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Surface wind direction for route S by year and month

General description

Technical description

General description

Table name: Surface wind direction for route S by year and month

This table was prepared by Work Package 2 (Box B) as part of INSROP Phase 2 (See Working Paper no. 121). The table includes Year, Month and a number of fields with numeric names. These numbers refer to ship route segments included in the Tbl_1 shapefile set, which is a part of the dataset provided by INSROP Project I.4.2. These segments are an extract of the ship routes as defined in INSROP Working paper no. 108 (1998), prepared by Work Package 1 (Box B) as part of INSROP Phase 2.

The calculation of surface wind direction is based on the standard methods. As initial information, the archive of surface atmospheric pressure fields at synoptic times for the 1964 to 1994 period available at the AARI was used (deltaPhi = 5°, deltaLambda = 10°)

The calculation of surface wind along the sub-segments of the selected routes included 5 stages.

1. Interpolation of atmospheric pressure from the geographical grid points to the rectangular grid points. For this purpose a method of finite elements for tetragonal complex elements was used (Segerlind, 1979). Surface atmospheric pressure was interpolated to the points of the grid covering the Arctic Ocean area (a step deltaX = deltaY =30 miles, the X axis is parallel to meridian 40°, the Y axis is parallel to meridian 130°).

2. Calculation of surface wind components at the rectangular grid points. Standard methods are used (Dynamic meteorology, 1976). The surface wind components are calculated by geostrophic wind using the empirical ratios (Ashik, 1995).

3. Averaging the surface wind components over a monthly period.

4. Interpolation of surface wind components to the middles of sub-segments. Similar to Item 1.

5. Calculation of the resulting surface wind direction.

The direction of the resulting wind relative to meridian of the location was determined from the means of surface wind components over a monthly period.

Technical description

Table source file name: p10_s.txt

Path: <NSR_DATA>\meteorol\workpackage2

Table type: DText table.

* Surface wind direction for route S by year and month

396 records, 144 descriptive fields.

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

[Year] -- "Year" (Numeric, no decimals)

[Month] -- "Month" (Numeric, no decimals)

[1] -- "1" (Numeric, no decimals)

...

[142] -- "142" (Numeric, no decimals)