dewpoint_from_specific_humidity
- dewpoint_from_specific_humidity(q[, p])
Computes the dewpoint temperature from the given specific humidity (
q
) and pressure (p
).- Parameters
- Return type
same type as
q
or None
The result is the dewpoint temperature in K units. On error None is returned. The following rules are applied when
q
is aFieldset
:if
q
is a pressure levelFieldset
nop
is neededif
q
is defined on ECMWF model levels (hybrid/eta)p
must be either a single LNSP (logarithm of surface pressure, identified by paramId=152) field or aFieldset
defining the pressure on the same levels asq
for other level types
p
must be aFieldset
defining the pressure on the same levels asq
.
The computation is based on the following equation:
\[e(q, p) = e_{wsat}(td)\]- where:
e is the vapour pressure (see
vapour_pressure()
)ewsat is the saturation vapour pressure over water (see
saturation_vapour_pressure()
)td is the dewpoint temperature