4. DATES OF LAND FAST ICE BREAKUP IN THE STRAITS.
This description below is based on the original one from AARI (See Expl.doc).
The source tables referred to are included in the Data_4.xls spreadsheet in the
\INSROP_GIS\Sourcedata\AARI-SOF 1996\tables folder.
A brief description of initial data.
The land fast ice was never formed in Long and Kara Gate straits during all
observations years. Hence data are transferred only for Sannikov and Vilkitsky
straits. The date of the final fast ice breakup corresponds to the instant when
fast ice over the entire strait area disintegrates into drifting ice floes.
Narrow fast ice strips along the shores of the straits are not taken into account.
For determining the dates of fast ice breakup, the charts of ice distribution
obtained from data of visual airborne observations for the period 1940-1985 and
satellite images for the period 1986-1994 were used. The error in determining
the date of fast ice breakup is, on average, 1-3 days.
A brief description of the processing/analysis method.
The series of the dates of fast ice breakup were obtained by analysing the ice
charts and satellite images. Based on these data, mean dates, standard
deviations, the occurrence frequency of 5-day intervals were calculated and the
earliest and the latest dates were selected.
A brief description of the data transferred.
The calculation results are transferred in the form of two ASCII files
(tbl_7.txt and tbl_8.txt), containing Tables 7 and 8.
Table 7 consists of the records including the following fields: No. of the
strait; name of the strait; mean date of the final fast ice breakup; standard
deviation; the earliest date; the latest date. Table 8 consists of the records
including the following fields: No. of the strait; the lower limit of the range (of
the dates of final fast ice breakup); the upper limit of the range; the number
of the cases within the range; the occurrence frequency of the range in
percentage expression. For recording the dates, the format dd.mm is used.
Path: <NSR_DATA>\icesnow\aari_sof
Table type: dBASE table.
* Dates of Fast ice breakup in straits
15 records, 6 descriptive fields.
Fields: [<Name>] -- <Alias> (type of field)
[Dates_id] -- "Dates_id" (Numeric, no decimals)
ID# of Date range
[Date_range] -- "Date range" (String, max. 13 characters)
Date range
[N_1] -- "No. of obs., Sannikov Strait" (Numeric, no decimals)
No. of observations, Sannikov Strait
[Fr__1] -- "Freq. of occurrence (%), Sannikov Strait" (Numeric, no decimals)
Percentage of observations, Sannikov Strait
[N_2] -- "No. of obs., Vilkitsky Strait" (Numeric, no decimals)
No. of observations, Vilkitsky Strait
[Fr__2] -- "Freq. of occurrence (%), Vilkitsky Strait" (Numeric, no decimals)
Percentage of observations, Vilkitsky Strait
Dates of Fast ice breakup in straits