See stage.

The value of atmospheric pressure to which the scale of a pressure altimeter is set so as to indicate airport elevation. The altimeter setting is included as part of an aviation weather observation.

A mercury barometer in which the lower mercury surface is larger in area than the upper surface. The basic construction of a cistern barometer is as follows: A glass tube one meter in length, sealed at one end is filled with mercury, and then inverted. Th ...

The difference between downward and upward (total) radiation; net flux of all radiation.

Moisture contained in the soil above the water table, including water vapor which is present in the soil pores. In some cases this term refers strictly to the humidity contained in the root zone of plants.

A colorless and odorless gaseous element. The lightest and apparently the most abundant chemical element in the universe. However, it is found only in trace quantities in the observable portion of our atmosphere, only about 0.00005 percent by volume of dr ...

An automatic, recording cloud height indicator.

A graphical representation of stage or discharge at a point on a stream as a function of time.

The meteorological visual range, which can be estimated from the average extinction coefficient using the Koschmieder equation.

See evaporation pan.

The rising of cold water from the deeper areas of the ocean to the surface. This phenomena often occurs along the California coast during the spring and summer.

A method of winds aloft observation in which the elevation and azimuth angles of a theodolite are read while visually tracking a pilot balloon. Balloon height data is estimated from assumed balloon ascension rates.

Any meteorological instrument, such as a radiosonde, in which the recording apparatus is located at some distance from the measuring apparatus.

An instrument which indicates the presence of dust particles in the atmosphere. Also spelled coniscope.

The effect upon the measurement of rainfall caused by the presence of the rain gauge.

Lacking a relationship to a time base or clock. In asynchronous communications, individual data characters are sent at an arbitrary rate.

A unit of pressure which directly expresses the force exerted by the atmosphere. Equal to 1000 dynes/cm2 or 100 pascals.

The outer, solid portion of the earth: the crust of the earth.

A type of rain gauge shield consisting of freely hanging, evenly spaced slats arranged circularly around the gauge. The advantage of this shield is that the slats do not easily accumulate snow, permitting its use on unattended gauges. See rain gauge shiel ...

Same as evaporative power.