Lamb weather types (reduced set) and gale days over the North Sea since 1948 based on NCEP/NCAR Reanalysis 1 daily mean sea level pressure fields

Sea level pressure is a fundamental weather and climate element and the very basis of everyday weather maps. Daily sea level pressure distributions provide information on the influence of high and low pressure systems, air flow, weather activity, and, hence, synoptic conditions.


Using sea level pressure distributions from the NCEP/NCAR Reanalysis 1 (Kalnay et al., 1996) and a simplified variant of the weather-typing scheme by Jenkinson and Collison (1977) atmospheric circulation over the North Sea has been classified as to pattern and intensity on a daily basis starting in 1948. A full account of the original weather-typing scheme can be found in Loewe et al. (2005), while the variant scheme has been detailed in Loewe et al. (2006). The analysis has been carried out on the original 16-point grid. Though formally valid at its central point (55°N, 5°E), results are representative of the North Sea region between 50°N-60°N and 0°E-10°E.


The modified scheme allows for six weather types, namely four directional (NE=Northeast, SE, SW, NW) and two rotational types (C=cyclonic and A=anticyclonic). The strength of the atmospheric circulation is classified by way of a peak-over-threshold technique, employing re-calibrated thresholds for the gale index G* of 28.3, 36.6, and 44.6 hPa for gale (G), severe gale (SG), and very severe gale (VSG), respectively (Loewe et al., 2013). Technically, the set of weather-typing and gale-classification rules is implemented as a lean FORTRAN code (lwtnssim.f), internally known as "Simple Lamb weather-typing scheme for the North Sea v1". The processing run was done on a Linux server under Debian 10 (Buster).


Both, weather types and gale days, form a catalogue of more than 70 annual calendars since 1948 that is presented and continuously updated to the present day at https://www.bsh.de/EN/DATA/Climate-and-Sea/Weather-and-Gales/weather-and-gales_node.html . This catalogue concisely documents synoptic conditions in the North Sea region. Possible benefits are manifold. Special events and episodes in regional-scale atmospheric circulation are easily looked up and traced. Beyond that, the dataset is well suited for frequency, trend, persistence, transition, and extreme-value statistics.

INSPIRE

Identification

File identifier
de.dkrz.wdcc.iso3893192 XML
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Series
Online resource
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None
Metadata language
English
Encoding
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NetCDF
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network Common Data Format
Projection
 

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Coupled resource

Coupled resource
 
 

Classification of data and services

Coupled resource

Coupled resource
 
 

Keywords

Other keywords

Theme

  • NCEP
Theme

  • re-analysis
Theme

  • Baltic Sea
Theme

  • North Sea
Theme

  • gale
Theme

  • ATMODAT (v3.0)
Theme

  • weather types
Theme

  • atmos
Theme

  • Meteorology and atmospheric sciences
 
 

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Date (Creation)
2022-02-07
 

Conformity

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Conformity
 

Conformity

Conformity
Conformity
 

Responsible organization (s)

Contact for the resource
Organisation name

Bundesamt für Seeschifffahrt und Hydrographie
Organisation name

Bundesamt für Seeschifffahrt und Hydrographie
Organisation name

Bundesamt für Seeschifffahrt und Hydrographie
Organisation name

Bundesamt für Seeschifffahrt und Hydrographie
 

Responsible organization (s)

Contact for the resource
Organisation name

Bundesamt für Seeschifffahrt und Hydrographie
Organisation name

Bundesamt für Seeschifffahrt und Hydrographie
Organisation name

Bundesamt für Seeschifffahrt und Hydrographie
Organisation name

Bundesamt für Seeschifffahrt und Hydrographie
 

Metadata information

Contact for the metadata
Organisation name

Bundesamt für Seeschifffahrt und Hydrographie
Organisation name

Bundesamt für Seeschifffahrt und Hydrographie
Organisation name

Bundesamt für Seeschifffahrt und Hydrographie
Organisation name

Bundesamt für Seeschifffahrt und Hydrographie
Organisation name

Bundesamt für Seeschifffahrt und Hydrographie
Date stamp
2022-02-18T04:25:23
 
 

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Conformance class 1: invocable

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Conformance class 2: interoperable

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Limitation
 

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Spatial extent

N
S
E
W
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Keywords

ATMODAT (v3.0) Baltic Sea Meteorology and atmospheric sciences NCEP North Sea atmos gale re-analysis weather types

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