D. Dethleff et al., THE LAPTEV SEA FLAW LEAD - DETAILED INVESTIGATION ON ICE FORMATION AND EXPORT DURING 1991 1992 WINTER SEASON/, Cold regions science and technology, 27(3), 1998, pp. 225-243
The main objective of this research paper is to estimate the new-ice p
roduction in the Laptev Sea flaw lead during the 1991/1992 winter seas
on. A one-dimensional energy balance model was applied to calculate oc
ean-to-atmosphere heat flux and the resulting new-ice formation over o
pen water. For a detailed estimate of regional ice production, the fla
w lead was divided into 14 sections based on the analysis of NOAA-sate
llite images and Russian ice charts. Opening and maintenance of the le
ad sections are controlled by offshore winds, whereas closing of open
water is caused by onshore winds. Since the orientation of the lead va
ries from section to section, the same regional wind forcing can cause
different local lead behavior. Model results reveal that the seasonal
ly accumulated thickness of new ice formed in the different lead secti
ons - under the assumption of instantaneous lateral new-ice removal fr
om the water surface - varies from 1.3 m to 13 m over temporarily open
water and may reach 20 m over permanently open water. The correspondi
ng ice volume produced in the sections varies between 3.4 km(3) and 59
km(3) and amounts to 258 km(3) for the entire lead. The significant r
egional variations in new-ice production are due to differences in (i)
the number of days that a lead section is open (open-lead days), (ii)
the oceanic heat loss during open-lead days, and (iii) the areal exte
nt of the lead sections. As compared to other studies, - at least duri
ng 1991/1992 winter season - the Laptev Sea flaw lead produced between
28 and 617% more initial sea ice than the Kara, Barents, East Siberia
n and Chukchi leads. Despite its limited areal extent of roughly 36,00
0 km(2), which represents only 8% of the entire Laptev Sea, the flaw l
ead produces about 32% of the annual shelf ice. The ice production in
the flaw lead is 5.3 times higher than the remainder of the shelf (7.4
m vs. 1.4 m). Furthermore, the Laptev Sea flaw lead produces 2.6% of
the ice annually formed the entire Arctic Mediterranean Sea and contri
butes about 9% to the volume of the Siberian branch of the Transpolar
Drift Ice System. This makes the Laptev Sea flaw lead a significant pr
oducer of Arctic sea ice on local and regional scales, whereas the con
tribution of lead ice to the entire volume of annually formed pack in
high northern latitudes amounts only to roughly 1.3%. (C) 1998 Elsevie
r Science B.V. All rights reserved.