New clues to air circulation in the atmosphereAugust 22, 2008Air circulates above the Earth in four distinct cells, with two either side of the equator, says new research out today (21 August) in Science. The new observational study describes how air rises and falls in the atmosphere above the Earth's surface, creating the world's weather. This process of atmospheric circulation creates weather patterns and influences the climate of the planet. It is important to understand these processes in order to predict weather events, and to improve and test climate models. Previous theories have claimed that there are just two large circular systems of air in the atmosphere, one either side of the equator. These theories suggested that air rises at the equator and then travels towards either the north or south polar regions, where it falls. The new research suggests instead that there are two cells in both the northern and southern hemispheres. In the first cell, air rises at the equator and then falls in the subtropics. In the second cell, air rises in the mid-latitudes - approximately 30 to 60 degrees north and south of the equator - and then falls in the polar regions. The researchers say that this second cell of rising air is a mechanism responsible for setting the distribution of temperature and winds in the mid-latitudes which has not been fully appreciated before. The mid-latitudes include the UK, Europe and most of the United States. Dr Arnaud Czaja from Imperial College London's Department of Physics and the Grantham Institute for Climate Change, one of the authors of the new research, explains: "Our model suggests that there is a second cell of air in each hemisphere which is characterised by air rising, clouds forming, storms developing and other processes associated with moisture in the air occurring in the mid-latitudes." Current theories to describe weather patterns in the mid-latitudes do not take these moisture-based processes into consideration. Dr Czaja argues that these theories are therefore incomplete, and that water vapour plays as much of an important role in the weather systems of the mid-latitudes as it does in the tropics, where it is a well-documented driver of weather events. The research team carried out their study by conducting new analyses of extensive meteorological data. Dr Czaja says that he hopes the research will lead to a more detailed understanding of how air circulation in our atmosphere works, and how it affects the weather: "With more attention than ever before being focused on understanding our planet's climate, weather systems and atmosphere, it's important that scientists challenge their own assumptions and current theories of how these complex processes work. I think our study sheds new light on the driving forces behind the weather in the mid-latitudes," Dr Czaja added. Imperial College London |
|||||||||||||||||||||
| Related Atmosphere Current Events and Atmosphere News Articles Peat fires drive temperatures up Peatlands, especially those in tropical regions, sequester gigantic amounts of organic carbon. Human activities are now having a considerable impact on these wetlands. Supervolcano eruption -- in Sumatra -- deforested India 73,000 years ago A new study provides "incontrovertible evidence" that the volcanic super-eruption of Toba on the island of Sumatra about 73,000 years ago deforested much of central India, some 3,000 miles from the epicenter, researchers report. New Method to Measure Snow, Soil Moisture With GPS May Benefit Meteorologists, Farmers A research team led by the University of Colorado at Boulder has found a clever way to use traditional GPS satellite signals to measure snow depth as well as soil and vegetation moisture, a technique expected to benefit meteorologists, water resource managers, climate modelers and farmers. New hydrogen-storage method discovered Scientists at the Carnegie Institution have found for the first time that high pressure can be used to make a unique hydrogen-storage material. ORNL, Los Alamos pioneer new approach to assist scientists, farmers Sustainable farming, initially adopted to preserve soil quality for future generations, may also play a role in maintaining a healthy climate, according to researchers at the Department of Energy's Oak Ridge and Los Alamos national laboratories. Oceans' uptake of manmade carbon may be slowing The oceans play a key role in regulating climate, absorbing more than a quarter of the carbon dioxide that humans put into the air. Warmer means windier on world's biggest lake Rising water temperatures are kicking up more powerful winds on Lake Superior, with consequences for currents, biological cycles, pollution and more on the world's largest lake and its smaller brethren. New Water Management Tool May Help Ease Effects of Drought Continued improvement of climate forecasts is resulting in better information about what rainfall and streamflow may look like months in advance. Earth's early ocean cooled more than a billion years earlier than thought: Stanford study The scalding-hot sea that supposedly covered the early Earth may in fact never have existed, according to a new study by Stanford University researchers who analyzed isotope ratios in 3.4 billion-year-old ocean floor rocks. A bubbling ball of gas The Sun is a bubbling mass. Packages of gas rise and sink, lending the sun its grainy surface structure, its granulation. Dark spots appear and disappear, clouds of matter dart up - and behind the whole thing are the magnetic fields, the engines of it all. More Atmosphere Current Events and Atmosphere News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||