Late Holocene climates of the Near East deduced from Dead Sea level variations and modern regional winter rainfall     

Yehouda Enzel  Revital Bookman  David Sharon  Haim Gvirtzman  Uri Dayan  Baruch Ziv  Mordechai Stein 《Quaternary Research》2003,60(3):263-273

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.  相似文献   

Stabilization of Atmospheric Concentrations of Greenhouse Gases     

Jean Koch  Uri Dayan  Shmuel Amir 《Climatic change》2003,57(1-2):227-241

Given the present commitment of the developed countries according to the Kyoto Protocol, most published scenarios demonstrate that global greenhouse gases concentrations would not be stabilized at any level. In order to stabilize these concentrations, a deeper global involvement is needed. Taking Israel as an example of a `recently-developed' country, we assess the role that such countries could play by assuming voluntary commitments in strengthening global involvement. This case as a model may encourage a global scheme for curbing carbon emissions, in which the more developed countries assume a stronger role and the less developed countries participate according to the principle of common but differentiated responsibility. The scheme builds on the inverse relation that exists between the per capita gross domestic product and the rate of increase of emissions due to economic growth. According to this theoretical scheme, the voluntary commitments assumed by the `recently-developed' countries encourage the more developed countries to deepen their involvement by assuming more stringent reductions of emissions at home and transferring technological and financial means to the less developed countries. The proposed scheme would enable non-Annex I countries, both `recently-developed' countries and less developed countries, to participate much earlier in the net mitigation of greenhouse gases.  相似文献   

Conservation tillage and input use   总被引：1，自引：0，他引：1  

N. D. Uri 《Environmental Geology》1997,29(3-4):188-201

 There continues to be a question as to the overall effectiveness of conservation tillage practices in reducing the impact of agricultural production on the environment. While it is generally recognized that water runoff and soil erosion will decline further, as tillage and mulch tillage systems are not used more extensively on cropland, what will happen to pesticide and fertilizer use remains uncertain. To gain some insight into this, the conservation tillage adoption decision is modelled. On the assumption that the decision to adopt conservation tillage is a two-step procedure, the first decision is whether or not to adopt a conservation tillage production system and the second concerns the extent to which conservation tillage should be used – appropriate models of the Cragg and Heckman (dominance) type are estimated. Based on farm-level data on corn production in the United States for 1987, the profile of a farm on which conservation tillage was adopted is that the cropland had above-average slope and experienced above-average rainfall, the farm was a cash grain enterprise, and it had an above-average expenditure on pesticides and a below-average expenditure on fuel and custom pesticide applications. Additionally, for a farm adopting a no-tillage production practice, an above-average expenditure was made on fertilizer. Received: 18 September 1995 · Accepted: 6 December 1995  相似文献   

Do regions outside the tropical Pacific influence ENSO through atmospheric teleconnections?     

H. Dayan  T. Izumo  J. Vialard  M. Lengaigne  S. Masson 《Climate Dynamics》2015,45(3-4):583-601

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A simple estimation of equatorial Pacific response from windstress to untangle Indian Ocean Dipole and Basin influences on El Niño     

T. Izumo  J. Vialard  H. Dayan  M. Lengaigne  I. Suresh 《Climate Dynamics》2016,46(7-8):2247-2268

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Strain path partitioning within thrust sheets: microstructural and petrofabric evidence from the Moine Thrust zone at Loch Eriboll,northwest Scotland     

R.D Law  R.J Knipe  H Dayan 《Journal of Structural Geology》1984,6(5):477-497

Quartz c axis fabrics and microstructures have been investigated within a suite of quartzites collected from the Loch Eriboll area of the Moine Thrust zone and are used to interpret the detailed processes involved in fabric evolution. The intensity of quartz c axis fabrics is directly proportional to the calculated strain magnitude. A correlation is also established between the pattern of c axis fabrics and the calculated strain symmetry.Two kinematic domains are recognized within one of the studied thrust sheets which outcrops immediately beneath the Moine Thrust. Within the upper and central levels of the thrust sheet coaxial deformation is indicated by conjugate, mutually interfering shear bands, globular low strain detrital quartz grains whose c axes are aligned sub-parallel to the principal finite shortening direction (Z) and quartz c axis fabrics which are symmetric (both in terms of skeletal outline and intensity distribution) with respect to mylonitic foliation and lineation. Non-coaxial deformation is indicated within the more intensely deformed and recrystallized quartzites located near the base of the thrust sheet by single sets of shear bands and c axis fabrics which are asymmetric with respect to foliation and lineation.Tectonic models offering possible explanations for the presence of kinematic (strain path) domains within thrust sheets are considered.  相似文献   

A severe autumn storm over the middle-east: synoptic and mesoscale convection analysis     

U. Dayan  B. Ziv  A. Margalit  E. Morin  D. Sharon 《Theoretical and Applied Climatology》2001,69(1-2):103-122

Summary  At times, a pronounced trough of low barometric pressure extends from equatorial Africa northward, over the Red Sea and the eastern Mediterranean countries, i.e., the Red Sea Trough. The associated weather is usually hot and dry, and consequently the atmosphere becomes conditionally unstable. In cases in which additional moisture is supplied and dynamic conditions become supportive, as the case analyzed here, intense thunderstorms occur, with extreme rain rates, hail and floods. The storm herein analyzed caused extensive damage both in casualties and property and evolved in two main consecutive phases: In the first a Mesoscale Convective System that moved from Sinai northward over Israel dominated, and in the second deep convection was organized mainly along a cold front. Data analysis indicates several synoptic-scale factors that had a supportive effect on the storm formation and intensification: Conditional instability established by the Red Sea trough, mid-level moisture transport from Northern Africa, and upper-level divergence imparted by both polar and subtropical jet streams over the Middle-East. Mesoscale features were further investigated by means of a hydro-meteorological observational analysis with high spatio-temporal resolution using raingauge and radar data, and satellite imagery. It is shown that local factors, particularly topographic effects, play a major role in the evolution, intensity and spatial organization of the convective activity. Our findings support results of a numerical study of another autumn rainstorm associated with the Red Sea trough. In the present case we identify an additional contributing factor, i.e., a mid-latitude upper-level trough that further intensified the storm as it was approaching the Middle-East. Received July 4, 2000 Revised January 16, 2001  相似文献   

Electron depletion in the wake of ionospheric spacecraft—A comparison between results from Langmuir probes and antennas     

Uri Samir  H. Weil 《Planetary and Space Science》1973,21(6):993-1000

In situ observations of the electron depletion in the wakes of satellites and rockets in the ionosphere using Langmuir type probes and antennas are analyzed and compared. The quantitative degree of agreement between the results is demonstrated and discussed. One consequence is an improved interpretation of results previously presented for the OGO II Satellite wake.  相似文献   

Estimating the surface wind speed over drifting pack ice from surface weather charts     

Uri Feldman  Philip J. Howarth  John A. Davies 《Boundary-Layer Meteorology》1979,16(4):421-429

Routine surface wind speed data, vital for the study of drifting pack ice, are not available for the polar oceans. Over sea, it has been demonstrated by Hasse that estimates of surface wind speed may be obtained from the geostrophic wind speed using linear formulae. Comparing estimated with observed data for six sites in Canada, it is found that the formulae may also be applied to obtain estimates of surface wind speed over pack ice.  相似文献   

The impact of the nitrogen carryover effect on economic activity and the environment     

Wen-yuan Huang  Russ W. Keim  Yao-chi Lu  N. D. Uri  Terry Kelley 《Environmental Geology》1998,34(2-3):116-127

 The economic and environmental consequences of soil nitrogen tests can have significant impacts on agricultural production. Some of these are explored here. The pre-side-dress soil N-test is evaluated for a hypothetical farmer growing corn at the ARS Sustainable Agriculture Demonstration Farm site in southern Maryland. For a farmer not currently using a soil N-test, adoption of this technology can lead to the enhancement of net farm income and the reduction in nitrogen loss to the environment. This will transpire only if the farmer is currently underestimating nitrogen carryover by more than 25% or applying nitrogen fertilizer based solely on an expected plateau-yield goal. Received: 13 February 1997 · Accepted: 13 May 1997  相似文献