- AVHRR: The Advanced Very High Resolution
Radiometer is a five channel radiometer flown on the polar orbiting
satellites. The visible and infrared detectors are primarily used
to study cloud cover and surface properties such as temperature
and vegetation cover.
- Conduction: The transfer of heat
during collisions among molecules. Heat is transferred from warm
objects to cold ones, the rate is proportional to their temperature
difference and their heat conductivity.
- Convection: The transfer of heat
by large movements of a gas or liquid.
- Electromagnetic Energy: Energy that is propagated by
electric and magnetic fields. Matter is not required to transfer of this
type of energy known also as radiant energy.
- Evaporative Cooling: Energy is required
to change the phase of water from a liquid to a vapor, which results
in a cooling of the surrounding environment.
- GOES: Geostationary Operational Environmental
- GOES 8: NOAA's geostationary satellite
launched in April 1994. GOES 8 is part of a series of new geostationary
satellites designed to improve weather forecasts and severe weather
warnings and watches.
- Heat Capacity: The ratio of the
amount of heat energy absorbed to the substance's temperature
- Heat Conductivity: Describes
a material's ability to transfer heat via conduction.
- Infrared Radiation: Electromagnetic radiation
with a wavelength between 3.5 and 500 microns. Remote-sensing
instruments work by measuring the radiation emitted by objects
in this spectral bandpass.
- Isobar: A line on a weather map joining
places of equal barometric pressure.
- Land Breeze: A surface wind blowing
from the land toward the sea during the night.
- Millibar (mb): A common unit used for measuring
atmospheric pressure. The average sea level pressure is approximately
1013 mb, or 29.92 inches of mercury.
- Pressure Gradient: The rate of change of
pressure over a horizontal distance.
- Pressure Gradient Force: A force due to
differences in pressure over some horizontal distance. It acts
from high to low pressure and is directly proportional to the
- Sea Breeze: A surface wind blowing
from the sea towards the land, usually during the day.
- Specific Heat: The amount of heat
needed to warm 1 gram of a substance 1C at sea-level pressure.
- Stratosphere: A region of the atmosphere
that lies between the troposphere and mesosphere. The lapse rate of
the stratosphere is stable, meaning the temperature is constant with altitude
or increases with altitude. The top of the stratosphere is
marked by the stratopause and the bottom by the tropopause. The majority of
atmospheric ozone is formed in the stratosphere.
- Synoptic Scale Circulation: Weather phenomena whose spatial scale is
similar in size to continents and oceans. Examples include fronts, cyclones and anticylones.
- Thermal Low: An area of low pressure
created by large surface heating.
- Thermal Circulation: A local or regional circulation system that
develops due to pressure gradients created by differences in surface heating.
- Troposphere: The lowest 10 to 20 km of the atmosphere.
The top of the troposphere, the tropopause, is characterized by a rapid change in the
- UV: Ultraviolet radiation with a wavelength
ranging between 0.2 and 0.4 microns.
- Urban Heat Island: Terminology
used to describe the fact that city temperatures are often warmer
that the surrounding region.
- Vapor Pressure: The partial pressure exerted by water vapor.
- Wavelength: The distance between
two consecutive crests, or troughs, of a wave.