods that improve upon current rates of data analysis by several orders of magnitude.
Advances in 1 to 2 μm Solid-State Lidar/Dial Technology: Laser Sources, Optical Detectors, and Fiber Amplifiers
Authors: Killinger Dennis K.
Published: February 2023

Recently, significant advances have been made in the development of new solid-state Lidar and DIAL systems that operate in the 1 to 2 μm wavelength range. These Lidar/DIAL developments encompass Coherent Heterodyne-detection Doppler Lidar, tunable direct-detection DIAL, Multi-element detector array Lidar sensors, and active laser illuminators for passive focal-plane array IR sensors. The development of these Lidar and DIAL systems is being led by advances in new laser sources, optical detectors, and new optical detection technology. This talk will review some of the recent progress in the following Lidar/DIAL technology areas and speculate on some potential areas of future growth in this field.
2.1 μm Ho Lidar Measurements of the Temporal and Spatial Variability in the Range-Resolved Extinction and Backscatter Coefficient of the Atmosphere
Authors: Saito Yasunori , Chan Kin Pui , Killinger Dennis K.
Published: February 2023

A 2.1 μm direct-detection Ho Lidar has been used to measure the range-resolved extinction coefficient and relative backscatter coefficient of the atmosphere as a function of time during the day. Significant spatial and temporal variability has been observed.
Lidar Wind and Temperature Measurements in the Middle Atmosphere
Authors: Chanin Marie-Lise
Published: February 2023

A better understanding of the interaction between the waves and the background wind in the altitude range 25 - 65 km, where there is still no possibility to monitor adequately the wind field, led us to the development of a new Doppler lidar designed to cover this height range. Therefore it had to rely on Rayleigh scattering from air molecules. Recently the possibility to extend the measurements of the mean winds in the lower atmosphere using the same principle has been studied and will be implemented in a near future.
Sodium and Rayleigh Lidar Studies of the Structure and Dynamics of the Stratosphere and Mesosphere
Authors: Gardner Chester S.
Published: February 2023

Modern lidar systems are capable of probing atmospheric composition and structure from the troposphere into the lower thermosphere with exceptional accuracy and resolution. Sophisticated ground based and airborne systems are now operated routinely and several organizations are developing satellite-borne lidars for deployment during the next decade. The last five years has been a period of substantial growth in lidar capabilities, particularly for middle atmosphere applications principally because of advances in certain critical areas of laser technology. Perhaps the most significant of these has been the development of highpower, ultra-stable, narrowband, lasers which are now being used in Doppler/temperature lidars. Most of the important lidar applications place challenging demands on die laser specifications. Narrow linewidths (~100 MHz), wavelength inability, high frequency stability (~1-10 MHz), diffraction limited beam quality and high average output powers (~1-100 W) are required for some of the most critical measurements. Systems utilizing dye lasers can achieve many of these specifications over much of the optical spectrum from the near IR to the near UV. However, dye lasers are complicated, cumbersome to operate and ill-suited for spacebome and some airborne applications.
Lidar Observed Trend in Stratospheric Background Aerosol
Authors: Jäger H.
Published: February 2023

The investigation of variations in stratospheric aerosol mass is important in studying the effects of heterogeneous chemistry and the relevant climatic implications. Data for stratospheric particle mass and other guantities, such as particle extinction or surface area, can be derived from lidar backscatter soundings. Lidar investigations have been performed at Garmisch-Partenkirchen (47.5°N, 11°E) since 1976. All backscatter profiles are measured at the 694.3 nm ruby wavelength and are treated in a similar way so that trends can be analysed: they are normalized above the aerosol layer by matching them with a calculated Rayleigh return which is based on radiosonde data, and they are corrected for molecular and particle extinction. By applying a height and time resolved aerosol model, which is based on the University of Wyoming balloon sonde data, the measured backscatter data were converted to particle mass data (Jager and Hofmann, 1991; 1988/90 data: D.J. Hofmann, personal communication, 1990). Figure 1 shows the lidar derived column mass in the 15 to 30 km height range.
Lidar Observations of Mt. Pinatubo Aerosol Above Atlanta, Georgia
Authors: Gimmestad G.G. , Patterson E.M. , Roberts D.W. , Gimmestad S.C. , Galyean C.P.
Published: February 2023

Stratospheric aerosol from the recent Mount Pinatubo eruption has been monitored over Atlanta, Georgia (33.8° N, 84.2° W) approximately biweekly beginning on June 30, 1991. The measurements were performed with a lidar system in the Electro- Optics Laboratory of GTRI.
Lidar Observations of Clouds at NASA Langley During ECLIPS Phases I and II
Authors: Winker D. M.
Published: February 2023

The Experimental Cloud Lidar Pilot Study (ECLIPS) was formulated in 1988 to explore the feasibility of obtaining a longterm climatology of cloud base height and cloud optical properties using groundbased lidar (WMO, 1988). Data obtained by all participants in ECLIPS will be collected in a single archive to form a database of lidar-derived cloud properties. This archive is being compiled at NASA Langley Research Center and will become part of the NCDC (National Climate Data Center) database when completed. Observations are made coincident with overpasses of the Advanced Very High Resolution Radiometer (AVHRR) instrument carried on the NOAA-10 and NOAA-11 satellites. The ECLIPS archive can then be used as ground validation for satellite retrieval methods, leading to improved predictions of surface energy balance from satellite radiance data.
Tropical Intercontinental Network of Aerosol Observations
Authors: Holben Brent N. , Tanré Didier , Eck Thomas F. , Lavenu François , Reagan John A. , Setzer Alberto
Published: February 2023

A new generation of portable sunphotometers will be used to monitor aerosol concentration and optical properties diurnally and annually in West Africa and South America beginning in 1992.
Elastic LIDAR Temporal and Spatial Characterization of Mexico City's Atmospheric Aerosol Layers and Structures.##
Authors: Quick C. R. , Archuleta F. L. , Hof D. H. , Karl R. R. , Tiee J. J. , Eichinger W. E. , Holtkamp D. B. , Tellier L.
Published: February 2023

Over the last two decades, Mexico City, like many large industrial and populous urban areas, has developed a serious air pollution problem, especially during the winter months. In February of 1991, a major measurements campaign was carried out in an attempt to gather sufficient information to allow a basic understanding of the meteorological processes that dominate the behavior of the atmosphere above the valley in which Mexico City is located. In addition to standard EPA ground based instrumentation designed to measure the concentration of major pollutants, numerous advanced measurement techniques were deployed including : tethersonde instrumentation, real-time infrared vehicle emission monitors, an aircraft laboratory and a mobile LIDAR system for aerosol characterization. The focus of this report is on the data obtained with the LIDAR system with regards to the spatial and temporal distribution of aerosol particles observed during high air pollution periods. The main LIDAR objective was to characterize aerosol layer formation/destruction and plume transport and dispersal.
Use of the DIAL Technique to Measure Atmospheric Water Vapor over Large Concentration Ranges
Authors: Ismail Syed , Grant William B. , Browell Edward V.
Published: February 2023

This paper examines the ability of the differential absorption lidar (DIAL) technique to remotely measure widely varying water vapor (H2O) concentrations. This discussion also includes an assessment of recent technology developments and future technology development needs.
Remote Sensing of Air Pollutants in Germany, Present Status and Plans for the Future
Authors: Klein Volker H. , Weber Konradin , Werner Christian
Published: February 2023

The Conference 'Laser in Remote Sensing' which was held in conjunction with the Laser '91 trade show in Munich was accompanied by a workshop, titled 'Optical Remote Sensing for Air Pollution Detection'. This special forum had been introduced for a vital and stimulating exchange of scientific information, user needs as well as regulations and guidelines, derived by national councils and agencies. This workshop demonstrated a broad common understanding of potentials and needs in the field of remote sensing of air pollutants and marked the beginning of an intensive collaboration between research institutes, the industry and national agencies. In this paper we will summarize the results of this workshop and the projected goals for future events.
Approximating Transmittance Perturbations for the Simultaneous Retrieval of Temperature and Moisture
Authors: Goldberg Mitchell D.
Published: February 2023

The perturbed form of the radiative transfer equation (RTE) for the simultaneous retrieval of temperature and moisture is given in Smith et al. (1985, 1991) as where ΔR is the deviation of the observed radiance from a mean or initial guess radiance. The first integral term in (1) physically represents the contribution of the Planck equivalent departure of the ambient temperature from a mean or initial guess temperature, ΔB, weighted by the vertical derivative of transmittance dτ which is evaluated for the initial condition. Any contribution to ΔR due to differences between the initial and ambient transmittance profiles, Δτ, are accounted for by the second integral term.
High-Resolution Measurements Of The Molecular Line Parameters In The Mid-Infrared Using A Tunable CO2 Laser
Authors: Cheo Peter K. , Chu Zhiping , Zhou Yi , Chen Weiqun
Published: February 2023

The differential absorption lidar (DIAL) technique can be used to remotely detect the trace gases in ambient air by observing the absorption of pulsed laser radiation as it propagates through the atmosphere when the laser is tuned on and off a molecular absorption line.1-3 This measurement depends critically on the assumed molecular absorption line strengths and widths. The purposes of the present study are to develop a CO2 laser system4-5 with very narrow linewidth (<50 KHz ~ 10-6 cm-1) and wide tunability (10 GHz ~ 0.3 cm-1) and to obtain accurate molecular absorption line parameters for remote sensing applications in the 9-12 μm where the CO2 laser wavelengths fall within the spectral absorption region of many pollutants in the atmosphere.
Measurements Of Multi-Field-Of-View Lidar Returns From Atmospheric Aerosols
Authors: Hutt D.L. , Bissonnette L.R. , Durand L.
Published: February 2023

As a beam of light propagates through the atmosphere, scattering by aerosol particles causes the beam profile to broaden. The profile of the beam as a function of range depends primarily on the aerosol phase function and the local scattering or extinction coefficient. A multi-field-of-view (MFOV) lidar has been developed1 which makes simultaneous measurements of the power directly backscattered from the central beam and multiscattered signals arising from the broadened part of the beam.
Detection of Minor Tropospheric Constituents using Fourier Transform Spectroscopy
Authors: Carleer M. , Colin R. , Vandaele A.C. , Simon P.C.
Published: February 2023

In the frame of TOPAS (Tropospheric OPtical Absorption Spectroscopy), an EURO-TRAC subproject supported by the Belgian State - Prime Minister’s Service - Science Policy Office and the ”Fond National de la Recherche Scientique”, a long path (788 m) absorption system has been constructed on the urban site of the campus of the Université Libre de Bruxelles. It consists of a Xenon high pressure emission source connected to a 30 cm Cassegrain type telescope. A parabolic mirror placed at a distance of 394 m reflects the light back into a similar telescope connected to a high resolution Fourier Transform spectrometer BRUKER IFS120HR. The two telescopes are mounted on alignment devices and the external mirror is equipped with a driving system operated from the laboratory. This system has been in operation since October 1990. Absorption structures of O2, O3, NO2 and SO2 have been observed in the UV region (25000-45000 cm-1). The spectra are recorded at a dispersion of 8 cm-1.
Remote Sensing of Time Variation of Pressure Heights at Fort Greeley, Alaska
Authors: Measure Edward M. , Barber Teddy L. , Larson Dick R. , Hulsey Randall J.
Published: February 2023

During the periods January 5 to February 2 and May 29 to June 28 1991, a large number of sequences of atmospheric microwave radiance measurements were made at Fort Greeley, Alaska using a multi-channel, surface-based, microwave radiometers. Measurements were made at 57.45 GHz, 55.29 GHz, 53.88 GHz, 51.07 GHz, 31.4 GHz, and 20.7 GHz. During each data taking period, a simultaneous radiosonde launch was made from a co-located launch site.
Comparison of Lidar Derived Cloud-Data with In-Situ Atmospheric Sensors
Authors: Fong A.Y. , Pal S.R. , Carswell A.I.
Published: February 2023

This study is concerned mainly with the analysis of the large data set generated during York University/Institute for Space and Terrestrial Science (ISTS) Lidar group involvement in the first and second phases of the Experimental Cloud Lidar Pilot Study (ECLIPS). The relatively high temporal resolution of our system, its 1064 and532nminfrared and visible transmission wavelengths and the development and application of automated data processing algorithms with multiple cloud layer capabilities [1] allow previously unexamined aspects of such analyses be undertaken. This paper focuses on observations of parameters of interest to improving current GCM (General Circulation Model) work which involves detailed cloud elements, in particular cirrus, and to test the validity of lidar as a cloud diagnostic instrument.
Recent Lidar Activities for Atmospheric Pollutant Control
Authors: Diehl Wolfgang
Published: February 2023

Abstract and summary unavailable.
Development of Laser Altimeter Sensors for Earth and Planetary Observations
Authors: Bufton Jack L. , Harding David J. , Blair J. Bryan , Garvin James B.
Published: February 2023

Laser altimeter sensors are a class of devices, developed for airborne and space-based applications, with a primary role of measuring the topography of the Earth and other planetary surfaces. Laser altimeters are mounted for nadir observation on aircraft or spacecraft platforms and provide a high-resolution, high-accuracy measurement of the elevation and horizontal variability of planetary surfaces. The basis of the altimeter measurement is the timing of the round-trip propagation of short-duration pulses of laser radiation between the platform and the surface. Vertical (i.e. surface elevation) resolution of the altimetry measurement is determined primarily by laser pulsewidth, surface-induced spreading in time of the reflected pulse, and the timing precision of the altimeter electronics. With conventional (~10 nsec wide) gain-switched pulses from solid-state lasers and sub-nsec resolution electronics, sub-meter vertical range resolution is possible from aircraft altitudes (0.5 km - 20 km) to orbital altitudes of several hundred kilometers. Laser divergence angle and altimeter platform height above the surface determine the laser footprint size at the surface, while laser pulse repetition-rate, laser transmitter beam configuration, and altimeter platform velocity determine the spacing between successive laser pulses. Typical sensor footprint diameters for an aircraft altimeter application are 1-10 m and are ~ 100 m for a spacecraft altimeter. Ideally, the pulse-rate is adjusted to make a contiguous profile of topography so that horizontal resolution is equal to the sensor footprint size. Successful operation of the laser altimeter sensor requires additional information on the laser altimeter platform pointing attitude and position 1. Recent major advances in laser gyros, star cameras, and kinematic positioning with the Global Positioning System permit recovery of platform effects to a sufficient level (e.g. 5-500 μrad for pointing angle and 10 cm - 1 m for position) to enable sub-meter laser altimetry for the operating altitudes and velocities of both aircraft and spacecraft platforms.
Remote Sensing of Atmospheric Trace Constituents Using Mid-IR Fourier Transform Spectrometry
Authors: Fischer H.
Published: February 2023

The impact of industrial and agricultural human activities on the environment has now reached such proportions that even global scale effects are clearly observed. These activities lead to a steady growth in the atmospheric abundance of several radiatively and chemically active trace gases which influence the greenhouse effect and the tropospheric and stratospheric ozone.
EASOE Campaign and Lidar Observation
Authors: Megie Gerard J.
Published: February 2023

Summary not available at press time.
Daytime Tropospheric Water Vapor Profile Measurements with a Raman Lidar
Authors: Bisson Scott. E. , Goldsmith J. E. M.
Published: February 2023

Water vapor is one of the most important quantities needed to define the state of the atmosphere. Water vapor plays an important role in determining the earth's radiation budget, both directly as an absorber of infrared radiation and through its role in cloud formation. Because convection effectively short-circuits greenhouse absorption at altitudes below about 6 km, surface temperatures depend strongly on the vertical distribution of water vapor. The vertical distribution of water vapor also determines convective stability, and hence storm development. Water vapor is highly variable, both spatially and temporally, and is one of the most uncertain parameters in GCMs (General Circulation Models). Therefore, knowledge of the vertical and temporal variations of water vapor are essential for understanding atmospheric processes.
Spatial and Spectral Information Densities from Satellite Sounding Instruments
Authors: Huang Hung-Lung , Purser R. J. , Smith William L.
Published: February 2023

Recently objective measures of the information densities in both the spatial and spectral domains have been developed in the context of satellite retrievals of temperature and moisture profiles of the atmosphere (Purser and Huang, 1993; Huang and Purser, 1993). Densities of two measures of "information" are formulated. The first measure, "degrees of freedom for signal" (DFS) corresponds approximately to the effective dimensionality of the constraints imposed upon each retrieval by the set of measurements (Wahba, 1985). The second measure is the decrease in "entropy" in the sense defined by Shannon (1984) in the theory of communication. The matrix algebra of optimal linear retrieval suggests very natural definitions of both of these quantities, not only as distributions in height but, with equal validity, as densities distributed in the infrared spectrum itself.
A mobile remote sensing laboratory for water vapor, trace gas, aerosol, and wind speed measurements
Authors: Slaughter Dennis , White William , Tulloch William , DeSlover Daniel
Published: February 2023

The Lawrence Livermore National Laboratory has developed a mobile field laboratory for remote measurement of atmospheric processes and observables that are important in global climate change, dispersal of hazardous materials, and atmospheric pollution. Specific observables of interest are water vapor, trace gases, aerosol size and density, wind, and temperature. The goal is to study atmospheric processes continuously for extended periods in remote field locations. This laboratory has just reached field ready status with sensors for aerosol and trace gas measurement based on established techniques. A development program is underway to enhance the sensor suite with several new techniques and instruments that are expected to significantly extend the state of the art in remote trace gas analysis. The new sensors will be incorporated into the lab during the next two years.
Techniques Used for Simultaneous 1.064um and 2.036um Airborne LIDAR Utilizing an Optical Parametric Oscillator
Authors: Blair J. Bryan , Afzal Robert S. , Spinhirne James D.
Published: February 2023

The Goddard Visible and Near IR Lidar(VIRL) 1 has been modified to the 2.1um region by replacing the Raman cell previously used to generate the 1.54 um pulse with an Optical Parametric Oscillator (OPO) 2 that can efficiently convert the 1.064um output of the system Nd:YAG laser to generate a pulse at 2.1um. The initial test and application of the 2.1um measurements was during a deployment of the lidar on the NASA DC-8 for the TOGA/COARE project in January-February 1993. For T/C, the DC-8 was flown to and out of Townsville, Queensland. The T/C flights were north to the region of the equator and back. From the transit and local flights, a data set of significant coverage is to be generated.
Lidar Measurements of Stratospheric Aerosols at Mauna Loa Observatory: 1974 to Present
Authors: DeFoor T. E. , Ryan S. , Hofmann D. J. , Dutton E. G.
Published: February 2023

The measurement of stratospheric aerosols using a ruby lidar system has been an ongoing program at the National Oceanic and Atmospheric Administration, Climate Monitoring and Diagnostic Laboratory, Mauna Loa Observatory (MLO) since 1974. The 18 year MLO stratospheric aerosol record includes measurements of the injection growth and decay of aerosols following two of this centuries more important stratospheric aerosol producing eruptions: El Chichon (Mexico, 1982) and Mt. Pinatubo (Philippines, 1991). Also evident in the MLO lidar record are a number of lesser events which include the 1980 eruption of Mt. Saint Helens, the 1981 eruption of Nyamuragira, and the 1984 eruption of Nevado del Ruiz. Apparent, too, is a relatively quiescent period between 1985 and 1991 during which stratospheric aerosols decayed to near background aerosol levels. During this period, stratospheric aerosol backscatter ranged from as high 1E-2 sr-1 (El Chichon) to as low as 6E-5 sr-1.
The Pinatubo Eruption in Relation to the El Chichon Event and the Stratospheric Background Load
Authors: Jäger H.
Published: February 2023

Long-term records of the stratospheric aerosol layer exhibit periods of low and high aerosol load. Both, the background periods and the volcanically perturbed periods, are of interest. Long-term lidar records, which cover up to two decades (e.g. DeFoor, 1993), show that the variability of the stratospheric aerosol content spans more than two orders of magnitude. Our interest is not only devoted to spectacular volcanic perturbations of the stratosphere. Of course, such events provide large signals, not only to our lidar systems, but also to atmospheric chemistry and radiation models; but the highly perturbed situation is not the normal state of the stratosphere. This is rather a state of more or less aged volcanic load. But there are also periods which are not affected by the build-up and the decay of volcanic perturbations. Such background periods have to be studied carefully to extract information on other sources of the stratospheric aerosol. Such sources might be the diffusion of sulphurous precursor gases into the stratosphere or convective processes, and, in addition, we cannot rule out sources resulting from anthropogenic activities.
Implications of Aerosol Phenomenology on Sensor and Algorithm Design
Authors: Westerman Steve
Published: February 2023

Atmospheric haze, or aerosols, can dramatically reduce the horizontal visibility in a region. During pollution outbreaks such haze can be so thick that it appears to hang in the air. Scientists have been studying the detailed composition, dynamics and effects of aerosols on emitted radiation for years. An eventual goal is to produce a global method for the remote determination of aerosol content. To date, results from these studies have had an impact on our understanding of the Earth-radiation budget, pollution source monitoring, and visible image correction. They have also indicated that the influence of aerosols is very difficult to assess because of its tremendous variation in time and space.
The HITRAN Molecular Database: Enhancements for Remote Sensing
Authors: Rothman Laurence S.
Published: February 2023

This paper summarizes some of the major updates, improvements, modifications, and future directions to the spectroscopic molecular database, HITRAN, that enhance its application for remote sensing.
Studies of Atmospheric Constituents from High Resolution Infrared Atmospheric and Laboratory Spectra
Authors: Goldman A. , Murcray F.J. , Blatherwick R.D. , Murcray F.H. , Kosters J.J. , Bonomo F.S. , David S.J. , Murcray D.G. , Rinsland C.P.
Published: February 2023

High resolution (0.002-0.003 cm−1) Michelson type interferometer systems have been used at the University of Denver since 1987 to obtain infrared solar absorption spectra of the stratosphere during several balloon flights ( 37 km), as well as ground-based solar spectra and laboratory spectra of molecules of stratospheric and tropospheric interest. The stratospheric spectra cover the 700-2200 cm−1 region and show many new spectral features of important atmospheric gases such as O3 (including 18O and 17O isotopic species), NO2, HNO3, O2, N2, COF2, ClONO2, SF6and others. The new spectral features are enhanced by the high resolution and long path spectra obtained during sunrise and sunset. Also, new features appear as the concentrations of some trace gases increases in the atmosphere. An ongoing project of high resolution stratospheric atlas, documents the stratospheric spectral features in selected regions.
Atmospheric Trace Molecule Spectroscopy (ATMOS) Data Analysis Method
Authors: Abrams M. C. , Gunson M. R. , Lowes L. L. , Zander R. , Rinsland C. P.
Published: February 2023

The Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment makes use of a Fourier transform spectrometer to measure solar spectra from the Space Shuttle payload bay. The data analysis strategy and method used during the ATLAS-1 mission will be described.
CO2 Non-LTE Excitation and Emission at 4.3 μm from a Line-by-Line Radiative Transfer Model
Authors: Nebel Henry , Wintersteiner P. P. , Picard R. H. , Sharma R. D. , Winick J. R.
Published: February 2023

In this report, infrared radiative excitation of the asymmetric stretch (v3 mode) vibrationally excited states of CO2 in the non-LTE region of the quiescent atmosphere is considered using a line-by-line (LBL) radiative transfer model1. A set of codes known collectively as Atmospheric Radiance Code (ARC) is used to calculate (1) the vibrational populations of states that emit at 4.3 μm, and (2) the resulting earthlimb radiance. The model calculations are then compared to earthlimb radiance data from the Spectral Infrared Rocket Experiment, or SPIRE2. The approach has previously been used to model CO2 15 μm emission3.
Comparison of Remotely Measured Multispectral Scattering Parameters For Tropospheric Aerosols.
Authors: Cutten D. R. , McCaul E. W. , Spinhirne J. D. , Menzies R. T. , Pueschel R. , Clarke A. D. , Bowdle D. A.
Published: February 2023

In Fall 1989 and Spring 1990 the National Aeronautics and Space Administration (NASA) conducted a number of survey flights on the NASA DC-8 aircraft over the Pacific Basin as part of the GLObal Backscatter Experiment (GLOBE). The main objective of these flights was to collect data on tropospheric aerosol backscatter, either by direct measurement or modeled from measurements of selected aerosol microphysical properties that cover a wide range of spatial and temporal scales. The primary intent of collecting these data is to predict the performance of space-borne lidar systems such as the Laser Atmospheric Wind Sounder (LAWS). Other goals of the GLOBE missions were to characterize the source and properties of aerosols in the middle to upper troposphere over the remote ocean regions.
Application of a New Iterative Technique for Determining Particulate Extinction Profiles from Airborne Lidar Data Obtained in Clear Tropospheric Conditions
Authors: Kovalev Vladimir A. , Viswanathan Ramesh
Published: February 2023

In this paper we present preliminary results of the application and potential of a new iterative extinction profile retrieval technique for lidar measurements. Lidar data were collected during May 11-14, 1992, in the Detroit, Michigan area, using a compact airborne nadir looking UV-DIAL.1,2 The system was developed for making simultaneous measurements of ozone, sulfur dioxide, and aerosol distributions in the lowest 3-4 km. of the troposphere. The aerosol data are used to obtain semi-quantitative information relating to the atmospheric boundary-layer structure and to develop correction procedure for the DIAL-derived concentrations that are influenced by differential scattering and extinction effects.
Evolution of the Pinatubo Volcanic Cloud Over Hampton, Virginia
Authors: Osborn Mary T. , Winker David M. , Woods David C. , DeCoursey Robert J.
Published: February 2023

A series of eruptions of the Philippine Mt. Pinatubo volcano in June 1991 climaxed in cataclysmic eruptions on June 15-16, which greatly perturbed the stratospheric aerosol layer. These eruptions yielded an estimated 20 megatonnes of SO2, which is nearly three times the amount produced by the eruptions of El Chichon in 1982 (Bluth et al., 1991). Lidar measurements taken at 694 nm by the 48-inch lidar system at Langley Research Center (LaRC) in Hampton, Virginia, show the vertical distribution, intensity and spread of the Pinatubo aerosol layers over this mid-latitude location. The peak stratospheric aerosol burden, which occurred in late February 1992, is equivalent to an optical depth of approximately 0.2 at 694 nm. In the subsequent nine months, the stratospheric loading has decreased with an l/e decay rate of 7.3 months. The magnitudes, transport times, and decay rates of the volcanic aerosol layers following Pinatubo and El Chichon are compared.
The Wavelength Dependence of the Total Extinction Coefficient Under Volcanic Conditions
Authors: Rodriguez Rene , Johnson Scott D. , Burris John , McGee Thomas
Published: February 2023

The use of the wavelength ratio as a value for the ratio of the total extinction coefficients at the Raman and Rayleigh wavelengths:1 has been recently used in the Rayleigh LIDAR equation to determine temperatures or ozone concentrations in the stratosphere. The wavelength dependence of the total scattering coefficient could also be useful for the inversion of LIDAR data to get the particle distribution.2 This work examines the dependence of the exponent c, referred to as the Power for the Total Extinction Coefficient Ratio (PTECR), on the index of refraction of the medium, the modal radius of the particle distribution, and the width or shape of the particle distribution. These parameters are expected to be significantly different from the normal atmospheric parameters during volcanic conditions. A Mie code, developed by Dave3 and modified for use on a PC, served to theoretically examine this dependence.
A Signal-Processing Approach for the Retrieval of Global Tropospheric CO Using the Atmospheric Infrared Sounder (AIRS)
Authors: Strow L. Larrabee
Published: February 2023

One goal of the Earth Observing Systems (EOS) is to measure concentrations of key atmospheric gases on a global scale in order to understand biogeochemical cycles in both the natural, unpolluted atmosphere, and in regions where anthropogenic activities have perturbed concentrations of gas-phase species. A particular concern in tropospheric chemistry is that increasing levels of carbon monoxide (CO) may lead to a decrease in atmospheric hydroxyl (OH) which would reduce the atmosphere's ability to scavenge other trace gases.
Retrieval of tropospheric and stratospheric distribution of HCI from ground-based FTIR spectra
Authors: Adrian G.P. , Baumann M. , Frank E. , Oelhaf H.
Published: February 2023

FTIR spectrometers are often employed from the ground to detect the column amount of trace gases. For most applications it is sufficient to derive the total column amount without retrieving any information on the vertical distribution of the trace gases. However, some knowledge on the vertical distribution would be helpful in any case for the interpretation of the received trace gas contents. Of still greater importance is the fact that the uncertainty of the total column amount may be high due to an incorrectly assumed a priori profile. There is a chance to reduce that by taking into account the full information content of spectral line shapes. This is in particular the case for gases which contribute both by tropospheric and stratospheric contents to the total column amount, e.g. HCI or NO2.
A Combined Lidar, Long-path Extinction and In-situ Aerosol Experiment in Southern Ontario
Authors: Hoff Raymond M.
Published: February 2023

During August, 1992, a number of colocated optical and chemical experiments were performed at the Center for Atmospheric Research Experiments at Egbert (north of Toronto), Ontario, Canada. These experiments were symbiotic in that they were designed to address a number of atmospheric research problems of interest to Canada, including the need to determine: (1) the deposition velocity of polynuclear aromatic hydrocarbons and trace metals, (2) the size distribution and hygroscopic behaviour of particles affecting eastern Canadian visibility, (3)the evolution of nitrogen chemistry at nighttime, (4) the formation of particulate nitrate from gaseous precursors, and (5) the need to understand the photochemical particle production processes in early morning sunrise events. This work involved AES scientists as well as scientists from Germany visiting Canada under a bilateral exchange program. This paper will present the initial results from these experiments.
Dual-wavelength CO2 Lidar Method for Distinguishing Ice, Water, or Mixed-phase Clouds
Authors: Eberhard Wynn L.
Published: February 2023

A dual-wavelength CO2 lidar technique is proposed that shows excellent promise for discriminating between ice and water within clouds. It could potentially provide more quantitative measurements of mixed-phase clouds than the depolarization technique of shortwave lidars.
Application of Optical Remote Sensing to the Study of Surface Fluxes Related To Cloud Formation
Authors: Porch W.M. , Shaw W.
Published: February 2023

One of the largest uncertainties in climate change prediction is associated with cloud formation. A change in cloudiness small enough to be undetectable by satellites can have a large impact on global climate. It is therefore very important to accurately measure the meteorological parameters associated with cloud formation. These parameters include water vapor, cloud condensation nuclei (CCN), and vertical lofting of air to colder altitudes. For boundary layer clouds, the vertical velocities associated with lofting need only be a few centimeters per second. The vertical velocity can be induced by topographical features and/or surface heat flux. We will describe an experiment that used optical techniques to quantify surface heat flux changes related to boundary layer cloud formation and cloud shadowing effects and relate these changes to convergence associated with vertical velocities over a dry prairie grassland. The major result of this experiment showed that optical turbulence at different scales provides heat and momentum flux changes associated with cloud effects on a time scale fast enough to resolve cloud formation and movement. Standard tower measurements, because they are not spatially averaged, require tens of minutes for valid comparable estimates.
Neural Nets for Temperature Retrievals
Authors: Motteler Howard E. , Strow L. Larrabee , Gualtieri J. Anthony , McMillin Larry , Lo James
Published: February 2023

We use neural networks to perform temperature retrievals [1,2] from simulated clear-air radiances for the Atmospheric Infrared Sounder (AIRS) [3]. Neural networks allow us to make effective use of the large AIRS channel set, giving good performance with noisy input. Using 653 temperature and surface sensitive channels, RMS error on retrievals with 0.2K noise is below 1.2K. We briefly describe the sort of networks we are using, describe our datasets, and present a number of representative results.
Real-Time Simultaneous Monitoring of Atmospheric Methane and Carbon Dioxide by using Diode Lasers
Authors: Tai Hideo , Toriumi Ryoichi , Uehara Kiyoji
Published: February 2023

Precise measurement of the atmospheric trace methane and carbon dioxide concentrations is essential to investigate the spatial and temporal variations of the green-house gases. A measurement system which is capable of monitoring these gases simultaneously in real time will be of great use.
Haloe Data Processing Techniques
Authors: Gordley Larry L. , Thompson Robert E. , Russell James M.
Published: February 2023

The Halogen Occultation Experiment (HALOE) 1was launched aboard the UARS satellite in September of 1991 and has performed flawlessly since activated on October 11, 1991. HALOE uses both broadband radiometry and gas correlation radiometry techniques during occultation to obtain measurements for inferring temperature, pressure, and mixing ratios of O3, H2O, NO2, HF, HCl, CH4, and NO.
The Satellite Project GOME: Potential Precision of Trace Gas Retrieval under Ozone Hole Conditions
Authors: Diebel D. , Burrows J.P. , Spurr R.J.D. , Rozanov V.V.
Published: February 2023

GOME (Global Ozone Monitoring Experiment) is an ESA satellite project, centered around the development of a new, diode-array based spectrometer [1]. It will measure the radiation back-scattered from the atmosphere and Earth's surface in the ultraviolet and visible range in nadir-viewing direction. This instrument will be launched in late 1994 on board the ERS-II satellite. The medium-high resolution (0.2 to 0.4 nm) and extended wavelength coverage (240 to 790 nm) of the instrument will enable profiles or column densities of different trace gases to be measured such as of O3, NO2, NO3, ClO, OClO, BrO, HCHO, and SO2 . In addition, the distribution of aerosols and surface spectral reflectance properties can be investigated.
Wind Profiling with the Volume Imaging Lidar: A Comparison with Aircraft and Balloon Based Measurements
Authors: Piironen A.K. , Eloranta E.W.
Published: February 2023

The University of Wisconsin Volume Imaging Lidar1 (VIL) provides vertical profiles of the horizontal wind inside the convective boundary layer. In this paper we outline the VIL wind profiling method and compare results with aircraft-based and balloon-based observations. The methods provide different spatial averages: radiosonde measurements are nearly point measurements, aircraft measurements are flight path averaged, and VIL measurements are area averaged.
Optically-Based Air Data Using Doppler-Shifted, High Spectral Resolution Lidar
Authors: Lempert W.R. , Forkey J. , Finkelstein N. , Miles R.
Published: February 2023

Optically-based velocimetry techniques have the potential to provide critical data for the maneuverability and control of supersonic/hypersonic aircraft under conditions where conventional sensors are unreliable. For example, at high speed, the calibration of pitot-pressure devices is uncertain. Recently, High Spectral Resolution Lidar (HSRL) incorporating a barium atomic vapor filter has been used to determine atmospheric temperature and backscatter ratio (1). In this paper, we present a concept for an air-born Optical Air Data System (OADS) based on a Doppler-shifted HSRL approach which we have termed Spectrally Filtered Rayleigh Scattering (FRS) (2).
Dial Lidar Measurements of Stratospheric Ozone in the Presence of Volcanic Aerosols
Authors: McGee Thomas J.
Published: February 2023

On June 15, 1991, Mt. Pinatubo in the Philippines explosively erupted, injecting large quantities of SO2 and dust particles directly into the stratosphere. The SO2 slowly reacted to form a concentrated and fairly thick layer of aerosol particles in the 15 to 32 km region of the stratosphere. When this layer was transported to latitudes at which a number of stratospheric lidars were operating, signals which had been dependent only on molecular scattering began to have a very large component due to Mie scattering from aerosols. Unlike Rayleigh scattering, the wavelength dependence of this Mie component is not well known.
New Lidar for the Network for the Detection of Stratospheric Change - Mauna Loa Observatory : System Description
Authors: Walsh T. Daniel , Lindquist L. Oscar , White Mary L. , Deslis Apostolis , McDermid I. Stuart
Published: February 2023

The development of differential absorption lidar (DIAL) systems for long-term measurements of stratospheric ozone and for potential inclusion in the Network for the Detection of Stratospheric Change (NDSC) [Kurylo and Solomon, 1990] began at JPL in 1986. The DIAL system at the JPL Table Mountain Facility (TMF, 34.4° N, -117.7° W) was developed specifically to have the characteristics suitable for long-term measurements as proposed for NDSC. Regular measurements of stratospheric ozone concentration profiles commenced in February 1988, with temperature measurements beginning in January 1990 and aerosol measurements in July 1991. This system has been fully described elsewhere [McDermid et al, 1990]. The new system incorporates some new developments compared to the TMF system and details of the new design are presented.
New Lidar for the Network for the Detection of Stratospheric Change - Mauna Loa Observatory : Initial Results
Authors: McDermid I. Stuart , Walsh T. Daniel
Published: February 2023

A new lidar system capable of simultaneous measurements of stratospheric ozone, temperature and aerosol profiles has been successfully built and tested. A detailed description of the design and implementation this new system will be given elsewhere [Walsh et al, 1993]. In this paper we will present some initial measurements made with this lidar and some intercomparisons with the existing stratospheric lidar at the JPL-Table Mountain Facility (TMF). Ozone profiles are obtained using the differential absorption lidar (DIAL) technique extended to include two Raman channels for aerosol correction [Singh et al, 1992]; temperature profiles are obtained from Rayleigh and Raman scattering lidar; aerosol backscatter ratio profiles are obtained from comparison of the elastic and Raman backscattered lidar signals.
An Overview of the SABER Experiment for the TIMED Mission
Authors: Mlynczak Martin G. , Russell James M.
Published: February 2023

The Sounding of the Atmosphere Using Broadband Emission Radiometry (SABER) experiment has been selected for flight on the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) mission expected to fly in the latter part of this decade. The primary science goal of SABER is to achieve fundamental and important advances in understanding of the energetics, chemistry, and dynamics, in the atmospheric region extending from 60 km to 180 km altitude, which has not been comprehensively observed on a global basis. This will be accomplished using the space flight proven experiment approach of broad spectral band limb emission radiometry. SABER will scan the horizon in 12 selected bands ranging from 1.27μm to 17μm wavelength. The observed vertical horizon emission profiles will be mathematically inverted in ground data processing to provide vertical profiles with 2 km vertical resolution, of temperature, O3, H2O, NO, NO2, CO, and CO2. SABER will also observe key emissions needed for energetics studies at 1.27μm [O2(1Δ)], 2μm [OH(υ=7,8,9)], 1.6μm [OH(υ=3,4,5)], 4.3μm [CO2(ν3)], 5.3μm (NO), 9.6 μm (O3), and 15 μm [CO2(ν2)]. These measurements will be used to infer atomic hydrogen and atomic oxygen, the latter inferred three different ways using only SABER observations. Measurements will be made both night and day over the latitude range from the southern to northern polar regions.
Atmospheric Lidar Using High-Energy 1.57 Micron Optical Parametric Oscillator
Authors: Harrell Sarah R. , Wilcox William , Killinger Dennis , Rines Glen A. , Schwarz Richard
Published: February 2023

We have developed an atmospheric lidar using a high-energy 1.57 micron optical parametric oscillator (OPO) source, and measured the temporal variation of the aerosol profile in the atmosphere out to a distance of about 5 km under various weather conditions. The lidar signal was detected using both an InGaAs APD and an InGaAs PIN photodiode to compare their performance.