Högfrekventa tryckvariationer under de senaste århundradena
Fysisk instrumenteringPhysical geographyMetrologiPhysical instrumentationMetrologyCarbon dioxideKoldioxidSkandinavienVäxthuseffektenGeomorphologyPedologyCartographyClimatologyNaturgeografiGeomorfologiMarkläraKartografiKlimatologiPhysics and AstronomyEarth and Environmental Sciences
Long time-series of pressure measurements often have high quality because the early instrumentsare more or less the same as the modern ones. A time-series from Lund consisting of three dailymeasurements from 1780-1997 has been homogenised and is therefore suitable for analysingpossible influences of the enhanced greenhouse effect. According to a two-layer model of theatmosphere one finds a shift in the frequency of baroclinic instability due to an increasedtemperature gradient caused by the increasing CO2. Baroclinic instability over the Atlantic Oceanis the main cause for frontal zone production, causing cyclonic activity over the southern part ofScandinavia. Changes to the baroclinic instability would therefore be traceable in the time seriesfrom Lund. The period 1859-1997 was analysed by spectral analysis. The measurements areunevenly sampled so prior to applying various techniques of spectral analysis it was necessary tointerpolate the time series to a regular grid. The series showed large variability with time but noclear trend was evident.