0
5 km
N
Piermont
45
23
44 00'
h
g f
1
P
W
A Apex Point
Z
j
L USA CRREL, Fixed Observation
e
O Orford Bridge
d
P Piermont Bridge
k
b
c
S Summit of N.H. Rte. 10
A
Clay
W Place of Most Frequent Least Temperature
a
Hollow
Z Fixed Observation Site
m
a-z Coordinating Points
Indian
1-5 Points of Specific Analysis
Pond
O
n
Orford
NEW
VERMONT
p
HAMPSHIRE
r
s
43 50'
Lyme
t
S
u
Observing Points
L
Hanover
River Plane Points
Figure 3 (cont'd).
43 40'
INSTRUMENTATION, OBSERVATIONS,
tion stations. We propose that an aspirated mov-
AND MEASUREMENT TECHNIQUES
ing probe is capable of making continuous near-
surface temperature measurements, which can be
It is extremely difficult to precisely measure
scaled to yield horizontal and vertical tempera-
ambient air temperature in near calm conditions
ture profiles.
over a snow surface as noted by Andreas (1986).
A diagram illustrating the technique for ana-
Aspiration of the sensor may disturb the stability
lyzing horizontal and vertical temperature gradi-
of the layer being measured, and the presence of
ents is shown on a cross section of a hypothetical
an observer or signal processing equipment may
small basin in Figure 4. The smoke from the house
disturb the heat budget of the sensitive volume.
chimney in the diagram flattens as an indication
The sensor must be radiationally shielded from
of temperature inversion at that elevation. A
both sky and snow, and because of the large tem-
series of temperature measurements along a
perature gradient above snow-covered ground,
transect of the basin A-B-C would produce the
the distance between the sensor and the snow
spatial variation in temperature shown below the
surface must be precisely maintained, without
cross section. Plotting the temperature as a func-
disturbing the surface in the vicinity of the sensor.
tion of measurement elevation would yield the
Maintenance of calibration, sensor height, and
vertical profiles AB and CB shown to the left of
surface integrity of 100 temperature sensors in
the diagram.
the area shown in Figure 3 would be a massive
All considerations of the data, and subsequent
undertaking. Additionally, access to all points of
analyses of the data sets or subsets, would have
interest might not be possible as the multiple own-
been first stratified by determining if the near
ers may not all be amenable to hosting observa-
surface air temperatures in the study area ap-
5
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