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
WAKE-UP provides new treatment option for stroke patients | International study led by UKE
17.05.2018 | Universitätsklinikum Hamburg-Eppendorf
First form of therapy for childhood dementia CLN2 developed
25.04.2018 | Universitätsklinikum Hamburg-Eppendorf
The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.
Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
25.05.2018 | Event News
02.05.2018 | Event News
13.04.2018 | Event News
25.05.2018 | Event News
25.05.2018 | Machine Engineering
25.05.2018 | Life Sciences