Meteorology Quiz 5 Review

Aneroid

A pressure-sensitive altimeter used in aircraft to measure altitude is a(n) ____ barometer.

10

According to the Standard Atmosphere, on average 25% of the atmosphere's mass (25% of presser is found above an altitude of approximately ______ km., or, stating it another way, 75% of the atmosphere's mass is found below that altitude.

1.0

Air pressure is equal to the total weight of a vertical column of air with a unit cross-sectional area extending from the place of measurement to the top of the atmosphere. Air pressure at sea level is approximately 14.7 pounds per square inch or approximately _____ kilograms per square centimeter.

29.92

Air pressure is reported un a variety of units. The air pressure unit most commonly reported to the public is based on the height of a column of mercury which exerts at its base the same pressure as the atmosphere at that place. This pressure measurement technique is adequate for many purposes because the height of the mercury column is directly proportional to air pressure. The acreage (standard) sea-level atmospheric pressure is ______ inches of mercury. This is equivalent to 76 cm or 760 mm of mercury.

Cools

Ascending, unsaturated air ______ at the rate of 9.8 celsius per 1000 m.

Equal

Avogadro's Law states that equal volumes of gases (or gas mixtures) measured under the same conditions of temperature and pressure contain ______ number of molecules.

5.5

Because air pressure is determined by the weight of the overlying air, knowing air pressure valves at sea level and at different altitudes makes it possible to determine the amount to atmosphere (by mass) that is above and below a particular altitude. For example, acreage sea-level air presser is approximately 1000 mb. At the altitude where the pressure is 500 mb, Half of the mass of an atmospheric column would be below and half above. From the Standard Atmosphere Table, this occurs at an average altitude of about ______ km above sea level.

Altitude

By employing this sea-level correction, surface weather maps are thus constant ____ maps.

1013.25

In the United States , meteorologists currently use the millibar (mb) unit as the standard unit of air pressure (equal to a hectoPascal). Standard sea-level air pressure is ______ mb.

Fall

Surface air pressure will _______ in regions where less air converges at the surface than ascends.

All of these

The ideal gas law us a relationship between

0

To compare air pressures from place to place on the Earth's surface, a reduction-to-sea-level adjustment is made. Consequently, on a surface weather map the assumption is made for purposes of air pressure analysis all stations are located at an altitude of _____ m above sea level.

Lower

Water vapor molecules have less mass than air "molecules." As a result, surface air pressure in a humid air mass would be _____ than that in a dry air mass if their temperatures and other characteristics are the same.

Expansional Cooling

When a volume of gas expands due to decreasing surroundings pressure the volume undergoes.

More

With an increase in altitude, air pressure decreases ____ rapidly in cold air than in warm air.