They're called 'isobars'.
Wind is caused by air flowing from high pressure to low pressure. Since the Earth is rotating, however, the air does not flow directly from high to low pressure, but it is deflected to the right (in the Northern Hemisphere; to the left in the Southern Hemisphere), so that the wind flows mostly around the high and low pressure areas.This effect of the wind "feeling the Earth turn underneath it" is important for very large and long-lived pressure systems. For small, short-lived systems (such as in the cold outflow of a thunderstorm) the wind will flow directly from high pressure to low pressure.The closer the high and low pressure areas are together, the stronger the "pressure gradient", and the stronger the winds. On weather maps, lines of constant pressure are drawn (as in the example, above) which are called "isobars". These isobars are usually labeled with their pressure value in millibars (mb). The closer these lines are together, the stronger the wind.Clouds do not form winds.The curvature of the isobars is also important to the wind speed. Given the same pressure gradient (isobar spacing), if the isobars are curved anticyclonically (around the high pressure in the above example) the wind will be stronger. If the isobars are curved cyclonically (around the low pressure in the example above) the wind will be weaker.Near the surface of the Earth, friction from the ground slows the wind down. During the day, when convective mixing is stirring up the lower atmosphere, this effect is minimized. At night, however, when convective mixing has stopped, the surface wind can slow considerably, or even stop altogether.Wind can be thought of one way that the atmosphere moves excess heat around. Directly or indirectly, wind forms for the promary purpose of helping to transport excess heat either away from the surface of the Earth, where sunlight causes an excess of energy buildup, or from warm regions (usually the tropics) to cooler regions (usually the higher latitudes).Extratropical cyclones accomplish much of this heat transport outside of the tropics, while in the tropics the trade winds, monsoons, and hurricanes transport much of the heat.
The pressure gradient force and the Coriolis effect are the main factors influencing the angle at which surface winds cross the isobars. The pressure gradient force creates wind flow from high pressure to low pressure, while the Coriolis effect deflects this flow to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. As a result, surface winds tend to cross the isobars at an angle as they follow the combination of these two forces.
The best map view to show the movement of surface air around a low-pressure system in the Northern Hemisphere is an isobaric map, where lines of equal pressure (isobars) are plotted. Surface winds around a low-pressure system flow counterclockwise in the Northern Hemisphere, so the isobars will show a series of concentric circles with closed contours around the low-pressure center.
Buys Ballots law says that if you stand with your back to the wind, the area of low pressure is on your left. It is referring to the area or centre, not individual isobars, although it follows that the pressure on your left will be generally lower than on your right.
A geostrophic wind is a wind that flows parallel to the isobars, i.e., lines of constant pressure. It is the result of a balance between the pressure gradient force and the Coriolis force. In the Northern Hemisphere, geostrophic winds blow clockwise around high pressure and counterclockwise around low pressure systems.
what is the similaraties between isobars and isotherms ]
Yea, where would you generally see isobars??
Isobars measure the air pressure in the sky and our atmosphere! I hope I helped a little!
Yes they do. Scientists make maps with isobars on them.
Those lines are "isobars."
Isobars are lines that eqaul pressure isotherms are line that equal tempature
Closely spaced isobars mean stronger winds, as it indicates a tight pressure gradient.
pressure