This shapefile was created from the routes-s file as prepared by INSROP
project I.5.8. The points included are the same as in the routes_c (see the I.5.8
folder in Ice and Snow category) shapefile set, which includes points defining 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.
A snowstorm is defined as an event where wind velocity is greater then 8 m/s,
air temperature is less than 0°C, and visibility as a result of snowstorm is
less than 2.5 km. Along coastal regions, the period of snowstorms is usually
October through May. In the northern regions this period is generally September
through June. Snowstorms are observed at the beginning of the winter (November,
December) when strong winds prevail and new snow can float in the air. Snow is
usually transported in the direction of prevailing wind flow. Mean annual number
of days with snowstorms is about 100-120 days in the Barents, Kara, and Chukchi
seas, and 60-80 days in the East Siberian and Laptev seas.
In winter, in the Bering, Kara, and Chukchi seas, snowstorms are present for
half of each month, but in some places this value reaches 17-20 days per month.
In the Laptev and East Siberian seas, the number of days with snowstorms ranges
from 3-6 per month, while in regions with orographic increasing of wind
velocities, 12-15 snowstorms occur per month (Tiksi, Ambarchik).
In the Barents Sea, frequency of snowstorms is 20-25% of the time with a
maximum in the vicinities of Novaya Zemlia, the Russkaia Gavan region, and at the
Karmakula station. Over the Kara Sea the frequency of snowstorms is 15-25% of
time of the cold season. The lowest number of snowstorms is observed in the north
and northeast part of the sea. Maximum frequency of snowstorms (20-25%) is
observed along the east coast of Novaya Zemlia, in the Karskie Vorota, at
Yugorskii Shar straits, at the west coast of Baidaratskaia Guba, north of the
Ob-Yenisey region, and at the Proliv Vilkitskogo strait. In the Laptev Sea, the
frequency of snowstorms in winter is 10-15% of time and increases to 20% of time
eastward from Vilkitskogo Strait.
In the East Siberian Sea, the frequency of snowstorms increases in the
southeast and at the Ambarchik (15-20%). The frequency of snowstorms ranges 5-10% of
time in the central part of the Laptev Sea and Chaunskaia Guba. In the Chukchi
Sea, the frequency of snowstorms is about 10-15%.
Mean durations of snowstorms in the Barents and Kara seas and northern Chukchi
Sea range from 900-1100 hours, while at the Ambarchik and Valkarkai stations
this value is about 800-900 hours. Over the East Siberian Sea and in the
southern Chukchi Sea, annual snowstorm duration ranges from 400 to 500 hours.
Probability of snowstorms is given only for the period from October through
April because this phenomenon occurs very rarely in summer.
Path: <NSR_DATA>\meteorol\i_5_8
GeoDataset type: Shapefile with Point features.
Coordinate system: Latitude/longitude in decimal degrees
Label field: Point
* Probability of snowstorms
335 Points, 9 descriptive fields.
Fields: [<Name>] -- <Alias> (type of field)
[No] -- "No" (Numeric, no decimals)
Point number
[Point] -- "Point" (String, max. 5 characters)
Point identifier
[October] -- "October" (Numeric, no decimals)
[November] -- "November" (Numeric, no decimals)
[December] -- "December" (Numeric, no decimals)
[January] -- "January" (Numeric, no decimals)
[February] -- "February" (Numeric, no decimals)
[March] -- "March" (Numeric, no decimals)
[April] -- "April" (Numeric, no decimals)
Probability of snowstorms