when i read that the air pressure is 1079 millibars what does that mean?

Question

I understand that there are roughly 2.5 millibars to 1" water gauge and that there are 1000 millibar to a bar. I understand that my gas pressure comes in to my house at 21 mbar and that this gas has been broken down by a piece of equipment from 2 bar of gas. But how does atmospheric pressure work. At the end of the weather each day they mention that the pressure in the air is for example 1080mb. how does that effect the day or the weather or what???????????

Answer 1

the air pressure will indicate what the weather is like. most of the time, the higher the better the day.

when there is a storm approaching, the power will drop and drop.

so 1080 is means a pretty clear nice day.

Answer 2

Static atmospheric pressure comes from the weight of the column of air above your head. It can be affected by atmspheric phenemona like ridges, troughs, and high and low pressure systems, which all serve (among many other factors) to alter the density of the air. Less dense air contains less molecules of air in a given volume, and is therefore lighter and generates less static pressure on the surface.

Average sea level pressure is 1013.25 mb. One bar is 100,000 pascals (Pa) of pressure, where a pascal is 1 Newton per Sq. Meter of pressure. So, a given measure of millibars illustrates how high or low the atmospheric pressure is at a given location, and whether it is higher or lower than average.

When the pressure is low (below 1013 mb), say due to a low pressure system coming through, this is often due to an uplifting effect on the atmosphere. Through the concepts of convergence and divergence (another topic altogether), air rises near a low pressure area. The upward motion reduces the force of the air on the surface, hence lowering the pressure. Think about putting a weight on a scale, then gently lifting up on the weight without actually picking it up.

In contrast, a high pressure area is generally a location of sinking air. It's kind of like taking that same weight mentioned above and pressing down on it more.

The upshot of this is in a low pressure situation, where you get naturally rising air, this movement encourages convective cloud development, often causing thunderstorms when the weather is warm enough. If you watch the weather on the news, you'll notice that most often, poor weather is associated either directly with a low pressure system or an extension of that system along a front or a trough (a lengthened area of low pressure instead of a central defined location).

In contrast, again, high pressure's sinking force tends to suppress the upward development of clouds by inhibiting convective motion. A high pressure system or a ridge (think trough but high pressure) produces this effect, generally speaking.

There are always exceptions to the rule, and the dynamic variables of weather are many and varied. Generally though, low pressure is associated with some less-than-desired weather phenemona, whilst high pressure encourages stability and tends to produce better weather.

Answer 3

The pressure of atmosphere is the weight of the overlying column of air over unit area at a particular level.Usually mercury barometer is used to measure the above pressure.In the barometer,the weight of a column of mercury is made to balance the pressure of the atmosphere over a mercury trough.The height of the column of mercury that balances the atmospheric pressure is given as the pressure value.But, for meteorological purposes, the pressure value is given in millibar.A mercury column of 76 centimetres equals 1013 millibar.This is arrived at as follows.
The weight of the column of mercury is given by
AHdg where A is the area of cross section of the tube,H is the height of the mercury column,d is the density of mercury and g is the acceleration due to gravity.
But the pressure is the weight per unit area.In that case, the above formula becomes p=Hdg where is "p" is the pressure.
If you take H=76, d=13.6 gm per cc, and g=980 cm per square centimetre, then the pressure value becomes p=76X13.6X980 dynes per square centimetre.
The above value becomes 1013 X 10 power 3 dynes per square centimetre.
But 10 power 3 dynes per square centimetre is called "one millibar".So the above value becomes 1013 millibar.
Similarly 1079 millibar can be converted to corresponding centimetre which will give the height of the vertical colomn of mercury which balances the atmospheric pressure of 1079 millibar.The value will be about 80.9 centimetre.

Answer 4

The air pressure is sufficient to support a column of mercury of height 1.079m

Answer 5

To make it very simple, High pressure means high humidity contain and low pressure means low humidity contain.
Based on the 1013.25 Mb Datum