G - I

G

Geostrophic wind A theoretical horizontal wind blowing in a straight path, parallel to the isobars or contours, at a constant speed. The geostrophic wind results when the Coriolis force exactly balances the horizontal pressure gradient force.

Glaciation The conversion of all the supercooled liquid water in a cloud into ice crystals, thus reducing the growth rate of ice crystals and hail.

Glaciated cloud A cloud or portion of a cloud where only ice crystals exist.
Guild A group of species belonging to a trophic level which consumes a common resource base in a similar fashion is known as Guild.
Example- Nector feeding birds form a Guild

H

Hail Solid precipitation in the form of chunks or balls of ice with diameters greater than 5 mm. The stones fall from cumulonimbus clouds.

Hailstones Transparent or partially opaque particles of ice that range in size from that of a pea to that of golf balls.

Hair hygrometer An instrument used to monitor relative humidity by measuring the changes in the length of human hair that accompany humidity variations.

Haze Fine dry or wet dust or salt particles dispersed through a portion of the atmosphere. Individually these are not visible but cumulatively they will diminish visibility.

Heat capacity The ratio of the heat absorbed (or released) by a system to the corresponding temperature rise (or fall).

Heterosphere The atmosphere above 80 km (50 mi) where gases are stratified, with concentrations of the heavier gases decreasing more rapidly with altitude than concentrations of the lighter gases.

Homosphere The atmosphere up to 80 km (50 mi) in which the proportionality of principal gaseous constituents, such as oxygen and nitrogen, is constant.

Hurricane A severe tropical cyclone having winds in excess of 64 knots (74 mi/hr).

Hydrograph An instrument that provides a continuous trace of relative humidity with time.

Hygrometer An instrument designed to measure the air's water vapor content. The sensing part of the instrument can be hair (hair hygrometer), a plate coated with carbon (electrical hygrometer), or an infrared sensor (infrared hygrometer).

Hypothermia The deterioration in one's mental and physical condition brought on by a rapid lowering of human body temperature. 

I 

Insolation The incoming solar radiation that reaches the earth and the atmosphere.

Intertropical convergence zone (ITCZ) The boundary zone separating the northeast trade winds of the Northern Hemisphere from the southeast trade winds of the Southern Hemisphere.

Inversion An increase in air temperature with height.

Ion An electrically charged atom, molecule, or particle.

Ionosphere An electrified region of the upper atmosphere where fairly large concentrations of ions and free electrons exist.

Isobar A line connecting points of equal pressure

Isotach A line connecting points of equal wind speed.

Isotherm A line connecting points of equal wind temperature.