Geoscience Reference
In-Depth Information
Figure 12.8
Hardware
components installed at a
typical SNOTEL site. (From
US National Atlas, 2011.)
inflated pliable pad put in place before snow was present (Fig. 12.8). The weight of
the snow is determined from the measured change in pressure in the snow pad,
and this and auxiliary information are then transferred by remote data capture
techniques to the centers responsible for monitoring snowpack. Such sites form
an already extensive and growing SNOTEL network in the USA. Although there
are issues with SNOTEL sensors related to the representativeness of the measure-
ments and associated with 'bridging' of snow influencing the measured pressure,
this technique has the advantage that sensors can be installed in remote locations
during the summer months when they are more accessible and then left to operate
with minimum supervision through the winter months.
Precipitation measurement using ground-based radar
In principle measuring precipitation using radar is simple. The approach involves
sending out a pulse of energy from a (usually revolving) dish and detecting the
'echo' or 'return' that is received from airborne hydrometeors such as rain, hail,
snow, etc. The time it takes for the echo to return allows the radar to determine the
