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
Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology
Pan-European study on “Smart Engineering”
30.03.2017 | IPH - Institut für Integrierte Produktion Hannover gGmbH
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
30.03.2017 | Health and Medicine
30.03.2017 | Health and Medicine
30.03.2017 | Medical Engineering