What is a dew point, a isobar, and a relative humidity.?

Question

What is a dew point, a isobar, and a relative humidity.?

Answer 1

The dew point is the temperature at which air is completely saturated. This can be achieved by rising air, nighttime radiational cooling, or advection.

An isobar is a line of equal pressure on a weather map. These are good for locating low and high pressure centers as well as areas of steep pressure gradient.

Relative humidity is a percentage of the amount of water vapor in a parcel of air. Relative humidity is calculated by the ratio of vapor pressure and saturation vapor pressure multiplied by 100. Vapor pressure is the measure of the water content in the air. Saturation vapor pressure is the maximum water vapor capacity of the air.

Answer 2

Dew point is the temperature at which precipitation falls.

Isobars are lines on a weather map that show air pressure.

Relative humidity is the amount of water vapor in the atmosphere and it's measured in percent. The higher it is, the more clouds are in the sky and the higher the chance of precipitation.

Answer 3

Dew point temperature is the temperature to which a parcel of air must be cooled adiabatically to reach saturation.  An isobar is a line of constant pressure.  Relative humidity is the ratio of the vapor pressure to the saturation vapor pressure with respect to water.

Answer 4

Dew point is the temperature at which air has to be cooled at a current pressure to condense into water. Isobars are lines on a weather map that show areas of equal pressure. if it is 1005 mb in LA, 1005 in SF, and 1004 in Boston, SF and LA would be linked by an isobar and boston wouldn't. Relative humidity is the amount of water vapor that exists in a gaseous mixture of air and water. The formula is

                          RH=pp/svp

pp=Partial pressure (look up on weather charts on the internet)

svp=Saturation vapor pressure of water at the temperature of the air (look table up on internet)

The tables for pp and svp use temperature; before finding the relative humidity, you must know the temperature of the air.