Stratification Energy before Lake Freezing: A minimal model to predict the duration of the pre-freezing period in lakes
SELF (v.1.0 - April 2020) 'Stratification Energy for Lake Freezing' minimal model: competition of cooling and wind mixing leading to ice formation in lakes
- Contact: Marco Toffolon Department of Civil, Environmental, and Mechanical Engineering, University of Trento (Italy) email: marco.toffolon@unitn.it
GitHub repository: https://github.com/marcotoffolon/SELF
INPUT FILES
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select folder with input data: Read from ASCII file 'a0_folder_run.txt' in the same directory of the Matlab scripts.
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lake properties and meteorological variables: Read from Excel file 'lake_data.xlsx' located in the folder defined above. Excel sheets:
- readme : instructions
- lake_info : main properties of the lake (including efficiency eta)
- meteo : meteorological variables (daily averaged values, ideally centered at midday)
- LSWT : values of lake surface water temperatuare (at midnights) Note that nr of midnights = nr of middays + 1
MATLAB SCRIPTS
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a1_PreProcData.m (MAIN) Pre.processing of the data to define full mixing date and ice-on date and prepare the forcing of the SELF model.
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a2_MainSELF.m (MAIN) Main program, reading data written from the pre-processing.
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folders_table.m (SUB) Create folders and read table with lake's input data.
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parameters.m (SUB) Set the parameters of the model.
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model_run.m (SUB) Run the model for the sequence of years.
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cooling_mixing.m (SUB) Compute the evolution of the temperature profile.
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energymix.m (SUB) Compute the energy required for mixing a part of the water column.
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all_plots.m (SUB) Plots water temperature's vertical profiles (optional).
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plot_Tsurf.m (SUB) Plot surface water temperature (optional).
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plot_meteo_forcing.m (SUB) Plot meteorological forcing (optional).
Functions to compute variables: . air_density : density of air at the lake's altitude . approx_density : water density approximated as a parabolic function of water temperature in the range 0-4°C . drag_coeff : wind drag coefficient as a function of wind speed . lw_absorption : longwave radiation absorbed by the lake . sw_absorption : longwave radiation absorbed by the lake . lw_emission : longwave radiation emitted by the lake . sensible_flux : sensible heat flux . latent_flux : latent heat flux
FOLDERS
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input files $ : working folder read from file "a0_folder_run.txt" /$/lake_data.xlsx /$/results/freezing_data.mat /$/results/meteo.mat
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output files /$/results/freezing_periods.txt (control file) /$/results/freezing_data.mat /$/results/meteo.mat /$/results/ctrl.txt (control file) /$/results/model.mat /$/figure/...