The physical hydrodynamic model GOTM was used to reconstruct the past water temperature of Lake Erken (Sweden) in order to investigate possible changes in its thermal structure during the period 1961-2017. To run the model, seven climatic parameters were used as forcing data: Wind Speed (m/s), Air Temperature (°C), Air Pressure (hPa), Relative Humidity (%), Cloud Cover (dimensionless value between 0-1), Precipitation (mm/day) and Shortwave Solar Radiation (W/m-2). This resource contains the model configuration file, input data of the model, the observed water temperature used to calibrate the model, and the output data.

The file 'erken.xml' is the model configuration file.

The input data of the model are:
- 'Erken_DailyPrec_1960-2017.dat': Lake Erken Daily Precipitation
- 'Erken_MetFile_1960-2017.dat': hourly dataset that contains Lake Erken Wind Speed, Air Temperature, Air Pressure, Relative Humidity and Cloud Cover
- 'Erken_HourlySWR_1960-2017.dat': hourly dataset of Lake Erken Shortwave Solar radiation
- 'ErkenObsTemp_1961-2017.dat': real daily water temperature data of Lake Erken

The file 'ErkenObsTemp_1961-2017.obs' contains the real daily water temperature data of Lake Erken and it was used to calibrate the model.

The output data of the model are:
- 'Mod_temp_hr_z.txt': contains the depth profile of lake Erken
- 'Mod_temp_hr_temp.txt': contains the calibrated modeled water temperature profile on daily time-step between 1960-2017.

The input data used to run the model were available between 1961-2017. To avoid that the initial state of the model could increase the errors during calibration, a 1-year simulation spin-up was used to minimize calibration errors. To make full use of the available input data, a copy of the 1961 meteorological data was appended at the beginning of the input files 'Erken_DailyPrec_1960-2017.dat', 'Erken_MetFile_1960-2017.dat' and 'Erken_HourlySWR_1960-2017.dat'. The data referred to the year 1960 are therefore only a copy of the 1961 data and they were used as spin-up year. For this reason, the data referred to the year 1960 in the output files should be discarded.