What is the polar front theory?
A theory originated by the Scandinavian school of meteorologists whereby a polar front, separating air masses of polar and tropical origin, gives rise to cyclonic disturbances that intensify and travel along the front, passing through various phases of a characteristic life history.
How many stages does the polar front theory have?
The polar front theory, also known as the Norwegian model, states that cyclones have a reasonably predictable, six-stage life cycle.
When was the polar front theory developed?
The well known Polar-front theory was described by the Bergen school early 20th century. The theory explains the formation, development and life cyles of cyclones. In short several stages of cyclone development can seperately be identified.
What happens along the polar front?
They tend to bring storms and rain to most of the planet. The polar front is involved because of the cold winds from the poles. These cold winds blow from the east between 60 to 90 degrees latitude. They can mix with the warm winds that are found closer to the equator.
What is a polar front quizlet?
polar front. the boundary between westerlies and the polar easterlies. cold front. cold air in advancing and pushing warm air out of area.
What meets at the polar front?
A polar front is an area where cold polar air mass meets warm tropical air masses. The line between these two air masses can be thousands of miles long.
Why mid-latitude originate at the polar front?
Mid-Latitude Cyclones The swirling air rises and cools, creating clouds and precipitation. Mid-latitude cyclones form at the polar front when the temperature difference between two air masses is large. These air masses blow past each other in opposite directions.
Who discovered polar front theory?
physicist Vilhelm Bjerknes
Extratropical cyclone tracks are displaced farther northward in July, reflecting the more northward position of the polar front in summer. Members of the Bergen school, founded by Norwegian meteorologist and physicist Vilhelm Bjerknes, first proposed the concept of the polar front.
What is polar front depression?
Frontal or Polar Depressions The leading edge of the wave is known as a “warm front” while the trailing edge is called a “cold front”. The cold front usually moves across the surface faster than the warm front. The pressure near the top of the wave falls sharply and a depression forms.
What is the polar front theory based upon quizlet?
The Polar Front theory is a five-stage model of how a midlatitude cyclone begins, grows, and then dissipates or decays. The theory also addresses the development of weather along the surface front.
What is a characteristic of polar fronts quizlet?
What is the usual movement of a polar front depression?
Frontal or Polar Depressions The cold front usually moves across the surface faster than the warm front. The pressure near the top of the wave falls sharply and a depression forms.
Why is polar front stronger in winter than in summer?
The wind speeds associated with the polar jet stream tend to be stronger in winter as compared to summer. This occurs because there is a greater contrast in temperature between the polar and mid-latitude regions.
Why do mid-latitude cyclones occur in winter?
Mid-latitude cyclones are huge weather systems that occur most often during the winter season in the United States. These low pressure areas pop up easily during winter because of the large temperature difference between the equator and the North Pole.
What is polar front Upsc?
Polar fronts is the boundary between the polar cell and the. ferrel cell in each hemisphere with sharp temperature gradient between two air. masses ,warm tropical air and cold polar. air.it is a stationary front as the air masses are not moving against each. other.
How does polar front depression form?
Which of the following best describes the phenomenon that typically develops at the surface beneath an area of divergence in the upper atmosphere?
Which of the following best describes the phenomenon that typically develops at the surface beneath an area of divergence in the upper atmosphere? Upper-level divergence causes a low pressure system, whereas upper-level convergence causes high pressure at the surface.
What conditions favor the formation of a frontal wave?
frontal wave Wave-like deformation of the line of a front between two air masses. The wave develops from the northward incursion of warm air and usually travels along the front, with colder air ahead and to the rear.
How does the polar front jet stream affect air masses?
As a component of the planetary-scale prevailing westerly circulation, the polar-front jet stream steers storms across the country. Hence, storms generally move from west to east. The polar-front jet stream is like a high-speed river of air in the upper atmosphere. It separates warm and cold regions at Earth’s surface.
What causes a disturbance in the polar front?
Coriolis Effect deflects winds to the right in the Northern Hemisphere, causing the winds to strike the polar front at an angle. Warm and cold fronts form next to each other. Most winter storms in the middle latitudes, including most of the United States and Europe, are caused by mid-latitude cyclones.
What is the polar front theory of cyclogenesis?
The Polar Front Theory of Cyclogenesis was developed in the early 1900s to explain the formation of mid-latitude cyclones. But what is a mid-latitude cyclone and why is it important? A mid-latitude cyclone is a large-scale low pressure system that travels eastward around the planet between 30 and 70 degrees latitude.
What do we know about the polar front theory?
Further, this theory clearly demonstrates the role of disturbances in the global atmospheric circulation. The polar-front theory was essentially constructed after a careful analysis of surface weather maps, without satisfactory aerological observations.
What is the wave stage of a polar front?
But under certain conditions, a wave forms in the polar front that leads to the wave stage. The wave deepens into a low-pressure center, winds begin to rotate counterclockwise, distinct cold and warm fronts develop, and a sector of warm air gets wedged between cold air.
What is Bjerknes’philosophy of the atmosphere?
The fundamental philosophy expounded by V. Bjerknes, and also by Richardson (1922), was that if the initial state of the atmosphere were completely described, it would then be possible to make a prognosis of the future states by use of the fundamental laws of hydrodynamics and thermodynamics.