Tau-value

From Glossary of Meteorology



tau-value

The time rate of changes of D-values at a fixed point defined by relation,
ams2001glos-Te4
where Δt is the change in time and ΔtD is the change in D-value during this time interval.

Tau-values are expressed in terms of feet per hour. Tau-value lines are drawn on 4D charts and compose the time dimension of these charts.


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