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Stable ice formation - Frequency of occurrences

General description

Technical description

General description

Table name: Stable ice formation - Frequency of occurrences

This table is created from the Tbl_43.txt and Tbl_44.txt files as prepared by INSROP Project I.4.2 as part of INSROP Phase 2. The table records refer to the center point of the coastal ice regions included in the Tbl_39 shapefile set, which is a part of the dataset provided by INSROP Project I.4.2.

2.7 Dates of stable ice formation

The date after which the autumn ice formation occurs continuously is assumed to be the onset of stable ice formation.

The frequency of occurrence of the stable ice formation dates was calculated for the same 19 regions as for the final landfast ice breakup dates. As initial information, the charts of isochrones of annual stable ice formation dates for 1940-1985 were used based on visual airborne ice reconnaissance data. In addition, the ice charts based on satellite imagery over the period 1968-1994 were used, as well as data from polar stations.

The accuracy of determining the onset of stable ice formation comprises 1 day at polar stations and 2-3 days in the open sea.

Technical description

Table source file name: tbl_44.txt

Path: <NSR_DATA>\icesnow\i_4_2

Table type: DText table.

* Stable ice formation - Frequency of occurrences

19 records, 9 descriptive fields.

Fields: [<Name>] -- <Alias> (type of field)

[Region_no] -- "Region No." (Numeric, no decimals)

[Num_obs] -- "Number of Observations" (Numeric, no decimals)

[Aug_21_31] -- "August 21-31" (Numeric, no decimals)

[Sep_01_10] -- "September 01-10" (Numeric, no decimals)

[Sep_11_20] -- "September 11-20" (Numeric, no decimals)

[Sep_21_30] -- "September 21-30" (Numeric, no decimals)

[Jan_01_10] -- "January 1-10" (Numeric, no decimals)

[Jan_11_20] -- "January 11-20" (Numeric, no decimals)

[Jan_21_31] -- "January 21-31" (Numeric, no decimals)