Cyclical changes in atmospheric pressure and sea surface temperature in the North Atlantic Ocean affect drought in the Sahel region on the southern Sahara rim. This has been revealed in an international study carried out by researchers from the University of Haifa, the French National Meteorological Service, Columbia University and the University of San Diego. The study was published recently in the scientific journal Atmospheric Science Letters (Royal Meteorological Society).
That climate variability in one region can have an effect on more distant areas is known in the climate research literature - the challenge being to locate these far-connections and understand their projections. The current study, co-authored by Dr. Shlomit Paz of the Department of Geography and Environmental Studies at the University of Haifa, analyzed a number of climate parameters in the North Atlantic over the 20th century, including atmospheric pressure at sea level and sea surface temperature. They revealed two "natural climate signals”: a multi-decadal signal of a period exceeding 40 years, and a quasi-decadal signal with periodicity ranging from 8 to 14 years. These two signals may cancel or enhance one another.
In order to establish these findings, the scientists compared them with climactic fluctuations as observed in coral and tree-ring studies, by which the temperature values of the past few hundred years can be reconstructed. The signals were identified in this case too.
Next the researchers identified a correlation between the cyclical waves and droughts in the Sahel region: When the Atlantic Ocean cools, there are droughts in the region, and when the Ocean temperature rises, rain returns to the Sahel region. They also found that during drought periods in the Sahel, the force of hurricanes in the Atlantic drops; and vice versa.
This is not merely a theoretical study, Dr. Paz explains. The Sahel region suffered drought over more than 20 years, from the 1970s to the mi-1990s, which caused deep environmental and social crises, such as hunger, civilian desertion, ethnic conflicts, and more. In 2007 the UN published a report stating that the situation in Darfur was intensified by the ongoing drought in the Sahel region and its surroundings.
This study contributes to information availability for climatic models, thereby improving their prediction capability. The researchers are currently investigating whether current human activity has an impact on these phenomena and are examining the effects of the signals on today's climate in Europe. They note that the thermal imbalance caused by urban development makes the research more challenging. "Today we are able to gain a better understanding of how the oceans play an important role in the earth's 'climate memory'. Once we become familiar with the natural signals, we will be able to better understand how the human factor correlates with climate," Dr. Paz states.
For more details contact Rachel Feldman • Tel: +972-4-8288722Amir Gilat, Ph.D.
Amir Gilat | University of Haifa
Study relating to materials testing Detecting damages in non-magnetic steel through magnetism
23.07.2018 | Technische Universität Kaiserslautern
Innovative genetic tests for children with developmental disorders and epilepsy
11.07.2018 | Christian-Albrechts-Universität zu Kiel
New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference
Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
17.08.2018 | Event News
08.08.2018 | Event News
27.07.2018 | Event News
17.08.2018 | Physics and Astronomy
17.08.2018 | Information Technology
17.08.2018 | Life Sciences