The Dead Sea is a terminal lake of one of the largest hydrological systems in the Levant and may thus be viewed as a large rain gauge for the region. Variations of its level are indicative of the climate variations in the region. Here, we present the decadal- to centennial-resolution Holocene lake-level curve of the Dead Sea. Then we determine the regional hydroclimatology that affected level variations. To achieve this goal we compare modern natural lake-level variations and instrumental rainfall records and quantify the hydrology relative to lake-level rise, fall, or stability. To quantify that relationship under natural conditions, rainfall data pre-dating the artificial Dead Sea level drop since the 1960s are used. In this respect, Jerusalem station offers the longest uninterrupted pre-1960s rainfall record and Jerusalem rains serve as an adequate proxy for the Dead Sea headwaters rainfall. Principal component analysis indicates that temporal variations of annual precipitation in all stations in Israel north of the current 200 mm yr−1 average isohyet during 1940–1990 are largely synchronous and in phase (∼70% of the total variance explained by PC1). This station also represents well northern Jordan and the area all the way to Beirut, Lebanon, especially during extreme drought and wet spells. We (a) determine the modern, and propose the past regional hydrology and Eastern Mediterranean (EM) climatology that affected the severity and length of droughts/wet spells associated with multiyear episodes of Dead Sea level falls/rises and (b) determine that EM cyclone tracks were different in average number and latitude in wet and dry years in Jerusalem. The mean composite sea level pressure and 500-mb height anomalies indicate that the potential causes for wet and dry episodes span the entire EM and are rooted in the larger-scale northern hemisphere atmospheric circulation. We also identified remarkably close association (within radiocarbon resolution) between climatic changes in the Levant, reflected by level changes, and culture shifts in this region.

A conceptual model is introduced describing the spatial distribution of two immiscible fluids in the pore space of sphere packings. The model is based on the ideal soil concept of homogeneous arrangement of identical spheres but is generalized to include random packing. It quantitatively analyzes the interfacial area between wetting and nonwetting fluids and between the fluids and the solid spheres, as a function of the saturation degree. These relationships depend on the packing arrangement of the spheres, the sphere radius, and the fluid-solid contact angle. The model focuses on the region of low saturation of the wetting phase, where the wetting phase is comprised of pendular rings. When the nonwetting phase appears as ganglia, the model assumes single-chamber ganglia. Three-dimensional graphical illustrations are provided. Three potential applications are pointed out:(1) to quantify the water-air interface in the unsaturated zone; (2) to analyze connate water interfacial area in petroleum reservoirs and to assess the effect of surfactants during enhanced oil recovery; and (3) to estimate the interface between groundwater and floating nonaqueous phase liquids above the water table.published reports have concentrated on the contaminant travel distances and dilution processes. Few studies examined the process of entrapment and/or mobilization of their residual saturation also [e.g., Roberts et al., 1982; Kramer, 1982; Atwater, 1984; Villaume, 1985]. Concurrently, many theoretical and empirical models were developed. These models focus on describing the relative permeability of each of the immiscible fluids under the whole range of saturation [Williams and Wilder, 1971; Bear, 1972; Somers, 1974; Dullien, 1979]. Other models have concentrated on mass transfer between phases; i.e., dissolution, volatilization, and absorption [Van Der Waarden et al., 1971; Pfannkuch, 1984; Roberts et al., 1985; Hunt et al., 1988a]. Several physically based mathematical models were established using different numerical codes [Faust, 1985; Pinder and Abriola, 1986; Corapcioglu and Baehr, 1987; Parker et al., 1987; Delshad and Pope, 1989]. During the last decade, restoration of contaminated aquifers has become the most important topic and is currently undergoing intensive development [Thornton and Wootan, 1982; Wilson and Conrad, 1984; Hunt et al., !988b; Baehr et al., 1989]. Practically, in most cases the pollution is removed by pumping, skimming, and ventilating. Recently, many researchers have been developing biorestoration strategies using microorganisms capable of degrading hydrocarbons Copyfight 1991 by the American Geophysical Union. Paper number 91WR00303. 0043-1397/9 !/9 ! WR-00303 $05.00 [Wilson and Wilson, !985; McCarty, 1988; McCarty et al., •9891.It seems, however, that inadequate attention has been devoted to microscale (pore scale) investigation, particularly to the geometrical distribution of the immiscible fluids within the pores. The interfaces between phases play an important rule in many processes, and thus analysis...

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