These tables were prepared by INSROP Project I.4.2 as part of INSROP Phase 2.
These table records refer to the center points of polynyas, as included in the
Tbl_37 shapefile set, which is a part of the dataset provided by INSROP Project
I.4.2.
Dimensions of major polynyas
The polynyas include areas of open water and young ice up to 30 cm thick, as
well as zones of very open and open ice with not more than 5 tenths
concentration located between the landfast ice boundary and close drifting ice floes. The
use of polynyas for shipping depends on their temporary stability, which is
estimated by the frequency of occurrence of polynyas (the percentage ratio of the
cases with the presence of polynyas to the total number of observations in the
region). At the frequency of occurrence of more than 75% the polynyas are
considered as recurring polynyas, 50-74% as stable and less than 50% - occasional.
Figure 2.1 schematically outlines the location of the regions of polynya
formation.
During the pre-satellite period, observations of polynyas were carried out
occasionally and belonged predominantly to the period of the maximum development
of landfast ice (March-May). Satellite obsevations allowed regular tracing of
the development of polynyas from the landfast ice formation to the onset of
spring-summer melting. That is why the tables contain data obtained from satellite
imagery.
For polynya characteristics (length average width), the ice charts of the
scale of 1:5000000 were used.
The statistical characteristics of 18 polynyas were determined from satellite
data for the second 10-day period of each month from November to June (11, 12,
1, ... , 6) over the period 1978-1995.
The polynya formation regions included are:
1 - Northern Novozemelskaya
2 - Southern Novozemelskaya
3 - Amderminskaya
4 - Yamalskaya
5 - Ob'-Yeniseyskaya
6 - Central Kara
7 - Western Severozemelskaya
8 - Eastern Severozemelskaya
9 - Northeastern Taimyrskaya
10 - Eastern Taimyrskaya
11 - Anabaro-Lenskya
12 - Western Novosibirskaya
13 - Northern Novosibirskaya
14 - Eastern Novosibirskaya (west)
15 - Eastern Novosibirskaya (east)
16 - Aionskaya
17 - Western Chukotskaya
18 - Eastern Chukotskaya.
Path: <NSR_DATA>\icesnow\i_4_2
Table type: DText table.
* Polynya data
144 records, 10 descriptive fields.
Fields: [<Name>] -- <Alias> (type of field)
[Month] -- "Month" (Numeric, no decimals)
[No] -- "Polynya No." (Numeric, no decimals)
[Numyears] -- "Number of observation years" (Numeric, no decimals)
[Freqocc] -- "Frequency of occurrence of polynya (%)" (Numeric, 1 decimal)
[Len_avg_km] -- "Average length (km)" (Numeric, no decimals)
[Len_max_km] -- "Maximum length (km)" (Numeric, no decimals)
[Len_min_km] -- "Minimum length (km)" (Numeric, no decimals)
[Wid_avg_km] -- "Average width (km)" (Numeric, no decimals)
[Wid_max_km] -- "Maximum width (km)" (Numeric, no decimals)
[Wid_min_km] -- "Minimum width (km)" (Numeric, no decimals)
Polynya data