42
Fig.2. A Radiation balance and
B energy balance over a firstyear snow-covered sea ice surface during periods in which
net radiation was on average
negative (early) and positive
(late) over the diurnal cycle.
Fluxes are representative of
pre-melt and the initial stages
of snow melt during the spring
transition of SIMMS '92
B
><
OJ
u::
><
~
u..
80
60
40
20
0
-20
-40
-60
30
20
10
0
-10
-20
-30
D.G. BARBER, A. THOMAS, AND T.N. PAPAKYRIAKOU
Q*ss
K +
Q"
Qabs 0:<
Q<
L*
QH
QE
~
~
[EltailYl
~
the upper sea ice surface, with secondary contributions through conductive heating at
the snow surface, Q, (Fig. 2B).
Later in the season we observe increased variability in each of the flux terms. The net
radiative flux for the snow-sea ice-ocean volume is positive, but the radiation balance
at the snow surface, Q* ,s> remains negative owing to the transmission of the solar radiation beyond the volume's near surface. Radiation absorbed within the snow volume is
comparable in magnitude with Q*. The surface volume is more strongly coupled to the
atmosphere, as turbulent losses to the atmosphere represent the major energy sink.
Energy losses are predominantly offset by ice production within the snow volume, as
conductive heating diminishes in response to the narrowing difference in temperature
between the atmosphere and ice surface.
3.2.3
Microwave Scattering
Recent research results (Drinkwater 1989; Winebrenner et al. 1994; Kwok and Cunningham 1994; Barber et al.1994; Barber et al.1995; and others) have shown that a distinct pattern exists for the seasonal evolution of the microwave scattering coefficient
(}"o over various sea ice types. Although these patterns are undoubtedly frequency- and
polarization-dependent it would appear that the C-VV manifestation for snow-covered
Fig.2. A Radiation balance and
B energy balance over a firstyear snow-covered sea ice surface during periods in which
net radiation was on average
negative (early) and positive
(late) over the diurnal cycle.
Fluxes are representative of
pre-melt and the initial stages
of snow melt during the spring
transition of SIMMS '92
B
><
OJ
u::
><
~
u..
80
60
40
20
0
-20
-40
-60
30
20
10
0
-10
-20
-30
D.G. BARBER, A. THOMAS, AND T.N. PAPAKYRIAKOU
Q*ss
K +
Q"
Qabs 0:<
Q<
L*
QH
QE
~
~
[EltailYl
~
the upper sea ice surface, with secondary contributions through conductive heating at
the snow surface, Q, (Fig. 2B).
Later in the season we observe increased variability in each of the flux terms. The net
radiative flux for the snow-sea ice-ocean volume is positive, but the radiation balance
at the snow surface, Q* ,s> remains negative owing to the transmission of the solar radiation beyond the volume's near surface. Radiation absorbed within the snow volume is
comparable in magnitude with Q*. The surface volume is more strongly coupled to the
atmosphere, as turbulent losses to the atmosphere represent the major energy sink.
Energy losses are predominantly offset by ice production within the snow volume, as
conductive heating diminishes in response to the narrowing difference in temperature
between the atmosphere and ice surface.
3.2.3
Microwave Scattering
Recent research results (Drinkwater 1989; Winebrenner et al. 1994; Kwok and Cunningham 1994; Barber et al.1994; Barber et al.1995; and others) have shown that a distinct pattern exists for the seasonal evolution of the microwave scattering coefficient
(}"o over various sea ice types. Although these patterns are undoubtedly frequency- and
polarization-dependent it would appear that the C-VV manifestation for snow-covered