Re-calibration of the MAGIC model with data from the National Lake Survey 2019.

Abstract

The MAGIC model (Model for Acidification of Groundwater In Catchments) was calibrated to the Norwegian 1000-lake survey data from both 1995 and 2019. The re-survey in 2019 provided a new point in time for generation of new forecasts for future lake chemistry. The acidification pressure on Norwegian lakes has decreased dramatically since the 1970s. For the majority of the lakes in the 1000-lake survey, the large reductions in S deposition since the peak years in the 1970s have resulted in decreased SO4 concentrations and increased ANC levels. Other driving factors that were previously masked by acid deposition may now become more apparent, as e.g., the effects of climate change. For MAGIC to fully simulate the effects of climate change, additional processes must first be included in the model.