CPC Information CPC Web Team HOME > Climate & Weather Linkage > Teleconnections > Arctic Oscillation : Current Conditions; Outlooks; References : Current Conditions; The daily AO index is constructed by projecting the daily (00Z) 1000mb height anomalies poleward of 20°N onto the loading pattern of the AO. The Arctic oscillation index is defined using the daily or monthly 1000 hPa Over most of the past century, the Arctic oscillation alternated between positive and negative phases. The Arctic oscillation appears as a ringlike (or "annular") pattern of sea-level pressure anomalies centered at the poles.
NCEP/Climate Prediction Center ATLAS 8. The Arctic Oscillation (AO) refers to an atmospheric circulation pattern over the mid-to-high latitudes of the Northern Hemisphere.
The southern hemisphere analogue is called the Antarctic oscillation or Southern Annular Mode (SAM). The southern hemisphere analogue is called the Antarctic oscillation or Southern Annular Mode (SAM).
It is also known as the Southern Annular Mode (SAM). auch Northern Hemispheric Annular Mode (NAM)) ist Ausdruck des Luftdruckgegensatzes zwischen den arktischen und den mittleren Breiten auf der Nordhemisphäre. It is an important Arctic climate index with positive and negative phases representing the state of atmospheric circulation over the Arctic. CPC Web Team HOME > Climate & Weather Linkage > Teleconnections > Antarctic Oscillation : Current Conditions; Outlooks; References : Current Conditions; The daily AAO index is constructed by projecting the daily (00Z) 700mb height anomalies poleward of 20°S onto the loading pattern of the AAO.
auch James A. Bradbury, Cameron P. Wake, Airmap/NOAA: The indices are standardized by standard deviation of the observed monthly AO index from 1979-2000. The current negative AO is reflective of mostly positive pressure/geopotential height anomalies across the Arctic with mixed pressure/geopotential height anomalies across the mid-latitudes. Please note that year-round monthly mean anomaly data have been used to obtain … The Arctic oscillation (AO) or Northern Annular Mode/Northern Hemisphere Annular Mode (NAM) is a weather phenomenon at the Arctic poles north of 20 degrees latitude. Die Arktische Oszillation (AO) (engl. The presence of continents and large landmasses disrupts the ringlike structure at the Arctic pole, while anomalies surrounding the Antarctic pole are nearly circular. In that month, the Arctic oscillation reached its most negative monthly mean value at about −4.266, in the entire post-1950 era (the period of accurate record-keeping).The greatest negative value for the Arctic oscillation since 1950 in January was −3.767 in 1977, which coincided with the coldest mean January temperature in New York City, Washington, D.C., Baltimore, and many other mid-Atlantic locations in that span of time, although the January Arctic oscillation has been negative only 60.6% of the time between 1950 and 2010, nine of the ten coldest Januarys in New York City since 1950 have coincided with negative Arctic oscillations.National Weather Service Climate Prediction Center and NWS Forecast Office, as of 2010 Please note that year-round monthly … When the AO is in its positive phase, a ring of strong winds circulating around the North Pole acts to confine colder air across polar regions.
Arctic Oscillation AO The Arctic Oscillation (AO) refers to variations in the difference in the atmospheric pressure patterns between northern mid-latitudes (about 45 degrees North) and the Arctic. The following statement from the A further, quite graphic illustration of the effects of the negative phase of the oscillation occurred in February 2010. The index varies over time with no particular periodicity, and is characterized by non-seasonal sea-level pressureanomalies of one sign in the Arctic, balanced by ano…
Higgins, R.W., Y. Zhou and H.-K. Kim, 2001: Relationships between El Niño-Southern Oscillation and the Arctic Oscillation: A Climate-Weather Link. The Arctic Oscillation (AO) is a leading teleconnection pattern in the Northern Hemisphere circulation. The Arctic Oscillation (AO) is a large scale mode of climate variability, also referred to as the Northern Hemisphere annular mode. It is calculated as the first Empirical Orthogonal Function (EOF) for height anomalies poleward of 20 degrees latitude for the Northern Hemisphere.
About Us Our Mission Who We Are Contact Us CPC Information CPC Web Team : HOME > Monitoring and Data > Monitoring Weather & Climate > Indices and Forecasts > Daily Arctic Oscillation Index : The daily AO index is constructed by projecting the daily (00Z) 1000mb height anomalies poleward of 20°N onto the loading pattern of the AO. Data using a 60-day running mean has implied the oscillation has been trending to more of a positive phase since the 1970s,This zonally symmetric seesaw between sea level pressures in polar and temperate latitudes was first identified by Climatologists are now routinely invoking the Arctic oscillation in their official public explanations for extremes of weather. Arctic Oscillation (AO) and North Atlantic Oscillation (NAO) [last update: 2011/03/02] It is only in recent years that scientists are starting to recognize the influence of atmospheric and oceanic cycles in influencing climate. The Arctic Oscillation (AO) is a large scale mode of climate variability, also referred to as the Northern Hemisphere annular mode.