Two projects are to be undertaken within the water-related activities of the World Climate Program (WCP-Water). Project A.1 is analyzing historical hydrological and related information with respect to climate change, and project A.2 is analyzing long time series of hydrological data and indices with respect to climate variability. To ensure uniformity within the WCP, the concepts of the variability and change in hydrology and climate are defined. In addition, the selection of the time series of data and the analysis of variability are discussed. The appendices contain a description of the projects, information required for each station, and a list of the projects' statistical formulas. M.G. PROCEEDINGS OF THE WMO REGION 3/4 TRAINING 1989 86 p Seminar held in Barbados, 22-26 Sep. 1986, and in Panama, 29 Sep. - 3 Oct. 1986 (WCDP-1; WMO/TD-227) Avail: NTIS HC/MF A05 Papers presented at the Training Seminar in Climate Data Management and User Services are presented. The following subject areas are covered: climate data management and standard user services; simple climate data applications such as the analysis of rainfall data to assist agricultural planning and decision making; and advanced climate data applications using climate and other geographical data for natural resource management and modelling. Author N91-10446# National Oceanic and Atmospheric Administration, Washington, DC. Office of Research and Applications. GEOGRAPHIC DISPLAY OF CIRCULATION MODEL DATA Kurt W. Hess and Peter J. Pytlowany (National Oceanographic Data Center, Washington, DC.) Aug. 1989 49 P Original contains color illustrations (NOAA-NESDIS-27) Avail: NTIS HC/MF A03 Circulation models of coastal area data can potentially be integrated with geographic locations, satellite data, and other types of information and used for analysis, prediction, and verification. The goal is to put circulation model data into a geographic mode for display in combination with other data fields. The satellite image display software allows for overlaying several planes of different types of data on top of a gridded field in geographic format, so the software is essentially a geographic information system. The satellite image processing system was used to analyze the NOAA polar orbiter's Advanced Very High Resolution Radiometer (AVHRR) data, including sea surface temperature, chlorophyll, and sediment concentration. The data are displayed with a geographic orientation using a matrix to hold data for a selected area of the earth surface. Compound images showing several data types result from overlaying the AVHRR field with other fields such as coastline geography, land masks, and scale bars. Author N91-10447# National Oceanographic Data Center, Washington, DC. MARINERS WEATHER LOG, VOLUME 33, NUMBER 1, R. M. DeAngelis 1989 73 p (PB90-179987) Avail: NTIS HC/MF A04 CSCL 04B This volume of the journal contains articles on these topics: Whale diary; Malstrom, the legend and the reality; Avoid the typhoon; Whale oil and wicks; Beyond the rainbow; Editor's desk; Marine observation program; Radio officer tips; Hurricane alley; North Atlantic Ocean; North Pacific Ocean; and Track charts and tables. Author N91-10448*# National Aeronautics and Space Administration. Langley Research Center, Hampton, VA. FIRE SCIENCE RESULTS 1988 David S. McDougal, ed. and H. Scott Wagner, ed. Washington Jul. 1990 394 p Workshop held in Vail, CO, 11-15 Jul. 1988; sponsored in cooperation with NASA, NSF, ONR, DOE, AFGL, and NOAA (NASA-CP-3083; L-16814; NAS 1.55:3083) Avail: NTIS HC/MF A17 CSCL 04B FIRE (First ISCCP Regional Experiment) is a U.S. cloud-radiation program that seeks to address the issues of a basic understanding and parameterizations of cirrus and marine stratocumulus cloud systems and ISCCP data products. The papers describe research analysis of data collected at the 1986 Cirrus Intensive Field Observations (IFO), the 1987 Marine Stratocumulus IFO, and the Extended Time Observations. The papers are grouped into sessions on satellite studies, lidar/radiative properties/microphysical studies, radiative properties, thermodynamic and dynamic properties, case studies, and large scale environment and modeling studies. For individual titles, see N91-10449 through N91-10535. N91-10449*# National Aeronautics and Space Administration. Goddard Space Flight Center, Greenbelt, MD. SYNOPTIC CONDITIONS PRODUCING CIRRUS DURING THE FIRE CIRRUS IFO David OC. Starr and Donald P. Wylie (Wisconsin Univ., Madison.) In NASA, Langley Research Center, FIRE Science Results 1988 Jul. 1990 P 3-10 (For primary document see N91-10448 01-47) Avail: NTIS HC/MF A17 CSCL 04B Although direct observations of cirrus clouds by the FIRE research aircraft were usually confined to the area of Intensive Field Observation (IFO) surface network, these cirrus were generally part of a more extensive zone of upper level cloudiness. It is these large scale patterns of cirriform cloud and their relationship to the corresponding synoptic environment which are the prime focus. Three conceptual models are presented and each of the individual cases are classified into one of these categories. Although the cases manifest significant differences in intensity and small scale structure, it is believed that they are best viewed in this unified context. The descriptions given are mostly qualitative, however, quantitative descriptions of the synoptic control and its relationship to cloud structure for all the IFO cases are summarized. The synoptic situations in which extensive cirriform clouds were observed are classified into three basic types: warm front cases, cold front cases, and closed low aloft cases. A simplified summary of each type of situation is presented. Author N91-10450*# Wisconsin Univ., Madison. Space Science and Avail: NTIS HC/MF A17 CSCL 04B The cirrus cloud climatology of Wylie and Menzel (1988) and some ancillary studies of cirrus clouds that have been made using the same data are summarized. The Wylie and Menzel climatology is a data set of cloud statistics extracted from the GOES/VAS satellite. With these data the geographical distributions of clouds, the seasonal changes, some diurnal changes, and also what atmospheric conditions cause the clouds can be described. Author N91-10451*# National Aeronautics and Space Administration. Goddard Inst. for Space Studies, New York, NY. ISCCP RESULTS FOR THE FIRE IFO REGIONS AND TIMES Abstract Only William B. Rossow In NASA, Langley Research Center, FIRE Science Results 1988 Jul. 1990 p 17 (For primary document see N91-10448 01-47) Avail: NTIS HC/MF A17 CSCL 04B The ISCCP analysis of cloud conditions during and in the vicinity of the FIRE cirrus and marine stratus Intensive Field Observations (IFOS) is presented in two forms: the standard climatology product, which is averaged to a nominal 250 km resolution and a pixel-by-pixel version that samples the original data at about 30 km spacing every three hours. These results are based on NOAA-9 and GOES-6 images covering October to November 1986 and July 1987 for the FIRE Extended Area. Comparisons of these results with other FIRE observations will serve to check the accuracy of the clear sky radiances inferred by the ISCCP analysis, which determines the accuracy of the cloud detections. Of more interest is the exploration of the dependence of the inferred cloud properties for direct evaluation of the role of small scale variability of cloud properties on the radiation field. This is illustrated by preliminary results obtained for the scales contained in the ISCCP data. The ISCCP analysis also sets the larger scale context of the FIRE data: (1) comparisons of the clouds occurring in the FIRE IFOS with nearby locations and times are presented, and (2) comparisons of the cloud conditions for the same month in other years are shown. Author N91-10452*# Colorado Univ., Boulder. Cooperative Inst. for Research in Environmental Sciences. CLOUD INFORMATION FOR FIRE FROM SURFACE WEATHER REPORTS Carole J. Hahn, Stephen G. Warren (Washington Univ., Seattle.), and Julius London In NASA, Langley Research Center, FIRE Science Results 1988 Jul. 1990 p 19-23 (For primary document see N91-10448 01-47) (Grant NAG2-206) Avail: NTIS HC/MF A17 CSCL 04B Surface weather observations of clouds were analyzed to obtain a global cloud climatology (Warren et al, 1986; 1988). The form of the synoptic weather code limits the types of cloud information which are available from these reports. Comparison of surface weather reports with instrumental observations during the FIRE field experiments can help to clarify the operational definitions which were made in the climatology because of the nature of the synoptic code. The long-term climatology from surface weather observations is also useful background for planning the location and timing of intensive field experiments. Author N91-10453*# National Aeronautics and Space Administration. Avail: NTIS HC/MF A17 CSCL 04B Recent cirrus cloud modeling studies have involved the application of a time-dependent, two dimensional Eulerian model, with generalized cloud microphysical parameterizations drawn from experimental findings. For computing the ice versus vapor phase changes, the ice mass content is linked to the maintenance of a relative humidity with respect to ice (RHI) of 105 percent; ice growth occurs both with regard to the introduction of new particles and the growth of existing particles. In a simplified cloud model designed to investigate the basic role of various physical processes in the growth and maintenance of cirrus clouds, these parametric relations are justifiable. In comparison, the one dimensional cloud microphysical model recently applied to evaluating the nucleation and growth of ice crystals in cirrus clouds explicitly treated populations of haze and cloud droplets, and ice crystals. Although these two modeling approaches are clearly incompatible, the goal of the present numerical study is to develop a parametric treatment of new ice particle generation, on the basis of detailed microphysical model findings, for incorporation into improved cirrus growth models. For example, the relation between temperature and the relative humidity required to generate ice crystals from ammonium sulfate haze droplets, whose probability of freezing through the homogeneous nucleation mode are a combined function of time and droplet molality, volume, and temperature. As an example of this approach, the results of cloud microphysical simulations are presented showing the rather narrow domain in the temperature/humidity field where new ice crystals can be generated. The microphysical simulations point out the need for detailed CCN studies at cirrus altitudes and haze droplet measurements within cirrus clouds, but also suggest that a relatively simple treatment of ice particle generation, which includes cloud chemistry, can be incorporated into cirrus cloud growth. Author N91-10454*# Colorado State Univ., Fort Collins. Dept. of Atmospheric Science. EVIDENCE FOR ASYMMETRIC INERTIAL INSTABILITY IN THE FIRE SATELLITE DATASET Duane E. Stevens and Paul E. Ciesielski In NASA, Langley Research Center, FIRE Science Results 1988 Jul. 1990 p 29-33 (For primary document see N91-10448 01-47) (Grant NSF ATM-83-52205) Avail: NTIS HC/MF A17 CSCL 04B One of the main goals of the First ISCCP Regional Experiment (FIRE) is obtaining the basic knowledge to better interpret satellite image of clouds on regional and smaller scales. An analysis of a mesoscale circulation phenomenon as observed in hourly FIRE satellite images is presented. Specifically, the phenomenon of interest appeared on satellite images as a group of propagating cloud wavelets located on the edge of a cirrus canopy on the anticylonic side of a strong, upper-level subtropical jet. These wavelets, which were observed between 1300 and 2200 GMT on 25 February 1987, are seen most distinctly in the GOES-West infrared satellite picture at 1800 GMT. The purpose is to document that these wavelets were a manifestation of asymmetric inertial instability. During their lifetime, the wavelets were located over the North American synoptic sounding network, so that the meteorological conditions surrounding their occurrence could be examined. A particular emphasis of the analysis is on the jet streak in which the wavelets were imbedded. The characteristics of the wavelets are examined using hourly satellite imagery. The hypothesis that inertial instability is the dynamical mechanism responsible for generating the observed cloud wavelets was examined. To further substantiate this contention, the observed characteristics of the wavelets are compared to, and found to be consistent with, a theoretical model of inertia instability by Stevens and Ciesielski. Author N91-10455*# National Aeronautics and Space Administration. Lola M. Olsen, Dominick lascone, and Mary G. Reph In NASA, The NASA Climate Data System (NCDS) at Goddard Space Flight Center is serving as the FIRE Central Archive, providing a centralized data holding and data cataloging service for the FIRE project. NCDS members are carrying out their responsibilities by holding all reduced observations and data analysis products submitted by individual principal investigators in the agreed upon format, by holding all satellite data sets required for FIRE, by providing copies of any of these data sets to FIRE investigators, and by producing and updating a catalog with information about the FIRE holdings. FIRE researchers were requested to provide their reduced data sets in the Standard Data Format (SDF) to the FIRE Central Archive. This standard format is proving to be of value. An improved SDF document is now available. The document provides an example from an actual FIRE SDF data set and clearly states the guidelines for formatting data in SDF. NCDS has received SDF tapes from a number of investigators. These tapes were analyzed and comments provided to the producers. One product which is now available is William J. Syrett's sodar data product from the Stratocumulus Intensive Field Observation. Sample plots from all SDF tapes submitted to the archive will be available to FSET members. Related cloud products are also available through NCDS. Entries describing the FIRE data sets are being provided for the NCDS on-line catalog. Detailed information for the Extended Time Observations is available in the general FIRE catalog entry. Separate catalog entries are being written for the Cirrus Intensive Field Observation (IFO) and for the Marine Stratocumulus IFO. Short descriptions of each FIRE data set will be installed into the NCDS Summary Catalog. Author N91-10456*# Colorado State Univ., Fort Collins. Dept. of Atmospheric Science. THE EFFECTS OF CLOUD RADIATIVE FORCING ON AN OCEAN-COVERED PLANET David A. Randall In NASA, Lahgley Research Center, FIRE Science Results 1988 Jul. 1990 p 39-43 Sponsored by NASA, Ames Research Center (For primary document see N91-10448 01-47) Avail: NTIS HC/MF A17 CSCL 04B Cumulus anvil clouds, whose importance has been emphasized by observationalists in recent years, exert a very powerful influence on deep tropical convection by tending to radiatively destabilize the troposphere. In addition, they radiatively warm the column in which they reside. Their strong influence on the simulated climate argues for a much more refined parameterization in the General Circulation Model (GCM). For Seaworld, the atmospheric cloud radiative forcing (ACRF) has a powerful influence on such basic climate parameters as the strength of the Hadley circulation, the existence of a single narrow InterTropical Convergence Zone (ITCZ), and the precipitable water content of the atmosphere. It seems likely, however, that in the real world the surface CRF feeds back negatively to suppress moist convection and the associated cloudiness, and so tends to counteract the effects of the ACRF. Many current climate models have fixed sea surface temperatures but variable land-surface temperatures. The tropical circulations of such models may experience a position feedback due to ACRF over the oceans, and a negative or weak feedback due to surface CRF over the land. The overall effects of the CRF on the climate system can only be firmly established through much further analysis, which can benefit greatly from the use of a coupled ocean-atmospheric model. Author The lidar data obtained by the Langley Aircraft Lidar in October 1986 in Wisconsin is being reduced in a transparent, simple fashion and will be published in its reduced form in a NASA Reference Publication (RP). This reduced data will also be submitted to the FIRE data archives. Some of this reduced data will be presented at the FIRE FSET Workshop to acquaint the science team with the data format to be used in the archive and the upcoming catalog contained in the RP. A new method was utilized in Wisconsin for obtain the depolarization ratio of aerosols. This method involves using a half-wave plate to calibrate the lidar under field conditions. The theory behind this technique will be presented at this workshop as well as some of the lidar calibration results. The lidar calibration will be utilized in interpreting some of the dual polarization lidar data obtained during the IFO in Wisconsin. Some of these data are also discussed. A continuous wave laser lab-type lidar simulator was constructed during the previous year. One of the primary reasons for the construction of the simulator was to attempt dual-polarization lidar-like calibrations under laboratory, rather than field conditions. The data collected by this system was used to experimentally check and thus, inspire confidence in the algorithms being used to interpret the lidar data obtained in the field. A computer program which simulates noisy lidar data was used as a part of this effort in order to obtain some feel for the noise in the inversion parameters as a function of noise in the actual measurements. The lidar simulation will be described in addition to presenting some of the lab-generated calibration data. Author N91-10458*# Wisconsin Univ., Madison. Dept. of Meteorology. OPTICAL AND MORPHOLOGICAL PROPERTIES OF CIRRUS CLOUDS DETERMINED BY THE HIGH SPECTRAL RESOLUTION LIDAR DURING FIRE Christian John Grund and Edwin W. Eloranta In NASA, Langley Research Center, FIRE Science Results 1988 Jul. 1990 p 49-53 (For primary document see N91-10448 01-47) (Contract N00014-85-K-0581; DAAG29-84-K-0069) Avail: NTIS HC/MF A17 CSCL 04B Cirrus clouds reflect incoming solar radiation and trap outgoing terrestrial radiation; therefore, accurate estimation of the global energy balance depends upon knowledge of the optical and physical properties of these clouds. Scattering and absorption by cirrus clouds affect measurements made by many satellite-borne and ground based remote sensors. Scattering of ambient light by the cloud, and thermal emissions from the cloud can increase measurement background noise. Multiple scattering processes can adversely affect the divergence of optical beams propagating through these clouds. Determination of the optical thickness and the vertical and horizontal extent of cirrus clouds is necessary to the evaluation of all of these effects. Lidar can be an effective tool for investigating these properties. During the FIRE cirrus IFO in Oct. to Nov. 1986, the High Spectral Resolution Lidar (HSRL) was operated from a rooftop site on the campus of the University of Wisconsin at Madison, Wisconsin. Approximately 124 hours of fall season data were acquired under a variety of cloud optical thickness conditions. Since the IFO, the HSRL data set was expanded by more than 63.5 hours of additional data acquired during all seasons. Measurements are presented for the range in optical thickness and backscattering phase function of the cirrus clouds, as well as contour maps of extinction corrected backscatter cross sections indicating cloud morphology. Color enhanced images of range-time indicator (RTI) displays a variety of cirrus clouds with approximately 30 sec time resolution are presented. The importance of extinction correction on the interpretation of cloud height and structure from lidar observations of optically thick cirrus are demonstrated. Author N91-10459*# National Center for Atmospheric Research, Boulder, CO. HYDROMETEOR DEVELOPMENT IN COLD CLOUDS IN FIRE Andrew J. Heymsfield, Nancy C. Knight, and Kenneth Sassen (Utah Univ., Salt Lake City.) In NASA, Langley Research Center, FIRE Science Results 1988 Jul. 1990 p 55-59 (For primary document see N91-10448 01-47) (Grant NASA Order L-98100-B; NSF ATM-85-13975) Avail: NTIS HC/MF A17 CSCL 04B The role of cirrus clouds, particularly in weather and climate processes, has been increasingly investigated. Numerical models have demonstrated the importance of the solar reflectivity and infrared radiation of cirrus clouds in the Earth's radiation budget and climate. These properties depend upon the cloud microphysical characteristics, density, and altitude and hence justify investigation. The results reported were obtained from cold clouds (-20 to -46 C) in the mid to upper troposphere during ten flights of the NCAR King Air as part of the First ISCCP Research Experiment (FIRE) in Wisconsin. Author N91-10460*# Utah Univ., Salt Lake City. Dept. of Meteorology. LIDAR AND AIRCRAFT STUDIES OF DEEP CIRRUS SYSTEMS FROM THE 1986 FIRE IFO In Kenneth Sassen, Andrew J. Heymsfield, and Nancy C. Knight (National Center for Atmospheric Research, Boulder, CO.) NASA, Langley Research Center, FIRE Science Results 1988 Jul. 1990 p 61-65 (For primary document see N91-10448 01-47) (Grant NASA Order L-08100-B; NSF ATM-85-13975) Avail: NTIS HC/MF A17 CSCL 04B Several NCAR King Air flight missions were conducted during the Wisconsin FIRE IFO experiment in support of the University of Utah polarization lidar observations of deep cirrus cloud systems at the Wausau ground site. Data collected from four cirrus systems are included in this analysis, including those of 22 and 28 October, and 1 and 2 November. Lidar data were generally obtained at 2 min intervals in the zenith direction over observation periods that ranged from approximately 4 to 10 h, bracketing the aircraft missions. The data were processed to yield height-time (HTI) displays of lidar linear depolarization ratio sigma and relative range-normalized return power P. King Air operations consisted of a combination of rapid profiling and Lagrangian spiral descents and stacked racetrack patterns in the vicinity of the field site. From the spiral descents are constructed vertical profiles of ice particle concentration N(sub i) and ice mass content IWC derived from PMS 2-D probe imagery and, when detected, FSSP cloud droplet concentration N(sub W) and liquid water content, LWC. Aircraft flight leg data are presented for the vertical velocity W and the same ice and water cloud content parameters. In addition, aerosol particle concentrations obtained with the ASAS probe are examined, and photographs of ice particles collected in-situ on oil-coated slides are presented to illustrate ice particle habit. Author N91-10461*# National Center for Atmospheric Research, Boulder, CO. VERTICAL VELOCITIES WITHIN A CIRRUS CLOUD FROM Avail: NTIS HC/MF A17 CSCL 04B A large and comprehensive data set taken by the NOAA CO2 Doppler lidar, the NCAR King Air, and rawinsondes on 31 October 1986 during the FIRE (First ISCCP Regional Experiment) field program which took place in Wisconsin are presented. Vertical velocities are determined from the Doppler lidar data, and are compared with velocities derived from the aircraft microphysical data. The data are used for discussion of particle growth and dynamical processes operative within the cloud. Author N91-10462*# Colorado State Univ., Fort Collins. Dept. of RADIATIVE PROPERTIES OF VISIBLE AND SUBVISIBLE (Grants AF-AFOSR-0143-88; NSF AST-86-12013; NSF Avail: NTIS HC/MF A17 CSCL 04B One of the main objectives of the First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment (FIRE) is to provide a better understanding of the physics of upper level clouds. The focus is on just one specific aspect of cirrus physics, namely on characterizing the radiative properties of single, nonspherical ice particles. The basis for further more extensive studies of the radiative transfer through upper level clouds is provided. Radiation provides a potential mechanism for strong feedback between the divergence of in-cloud radiative flux and the cloud microphysics and ultimately on the dynamics of the cloud. Some aspects of ice cloud microphysics that are relevant to the radiation calculations are described. Next, the Discrete Dipole Approximation (DDA) is introduced and some new results of scattering by irregular crystals are presented. The Anomalous Diffraction Theory (ADT) was adopted to investigate the scattering properties of even larger crystals. In this way the scattering properties of nonspherical particles were determined over a range of particle sizes. Author N91-10463*# National Aeronautics and Space Administration. Ames Research Center, Moffett Field, CA. CIRRUS MICROPHYSICS AND RADIATIVE TRANSFER: A CASE STUDY Stefan A. Kinne, Thomas P. Ackerman, and Andrew J. Heymsfield (National Center for Atmospheric Research, Boulder, CO.) In NASA, Langley Research Center, FIRE Science Results 1988 Jul. 1990 p 81-83 (For primary document see N91-10448 01-47) Avail: NTIS HC/MF A17 CSCL 04B During the Cirrus Intensive Field Operations of FIRE, data collected by the NCAR King Air in the vicinity of Wausau, WI on October 28 were selected to study the influence of cirrus cloud microphysics on radiative transfer and the role of microphysical approximations in radiative transfer models. The instrumentation of the King Air provided, aside from temperature and wind data, up-and downwelling broadband solar and infrared fluxes as well as detailed microphysical data. The aircraft data, supplied every second, are averaged over the 7 legs to represent the properties for that altitude. The resulting vertical profiles, however, suffer from the fact that each leg represents a different cloud column path. Based on the measured microphysical data particle size distributions of equivalent spheres for each cloud level are developed. Accurate radiative transfer calculations are performed, incorporating atmospheric and radiative data from the ground and the stratosphere. Comparing calculated to the measured up- and downwelling fluxes at the seven cloud levels for both the averaged and the three crossover data will help to assess the validity of particle size and shape approximation as they are frequently used to model cirrus clouds. Once agreement is achieved the model results may be applied to determine, in comparison to a cloudfree case, the influence of this particular cirrus on the radiation budget of the earth atmosphere system. Author N91-10464*# Utah Univ., Salt Lake City. Dept. of Meteorology. SUBVISUAL CIRRUS CLOUD PROPERTIES DERIVED FROM A FIRE IFO CASE STUDY Kenneth Sassen, M. K. Griffin, and G. C. Dodd In NASA, Langley Research Center, FIRE Science Results 1988 Jul. 1990 p 85-88 (For primary document see N91-10448 01-47) (Grants NAG1-686; NAG1-718; NSF ATM-85-13975) Avail: NTIS HC/MF A17 CSCL 04B From the central Wisconsin IFO field at Wausau, the Mobile Polarization Lidar and a surface radiation station from the Lamont-Doherty Geological Observatory observed two very tenuous cirrus clouds on 21 October 1986. The clouds were present just below the height of the tropopause, between -60 to -70 C. The first cloud was not detected visually, and is classified as subvisual cirrus. The second, a relatively narrow cloud band that was probably the remnants of an aircraft contrail, can be termed zenith-subvisual since, although it was invisible in the zenith direction, it could be discerned when viewed at lower elevation angles and also due to strong solar forward-scattering and corona effects. The observations provide an opportunity to assess the threshold cloud optical thickness associated with cirrus cloud visibility. Ruby lidar backscattered signals were converted to isotropic volume backscatter coefficients by applying the pure-molecular scattering assumption just below the cloud base. The backscattering coefficient due to the cloud is then obtained and expressed in relation to the molecular backscattering coefficient in terms of the scattering ratio R. The linear depolarization ratio for the cloud is computed after removing the essentially parallel-polarized scattering contribution from air molecules. The values are also applied to determine the cloud optical thickness through the use of backscatter-to-extinction ratio, and the concentration of cloud N91-10465*# Wisconsin Univ., Madison. Cooperative Inst. for Meteorological Satellite Studies. MULTI-SPECTRAL WINDOW RADIANCE OBSERVATIONS OF CIRRUS FROM SATELLITE AND AIRCRAFT, NOVEMBER 2, 1986 PROJECT FIRE William L. Smith, H. E. Revercomb, H. B. Howell, and M.-X. Lin (National Meteorological Bureau, Beijing, China) In NASA, Langley Research Center, FIRE Science Results 1988 Jul. 1990 p 89-93 (For primary document see N91-10448 01-47) (Contract NAS1-18272) Avail: NTIS HC/MF A17 CSCL 04B High resolution infrared radiance spectra achieved from the NASA ER2 airborne HIS experiment are used to analyze the spectral emissivity properties of cirrus clouds within the 8 to 12 micron atmospheric window region. Observations show that the cirrus emissivity generally decreases with increasing wavenumber (i.e., decreasing wavelength) within this band. A very abrupt decrease in emissivity (increase in brightness temperature) exists between 930/cm (10.8 microns) and 1000/cm (10.0 microns), the magnitude of the change being associated with the cirrus optical thickness as observed by lidar. The HIS observations are consistent with theoretical calculations of the spectral absorption coefficient for ice. The HIS observations imply that cirrus clouds can be detected unambiguously from the difference in brightness temperatures observed within the 8.2 and 11.0 micron window regions of the HIRS sounding radiometer flying on the operational NOAA satellites. This ability is demonstrated using simultaneous 25 km resolution HIRS observations and 1 km resolution AVHRR imagery achieved from the NOAA-9 satellite. Finally, the cirrus cloud location estimates combined with the 6.7 micron channel moisture imagery portray the boundaries of the ice/vapor phase of the upper troposphere moisture. This phase distinction is crucial for infrared radiative transfer considerations for weather and climate models, since upper tropospheric water vapor has little effect on the Earth's outgoing radiation whereas cirrus clouds have a very large attenuating effect. Author N91-10466*# National Aeronautics and Space Administration. Francisco P. J. Valero, Thomas P. Ackerman (Pennsylvania State Measurements of the upwelling infrared radiance at 10.5 and 6.5 microns were obtained during the FIRE cirrus Intensive Field Observations using a radiometer with a 15 deg cone nadir field-of-view flown on the NASA Ames ER-2. Data are recorded at a frequency of 1 Hz and the radiometer is continuously calibrated with a liquid nitrogen blackbody source, thereby providing a large number of very accurate radiance values during the course of a several hour flight. For this study, the focus is on the statistical properties of the cirrus deck as deduced from the radiance data. The data acquired on 28 October 1986 is stressed, but some data from the other flights are also shown for comparison purposes. Author N91-10467*# National Aeronautics and Space Administration. Ames Research Center, Moffett Field, CA. THE RADIATION BUDGET OF A CIRRUS LAYER DEDUCED FROM SIMULTANEOUS AIRCRAFT OBSERVATIONS AND MODEL CALCULATIONS Abstract Only Several aircraft were employed during the FIRE Cirrus IFO in order to make nearly simultaneous observations of cloud properties and fluxes. A segment of the flight data collected on 28 October 1988 during which the NASA Ames ER-2 overflew the NCAR King Air was analyzed. The ER-2 flew at high altitude making observations of visible and infrared radiances and infrared flux and cloud height and thickness. During this segment, the King Air flew just above the cloud base making observations of ice crystal size and shape, local meteorological variables, and infrared fluxes. While the two aircraft did not collect data exactly coincident in space and time, they did make observations within a few minutes of each other. For this case study, the infrared radiation balance of the cirrus layer is of primary concern. Observations of the upwelling 10 micron radiance, made from the ER-2, can be used to deduce the 10 micron optical depth of the layer. The upwelling broadband infrared flux is also measured from the ER-2. At the same time, the upwelling and downwelling infrared flux at the cloud base is obtained from the King Air measurements. Information on cloud microphysics is also available from the King Air. Using this data in conjunction with atmospheric temperature and humidity profiles from local radiosondes, the necessary inputs for an infrared radiative transfer model can be developed. Infrared radiative transfer calculations are performed with a multispectral two-stream model. The model fluxes at the cloud base and at 19 km are then compared with the aircraft observations to determine whether the model is performing well. Cloud layer heating rates can then be computed from the radiation exchange. Author N91-10468*# National Aeronautics and Space Administration. Goddard Space Flight Center, Greenbelt, MD. LIDAR AND RADIOMETER RESULTS FROM THE ER-2 FOR James D. Spinhirne In NASA, Langley Research Center, FIRE The airborne lidar and radiometers which were flown during the FIRE cirrus and marine stratus field experiments had multiple objectives. Cloud parameters of direct interest, such as cirrus infrared emittance or convective scales for marine stratus, may be derived from the observations and analyzed along with the available cloud physics and meteorological observations. Additionally however a stated goal of the FIRE studies was to validate satellite cloud retrievals. To this end a number of derived products are to be available from the basic lidar and radiometer observations. The characteristics of the derived products are described, and in addition analysis results for cloud radiometric and structure parameters are presented. This extended abstract will be used to describe the available data products and the associated presentation will emphasize case study analysis results. Author N91-10469*# Rutgers- The State Univ., New Brunswick, NJ. Dept. of Geography. IDENTIFICATION OF CIRRUS OVER WAUSAU DURING THE 1986 FIRE IFO FROM GROUND-BASED RADIOMETER DATA David A. Robinson and Allan Frei (Lamont-Doherty Geological Observatory, Palisades, NY.) In NASA, Langley Research Center, FIRE Science Results 1988 Jul. 1990 p 105-109 (For primary document see N91-10448 01-47) (Grant NAG1-653) Avail: NTIS HC/MF A17 CSCL 04B The potential of using irradiation data to indicate episodes of cirrus cloudiness during the daylight hours is explored. Thresholds separating cirrus from other clouds and clear skies are determined using four days of irradiation data, hourly weather observations, sky photographs, sky video, and occasional lidar observations. |