Robert L. Mancuso

LONG TERM REGIONAL PATTERNS AND TRANSFRONTIER EXCHANGES OF AIRBORNE SULFUR POLLUTION IN EUROPE

Abstract This paper reports on progress to date of an ongoing effort to develop, evaluate and apply a European Regional Model of Air Pollution (EURMAP). This model is capable of calculating longterm (monthly, seasonal and/or annual) averages of the contributions from SO 2 in individual emittor countries to SO 2 and SO 4 2− concentrations, dry deposition and wet deposition in receptor countries. The model covers all of western and central Europe, a geographical area 2100 km × 2250 km in size. A trajectory-type approach is used, which involves the tracking of pollutant ‘puffs’ released from each emissions cell in an extensive 32 × 36 grid. Meteorological data in the form of wind and precipitation values from some 45 upper-air and 535 surface stations are input at 6-hourly intervals for use in the calculations of puff transport and wet deposition. A wet deposition coefficient is used that depends upon precipitation rate. The preliminary model has been used to calculate annualized as well as monthly mean maps for January, April, July and October 1973 of SO 2 and SO 4 2− concentration, dry deposition and wet deposition patterns resulting from SO 2 emissions in 13 countries in western and central Europe. The dry and wet deposition patterns are presented, along with values of calculated international exchanges of SO 2 and SO 4 2− wet and dry deposition among these various countries. The EURMAP results are compared with those from Fishers (1975) model and the LRTAP model (Ottar, 1978; OECD, 1977). In many (but not all) respects the results from the three models are similar. The possible reasons for the differences revealed by this comparison are examined.

A practical and economic method for estimating wind characteristics at potential wind energy conversion sites

Abstract In order to assess the economic viability of installing a wind energy conversion system (WECS) at a site; it is necessary to know the wind characteristics at that site. Since it is usually impractical to measure wind at all potential sites over a suitably long period of time, it is necessary to develop a methodology that can provide accurate estimates of wind economically at potential WECS sites from data that are already available. A physically based, three-dimensional model has been developed that incorporates the effect of underlying terrain and uses available, conventional wind information from selected nearby weather stations. This model—called COMPLEX—is essentially an objective analysis computer program that interpolates values of wind from observations at irregularly spaced stations. The required statistical wind characteristics are estimated from the synthesized hourly winds, which are obtained by using the COMPLEX model; the model is used in conjunction with a method for reducing the number of variables while still retaining most of the information of the original data set. This involves eigenvectors of the covariance matrix of the original data set. The linear characteristics of the COMPLEX model have been used to obtain solutions directly for only the few eigenvectors of the input for any arbitrary set of observations from linear combinations of those solutions. We describe here an example of the application of the method to a potential wind energy conversion site at Boone, North Carolina.

CLEAR AIR TURBULENCE FREQUENCY AS A FUNCTION OF WIND SHEAR AND DEFORMATION1

Abstract The probability is determined that an aircraft will encounter moderate or severe high-level turbulence during a 100-mi. flight segment when particular values of certain meteorological quantities exist in that locality. The turbulence data used are pilot reports collected by the U.S. Weather Bureau Clear Air Turbulence Project, for March 12–24, 1962 and February 4–9, 1963. The meteorological quantities which were computed from standard data include vertical vector wind shear, vertical wind direction shear, temperature lapse rate, horizontal wind shear, vorticity, and resultant deformation. A correlation of 0.45 was found between turbulence frequency and the product of vertical vector wind shear and deformation. This value is the highest correlation found so far with data of this type. The product of wind shear and deformation is an important factor in the development of fronts. One might expect that a tendency for frontogenesis would correlate better with turbulence than would frontolysis. The dat...

An objective isobaric/isentropic technique for upper air analysis

Abstract An objective meteorological analysis technique has been developed to provide both horizontal and vertical (cross-sectional) upper air analyses. The horizontal analyses are made at grid points that lie on isobaric levels in a conventional manner. However, the interpolation of values other than temperature at a grid paint is performed on an isentropic surface that passes through the grid point. The vertical analyses are based on all surrounding radiosonde data and are not confined to a line of stations. They are calculated in an equivalent manner as the horizontal analyses, except that the grid points lie in a vertical plane. The objective analyses have been evaluated by comparing the computer-generated results of two different versions (A and B) with subjective hand analysts. Comparisons for one test case are presented in this paper. The computer analyses show good agreement with the subjective analyses, and depict the baroclinic features of both the temperature and wind fields. In particular, the...

ANALYZING AND FORECASTING CLEAR-AIR TURBULENCE PROBABILITIES OVER THE UNITED STATES1

Abstract Pilot reports from special turbulence-reporting periods were used to investigate methods of analyzing and forecasting clear-air turbulence over the United States. Meteorological analyses for the special reporting periods were made objectively by computer using only standard upper air rawinsonde measurements. The wind analyses were built upward from the 400-mb level to the 200-mb level using thermal wind shears to compensate for missing wind data in high-speed portions of the flow. The best meteorological indicators of turbulence were found to be the vertical vector wind shear and the product of wind shear and horizontal deformation. To a somewhat lesser extent, large gradients of relative humidity (at the 400-mb level) and large magnitudes of divergence also tended to be associated with turbulent regions. Turbulence analyses based on both meteorological relationships and pilot reports were made. These analyses are in terms of the probability of encountering significant turbulence (moderate or sev...

ON THE ANALYSIS OF CLEAR AIR TURBULENCE BY USE OF RAWINSONDE DATA1

Regions of clear nir turhulencc in the upper troposphere and lowcr stratosphere are classified into four groups, and the characteristics of each group are summarized. An empirical turbulcnce index is dcfincd that describes meteorological conditions associnted with a type of turbulent region that is rclatively large and that sometimes contains severe turbulence. The turbulence index, Richardson’s number, and other nleteorologicnl quantities are described in relation to a clearly defined case of turbulence observed by a research aircraft. For the period Il/lnrch 12-24, 1962, vcrtical shear, lapse mtc, Richardson’s number, and the tnrbulcnce index were cnlculatcd by electronic computer from rawinsonde data ovcr the United States. These compnted qllantities are compnred with pilot reports of turbulcnce. Individual maps are prcscntcd that illustrate substantial agreemcnt between computed quantities and turbulence reports. Standard statistical tests show that both Richardson’s number and the turbulcnce index have definite skill in turbulence analysis. Suggestions are given for further improvement of criteria for analyzing tnrbulcnce. To enhance turbulence research and operational analysis, the writers believe that a turbulence sensor opcrnted as an integral p:wt of the radiosonde systcrn is rery desirable.