Hydrothermal Estimation of Vertical Ground-Water Flow, Cañutillo, Texas     

Shirley C. Wade  Marshall Reiter 《Ground water》1994,32(5):735-742

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Analytic solutions to long's model: A comparison of nonhydrostatic and hydrostatic cases     

Mr. Qi Hu  Prof. E. R. Reiter  Prof. R. A. Pielke 《Meteorology and Atmospheric Physics》1988,39(3-4):184-196

Summary In this paper, analytic solutions of the nonhydrostatic and hydrostatic forms of Long's model were obtained under two different sets of vertical boundary conditions: The first uses a sumusoidal obstacle at the lower boundary and a rigid-lid top for the upper boundary. The second set applies an isolated obstacle of the Witch of Agnesi type at the lower boundary, while still using a rigid lid at the top. Following the solution evaluations, comparisons between the nonhydrostatic and hydrostatic solutions were processed in order to describe several influences introduced by using the hydrostatic assumption in this model.Through comparisons we have found that, in the case of a sinusoidal lower boundary condition, the hydrostatic solution is obtained as the zero mode of the nonhydrostatic solution. The influence of the hydrostatic assumption on the model solution is trivial in this case. When an isolated lower boundary condition is applied, however, the solutions illustrate dramatic differences, showing the significance of the effect of hydrostatic assumption on this model's solutions. These effects vary considerably with the model parameters as well. The comparison results also reveal that the realization of the hydrostatic assumption in this model's solutions is accomplished through the vertical boundary conditions used in the model evaluations.With 5 Figures  相似文献   

Modeling heavy precipitation in complex terrain     

Prof. Dr. D. F. Tucker  Dr. E. R. Reiter 《Meteorology and Atmospheric Physics》1988,39(3-4):119-131

Summary A numerical prediction model is described which uses the full set of prognostic equations on a domain roughly the size of the United States with a 96 km horizontal grid resolution and six sigma-coordinate levels. Within this grid resides a nested domain of approximately 1000×1000 km with 24 km horizontal resolution. In this nested grid only modifications to the wind field by the better resolved terrain are considered on the lowest two sigma levels. The terrain effects necessitate adjustments in the location of these two sigma levels. Adjusted wind fields cause modifications in the mass and moisture divergence fields, hence in precipitation. These modifications are averaged into the appropriate meteorological fields on the larger grid.The algorithms used by our model allow continuous interaction between both grids with high computational efficiency.The relative importance of synoptic forcing and terrain is demonstrated for the cases of the Big Thompson, Colorado, flood of 1976 and the Cheyenne, Wyoming, flood of 1985.With 15 Figures  相似文献   

Book review     

Elmar R. Reiter 《Meteorology and Atmospheric Physics》1993,51(1-2):139-140

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Determination of the concentration of chemical main and trace elements (chemical matrix) in the aerosol from 1972 to 1982 at a north-alpine pure air mountain station at 1780 m a.s.l.     

Director Dr. R. Reiter  R. Sladkovic  K. Pötzl 《Theoretical and Applied Climatology》1985,36(1):43-66

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The atmospheric heat budget over the western part of the Tibetan plateau during Monex, 1979   总被引：1，自引：0，他引：1  

Feng Zhiqiang  Elmar R.Reiter  Chen Longxun 《大气科学进展》1985,2(4):455-468

The atmospheric heat source strength over western Tibet has been computed for the period beginning with the last ten days in May, 1979 and extending through August, 1979. Our results show a significantly smaller heat source than that obtained by other authors. The discrepancy is mainly due to adjustments in the dray, coefficient suggested by observations and numerical modeling experiments. We subdivided western Tibet into northern and southern parts. In the north sensible heating, SH, provides the dominant input into the atmospheric heat source, whereas in the southern part latent heat, LP, offers a significant contribution after the start of the rainy season.Detailed heat budget calculations were also carried out over limited regions of southwestern Tibet which hau good station coverage. During periods with area-averaged rainfall ≤1 mm/day an atmospheric heat source maximum was located over southwestern Tibet near the 500 hPa level, while a heat sink dominated the upper troposphere in a layer of subsidence. When rainfall exceeded 4 mm/day, ascending motions and heal sources prevailed throughout the troposphere with maxima near 400 hPa. Time series analyses of the heat sourcs components show that the total atmospheric heat source is strongly modulated by the release of latent heat. Atmospheric radiational cooling reveals a phase shift in its relation with precipitation. During the first part of the observation period a correlation of that cooling exists mainly with the net radiation at the top of the atmosphere, during the last part with the net radiation at the ground.  相似文献   

Determination of the concentration of chemical main and trace elements (chemical matrix) in the aerosol from 1972 to 1982 at a North-alpine pure air station at 1780 m a.s.l.     

R. Reiter  K. Pötzl  R. Sladkovic 《Meteorology and Atmospheric Physics》1984,35(1-2):1-30

Summary Aerosol particles have been separated by filter at a mountain station at 1780 m a.s.l. continuously since 1972. The station (a WMO-BAPMoN station with extended program) is freely exposed to all sides and in no way influenced by local aerosol sources. In the cold seasons it lies almost exclusively above the convection layer (very often over inversions) so that real background data can be acquired in these cases. By means of analytical methods the chemical components are determined on the exposed filters. This includes (apart from crust elements) also cations and anions from man-made and maritime sources as well as some important trace elements (in all, 15 components). Filters are exposed over 1–4 days. Filter exchange is determined by the respective weather situation with due regard to all changes so that the requirements for a reasonable correlation of the measured values with the meteorological conditions are met. Additionally, all meteorological parameters are determined, as well as intensity of the vertical exchange, number density of Aitken nuclei, concentration of natural radioactivity (RaB), and other variables. In the present paper the components of the aerosol chemical matrix are related to the behavior of the parameters below and the results are discussed in detail: Dependence of the individual components on total aerosol mass per volume, type of air mass; representation of two single cases of long-range transport of crust elements (source areas: Sahara, Colorado); vertical exchange coefficient, concentration of natural radioactivity, temperature gradient between valley and mountain station, temperature at the sampling site, relative humidity, precipitation rate, wind direction. occurrence of fog.Zusammenfassung An einer allseitig frei exponierten Bergstation in 1780 m NN werden seit 1982 die Aerosolpartikel auf Filtern gesammelt. Die Station (eine WMO-BAPMoN-Station mit erweitertem Programm) wird nicht durch lokale Aerosolquellen in irgendeiner Weise beeinflußt. Sie liegt in den kalten Jahreszeiten fast ausschließlich über der Konvektionsschicht (sehr oft oberhalb von Inversionen), so daß in diesen Fällen echte Background-Daten erfaßt werden. Mittels analytischer Verfahren werden an den exponierten Filtern alle chemischen Hauptkomponenten (von den Krustenelementen abgesehen auch die Kationen und Anionen sowohl anthropogenen als auch maritimen Ursprungs), sowie einige gewichtige Spurenelemente (insgesamt 15 Komponenten) bestimmt. Die Filter werden 1–4 Tage lang exponiert. Der Filterwechsel wird durch den jeweiligen Wetterzustand bzw. seiner Veränderung gesteuert, so daß eine gute Voraussetzung für eine Zuordnung der Meßwerte zu den meteorologischen Bedingungen gegeben ist. Zusätzlich werden alle meteorologischen Parameter, sowie die Intensität des Vertikalaustausches, Zahl der Aitken-Kerne, Konzentration der natürlichen Radioaktivität (RaB) und andere Größen bestimmt. In der vorliegenden Arbeit werden die Komponenten der chemischen Aerosolmatrix zum Verhalten der folgenden Parameter in Beziehung gesetzt und die Ergebnisse eingehend diskutiert:Abhängigkeit der Einzelkomponenten von: Gesamt-Aerosohnasse pro Volumen; Typ der Luftmasse und Darstellung von zwei Einzelfällen eines Ferntransportes von Krustenelementen (Quellgebiete: Sahara, Colorado); vertikaler Austauschkoeffizient; Konzentration der natürlichen Radioaktivität; Temperaturgradient zwischen Tal- und Bergstation; Temperatur an der Probennahmestelle; relative Feuchte; Niederschlagsintensität; Windrichtung; Auftreten von Nebel.

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Bestimmung der Konzentration chemischer Haupt- und Spurenstoffe (chemische Matrix) im Aerosol von 1972 bis 1982 an einer nordalpinen Reinluftstation in 1780 m NN.Teil II: Parametrische Korrelationsanalyse der chemischen Matrix mit Berücksichtigung meteorologischer Größen

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Numerical simulation of the development of vortices over the Qinghai-Xizang (Tibet) Plateau     

R. Shen  E. R. Reiter  J. F. Bresch 《Meteorology and Atmospheric Physics》1984,35(1-2):70-95

Summary Some of the vortices which develop over the Tibetan plateau during summer give rise to severe weather over eastern China. These weather developments can be difficult to forecast, but have been simulated successfully in a recently developed numerical model. It will be shown that different vortices respond differently to topographic effects, to nonlinear processes and to sensible and latent heating in their formation, maintenance, and motion. Elevated terrain appears to enhance the influence of thermodynamic processes, block airflow, and increase frictional dissipation.Sensible heating sometimes collaborates with topography in blocking cold air intrusions and is not only a function of terrain elevation but also of the synoptic situation. Without the input of latent heating, vortices over the eastern part of the Tibetan plateau tend to degenerate.

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Numerische Simulation von Wirbelbildungen über dem Hochland von Tibet

Zusammenfassung Einige der sich im Sommer über dem Hochland von Tibet entwickelnden Wirbel verursachen Unwetter in Ostchina. Die Vorhersage dieser Entwicklung kann schwierig sein, sie werden aber von einem kürzlich vorgestellten numerischen Modell erfolgreich simuliert. Es wird gezeigt, daß verschiedene Wirbel verschieden auf die Orographie, auf nichtlineare Vorgänge sowie auf fühlbare und latente Wärme in ihrer Entstehung, Erhaltung und Bewegung reagieren. Ein Hochland scheint den Einfluß thermodynamischer Vorgänge zu verstärken, Strömungen zu blockieren und die Reibungsdissipation zu steigern.Die fühlbare Wärme verhindert manchmal gemeinsam mit der Topographie Kaltlufteinbrüche, hängt aber nicht nur von der Hochland-sondern auch von der synoptischen Situation ab. Ohne latente Wärme neigen Wirbel über dem Ostteil des Hochlandes von Tibet zur Degeneration.

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With 22 Figures  相似文献   

Die vertikale Windstruktur beim Merkur —Schwerpunkt „Tagesperiodische Windsysteme” aufgrund von aerologischen Messungen im Inntal und im Rosenheimer Becken     

Direktor Dr. R. Reiter  H. Müller  R. Sladkovic 《Theoretical and Applied Climatology》1984,33(4):359-372

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Concentration of trace gases in the lower troposphere,simultaneously recorded at neighboring alpine stations Part III: Sulfur dioxide,nitrogen dioxide,nitric oxide     

Dr. R. Reiter  Dr. R. Sladkovic  Dr. H. -J. Kanter 《Meteorology and Atmospheric Physics》1987,37(2):114-128

Summary The importance of representative and long-term recordings of the trace gases SO₂, NO _x , and NO is explained. Recordings taken under different background conditions and, moreover, simultaneously at neighboring mountain stations, together with other meteorological parameters, are of special interest.The recording stations for the determination of the mentioned gases (a valley station at 740 m a.s.l., a nearby mountain station at 1780 m a.s.l.), the measuring methods, calibration procedures, and zero-air supply are described.The main part deals with the representation of consistent data of trace gases obtained at the two stations (NO only in the valley floor). Special attention was given not only to longterm trends but also to the seasonal and diurnal variations, and to the dependence of the gas concentrations on meteorological parameters. Only on the basis of such a parameterization, the time variations become understandable and the causes can be explained as well as possible. Finally, correlations between the concentrations of the different gas components are shown.With 15 Figures  相似文献