Get Your Favorite Lake Modelled!
This online version of FLake allows calculation of the approximate temperature and mixing pattern
in any shallow freshwater lake around the world.
Everything you need to know are the geographical coordinates,
average depth of the lake and some estimate of lake water clarity.
Apart from providing with the outlook of the FLake functionality, the online version of the model can help answering
many frequently asked questions about lakes:
In that way, this online tool can be of practical interest for many people, as for example:
- "What is the typical surface temperature in the lake ZZ at the day YY of the month XX?"
- "Does the lake surface freeze in winter?"
- "At which depth the strong temperature drop (thermocline) occurs?"
- ..and many others.
- Researchers looking for information on typical seasonal temperature course, stratification pattern, mean ice cover duration
in a lake, where no measurements are available;
- Fishermen, anglers, divers interested in the vertical position of the thermocline
in order to locate the fish habitats;
- Anyone wno plans to spend holidays at an outlying lake in unpopulated area
and wants to know if the water temperature will be good for bathing during that time.
External forcing of the model is adopted from the
Global Data Assimilation System (GDAS) Archive.
It consists of 3-hourly, global, 1 degree latitude longitude datasets of main meteorological parameters as provided by the
GDAS model output of National Centers for Environmental Prediction (NCEP).
Currently, the data sets cover the one-year period from November 2005 to November 2006 (a hydrological year). The model is run
for several years applying repeatedly the same 2005/2006 meteorological data unless the model output arrives at the
steady-state year cycle.
Although such output cannot be directly considered as climatic mean
(which would imply using of the climatic mean meteorology input),
the procedure provides with a kind of approximation to it, simulating the artificial situation of a
"perpetual year" 2005/2006.
Initial state of the model run is the fully mixed vertically temperature distribution. The initial temperature guess
is drawn from the annual mean air temperature at the lake location. The validity of this approximation is supported by the
fact that the model usually needs less than 5 iterations to arrive at the "perpetual year" solution.
Provide following input by filling the form at top of this page:
- Geographical coordinates: latitude (positive north) and longitude (positive east) in whole degrees.
Try Google Earth or
lakes wiki if the coordinates of Your lake are unknown;
- Mean lake depth in metres. The values for some lakes can be found
in the External parameters datasets .
- Water transparency is maybe the most uncertain input parameter, which can be thought as the maximum depth at
which you can still see bright submerged objects. Water transparency strongly affects vertical mixing and, as a result, redistribution of the
heat across the water column. You can choose among four typical grades. Experimenting with different transparency values can help revealing
its role in lake temperature distribution.
Currently, the model output is organized in two figures, one for the lake temperature evolution at the lake surface and
at the lake bottom, another for the depth of the thermocline. The thermocline divides the upper mixed layer from quiescent deep
waters, marked in the figure as light-blue and deep-blue areas correspondingly.
- We are highly interested in your feedback. Please send us
any bug reports, questions, recommendations, requests.
- We take no responsibililty for the model results. Please remember: this online version relies on
extremely simplified configuration and aimed at providing only rough overview of the real processes in lakes. Do not make any
important decisions based on the model results.
- The model is free for non-commercial use. Contact us if you apply the
model in your research, education, hobby etc.