Clouds which cover between 6/10 and 9/10 of the sky. See Sky Terminology.

A recording anemoclinometer.

Temperature to which absolutely dry air would have to be brought in order for it to have the same density as moist air, considered at the same pressure.

Balance of the water resources of a region, comparing precipitation and inflow with outflow, evaporation, and accumulation.

A type of precipitation composed of unbranched crystals in the form of needles, columns, or plates. Usually has a very slight downward motion and may fall from a cloudless sky.

In radiometry, a measure of the intrinsic radiant intensity emitted by a radiator in a given direction.

The addition of one or more redundant bits to information to verify its accuracy.

See feed.

Companion to the wet-bulb thermometer in a psychrometer. Used to measure ambient air temperature.

Read Only Memory. A memory that cannot be altered in normal use of a computer, Usually used to store information permanently, such as firmware programs.

A direct-vision nephoscope constructed in the following manner: A grid-work of bars is mounted horizontally on the end of a vertical column and made free to rotate about the vertical axis. The observer rotates the grid and adjusts his or her position unti ...

See calorie.

A subtle, diumal component of the wind velocity leading to a diumal shift of the wind or turning of the wind with the sun, produced bv the east-to-west progression of daytime surface heating.

The statement that the viscosity of air is independent of the density of air.

The sum of solar and terrestrial radiation.

An inert gas. A colorless, monatomic element which is found to occur in dry air to the extent of only 0.000524 percent by volume. Helium is very light, having a molecular weight of only 4.003 and specific gravity referred to air of 0.138. Because helium i ...

Same as dew-point hygrometer.

Eluding precise prediction, completely irregular.

A component of the wind (often using Cartesian coordinates. i.e. X and Y wind vectors). Also, an arrow representing wind velocity, drawn to point in the direction of the wind and with a length proportional to wind speed.

Wind with a speed between 7 and 10 knots (8 and 12 mph), Beaufort scale number 3.