A remote indicator for wind speed and direction used in conjunction with a contact anemometer and a wind vane. The indicator consists of a center light, connected to the contact anemometer, surrounded by eight equally spaced lights which are individually ...

The atmospheric pressure at mean sea level either directly measured by stations at sea level or empirically determined from the station pressure and temperature by stations not at sea level. Used as a common reference for analyses of surface pressure patt ...

A weakly colored lunar halo identical in form and optical origin to the solar parhelion.

Same as instrument shelter.

A method of streamflow routing which assumes that storage is a linear function of the weighted flow in the reach and is adaptable to a simple mathematical solution.

Barometer in which pressure is determined by balancing air pressure against the weight of a column of mercury in an evacuated glass tube.

An evaporation pan in which the evaporation is measured from water in a pan floating in a larger body of water.

The wind speed and direction at various levels in the atmosphere above the level reached by surface weather observations.

The study of waters (including oceans, lakes, and rivers) embracing either: (a) their physical characteristics, from the standpoint of the oceanographer or limnologist; or (b) the elements affecting safe navigation, from the point of view of the mariner. ...

A mercury barometer of the fixed cistern type in which a moveable scale terminating in an ivory point is used to compensate for the variations in the height of the mercury in the cistern

Root Mean Square. This notation is used frequently with error analysis. In that context, it is the square root of the arithmetic mean of the squares of the deviations of the individual calibration points from the theoretical or ideal response.

An anemometer which derives wind speed from measurements of dynamic wind pressures. Wind blowing into a tube develops a pressure greater than the static pressure, while wind blowing across a tube develops a pressure less than the static. This pressure dif ...

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

An instrument for measuring the pressure of the atmosphere. The two principle types are aneroid and mercurial.

Of or pertaining to rain.

A unit of power equal to one joule per second or 10' ergs per second.

A wind scale adapted by the U.S. Forest Service for use in the forested areas of the northern Rocky Mountains (NRM). It is an adaptation of the Beaufort wind scale. The difference between these two scales lies in the specification of the visual effects of ...

A line drawn through geographical points having the same pluvial index.

An instrument for the measurement of the radon content of the atmosphere.

The minimum temperature shown by a minimum thermometer exposed in an open situation with its bulb at the level of the tops of the grass blades of short turf.