Kinneret

Simulations to investigate the annual temperature profile.

A correct evolution of the temperature field is essential as a proper basis for bio-geochemical simulations.

pyGETM contains some configuration settings that influences the structure of the temperature field. In the following simulations are carried out where these settings are changed. As a measure of the impact a Hovmöller diagram is produced at the deepest point of the lake - i.e. around 43 m. A very important process for the development of the temperature distribution is the distribution of the short wave radiation through the water column. As an illustration is below given the results of a 4 year GOTM simulation for the deepest point of Lake Kinneret where two different Jerlov water types are used. The meteo-forcing is ERA5.

It is clear that the penetration depth os the short wave radiation has a strong impact on the temperature field.

An inherent issue with the sigma-coordinate models are the pressure-gradient

Run 1 - reference run

Run 2

• Scale factor on wind is 0.75

Run 3

• Jerlov type III - (A=0.78, g1=1.4, g2=7.9)

Run 4

• Salt: 0.4 -> 0.1
• Jerlov: II -> III
• Read from gotm.yaml- instead of using GOTM defaults

Run 5

• As 4 - but with wind scaling of 0.75

Run 6

• As 5 but with Dgamma=20

Run 7

• As 6 but with Albedo according to Cogley (default is Payne)

Run 8

• As 1 - but with 15 vertical layers

Run 9

• As 1 - but with a minimum depth of 5 m

Run 10

• As 1 - but with
• Pure sigma coordinates
• Minimum depth is set to 5 meter