THE LAPTEV SEA FLAW LEAD - DETAILED INVESTIGATION ON ICE FORMATION AND EXPORT DURING 1991 1992 WINTER SEASON/

Citation
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
Citations number
26
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Geosciences, Interdisciplinary",Engineering,"Environmental Sciences
Journal title
ISSN journal
0165-232X
Volume
27
Issue
3
Year of publication
1998
Pages
225 - 243
Database
ISI
SICI code
0165-232X(1998)27:3<225:TLSFL->2.0.ZU;2-G
Abstract
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.