Showing papers in "Bulletin of the American Meteorological Society in 1988"
TL;DR: In this paper, the authors proposed a tropical rainfall measurement mission (TRMM) for a three-year operational period, with the satellite's orbit being low-altitude (320 km) and low-inclination (30 to 35 deg).
Abstract: The proposed Tropical Rainfall Measuring Mission (TRMM) satellite (presently in its third year of planning), is described. The TRMM satellite, planned for an operational duration of at least three years beginning in the mid-1990s, is intended to obtain high-quality measurements of tropical precipitation by means of information derived from a quantitative spaceborne radar, a multichannel passive microwave radiometer, and an AVHRR. The satellite's orbit will be low-altitude (320 km), for high resolution, and low-inclination (30 to 35 deg), for making it possible to visit each sampling area twice a day. Radar and passive microwave algorithms and rain-retrieval algorithms to be used in precipitation measurements are discussed together with cloud dynamical models designed to test these algorithms.
844 citations
TL;DR: In 1987, the International Satellite Land Surface Climatology Project (ISLSCP) conducted a major field experiment aimed at the development of superior methods for relating satellite remote sensing to biological and physical parameter and exchange process data obtained during simultaneous ground truth measurements as mentioned in this paper.
Abstract: In 1987, the International Satellite Land Surface Climatology Project (ISLSCP) will conduct a major field experiment aimed at the development of superior methods for relating satellite remote sensing to biological and physical parameter and exchange process data obtained during simultaneous ground truth measurements. This, the First ISLSCP Field Experiment, will attempt to arrive at a better understanding of the role of the land surface in the behavior of the global climate system, as required by next-generation global circulation models and general biospheric models. The field experiment will be conducted in the Konza Prairie of Kansas.
537 citations
TL;DR: In this paper, a detailed chronology of the changes in the analysis-forecast system at NMC and ECMWF has been compiled and the main impacts on the analyses have been identified.
Abstract: In order to help establish a global climate record data sets of global analyses from the U.S. National Meteorological Center (NMC) and the European Centre for Medium Range Weather Forecasts (ECMWF) have been comprehensively evaluated. A detailed chronology of the changes in the analysis-forecast system at NMC and ECMWF has been compiled and the main impacts on the analyses have been identified. Discontinuities have been found in certain characteristics of the analyses when major changes occur. The main quantities so affected are the divergent wind component and associated vertical motion fields, and the moisture fields. A detailed intercomparison of the two data sets and statistical results show fairly widespread agreement between the analyses from the two centers over the Northern Hemisphere extratropics. In general, the quality of the analyses is much lower in the tropics and Southern Hemisphere. This is reflected in much greater differences in wind fields south of 20°N, with root-mean-square difference...
287 citations
TL;DR: The first International Satellite Cloud Climatology Project Regional Experiment (FIRE) as discussed by the authors was used to study extensive fields of stratocumulus clouds off the coast of California, where measurements on the regional and detailed local scales were taken, allowing for a wide interpretation of the mean, turbulent, microphysical, radiative, and chemical characteristics of stratocalumulus.
Abstract: The First International Satellite Cloud Climatology Project Regional Experiment (FIRE) to study extensive fields of stratocumulus clouds off the coast of California is presented. Measurements on the regional and detailed local scales were taken, allowing for a wide interpretation of the mean, turbulent, microphysical, radiative, and chemical characteristics of stratocumulus. Multiple aircraft and ground-based remote-sensing systems were used to study the time evolution of the boundary layer structure over a three-week period, and probes from tethered balloons were used to measure turbulence and to collect cloud-microphysical and cloud-radiative data. The observations provide a base for studying the generation maintenance and dissipation of stratocumulus clouds, and could aid in developing numerical models and improved methods for retrieving cloud properties by satellite.
243 citations
TL;DR: In this article, the use of model-based global data sets of atmospheric circulation for studying fundamental dynamical and physical processes is discussed, focusing on limitations of the available modelbased data sets, and the most comprehensive technique for integrating space and in situ observations to produce this type of data set would be a four-dimensional data assimilation system with a realistic physical model of the type employed in operational numerical weather prediction.
Abstract: The use of model-based global data sets of atmospheric circulation for studying fundamental dynamical and physical processes is discussed, focusing on limitations of the available model-based data sets. Data from the Global Weather Experiment in 1979 were analyzed by two authorized level IIIb data centers in 1980 and in 1981. The analyses led to difference in data-sparse regions such as the tropics. Study areas which can be addressed by an internally-consistent long-term multivariate data set for the atmospheric circulation are considered, including mean climate, forcing for the ocean models, global hydrological cycle, atmospheric energetics, intraseasonal variability, land surface processes, and structure and variability of vertical velocity, divergence, and diabatic heating. It is concluded that the most comprehensive technique for integrating space and in situ observations to produce this type of data set would be a four-dimensional data assimilation system with a realistic physical model of the type employed in operational numerical weather prediction.
181 citations
TL;DR: The field phase of the Genesis of Atlantic Lows Experiment (GALE) was conducted from 15 January to 15 March 1986 as mentioned in this paper, with the objectives of GALE were to study mesoscale and air-sea interaction processes in East Coast winter storms, with particular emphasis on their contributions to cyclogenesis.
Abstract: The field phase of the Genesis of Atlantic Lows Experiment (GALE) was conducted from 15 January to 15 March 1986. The objectives of GALE were to study mesoscale and air-sea interaction processes in East Coast winter storms, with particular emphasis on their contributions to cyclogenesis. This project area, specail observing systems, and field operations are described. There were thirteen special observing periods during the field phase including eight cases of cyclogenesis. Meterological and oceanographic phenomena on which special observations were collected include: cyclogenesis, rainbands, cold fronts, coastal fronts, cold-air damming, jets streaks, tropopause folding, low-level jets, cold-air outbreaks, lightning and marine boundary layer interactions with Gulf Stream and mid-shelf oceanic fronts. Preliminary research findings and operational implications are presented. GALE data documents are listed. The GALE data set is open to all interested scientists.
105 citations
TL;DR: In this article, the authors compare line-by-line-model fluxes with selected aircraft observations and show a spread of 10-20 percent for the sensitivity of the models to changes in important radiation variables, such as carbon dioxide amounts and water vapor amounts.
Abstract: An international program of intercomparison of radiation models has been initiated because of the central role of radiative processes in many proposed climate change mechanisms. Models ranging from the most detailed (line-by-line) to the most-highly parameterized have been compared with each other and with selected aircraft observations. Although line-by-line-model fluxes tend to agree with each other to within one percent (if the water-vapor–continuum absorption is ignored), the less-detailed models show a spread of 10–20 percent. The spread is even larger (30–40 percent) for the sensitivities of the models to changes in important radiation variables, such as carbon dioxide amounts and water-vapor amounts. These spreads are disturbingly large. Lacking highly accurate flux observations from within the atmosphere, it has been customary to regard line-by-line–model results as “the truth.” However, uncertainties in the physics of line wings and in the proper treatment of the water-vapor continuum make it imp...
105 citations
TL;DR: The historical background of the attempts to collect water directly from the coastal stratocumulus decks is reviewed in this paper, as well as meteorological and geographical considerations important to the collection of the cloud water.
Abstract: Many parts of the world are currently suffering water shortages. Few areas, however, have as little precipitation and groundwater available to alleviate the problem as does the northern coast of Chile. The historical background of the attempts to collect water directly from the coastal stratocumulus decks is reviewed in this paper as are the meteorological and geographical considerations important to the collection of the cloud water. Calculations of water availability and cost indicate that this may well be an important source of water for some coastal regions. A combined research and applied project to study the properties of high-elevation fogs and their use as a water supply will be conducted by Chilean and Canadian agencies from late 1987 to the end of 1988.
85 citations
TL;DR: The Dynamics and Chemistry of the Marine Stratocumulus (DYCOMS) experiment was carried out during the summer of 1985 over the eastern Pacific Ocean using the NCAR Electra aircraft.
Abstract: A combined atmospheric chemistry-meteorology experiment, the Dynamics and Chemistry of the Marine Stratocumulus (DYCOMS), was carried out during the summer of 1985 over the eastern Pacific Ocean using the NCAR Electra aircraft. The objectives were to 1) study the budgets of several trace reactive species in a relatively pristine, steady-state, horizontally homogeneous, well-mixed boundary layer capped by a strong inversion and 2) study the formation, maintenance and dissipation of marine stratocumulus that persists off the California coast (as well as similar regions elsewhere) in summer. We obtained both mean and turbulence measurements of meteorological variables within and above the cloud-capped boundary layer that is typical of this region. Ozone was used successfully as a tracer for estimating entrainment rate. We found, however, that horizontal variability was large enough for ozone that a correction needs to be included in the ozone budget for the horizontal displacement due to turns even though th...
78 citations
TL;DR: The Experiment on Rapidly Intensifying Cyclones over the Atlantic (ERICA) field study is designed to determine physical mechanisms and processes, and their critical spatial and temporal combinations, which can account for the wintertime phenomenon of explosively developing over-ocean atmospheric storms as mentioned in this paper.
Abstract: The Experiment on Rapidly Intensifying Cyclones over the Atlantic (ERICA) field study is designed to determine physical mechanisms and processes, and their critical spatial and temporal combinations, which can account for the wintertime phenomenon of explosively developing over-ocean atmospheric storms. Theoretical and numerical modeling research, during the five-year Office of Naval Research (ONR) Heavy Weather at Sea Accelerated Research Initiative ERICA program, comprises continuing effort, including the field study scheduled for 1 December 1988–28 February 1989. The ONR core field study is supplemented by the substantial participation of many other agencies and universities from the United States and Canada. Data will be obtained over the North Atlantic Ocean from Cape Hatteras to beyond Newfoundland, centered east of Cape Cod and south of Nova Scotia. The general timing and siting is chosen through consideration of historical storm occurrence data. Measurements in individual rapidly intensifying stor...
61 citations
TL;DR: In this paper, the first results for diurnal cycles derived from the Earth Radiation Budget Experiment (ERBE) were presented for the combined EBE and NOAA-9 spacecraft for April 1985.
Abstract: First results for diurnal cycles derived from the Earth Radiation Budget Experiment are presented for the combined Earth Radiation Budget Satellite and NOAA-9 spacecraft for April 1985. Regional scale longwave radiation data are analyzed to determine diurnal variations for the total scene (including clouds) and for clear-sky conditions. The longwave diurnal range was found to be greatest for clear desert regions (up to about 70 W/sq m) and smallest for clear oceans (less than 5 W/sq m). Local time of maximum longwave radiation occurs at a wide range of times throughout the day and night over oceans, but generally occurs from noon to early afternoon over land and desert regions.
TL;DR: In this paper, the years of occurrence of these early droughts were compared with the chronologies of El Niñ:o-Southern Oscillation (ENSO) events, as determined by Hamilton and Garcia (1986) and Quinn et al. (1978) from documentary evidence of northern Peruvian rainfall.
Abstract: Early documentary records of the British colony of New South Wales, Australia, have been examined for evidence of droughts. The years of occurrence of these early droughts were compared with the chronologies of El Niñ:o-Southern Oscillation (ENSO) events, as determined by Hamilton and Garcia (1986) and Quinn et al. (1978) from documentary evidence of northern Peruvian rainfall. Most droughts were associated with ENSO events, and vice versa, confirming the relationship found in many studies using more-recent instrumental data. The study demonstrates the stability, over a long period, of the correlation between Australian droughts and ENSOs.
TL;DR: In this article, the authors compare physical and statistical results, to show consistency, and to help provide limits to what one might expect when winter snowpack augmentation is applied within s...
Abstract: Cloud seeding to increase Winter snowpacks over mountainous regions of the western United States have been in existence for almost 40 years. However, our understanding of the physical processes taking place in the clouds in response to this seeding and the expected precipitation increases are still subjects of great scientific interest and investigation. Recent field observations that have emphasized direct physical observations of winter clouds, their structure and liquid water content, as well as their response to the injection of glaciogenic seeding agents have aided to our knowledge. These physical observations are helping to provide some insight into the mechanisms of precipitation increases, inferred from statistical analyses, that have been reported in certain winter orographic cloud seeding programs. This paper attempts to compare physical and statistical results, to show consistency, and to help provide limits to what one might expect when winter snowpack augmentation is applied within s...
TL;DR: In this paper, historical weather records of China in the governmental archives are discussed and their use for the reconstruction of past climate is assessed, including the Clear and Rain Records and the Inches of Rain and Snow.
Abstract: Some historical weather records of China in the governmental archives are discussed. The records in the pre-Qing period (before 1636) am briefly summarized and their use for the reconstruction of past climate is assessed. The more-elaborate weather records of the Qing dynasty, the Clear and Rain Records and the Inches of Rain and Snow, are examined in more detail.
TL;DR: The Convection Initiation and Downburst Experiment (CINDE) was conducted in the Denver, Colorado area from 22 June to 7 August 1987 to study processes leading to the formation of deep convection and the physics of downbursts as discussed by the authors.
Abstract: The Convection Initiation and Downburst Experiment (CINDE) was conducted in the Denver, Colorado area from 22 June to 7 August 1987 to study processes leading to the formation of deep convection and the physics of downbursts. A total of 6 Doppler radars, 87 mesonet stations. 3 research aircraft, 8 sounding systems and numerous photographic facilities were deployed within an 85 km × 85 km area. A comprehensive data set was obtained including measurements of convergence lines, downbursts, and tornadoes that occurred on 35, 22, and 11 days, respectively. This paper describes the objectives of the experiment and the specific facilities employed. Highlights and preliminary results are presented for several studies underway to show the type of data collected and to illustrate the sorts of analyses being pursued. Examples chosen include the topics of cloud initiation on stationary convergence lines, terrain- induced circulations, downbursts, tornadoes, and tracking chaff in precipitation-fitted regions.
TL;DR: In this article, the authors traced back to their initiation sites to determine areas of repeated thunderstorm genesis over the Sangre de Cristo Mountains of Colorado and New Mexico using three summers of GOES data and found that genesis-zone activity depended on the direction of the winds above the ridgetops.
Abstract: Thunderstorms were traced back to their initiation sites to determine areas of repeated thunderstorm genesis over the Sangre de Cristo Mountains of Colorado and New Mexico. Using three summers of GOES data it was found that genesis-zone activity depended on the direction of the winds above the ridgetops, indicating upper-level wind direction to be a likely “necessary” (but not “sufficient”) predictor of the location of mountain-thunderstorm initiation. Some individual topographic features associated with each genesis zone can be identified.
TL;DR: The Nimbus-7 Global Cloud Climatology (N7GCC) has been produced from measurements made between April 1979 and March 1985 using the Temperature Humidity IR Radiometer and the Total Ozone Mapping Spectrometer on the Nimbus 7 satellite as mentioned in this paper.
Abstract: The Nimbus-7 Global Cloud Climatology (N7GCC) has been produced from measurements made between April 1979 and March 1985 using the Temperature Humidity IR Radiometer and the Total Ozone Mapping Spectrometer on the Nimbus-7 satellite. The N7GCC gives, near local noon and midnight, the fractional area covered by high-level, middle-level, and low-altitude clouds, and the total fractional area covered by all clouds. Statistics for cirrus, deep convective, and warm low-altitude clouds and the cloud and clear-sky radiances with correlative surface temperatures are also included. The N7GCC is compared with other cloud data sets, including the International Satellite Cloud Climatology Project.
TL;DR: In this article, three examples of impacts that may be predictable by monitoring simple indices of ENSO are discussed, and the advantages and disadvantages of such direct prediction of impacts are considered.
Abstract: The El Nino-Southern Oscillation (ENSO) phenomenon affects the atmosphere and ocean over much of the globe. The resultant atmospheric and oceanic anomalies can produce a variety of biological and societal impacts. Three examples of impacts that may be predictable by monitoring simple indices of ENSO are discussed. The advantages and disadvantages of such “direct” prediction of impacts are considered.
TL;DR: The Genesis of Atlantic Lows Experiment (GALE) as mentioned in this paper focused an intensive data-gathering effort along the mid-Atlantic coast of the United States from 15 January through 15 March 1986.
Abstract: The Genesis of Atlantic Lows Experiment (GALE), focused an intensive data-gathering effort along the mid-Atlantic coast of the United States from 15 January through 15 March 1986. Here, the general objectives and experimental layout are described with special emphasis on the planetary-boundary-layer (PBL) component of GALE. Instrumentation is described for buoys, ships, research aircraft, and towers. The networks of the cross-chain long range aid to navigation (LORAN) atmospheric sounding system (CLASS) and the portable automated mesonet (PAM II) are described and their impact on the operation of GALE is outlined. Special use of dual-Doppler radar to obtain detailed wind measurements in the PBL is discussed. Preliminary analyses for a selected observational period are given. Detailed observations of the offshore coastal front reveal direct mesoscale circulations imbedded in the frontal zone. Later in the period, during an intense cold-air outbreak, sensible-heat and latent-heat fluxes over the co...
TL;DR: In this article, a wind-profiling Doppler radar was installed by the Acronomy Laboratory on Christmas Island during late 1985 as part of the Tropical Ocean Global Atmosphere (TOGA) Program.
Abstract: Wind profilers can provide useful wind data from remote regions of the globe, and incorporation of upper-level wind profiler data into analysis products can significantly improve the quality of analyses in data sparse regions. A wind-profiling Doppler radar was installed by the Acronomy Laboratory on Christmas Island during late 1985 as part of the Tropical Ocean Global Atmosphere (TOGA) Program. The Christmas Island profiler is self-contained and operates essentially unattended. Since April 1986, data from the Christmas Island profiler have been telemetered via GOES Satellite to provide hourly-averaged soundings of the wind four times daily keyed to the standard synoptic observing times and incorporated routinely onto the Global Telecommunication System (GTS) for world-wide distribution. In 1987 both NMC and ECMWF began using Christmas Island wind profiler observations in preparing their global analysis and forecast products. Detailed comparisons of NMC and ECMWF analyses with Christmas Island w...
TL;DR: The scientific results of the Seasat mission are reviewed in this article, including altimeter, scatterometer, microwave radiometer, and imaging radar studies, showing that global calibrations of satellite observations are much more accurate than measurements made at points on the ocean.
Abstract: The scientific results of the Seasat mission are reviewed, including altimeter, scatterometer, microwave radiometer, and imaging radar studies. The analyses of Seasat data showed that global calibrations of satellite observations are much more accurate than measurements made at points on the ocean. It is found that the accuracy of satellite measurements of a particular variable are improved if the variable is measured by different instruments on the same satellite. The results suggest that important oceanographic variables can be mapped from space with accuracies required by climatological and scientific studies.
TL;DR: In this paper, a measurement program has been developed to measure whether data validators make the proper decision when editing data, which is accomplished by replacing valid data with known errors (so-called seeds) and then monitoring the validater's decisions.
Abstract: The National Climatic Data Center is committed to archiving and disseminating data of high quality. Automated screening of data has proven to be very effective in isolating suspect and erroneous values in large meteorological data sets. However, manual review by validators is required to judge the validity and correct the data that is rejected by the screens. Since the judgment of the validators affects the quality of the data, the efficacy of their actions is of paramount importance. Techniques have been developed to measure whether data validators make the proper decision when editing data. Measurement is accomplished by replacing valid data with known errors (so-called “seeds”) and then monitoring the validater's decisions. Procedural details and examples are given. The measurement program has several benefits: (1) validator performance is quantitatively evaluated; (2) limited inferences about data quality can be made; (3) feedback to the validators identifies training requirements and operati...
TL;DR: The Unidata program is described and the services and benefits it will provide to university educators and researchers are discussed in this paper, where the authors discuss the benefits of the program.
Abstract: The Unidata program is described and the services and benefits it will provide to university educators and researchers are discussed.3
TL;DR: In this article, a technique called Model Output Enhancement (MOE) was developed for the generation and display of mesoscale weather forecasts, which is used to derive mesoscales or high-resolution (order of 1 km) weather forecasts from synoptic-scale numerical weather-prediction models by modifying model output with geophysical and landcover data.
Abstract: A technique called Model Output Enhancement (MOE) has been developed for the generation and display of mesoscale weather forecasts. The MOE technique derives mesoscale or high-resolution (order of 1 km) weather forecasts from synoptic-scale numerical weather-prediction models by modifying model output with geophysical and land-cover data. Mesoscale forecasts generated by the MOE technique are displayed as color-class maps overlaid on perspective plots of terrain. The MOE technique has been demonstrated in the generation of mesoscale maximum-temperature and minimum-temperature forecasts for case-study days of clear-sky conditions over the Commonwealth of Pennsylvania. The generated forecasts were evaluated using data from selected climatological stations.
TL;DR: The recent case of the rising level of the Great Salt Lake indicates that resource managers are often unprepared to respond to climate related impacts, except in an ad hoe and costly fashion.
Abstract: Societal responses to climatic fluctuations can be difficult and costly. The recent case of the rising level of the Great Salt Lake indicates that resource managers are often unprepared to respond to climate related impacts, except in an ad hoe and costly fashion. Precipitation in the Great Salt Lake drainage basin between 1982 and 1986 averaged 134 percent of normal, resulting in a rise in the level of the Great Salt Lake of 3.66 m (12 ft) to a new historic record high level of 1283.77 m (4211.85 ft). This rise in the level of the take has had widespread adverse impacts, forcing resource managers to implement costly emergency flood mitigation measures. Policymakers, however, have been unwilling to implement long-term policies aimed at adapting to fluctuating lake levels, relying instead on crisis management while hoping that the lake will soon recede. The water level of the Great Salt Lake, its impacts and adjustments, and an assessment of the long-term adjustment options are discussed.
TL;DR: The pH results indicate rainwater acidity in the Hunter Region is similar to that of remote areas of the world as discussed by the authors, and pH values less than 5.0 were measured 37.3 percent of the time in the event-activated rainfall samples.
Abstract: Field measurements for the Hunter Region Acid Rain Project were conducted as a major co-operative effort by the New South Wales State Pollution Control Commission, the Electricity Commission of New South Wales, and the University of Newcastle in Australia. Rainfall collection using open and event-activated collectors at 32 sites occurred for 44 events between October 1984 and March 1986, providing the most detailed acid-rain data base available for an Australian region. The structure and organization of the project are described and results of the pH measurements, which indicate volume-weighted pH averages between 4.9 and 5.6, depending on season and type of gauge, are presented—pH values less than 5.0 were measured 37.3 percent of the time in the event-activated rainfall samples. The pH results indicate rainwater acidity in the Hunter Region is similar to that of remote areas of the world.
TL;DR: The COST-72 project as mentioned in this paper was a continuation project of the COST Project 72 and it was used to establish a weather-radar network in the European Economic Community (EEC).
Abstract: During the last few years there has been considerable activity in Western Europe aimed at establishing national radar networks. Concurrent with this work, several bilateral agreements to exchange weather-radar data across national boundaries have been established. Effective international cooperation was stimulated by the European Economic Community (EEC) sponsored COST Project 72 and this has led to the setting up of a continuation project of weather-radar networking known as COST-73. In this paper, the aims of the COST-72 project and the degree to which they were achieved are outlined. A foundation was developed upon which the new COST-73 project has begun to build.
TL;DR: The United States Department of Energy and the People's Republic of China (PRC) Chinese Academy of Sciences signed an agreement on 19 August 1987 to carry out a joint research program on the study of CO2-induced climate changes as mentioned in this paper.
Abstract: The United States Department of Energy and the People's Republic of China (PRC) Chinese Academy of Sciences signed an agreement on 19 August 1987 to carry out a joint research program on the study of CO2-induced climate changes. The joint program has four tasks—analysis of general circulation models (GCMs), preparation and analysis of proxy and instrumental data, the study of the relationship between large- and regional-scale climates, and CH4 measurements. The program structure, technical tasks, and the initial research progress are described.