The ratio of the amount of light reflected by a non-luminous body to the amount incident upon it. Some surfaces, for example clouds and snow, reflect back a lot of light and therefore have a high albedo. Forested areas absorb much more light and only reflect back a small amount. The overall albedo of the earth is about 0.3, or 30 percent, which means that 30 percent of the solar radiation is reflected back into space.
AYURVEDIC MEDICINE:
An ancient Hindu system of medicine, still very popular in India. The principles come from the Vedas, and involve diet and herbal remedies.
CASTELLANUS TURRETS:
A large cloud formation that appears like a mass of castle turrets when seen from the side.
CLIMATE:
The average weather conditions of a place or region throughout the seasons.
CORIOLIS EFFECT:
A result of the deflective force of the earth's west to east rotation. Winds, ocean currents and aircraft are deflected to the right of their direction of travel in the Northern Hemisphere and to the left in the Southern Hemisphere.
CUMULIFORM ANVIL:
A wedge-shaped cloud formed on the head of a large cumulonimbus cloud, which is flattened by winds at the lowest levels of the stratosphere - roughly, 20,000 feet.
CUMULONIMBUS:
A very heavy and dark cloud, characterized by extensive vertical development. The clouds are often around 17,000 feet in depth, and can take a typical anvil shape. They are classic thunderstorm clouds, which usually bring heavy rain, hail or snow.
CYCLONE:
A region of low atmospheric pressure, often referred to as a depression. Also, a region of extremely low atmospheric pressure, relatively small, but producing violent weather effects. Both types of cyclones are characterized by anti-clockwise wind circulation in the Northern Hemisphere and clockwise in the southern.
DESERT:
An almost barren tract of land in which precipitation is so scanty or spasmodic that it will not adequately support vegetation.
FLOODPLAIN:
Flat land on either side of a river that is periodically flooded. When the floodwaters recede, alluvial sediments are deposited that are rich in organic nutrients, creating fertile areas suitable for farming.
GEOTHERMAL HEATING:
Heat received from the earth's interior, usually from geysers and hot springs in the form of hot water and steam. Beneath the earth's crust is the mantle, which consists of molten rock (magma) that causes the crust to rise in temperature with an increase in depth.
ISOBARS:
A line on a map which joins places with equal atmospheric pressure. The pressure readings are first adjusted to sea level to ensure comparability in the horizontal.
ISOTHERMS:
A line on a map joining places having the same temperature at the same time, or having the same average temperature over a certain period.
JET STREAM:
A strong wind blowing within a narrow stream in the upper troposphere, usually at an altitude of between five and ten miles.
KINETIC ENERGY:
The energy an object has because of its motion. Kinetic energy can come from rotation about an axis, translation, vibration, or a combination of motions.
MASSIF:
A mountainous mass which breaks up into peaks toward the summit, and exhibits generally uniform characteristics. A well-known example is the Massif Central in France, and the largest example is the Himalayas.
MICRON:
Sometimes expressed as a micrometer: a very small unit of size equal to one millionth of a meter.
MILLIBAR:
A unit of atmospheric pressure; one thousand millibars equals 29.53 inches of mercury at 32 degrees Fahrenheit.
NIMBOSTRATUS:
A type of low cloud, usually dark grey in color, with an almost uniform base. It often brings continuous precipitation. A thick mass of nimbostratus is often associated with the front of a depression.
OROGRAPHIC RAIN:
Rain which is caused by mountains in the path of moisture-laden air. The air is forced to rise, and therefore cool. If there is sufficient water vapor present it will be deposited as rain on the high ground.
POTENTIAL ENERGY:
Stored energy that depends on the relative position of various parts of a system i.e. A spring has more potential energy when compressed or stretched. There are different kinds of potential energy; for example, chemical, electrical and gravitational. In the atmosphere it arises as a consequence of a body of air's position in the field of gravity.
PRECIPITATION:
The collective name for moisture, in either liquid or solid form, which falls to the earth from the atmosphere. It can, therefore, include not only rain, but dew, hail, sleet and snow.
SALINITY:
The degree of saltiness of oceans, seas, lakes and rivers, usually expressed in parts per thousand. The average salinity of sea-water is 35 parts per thousand.
SOLSTICE:
Either of the dates at which the sun is overhead farthest north or south of the equator each year. They occur in June and December respectively.
SPECIFIC HEAT CAPACITY:
The quantity of heat required to raise the temperature of a unit mass (2.21 lbs.) of a substance by one degree Centigrade.
SUMMER HEMISPHERE:
The half of the Earth experiencing the warmest season of the year. The Northern Hemisphere has summer from June to August, the Southern Hemisphere from December to February.
TOPOGRAPHIC MAP:
A map of sufficiently large scale to show the detailed surface features of an area, including its height above sea level, indicated by contour lines, and such physical features as roads, rail lines and rivers.
TROPICAL:
Of, or relating to, the region of the world that lies between the Tropic of Cancer (23.5 degrees north) and the Tropic of Capricorn (23.5 degrees south). Within this zone, the sun is directly overhead twice per year and is never very oblique to the earth. The weather is generally hot.
TROPOSPHERE:
The lower layers of the atmosphere extending from the surface of the earth to a height of seven to eight miles, where it meets the stratosphere. It is characterized by a decrease in temperature with a rise in height. Whereas, the stratosphere has a nearly constant temperature. The troposphere contains most of the earth's clouds and weather systems.
WINTER HEMISPHERE:
The half of the Earth experiencing the coldest season of the year. The Northern Hemisphere has winter from December to February, the Southern Hemisphere from June to August.
