摘要:

ABSTRACTDue to the rareness of meteorological data from the 18th century, it is important that all existing observations are evaluated in the best way possible. For that purpose the early climatological records from Uppsala have been reanalysed.The analysis includes both a check and recalibration of the wide variety of thermometers used before 1751, against the old Celsius thermometer, and takes into account the actual observational times given in the journals.The resulting monthly and yearly mean temperatures 1722–32 and 1739–51 are compared with the present day mean values, which suggests that the winters of the period before 1752 were somewhat warmer than today, while the summers during the period 1722–32 were a bit colder. The data from before 1739 should, however, be regarded with caution due to the thermometer placing of that time.A comparison between the wind direction distributions during the periods 1722–50 and 1951–80 shows that the frequency of winds from the western sector were much more abundant during the early period. This in turn points at the possibility of a more maritime climate during those days, which is in agreement with the temperature data.Plots of annual and seasonal mean temperature data for the whole period 1722–1989 are also included.

ISSN:0435-3676    

DOI:10.1080/04353676.1990.11880310

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

ABSTRACTFor Karesuando in northernmost Sweden the extraordinary warm period 1931–1940 and the much colder one 1979–1988 are compared with respect to length of growing season and occurrence of frost during the summer months. Although the difference between the selected periods is quite striking, as far as average summer and winter temperatures are concerned, it turns out that the length of the growing season as well as the frost conditions have been rather more favourable during the later, colder, decade than during the earlier.There is also evidence that the occurrence of extreme areal precipitation over 24 hours shows little or no correlation with the average long term temperature conditions.

ISSN:0435-3676    

DOI:10.1080/04353676.1990.11880311

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

ABSTRACTThe article shows some aspects of the temperature climate in a valley and its surroundings at Máze on Finnmarksvidda, where three meteorological observation stations have been in operation since the autumn of 1981. The stations are situated at the bottom, on the side and at the top of the valley.Temperature inversions are most frequent in the winter and, during the period of observation, especially frequent in December. As expected, inversions are uncommon in the summer. The frequency of inversion shows no variation during the day in the months November, December and January. The greatest daily variation takes place in the season February-May.Inversions are more frequent in cold winters than in mild winters. But in the interval below -15°C there is no correlation between the monthly mean temperature and the frequency of the valley inversion. In extremely cold weather the inversion near the valley floor is often weak and may even be missing.Temperature inversions in the valley very decisively affect the temperature data so that the mean temperature increases with elevation in the season from November to March.

ISSN:0435-3676    

DOI:10.1080/04353676.1990.11880312

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

ABSTRACTDuring nine years (1980–88) observations have been carried out about the relationship between the air temperature, soil temperature and the snow cover on three different points or sites. Two of the points lie on a glacial till slope, one in an old spruce forest and the other in a clear felled area. The third point lies on a clear felled area on level sediment. The maximum difference between the first day free from snow and the beginning of warming of the mineral soil surface below vegetation and humus was only four days. On the contrary there were great differences between the sites in the relationship between the start of warming of the soil surface and the start of warming of deeper soil layers, depending on different frost conditions at the sites. The ground frost, which delays the start of warming in the spring, was much more frequent and heavy on level sediment than on the till slope. The difference between the sites depends, in addition to different physical soil conditions, on much colder winter climate on the level sediment area. The start of the growing season, determined by the air mean temperature per day to estimate the first day free from snow or warming of the top ground layer could be used as a rule of thumb in average, but the method failed separate springs, especially in the forest. Early in the spring a change of the temperature gradient in frozen and dry soil was observed. This change was associated with the start of the infiltration of melt water in the soil and occurred nearly at the same time as the mean air temperature per day exceeded 0.5°C. A couple of days later free water in the soil was indicated by gypsum blocks.

ISSN:0435-3676    

DOI:10.1080/04353676.1990.11880313

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

ABSTRACTStudies of the ground temperatures and hydrological conditions at four sites on a subalpine heath and in the birch forest in the subarctic valley in Abisko from 1984–87 show that a clear relationship exists between ground temperature and climatic parameters, especially precipitation through the effects of snow cover. The effects of precipitation poor summers in 1985–87 and the colder than normal and snow poor winters of 1985 and 1987 were instrumental in intensifying the effects of seasonal frost at all of the sites.

ISSN:0435-3676    

DOI:10.1080/04353676.1990.11880314

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

ABSTRACTSnow and frost measurements were made on a palsa mire in Utsjoki, northernmost Finland from September, 1984 to October, 1985. Snow cover was unusually thin and January and February were very cold. Frost penetrated in natural conditions down to maximum depth of 73 cm into the peat. Some of the frost stayed unmelted through the thawing season. Rather good multiple and logarithmic regressions were found between snow and frost depths of March and April. This type of condition makes possible a new palsa formation.

ISSN:0435-3676    

DOI:10.1080/04353676.1990.11880315

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

ABSTRACTGeomorphic responses to climatic fluctuations in the periglacial mountain environment of northern Sweden, especially the Abisko mountains, are discussed. Although the frequency and magnitude of rapid mass movements are related to climatic conditions, the depositional patterns of the processes and the variable availability of source material complicate their use as climatic indicators. Possibly, debris flows and slushflows were frequent during the Little Ice Age, according to lichenometric dating of old deposits. Field observations suggest a fairly high frequency also during the last few decades. Boulder pavements, moraine-like ridges and glacial striae in front of major snow- fields indicate these were previously larger and in some cases active as small glaciers perhaps in the cold beginning of the 1900's. During the warm 1920–30's snowpatches and glaciers, as well as permafrost mounds were affected by a general degeneration. Climatic inferences made from the mentioned features are still very crude. Tentatively, it is suggested that they are presently beginning to respond to the cooling trend affecting northern Scandinavia since about 1940. The anticipated impact of a greenhouse warming of the atmosphere has thus so far not been noticeable in this high latitude area.

ISSN:0435-3676    

DOI:10.1080/04353676.1990.11880316

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

ISSN:0435-3676    

DOI:10.1080/04353676.1990.11880309

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor