What do these high pressures on surface map mean?

Question

please explain this isobar map to me. Whats causing these 2 high pressure point in the center of the map?

do they repel the cold and warm fronts or did the fronts cause them?

http://s74.photobucket.com/albums/i267/ratgirl102486/?action=view¤t=mondaymarchisobars.gif

http://i74.photobucket.com/albums/i267/ratgirl102486/mondaymarchisobars.gif

Answer 1

The high pressure areas(a system of closed isobar with high pressure at centre) are the regions where the atmosphereic pressure increases from the periphery towards the centre.The winds will be blowing clockwise in the northern hemisphere.But the wind will be light as the pressure gradient will be less when compared to a low pressure area.Weather will be fair in summer but in winter,there is the possibilty of formation of fog.

Between two such high pressure areas,the pressure  may fall.The line connecting such high pressure areas is called a ridge.

High pressure is developed when cold air sinks over a place.At surface levels,more air goes out than the air that enters the high pressure area(divergence).Warm or cold fronts are not required for the formation of high pressure areas.Unequal heating of the surface by the solar radiation is the main reason for the formation of many high and low pressure areas.

Answer 2

Winds flow toward areas of low pressure, so in essence you can say that high pressure repels weather change.  Most high pressure areas are caused by sunlight heating the air in an area, which expands the air.

Answer 3

high preasure zones  want to be the equal with the low preasure zone.So the high preasure zone whooshes to the low preasure zone an as its doing so it makes wind.try an experement all you need is a balloon blow up the balloon and tie it up if you pop it it will make a bang because high preasure is in the balloon and low preasure outside. hope this helps

Answer 4

I am afraid Edward is wrong here.

The sun heats the earth surface and the air near it. That air climbs creating a low pressure. High pressures are zones where the air sinks like over the poles where it is very cold.

But the adiabatic effect makes rising air to cool down and sinking air to warm up.

In a high pressure, the air sinks (thus increase pressure) and heats up by adiabatic effect (the same happens when you e.g. pump the tyres of your bicycle; the pump gets hot by compression).

When the air warms up, any moisture in it will change from water droplets to gas and clouds will dissolve.

Because it happens very slowly, there will be very little wind; something you can see from the spaced isobar lines.

The only 'danger' of a high pressure is that the warmer air above keep the moisture from the night to rise and you get early morning fog.

Answer 5

A strong enough area of high pressure or ridge can block at least temporarily systems that are approaching it.