Sentences with phrase «polar air»

As the world cools because of decreasing solar activity the dome of cold polar air expands.

That's prevented colder, polar air from dropping into the region and set up an exceptional stretch of weather.

Global warming will reduce the difference as polar air warms more than tropical air.

When polar air neither retreats nor advances, the polar front is called a stationary front.

A more intense surge of truly polar air will move in next week.

The reason they occur in the middle latitudes is because they occur at the boundary between cold polar air and warmer tropical air.

When the AO index is negative there tends to be low pressure in the polar region, weaker zonal winds, and greater movement of frigid polar air into middle latitudes.

Similarly, slow moving polar air will be left behind by the rotating Earth and look like it is moving from east to west if it is pulled equatorward by a pressure difference.

A low - altitude flow of warm, moist air from an ocean area combined with a flow of cold, dry polar air high up creates maximum instability, which means that parcels of air heated near the surface rise rapidly, creating powerful updrafts.

Some of the coldest air in the northern hemisphere — yes, associated with the polar

Thus instead of a strong zonal wind that keeps cold polar air locked in the Arctic, there is a tendency for a less zonal flow and thus more cold air outbreaks to middle latitudes.

IPCC Reports claim increased CO2 levels will increase polar air temperature more than the tropical air.

The mechanism proposed is a spinning up of the Pacific trade winds and surface gyres as a result of colder and denser polar air.

Then, a few thousand miles east, the jet stream dives south, bringing polar air to the East Coast.

These wind patterns would tend to keep polar air over the Arctic.

When polar air dipping southward collides with rising warm tropical air, the meet - up causes a powerful atmospheric wave with rollercoaster - like patterns that propagate eastward around the globe.

The dome of polar air expands in winter and shrinks in summer.

Fig 4: Modified vertical temperature profiles -LRB----- line) typical of: a) tropical air cooled from below and b) polar air heated from below on its way to the British Isles.

One hypothesis suggests that the shrinking temperature difference between the Arctic and the mid-latitudes will lead to a slowing of the jet stream, which circles the northern latitudes and normally keeps frigid polar air sharply separated from warmer air in the south.

At this location, frontal lifting associated with mid-latitude cyclones moves warm subtropical air over cold polar air producing clouds and precipitation.

Usually in winter, the air masses above the Arctic have low pressure, and the entire area is surrounded by a circular vortex of wind currents, keeping the frigid polar air contained.

In autumn 1939 naval activities squeezed the heat out of the seas more quickly, freeing the way for polar air from the high North and Northeast.

There's effectively a storm factory over the Atlantic, caused by cold polar air pressing up against warm, tropical air, causing weather systems to form.

That is the reason for the observation of more frequent and intense incursions of polar air across middle latitudes in recent years.

In this discussion a cold Wave is when polar air on the poleward side of the Jet Stream covers eastern North America and Western Europe as in Figure 2.

In order to ascertain whether there is a global warming or cooling trend it is necessary to wait several years and then compare the volume and intensity of the cold polar air masses as a whole between the dates chosen.

Cold fronts occur at the leading edge of equatorward - moving polar air.

It's unlikely that truly polar air will invade the Lower 48 for the rest of the month, which marks the end of meteorological winter.

Thus instead of a strong zonal wind that keeps cold polar air locked in the Arctic, there is a tendency for more cold air outbreaks to middle latitudes.

If you look at some of the recent posts on NASA's Goddard site regarding the upper altitude (@ 700mb) polar air temperatures and the NCEP NESDIS Jet Stream / Barometric data the transport appears to be possible.

These phenomena develop along the polar front, which separates colder polar air from warmer tropical air, when sufficiently large temperature differences occur across the frontal boundary in the lower troposphere.

The idea is that melting sea ice in the Arctic can weaken the jet stream, allowing frigid polar air to travel farther south.

On a global scale it occurs between cold polar air and warm tropical air along the Polar Front (Figure 1).

When a large surge of polar air moves equatorward it draws a pulse of energy from the oceans in the lower latitudes and pumps it into the stratosphere where most of that energy is pushed out to space but a portion is not pushed out and descends again thus strengthening the high pressure systems on the poleward side of the mid latitude jets.

The summer weather in the UK and northwest Europe is influenced by the position and strength of the Atlantic jet stream — a ribbon of very strong winds which are caused by the temperature difference between tropical and polar air masses.

Half the passengers on the ship were standing on top of the bridge breathing in the cold polar air, mesmerised by the stunning beauty of the landscape unfolding before them.

The ocean around Antarctica is warmer than both the continent's icy surface and the polar air.

At least nine deaths have been reported across the country connected with the polar air mass that swept over North America during the past few days.

When the strong winds that circle the Arctic slacken, cold polar air can escape and cause extreme winter chills in parts of the Northern hemisphere.

«These chemicals enter the atmosphere at lower latitudes where they were used, and are then deposited down from the cold polar air, so Arctic animals are more highly exposed than animals in more temperate or equatorial regions,» University of Florida researcher Margaret James (who wasn't involved in the study) told New Scientist.

During El Niño events, western North America experiences greater flows of maritime air and reduced flows of cold polar air from Canada.

The boundary between cold polar air and warmer tropical air marks the position of the Polar Front.