Global warming an univariate estimation of sea temperature data

The objective of this report is to analyse how the sea temperature off Lista in Rogaland in the south and Skrova in Nordland in the north has evolved during the period 1936-2003. More precisely, is there a difference between 'South' and 'North'? Furthermore, we analyse whether the temperature has changed over time. Are changes in temperature just white noise, or is the process non-stationary due to trend or change in volatility? Is it possible to detect any climate change in the temperature data? We ask what kind of data generating process can describe the temperature data at Lista and Skrova.