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Clayton E. Jensen

Abstract

Adiabatic vertical velocities are computed for atmospheric layers and used to modify dewpoint-depression fields in twelve-hourly steps. Horizontal advection of moisture is accommodated by the Jacobian operator with height and dewpoint-depression fields as arguments. Assuming a certain correspondence exists between dewpoint-depression and amount of cloudiness, 24-, 36-, and 48-hr cloud forecasts are made for specific atmospheric layers; for example, 850–700, 700–500, 500–300, and 300–200 mb. For the lower two layers, airframe icing forecasts are produced on the basis of predicted conditions of cloudiness, temperature, and lapse rate. The 4-layer cloud forecasts in combination with a persistence term are converted to measures of total cloud cover and verified against machine nephanalyses based upon surface reports. Some cloud forecasting skill over persistence is evident in the model.

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Clayton E. Jensen

The trend in the funding of Federal meteorological services and research over the past decade has been assessed. The major thrusts of this analysis have been directed toward determining the service improvements that have occurred, the impact of inflation over the years, and the directions for future programs. The increases in radar surveillance of severe storms, the improved capability of remote sensing from satellites, the steady rise in computer power, and the expansion of warning dissemination systems are examples of program highlights discussed. While the annual Federal expenditures for meteorology have more than doubled over the past decade and have kept somewhat ahead of inflation, Federal manpower in operational meteorology peaked in the middle of the decade and is now at a level below that of ten years ago. The major meteorological functions of monitoring, forecast and warning preparation and dissemination, as well as the research that supports these functions, are all characterized by a high degree of interagency and international cooperation. Most of the information presented has been assembled from the records of the Federal Coordinator for Meteorological Services and Supporting Research and the Interdepartmental Committee for Atmospheric Sciences.

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CLAYTON E. JENSEN, JAY S. WINSTON, and V. RAY TAYLOR

Abstract

The technique of stepwise multiple regression is applied to 45 days of data in establishing functional relations between the heights of the 500-mb. surface and TIROS IV long-wave radiation data during the period March to June, 1962. Twenty-six points were selected for height specification in the general area of the eastern Pacific and the North American Continent, Sixty points were selected as a source of radiation “predictors” in a larger area that not only encompasses most of the 26 height, points but extends farther westward across the Pacific. Sample charts show the correlation fields that result when the height values at, each point are correlated with the radiation data at each of 60 points. The screening process that selects the best, predictors is arbitrarily stopped at preset numbers of predictors. The resulting regression equations are evaluated on both dependent and independent samples. Even though the independent results are not outstanding for this particular sample, the method itself appears to offer promise for height and height contour specification over areas where direct measurements of heights are sparse or missing entirely.

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