Browsing by Subject "äärilämpötila"

Microclimate research is an important part of research about our warming earth. Microclimate refers to a local climate that is partially independent of the free atmosphere formed in an area of a few square meters to a few square kilometers. In this study, the level of consideration of the microclimate is the air layer in the immediate vicinity of the earth's surface. Microclimates are characterized by air temperature, air humidity, timing of the seasons, and the variety of organisms that thrive in the area, which differ from the wider climate. Local microclimates arise from the interaction of atmospheric processes and environmental factors in the area. The thesis examines how the extreme temperatures of microclimates vary in different vegetation zones in Finland. Two research areas are located in the tundra vegetation zone in the northern parts of Finland, and the remaining five research areas are in the boreal vegetation zone. The research questions are: 1) How do the extreme temperatures (minimum and maximum temperatures) of the warmest month of the growing season, July, vary in the study areas? 2) Which environmental factors affect the extreme temperatures of the research areas? Environmental factors to be considered are ground level above sea level, relative ground level, slope, distance to the nearest bodies of water, canopy cover, solar radiation and windiness. According to the results, the minimum temperatures were statistically significantly affected by the canopy coverage mainly negatively, the absolute ground level mainly negatively and the slope, with the trend varying between negative, positive and unimodal depending on the study area. The environmental factors that had the greatest influence on the maximum temperatures were the absolute ground level, negatively in the south and positively in the north, the canopy coverage mostly negatively, and the relative ground level mostly positively. The research results were largely in line with the hypotheses. In the south, abundant forest vegetation lowered the maximum temperatures of forest environments and raised the minimum temperatures. In central Finland, in the study area covered by wetlands, lakes and fragmented forests, especially the distance to water bodies affected the extreme temperatures. In northern Finland, the tundra vegetation led to the strongest temperature fluctuations. The maximum temperatures of the research areas varied less than the minimum temperatures. The maximum temperatures in July remained between 21.3 and 31.7˚C degrees, the range was 10.4˚C. The minimum temperatures remained between -3.3 and 5.2 ˚C degrees, the range was 8.5 ˚C degrees. In the future, microclimate-related research in the Nordic countries could focus even more precisely on the interannual variations of micro-level temperature observations over a longer period of time, as well as on the specification of the characteristics that affect the temperatures in different vegetation zones.