Four years ago, torrential rains battered the Southern US, mudslides struck in Peru - and the inhabitants of Canada`s west coast saved up to 30% on their winter heating bills. The cause? El Niño, a huge temperature shift in the Pacific Ocean which spawns climate changes globally. Today, using satellite Earth observation data, scientists are detecting the early warning signs of a new El Niño event and predicting that it will develop over the next 3 to 6 months, bringing climate changes to countries thousands of miles from the western Pacific, birthplace of the event itself.
"In normal years, there`s a large area of warm water in the western Pacific and colder water at the eastern side. In El Niño years, that warm water shifts eastward, which has major effects on the atmosphere above the ocean and thus the climate of the nearby countries," explains Joel Picaut, of France`s Centre National d`Etudes Spatiales.
Imaging from space using radar altimetry and sea surface temperature measurements reveals that the trade winds near the Equator pile up a mass of water, warmed by the sun on its journey across the Pacific, which covers an area the size of Europe. This so-called `warm pool` off the Philippine coast is in fact a plateau in the sea some 30 cm high and with a temperature of approximately 29°C - 5°C above average. In contrast, the water off the Galapagos Islands on the other side of the Pacific is normally a mere 20°C. When an El Niño event takes place, all this changes.
"No one is yet quite sure of the mechanism that causes an El Niño," comments Picaut. "It`s clear that the movement of the warm water and the change in the wind patterns are closely linked, but we do not yet know which is the cause and which the effect." The warm water in the west causes convection in the atmosphere and a relatively constant wind from east to west - the trade winds. When the El Niño cycle begins, the trade winds reduce, no longer pushing water toward the warm pool and the mass of warm water begins to flow eastward, toward the Galapagos Islands and the Peruvian coast. "Over a period of 1-2 weeks, we see so-called `westerly wind bursts`, in which the direction of the trade winds reverses. At the equator, you see a very interesting effect, where the wind and the Earth`s rotation combine to trigger `Kelvin waves`, which are like a wall of water 30 cm high moving across the pacific at about 200 km per day. You can see the Kelvin waves clearly and monitor their progress using radar altimeter and sea surface temperature data," says Picaut. These fast-moving Kelvin waves are the heralds of the more sedate progress of the main body of water, which travels at only 30 km per day. In January, scientists detected such a Kelvin wave near the International Date Line in the central Pacific.
Jerome Benveniste | alphagalileo
Sediment from Himalayas may have made 2004 Indian Ocean earthquake more severe
26.05.2017 | Oregon State University
Devils Hole: Ancient Traces of Climate History
24.05.2017 | Universität Innsbruck
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy