TY - JOUR
AU - PERRY, A. H.
AB - LAMB1 has recently drawn attention to the striking fluctuation in frequency of the westerly “weather type” over the British Isles in the last five decades. The frequency of westerly airflow has declined dramatically since the 1920s and 1930s, and this change has contributed to an increase in severe winters and cool summers since 1940. Dzerdzeevski2 suggested that “all changes in temperature and precipitation … are associated with changes in frequency and duration of large-scale circulation patterns”. It is equally possible, however, that changes in the weather characteristics of individual circulation types may account for some climatic fluctuations, and a preliminary test of this idea has been carried out using daily maximum and minimum temperatures at Eskdalemuir (55° 19′ N, 03° 12′ W), elevation 242 m, for January, April, July and Octobor 1925–35 and 1957–67. This upland observatory was selected because it has an unchanged site and surroundings and because the observational standards can be guaranteed to be of the highest order. The differences between the two periods of the mean daily minimum in July and October and the mean daily maximum in October are significant with Student's t test (Table 2), while those of the January maximum and April minimum are just outside the 5 per cent level. The other three differences are not significant. This rather unsatisfactory feature of the data has had to be ignored in the present exploratory study in view of the work involved in the calculation of weather-type averages for even a limited number of years.
TI - “Weather-type” Frequencies and the Recent Temperature Fluctuation
JF - Nature
DO - 10.1038/222463a0
DA - 1969-05-03
UR - https://www.deepdyve.com/lp/springer-journals/weather-type-frequencies-and-the-recent-temperature-fluctuation-I7zBwlcCP0
SP - 463
EP - 464
VL - 222
IS - 5192
DP - DeepDyve
ER -