Paleo-climate

Ori Adam

Ori Adam

Senior Lecturer
Head of the academic committee of the Hebrew University Climate Science Center (HUCS)
Academic head of the Hebrew University Research Computing Service
Room 307 North
972-2-6586514

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In my group we study the large-scale dynamics of the atmosphere and oceans and the interactions between them, with emphasis on tropical climate dynamics. We aim to improve our understanding of variations in the present and past climates, and the governing dynamic and thermodynamic mechanisms that drive them. We also strive to mediate between theoretical and applied geophysical practices, by developing tools and methods for applications such as bias reduction in climate models, interpretation of paleo records, and quantification of variations of the tropical rain belt.
 

The theoretical tools we use include idealized models of the atmosphere and oceans which are amenable to mathematical analysis, an idealized general circulation model (FMS), as well as the analysis of comprehensive climate models (e.g., CMIP and PMIP models). We also aim to anchor the research in observations. To handle the large variety of observational and modeling datasets, we use a software tool called GOAT (Geophysical Observation Analysis Tool).

Current research projects include:

  • Idealised coupled cloud-ocean-atmosphere models
  • The effect of continent distribution on tropical climate
  • The relation of the atmospheric energy budget and tropical precipitation
  • Origin and nature of the double ITCZ bias
  • Variations of the tropical rain belt in the present and past climates
  • Relating the Hadley cell strength to the atmospheric energy budget
 
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YBD sampling GFZ

Dr. Yoav Ben Dor

Postdoctoral fellow, advised by Yigal Erel and Mordechai Stein
Room 17

 

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Research interests: Paleoclimate, hydrology, limnology, sedimentary petrography, sedimentology, pedology, quaternary research, geochronology

Reasearch Topic: Saharan dust & the Neolithic Agriculture Revolution in the Jordan Valley

 

Abstract:

My current study focuses on the environmental and soil-related conditions in the Levant that could have provided prehistoric humans with the advantages required to initiate the Neolithic Agriculture Revolution (NAR) following the end of the last glacial period (~15th to 11th millennium BP). We investigate the properties and origins of soils and sedimentary sequences that accumulated prior, during and after the NAR with close context to renowned archaeological sites including Gilgal, Netiv Hagdud and Fazael, and analyze them within the broad climatological and hydrological framework. Through this inter-disciplinary study of the soils that served the earliest farmers of the Levant, we wish to see whether local conditions that followed the last glacial period provided an unplanned natural advantage to the people that inhabited the Jordan Valley. This research relies on establishing the chronology of the studied sections using OSL and 14C dating techniques, and further sedimentary and soil-related analyses, which include detailed field description and mapping, soil texture and grain-size measurements, and other fertility-related properties such as exchangeable cations composition, sodium and potassium adsorption, available sulfur and phosphorus, as well as chemical and multiple isotopic analyses.

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Amos Frumkin

Amos Frumkin

Professor
Room 303 South
972-54-8820489

 

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Research Interests

(1) Karst and caves systems within the environment serve as the major arena for my research. Understanding karst helps me in solving questions in a diversity of research fields, such as paleoclimate, geomorphic evolution, paleohydrology, tectonics, environmental problems, human impact on ecosystems, and human use of underground space. Our group uses various methods for research, such as field observation and survey, hydrological measurements, geochemical analysis of water and rocks, stable isotopes analysis of water and sediments, radiometric dating (e.g. radiocarbon, U series, cosmogenic isotopes), geographic information systems, borehole analysis, and geophysical methods for analyzing the sub-surface. Evolution of aquifers as a result of enlarging karst conduits is an important focus of my research. Understanding such processes allows better utilization of the water resources of Israel and its neighbors, and avoiding pollution. Our group studies the recharge vadose zone at the mountains in central Israel, concentrating on recharge through karst shafts and cave drips injecting water and potentially pollution into the aquifer. Much of my research is focused in the phreatic, confined and hypogenic parts of the aquifers. It is found that most Israel's carbonate caves have initiated and developed to full size under such conditions. Ageing and dying stages of cave life are studied through excavations in filled caves.

Caves preserve unique records of the geological history of their region. They form along structural lines, they are deformed and uplifted with the rock, and they preserve ancient sediments with geological records. We study such features of tectonics, diapir rising rates and morphostructure of the Dead Sea basin and its shoulders.

cave

(2) Paleoclimate and paleoenvironment: Reconstructing past environments is a major challenge in my research, addressing the need to calibrate climatic models and predict future environmental change. Karst caves function as shielded sediment traps within continental regions under erosional conditions. Therefore cave sediments have a great potential for climatic reconstruction in inhabited regions. We have succeeded in obtaining detailed well-dated climatic records for the Quaternary in Israel. The results solve some important questions on climate change during the Quaternary in the Levant and other regions, how it could influence humans, and the nature of climatic belts migration during glacial/interglacial cycles. The answers obtained have direct impact on understanding present and future climatic change. We have extended the paleoclimatic studies to lava caves, ancient wood preserved in caves, and to stromatolite caves in the Dead Sea basin. We obtained paleoenvironmental records for various climatic regions, such as the northern-central Dead Sea catchment, where we showed that glacials were wetter than interglacials in the Levant. Environmental catastrophes during the Holocene received particular attention, due to their relevance to present and future global change.

cave

(3) Geoarchaeology: We mainly concentrate in using earth sciences methods for understanding human evolution, ancient water systems, natural processes in inhabited caves, and reasons for human use of caves in the past. The collaboration with archaeologists and earth scientists from several universities is very productive. We combine detailed geological and archaeological field study with modern laboratory methods in order to answer open questions. Among our studies: Dating of early Paleolithic cave inhabitants; paleoclimatic corridors for human migration out of Africa; understanding technical innovations and dating ancient water supply systems; understanding cave usage by humans, such as during Bar-Kokhba Revolt, using underground archaeoloy; comparing field evidence with historic and archaeologic records.

gliding

 

 

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Yoni Goldsmith

Yonatan Goldsmith

Senior Lecturer
Room 14 South

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Research Interests 

Understanding how global warming will effect water availability is one of the crucial questions of our time.

My research is aimed at quantifying past changes in rainfall and evaporation in different places around the world (China, Mongolia, western US, Middle East) in order to understand the natural variability of rainfall and evaporation and the processes that govern this variability.

I combine geomorphology with isotope geochemistry (compound specific stable isotopes (dD, d13C), traditional stable isotopes (dD, 18O, d13C), clumped isotopes and U/Th dating) to investigate how the status of lakes has changed through time. I use hydrological models and outputs of climate models to quantify and evaluate the empirical data I collect.

I’m also interested in how human societies respond to climate change throughout history and in the present.

Ongoing projects:

  • Quantifying the migration of the East Asian Monsoon during the Late Quaternary in China and Mongolia
  • Reconstructing paleo-intensity of the Indian Monsoon using lake-area fluctuations from Lake Chenghai, Southern China
  • Developing and applying compound specific stable isotope biogeochemistry to problems in terrestrial hydroclimate, East Asia, West Asia, Western USA
  • Chemical and isotopic processes of shoreline tufa formation in Mono Lake, USA.

Curriculum Vitae

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Efrat Morin

Efrat Morin

Professor
Room 308 South
972-2-6584469

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Research Interests:

I am interested in understanding, modeling and predicting dominant processes and interactions of hydrological and meteorological systems at different space-time scales. I am in particular interested in space-time patterns of precipitation fields and how these are related to meteorological controls on one hand and to hydrological impacts on the other. Precipitation data from remote sensing systems (radar and satellite) are often used in my research, where their uncertainty is also considered. With my group we investigate extreme precipitation and floods at a range of scales. We develop and utilize process-based and data-driven models in deterministic and stochastic frameworks. We examine climate variability and climate change in present, past and future conditions and their effects on different environmental systems that are of interest in hydrological, geomorphologic, agricultural and ecological fields of research.

 

Curriculum Vitae

 

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