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The development of Lamb weather types: from subjective analysis of weather charts to objective approaches using reanalyses
Author(s) -
Jones Phil D.,
Osborn Tim J.,
Harpham Colin,
Briffa Keith R.
Publication year - 2014
Publication title -
weather
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.467
H-Index - 40
eISSN - 1477-8696
pISSN - 0043-1656
DOI - 10.1002/wea.2255
Subject(s) - meteorology , environmental science , climatology , geography , geology
We provide a brief review of the history of daily weather-type analyses for the British Isles. This review is necessarily focused on the pioneering work of Hubert Lamb and points to later and continuing work that he fostered in this area. Hubert Lamb’s first mention of weather types in the context of the British Isles can be found in Lamb (1950). In this extensive paper, he reviews various schemes used to characterise atmospheric circulation dating back to the nineteenth century, including that from Germany, which became the pan-European scheme we know today as Grosswetterlagen (GWL, Hess and Brezowsky, 1969). Lamb lays out the basic classification of his subsequent weather-type catalogue that built on the earlier work of Levick (1949; 1950) for the years from 1898 to 1947 across the British Isles, and discusses the annual and seasonal frequency of the types, spells and singularities of the weather throughout the year. The study of singularities (the occurrence of similar weather patterns at the same time each year) arose out of research that was intended to assist in long-range forecasting studies (see background to weather typing in Kelly et al., 1997). However, work on singularities has fallen out of favour in recent years. During the 1960s, Lamb (1972a) produced the final version of his British Isles weather-type catalogue beginning in the year 1861 (henceforth referred to as Lamb weather types, LWTs). He kept this catalogue up to date until his death in 1997. Lamb (1991) additionally classified a consistent analysis by always using the 1200 UTC chart, centring this version on the civil day. The series from 1871 to the present day is used in this short paper, together with the original catalogue developed by Lamb (1972a) and the first objective analysis (Jones et al., 1993). The objective scheme developed by Jenkinson and Collison (1977) uses three measures of the circulation derived from the gridded sea-level-pressure field across the British Isles (see figure A1 in Jones et al., 2013, for their derivation): the strength (F), vorticity (Z – i.e. shear and curvature) and direction (D) of the large-scale geostrophic flow.