Showing papers in "Bulletin of the American Meteorological Society in 1984"
TL;DR: The three-satellite ERBE will provide upgraded data on changes in the input and outflow of energy which drives climatic phenomena as mentioned in this paper, which will be flown in the mid-1980s.
Abstract: The three-satellite ERBE will be flown in the mid-1980s and will provide upgraded data on changes in the input and outflow of energy which drives climatic phenomena. The spacecraft will carry radiometers, self-calibration equipment, and be programmed with inversion and averaging algorithms. Radiation will be scanned at 0.2-5 and 5-50 microns. The ACRIM detector, similar to that on the SMM spacecraft, will measure the incoming solar radiation at the 600 km sun-synchronous orbit travelled by the three ERBE spacecraft. Data transmitted to the NASA-Langley Center will be analyzed with algorithms which extract radiant flux data from the measured radiances.
558 citations
TL;DR: In this paper, the seasonal mean structure, transient variation, including intraseasonal to interannual, and synoptic to planetary scale fluctuations are discussed separately for the two monsoon components.
Abstract: Observations concerning the summer and winter monsoons of East Asia and their global associations are reviewed. The seasonal mean structure, transient variation, including intraseasonal to interannual, and synoptic to planetary scale fluctuations are discussed separately for the two monsoon components. Similarities and differences between the East Asian monsoon and that of India are also surveyed. We also present a description of the current status of monsoon related observational and theoretical research and highlight important scientific problems. The importance of understanding the long-term anomalies of the monsoon is stressed, and an attempt is made to put the East Asian monsoon in a global perspective with a view towards identifying with the problems of long-range weather forecasting or short-term climate prediction, in general. Finally, sonic future directions of research are suggested.
425 citations
TL;DR: The National Oceanic and Atmospheric Administration (NOAA) satellites have provided over eight years of observations from which estimates of the earth's total longwave emittance can be derived as mentioned in this paper.
Abstract: National Oceanic and Atmospheric Administration (NOAA) satellites have provided over eight years of observations from which estimates of the earth's total longwave emittance can be derived. Changes in satellite instrumentation, orbit, and algorithms used in obtaining these estimates are briefly summarized. The algorithms used by NOAA in obtaining a longwave radiation data set are provided.
315 citations
TL;DR: The first International Satellite Cloud Cover Project Regional Experiment (FIRE) as mentioned in this paper was proposed to develop physical models and parameterizations of fractional cloud cover over the Pacific Basin in order to determine fractional Cloud cover parameters, satellite observations by radar and lidar instruments combined with in situ measurements of the cloud-capped marine boundary layer.
Abstract: A detailed description of the goals and methodology of the First International Satellite Cloud Cover Project Regional Experiment (FIRE) is presented The purpose of the experiment is to develop physical models and parameterizations of fractional cloud cover over the Pacific Basin In order to determine fractional cloud cover parameters, satellite observations by radar and lidar instruments will be combined with in situ measurements of the cloud-capped marine boundary layer A description of a candidate experiment for the program is presented, and some general problems connected with the statistical characterization of satellite imagery are discussed
268 citations
TL;DR: In this article, the root mean square differences of about 0.6°C are found between satellite and drifter, whereas with ships-of-opportunity they are 1.8°C.
Abstract: Multi-window infrared measurements, together with visual channel observations, enable relatively high-resolution and accurate local, regional, and global retrievals of ocean surface temperatures to be repetitively and routinely obtained from operational environmental satellites. Drifting buoys appear to be the best means to date of validating the satellite estimates. Root mean square differences of about 0.6°C are found between satellite and drifter, whereas with ships-of-opportunity they are 1.8°C. Fixed buoy comparisons fall between these extremes.
197 citations
TL;DR: In this article, the AMS Steering Committee for the EPA Cooperative Agreement on Air Quality Modeling considered the question of uncertainty in air quality modeling, and the group agreed that air quality model results should be viewed as contained both reducible error and inherent uncertainty.
Abstract: Under the direction of the AMS Steering Committee for the EPA Cooperative Agreement on Air Quality Modeling, a small group of scientists convened to consider the question of uncertainty in air quality modeling. Because the group was particularly concerned with the regulatory use of models, its discussion focused on modeling tall stack, point source emissions. The group agreed that air quality model results should be viewed as contained both reducible error and inherent uncertainty. Reducible error results from improper or inadequate meteorological and air quality data inputs, and from inadequacies in the models. Inherent uncertainty results from the basic stochastic nature of the turbulent atmospheric motions that are responsible for transport and diffusion of released materials. Modelers should acknowledge that all their predictions to date certain some associated uncertainty and strive also to quantify uncertainty. How can the uncertainty be quantified. There was no consensus from the group as to precisely how uncertainty should be calculated. One subgroup, which addressed statistical procedures, suggested that uncertainty information could be obtained from comparisons of observations and predictions. Following recommendations from a previous AMS workshop in performance evaluation (Fox, 1981), the subgroup suggested construction of probability distribution functions from the differences between observationsmore » and predictions. Furher, they recommended that relatively new computer-intensive statistical procedures be considered to improve the quality of uncertainty estimates for the extreme value statistics of interest in regulatory applications. A second subgroup, which addressed the basic nature of uncertainty in a stochastic system, also recommended that uncertainty be quantified by consideration of the differences between observations and predictions.« less
110 citations
TL;DR: A pulse-Doppler radar on board a National Oceanic and Atmospheric Administration (NOAA) WP-3D research aircraft has been used to map the wind field in the vicinity of the developing eye wall of Hurricane Debby, which occurred in 1982 as discussed by the authors.
Abstract: A pulse-Doppler radar on board a National Oceanic and Atmospheric Administration (NOAA) WP-3D research aircraft has been used to map the wind field in the vicinity of the developing eye wall of Hurricane Debby, which occurred in 1982. The Doppler-derived winds in the eye wall region compare favorably with winds measured aboard the aircraft. The Doppler radar allowed the wind field to be documented in much more detail than has been possible in previous hurricane studies. The maximum winds were found radially, just inward of the band of maximum radar reflectivity, and were concentrated in two mesoscale maxima. A mesoscale trough associated with the developing eye wall sloped upwind and radially outward through the 1–5 km layer. The trough was best defined at 2–3 km, where it contained a closed mesocyclonic circulation.
99 citations
TL;DR: A coherent Doppler lidar has been used in an aircraft to measure the two-dimensional wind field in a number of different atmospheric situations as discussed by the authors, including flights in California, in Oklahoma at the National Severe Storms Laboratory, and in Montana at the Cooperative Convective Precipitation Experiment.
Abstract: A coherent Doppler lidar has been used in an aircraft to measure the two-dimensional wind field in a number of different atmospheric situations. The lidar, a pulsed CO2 system, was installed in the NASA Convair 990, Galileo II, and flown in a summer field program that included flights in California, in Oklahoma at the National Severe Storms Laboratory, and in Montana at the Cooperative Convective Precipitation Experiment (CCOPE). This paper provides a brief description of the instrumentation and summarizes the research flights. Examples of some of the results are given along with plans for future use of the lidar.
87 citations
TL;DR: In this article, an abbreviated historical account of the evolution of the satellite meteorology program is presented, focusing on the role of the space program in establishing atmospheric manifestations of Benard-Rayleigh convection, as well as the applicability of classical thermal convection studies to atmospheric processes.
Abstract: An abbreviated historical account of the evolution of the satellite meteorology program is presented. Emphasis is placed on the importance of the satellite and its space platform for observing and studying atmospheric convection. Particular attention is focused on the role of the space program in establishing atmospheric manifestations of Benard-Rayleigh convection, as well as on the applicability of classical thermal convection studies to atmospheric processes. Examples of mesoscale cellular convection and related convective phenomena are presented and discussed briefly.
83 citations
TL;DR: In this paper, the authors describe the current hydrologic forecasting program of the U.S. National Weather Service (NWS) and highlight the relevance of Quantitative Precipitation Forecasting (QPF) products to real-time hydrology forecasting.
Abstract: Quantitative hydrologic forecasting usually requires knowledge of the spatial and temporal distribution of precipitation. First, it is important to accurately measure the precipitation falling over a particular watershed of interest. Second, especially for small watersheds and/or for longer forecast lead times, forecasts of precipitation are critical to the achievement of the greatest possible hydrologic forecast accuracy and longest possible lead time. This paper describes the current hydrologic forecasting program of the U.S. National Weather Service (NWS) and highlights the relevance of Quantitative Precipitation Forecasting (QPF) products to real-time hydrologic forecasting. Specific requirements for QPF products in support of hydrologic forecasting applications are defined and current operational QPF procedures are reviewed to determine to what extent they meet these requirements. It is concluded that no known QPF procedures capable of fulfilling all desired requirements are currently availa...
81 citations
TL;DR: In this article, the authors present an observational network designed to study the development and evolution of diurnal convection and squall lines over the northern part of the Ivory Coast, which is an example of a tropical savanna region at the southern edge of the Sahel.
Abstract: During May and June 1981 several French research organizations, the University of Abidjan (Ivory coast) and the Agency for security of Aeronautical Navigation (ASECNA), participated in the observational field program called “Convection Profonde Tropicale 1981” (COPT 81). COPT 81 was directed toward developing a better understanding of the dynamical and electrical features of precipitating convection in continental tropical regions. The observational network was designed to study the development and evolution of diurnal convection and squall lines over the northern part of the Ivory Coast, which is an example of a tropical savanna region at the southern edge of the Sahel. It consisted of two Doppler radars, a central meteorological station equipped for the reception of satellite data, rawin sounding and interrogation of remote targets, an acoustic sounder, a central electrical and electro-magnetical station, and a set of remote ground meteorological and electrical stations. Some experimental resul...
TL;DR: In this paper, the concept of merging clouds is traced from the earliest radar and aircraft studies through some of the more recent observational and numerical studies dealing with multiple cloud interactions, and a historical review is presented.
Abstract: While the idea of “merging” clouds may seem to be conceptually simple on first consideration, the term has been employed in a variety of ways. Despite its wide usage over the past several decades, there appears to be no consensus as to the definition of “merger.” In this historical review, the concept of merging is traced from the earliest radar and aircraft studies through some of the more recent observational and numerical studies dealing with multiple cloud interactions.
TL;DR: The Boundary Layer Experiment-1983 (BLX83) as mentioned in this paper was a field experiment that combined remote sensors, surface observations, balloon platforms, and aircraft measurements to study the kinematics at the top of the convective boundary layer.
Abstract: Interactions between fair-weather cumulus clouds and mixed-layer thermals were the focus of a one-month field experiment in Oklahoma. This experiment, called Boundary Layer Experiment—1983 (BLX83), combined remote sensors, surface observations, balloon platforms, and aircraft measurements to study the kinematics at the top of the daytime convective boundary layer. Emphasis was placed on the study of the entrainment zone, and on the relationship between individual therma1s as identified by lidar and turbulent motions and fluxes as measured by aircraft and sodar.
TL;DR: In this paper, a descriptive study of the value of weather information used by fruit growers in the Yakima Valley of central Washington to decide when to protect their orchards against freezing temperatures is presented.
Abstract: This paper reports some results of a descriptive study of the value of weather information used by fruit growers in the Yakima Valley of central Washington to decide when to protect their orchards against freezing temperatures. Specifically, the study provides data concerning the decision-making procedures of individual orchardists, the growers' use of weather information including frost (i.e., minimum temperature) forecasts, and the dimensions of the value of such forecasts. Results from the descriptive study regarding the orchardists' information-processing and decision-making procedures are compared with the procedures included in a previous prescriptive study of the fruit-frost problem in the same geographical area (Katz et al., 1982). The prescriptive study employed a dynamic decision-making model and yielded estimates of the economic value of frost forecasts under the assumption (inter alia) that the orchardists' decisions were based solely on these forecasts. On the other hand, the descriptive stud...
TL;DR: A review of 10 rural diffusion models revealed that none of the models can be considered up-to-date scientifically, and that there is no basis for choice among them in terms of predictive accuracy.
Abstract: An American Meteorological Society committee, working cooperatively with the U.S. Environmental Protection Agency (EPA), has sponsored a peer review and evaluation of 10 rural diffusion models that are now used in regulatory procedures or have been submitted to EPA for such use. This review revealed that none of the models can be considered up-to-date scientifically, and that there is no basis for choice among them in terms of predictive accuracy. Regardless of the scientific merit of any model, significant inaccuracy in the predictions would arise from the inherent uncertainty in the diffusion process and from inadequacies of the input data.
TL;DR: The original application was for comparing the FGGE dataset motion fields with satellite film loops, and applications have broadened to include model-generated data.
Abstract: For the past two years, the authors have been involved in the production of computer-animated movies at the National Center for Atmospheric Research (NCAR). The computer- generated frames are high-quality graphs of two- and three-dimensional variables featuring trajectories, contour lines, shading patterns, or three-dimensional surfaces (viewed in perspective). The original application was for comparing the FGGE dataset motion fields with satellite film loops. Applications have broadened to include model-generated data. Computer animation is particularly useful for efficiently previewing and presenting large quantities of data. Experiments with stereo images have also been made.
TL;DR: In this article, it is argued that the flooding is the result of the convergence of three factors: 1) the 17-year period of filling Lake Powell (Glen Canyon Dam) has ended and the system of water storage reservoirs on the river now considered full.
Abstract: The flooding in the lower basin of the Colorado River during the spring and summer of 1983 led to discussion of the management of the heavy spring runoff from the upper basin. This analysis stresses that the reasons for the flooding go beyond the climatic events of the year and the U.S. Bureau of Reclamation's response to them. It is argued that the flooding is the result of the convergence of three factors: 1) the 17-year period of filling Lake Powell (Glen Canyon Dam) has ended and the system of water storage reservoirs on the river now considered full; 2) during the filling period, physical encroachment into the lower basin flood plain accelerated; and 3) the climatic variability experienced in the Colorado River Basin.
TL;DR: In this article, a mail survey was sent to 900 Texas farmers and ranchers asking them to rank the importance of various agrometeorological information types to their operations, and querying their willingness to pay for weather information.
Abstract: A mail survey was sent to 900 Texas farmers and ranchers asking them to rank the importance of various agrometeorological information types to their operations, and querying their willingness to pay for weather information. Most producers ranked as important those information types commonly broadcast over public media. Few producers would be willing to pay for weather information. Comments indicated a distrust of weather information, especially forecasts.
TL;DR: In this article, a long-time series of mean areally averaged winter temperatures in the contiguous United States depicts an unprecedented spell of abnormal winters beginning with the winter of 1975-76.
Abstract: A long-time series (1895–1984) of mean areally averaged winter temperatures in the contiguous United States depicts an unprecedented spell of abnormal winters beginning with the winter of 1975–76. Three winters during the eight-year period, 1975–76 through 1982–83, are defined as much warmer than normal (abnormal), and the three consecutive winters, 1976–77 through 1978–79, much colder than normal (abnormal). Abnormal is defined here by the least abnormal of these six winters based on their normalized departures from the mean. When combined, these two abnormal categories have an expected frequency close to 21%. Assuming that the past 89 winters (1895–1984) are a large enough sample to estimate the true interannual temperature variability between winters, we find, using Monte Carlo simulations, that the return period of a series of six winters out of eight being either much above or vouch below normal is more than 1000 years. This event exceeds the calculated return period of the three consecutive...
Journal Article•
TL;DR: The Alaska Workshop on Gravity Waves and Turbulence in the Middle Atmosphere had as its purpose the assessment of current theoretical understanding and observational capabilities in this field, as well as to suggest what additional studies would further knowledge of these processes and their effects on the large scale circulation of the middle atmosphere.
Abstract: The Alaska Workshop on Gravity Waves and Turbulence in the Middle Atmosphere had as its purpose the assessment of current theoretical understanding and observational capabilities in this field, as well as to suggest what additional studies would further knowledge of these processes and their effects on the large scale circulation of the middle atmosphere. While it is judged that current understanding is primitive, theoretical and modelling studies are held to be able to contribute important quantitative data on gravity wave excitation, propagation, and dissipation mechanisms and effects. The combination of several observational systems is considered capable of expanding the present knowledge of gravity wave and turbulence morphology, parameters, and processes.
TL;DR: The first reference associating the turning with the earth rotation through the latter's deflecting effect appears to have been made by the Austrian meteorologist and climatologist von Hann in 1901 as mentioned in this paper.
Abstract: The deflecting effect of the earth's rotation on winds has been known since the writings of Hadley in 1735, and observations of the clockwise diurnal directional turning of the sea and land breezes in the Northern Hemisphere have been published in quantity since 1801. But, the first reference associating the turning with the earth rotation through the latter's deflecting effect appears to have been made by the Austrian meteorologist and climatologist von Hann in 1901. Jeffreys' (1922) conclusion that the earth's rotation is not relevant to the dynamics of the sea and land breezes, was based on an overestimate of the speed and an excessive underestimate of the landward penetration of the sea breezes. In 1934 Brunt suggested that the Earth's rotation may be important. Neither Jeffreys nor Brunt seem to have been aware of yon Hann's statement and examples. Haurwitz (1947) was the first to show dynamically that the Coriolis force can explain the observed diurnal directional turning of the sea and lan...
TL;DR: In this paper, three workshops have been conducted in order to define a research program which would in the course of five years lead to a concensus on methodologies for the conversion of satellite-measured irradiances into quantitative data concerning the earth's surface.
Abstract: Three workshops have been conducted in order to define a research program which would in the course of five years lead to a concensus on methodologies for the conversion of satellite-measured irradiances into quantitative data concerning the earth's surface. Standardized data analysis algorithms would be the major product of this concensus. The three workshops have recommended the evaluation of retrospective satellite data, starting from the July, 1972 initial operation of Landsat-1, in order to demonstrate whether they can be used to detect climate-related or man-induced changes on the earth's surface quantitatively. Also suggested is the validation of current satellite data with ground truth campaigns in several different regions, and the preparation of an operational phase involving the testing of the selected data extraction algorithms for conversion of satellite-measured radiances into albedo, moisture, and vegetation data.
TL;DR: The results of the attempts of using VAS (visible IR spin scan radiometer atmospheric sounder) data for predicting tropical cyclones are reported as mentioned in this paper, with the results of using the McIDAS software was, by the 1983 hurricane season, upgraded to providing imagery and mass, motion and moisture patterns using the satellite data.
Abstract: The results of the attempts to use VAS (visible IR spin scan radiometer atmospheric sounder) data for predicting tropical cyclones are reported. VAS, mounted on a GEO platform, has 14 detectors for upwelling radiance. The McIDAS software was, by the 1983 hurricane season, upgraded to providing imagery and mass, motion and moisture patterns using the satellite data, which also permitted determinations of accurate temperature and moisture profiles. Comparisons made between VAS and radiosonde data revealed fairly close agreement of satellite and in-situ conditions during the 1983 season. When combined with data from the Tiros operational vertical sounder (TOVS) to define wind streamlines and predict the path of a hurricane from data fed into numerical models, sufficiently good agreement was obtained to initiate plans to forecast a hurricane trajectory during the 1984 season.
TL;DR: A combination of published and archival observations from the Smithsonian Institution's Astrophysical Observatory (APO) is presented and analyzed in this article, focusing on the data from the two primary sites, Mount Montezuma, Chile, and Table Mountain, California, from 1923 to 1957.
Abstract: A combination of published and archival observations from the Smithsonian Institution's Astrophysical Observatory (APO) is presented and analyzed. This paper concentrates on the data from the two primary sites—Mount Montezuma, Chile, and Table Mountain, California, from 1923 to 1957. Baseline values and their variations are presented for solar aureole brightness, precipitable water vapor, pyrheliometry, corrected pyrheliometry, and spectrobolometry. In addition to clouds and water vapor, possible causes for the observed variations in atmospheric transmission are volcanic eruptions, nuclear weapons testing, and aerosols from plants. Physical theories may not be sufficient to explain climate change, and considerations of biological processes may be required.
TL;DR: A simple diagram representing the relative contributions of observations and models to the current level of forecast skill and to the ultimate predictability of atmospheric phenomena is interpreted in this note.
Abstract: In operational numerical weather prediction systems, both observations and numerical models contribute to the skill of the forecast. A simple diagram representing the relative contributions of observations and models to the current level of forecast skill and to the ultimate predictability of atmospheric phenomena is interpreted in this note. The forecast skill of 500 mb heights and an estimate of the ultimate predictability of this variable are used in a quantitative illustration of the diagram.
TL;DR: Omega dropwindsondes (ODWs) were released from two NOAA WP-3D aircraft to measure the environmental wind field in the middle and lower troposphere within 1000 km of the center of Hurricane Debby on 15 and 16 September 1982.
Abstract: Omega dropwindsondes (ODWs) were released from two NOAA WP-3D aircraft to measure the environmental wind field in the middle and lower troposphere within 1000 km of the center of Hurricane Debby on 15 and 16 September 1982. The observations were coded in standard formats and transmitted from the aircraft to the National Hurricane Center (NHC) and the National Meteorological Center (NMC) before operational forecast deadlines. The ODW winds clearly indicated the location and strength of a midtropospheric trough in the westerlies that was the major synoptic-scale feature affecting Debby's motion. On 16 September, the dropwindsondes also identified a smaller scale cutoff low in the northern part of the trough. The cutoff low that was centered about 500 km to the north northwest of Debby affected the hurricane's motion from midday on the 16th to midday on the 17th. The ODWs provided NHC with timely information that was used subjectively in determining the official forecasts of Debby's track. The poten...
TL;DR: In this article, detailed insulation measurements have been carried out in Fairbanks for the last four years, beginning on 15 November 1982, and showed substantial changes, believed to be due to the dust cloud of El Chichon.
Abstract: Detailed insulation measurements have been carried out in Fairbanks for the last four years. Beginning on 15 November 1982, these measurements showed substantial changes, believed to be due to the dust cloud of El Chichon. The volcano, situated in Mexico, erupted most intensely on 4 April 1982, putting a large amount of material into the atmosphere. The long travelling time to the North is in line with results found by Rao and Bradley (1983). Compared to clear-day data for previous years, clear days for the time period 15 November 1982–31 May 1983 showed a decrease in the direct beam of24.8%, an increase in the ratio of diffuse to global radiation of 76%, and a decrease in the global radiation of about 5%. A decrease in the direct beam, a substantial increase in the diffuse radiation, and a small decrease in the global radiation are typical for increased turbidity of the atmosphere, but the volcanic cloud caused changes greater than those due to "normal" turbidity changes.