Geoscience Reference
In-Depth Information
SH = 17.3g/kg
RH = 100%
Dew point = 20°C (68°F)
SH = 9.4g/kg
RH = 54%
Dew point = 10°C (50°F)
Air mass
Air mass
(a) Air mass temperature = 20°C (68°F); MH = 17.3 g/kg
(b) Air mass temperature = 20°C (68°F); MH = 17.3 g/kg
SH = 13.4g/kg
RH = 78%
Dew point = 16°C (61°F)
SH = 9.4g/kg
RH = 74%
Dew point = 10°C (50°F)
Air mass
Air mass
Evaporation
(c) Air mass temperature = 20°C (68°F); MH = 17.3 g/kg
(d) Air mass temperature = 15°C (59°F); MH = 12.83 g/kg
Figure 7.12 Humidity examples.
(a) Hypothetical air mass with air temperature of 20°C (68°F) and relative humidity of 100%.
(b) Same air mass, now with a relative humidity of 54%. (c) Same air mass, but now with increased relative humidity due to higher
specific humidity. (d) Same air mass with a cooled air temperature of 15°C (59°F) and relative humidity of 74%.
Atmospheric Humidity
Although the concept of humidity is fundamentally a simple one,
students often have difficulty with it because the terms can seem
to be interchangeable. Another problem is that it is sometimes
hard to understand these processes when we are simply reading
about them. Like many concepts in physical geography, humidity
is particularly well suited for simulation to enhance understand-
ing. In this context, go to the
Geo Media Library
and select
Atmospheric Humidity
. This simulation is designed so that
you can interact with the concept of humidity and assess how
it varies depending on environmental circumstances. You will be
presented with a variety of scenarios in which you can manipu-
late the amount of maximum humidity and specific humidity in
a hypothetical air mass so that changes in the relative humidity
and dew-point temperature occur. As you work your way through
these scenarios, remember that they are representative of an al-
most infinite number of combinations. When you complete the
simulation, be sure to answer the questions at the end to test
your understanding of this important concept.
