surface fluxes

[nuno@fis.ua.pt]

Hi,
I need to compute surface fluxes. What is the best way of doing that?
Do I have to compute all the contributions (solar shortwave radiation, atmospheric and water longwave radiation latent and sensible heat fluxes) or just the contributions that I consider important?
Nuno

[luis_at_mohid.com]

Hi Nuno,

If you want to run with surface fluxes in order to compute water temperature variation, you need to run the following properties:

At the atmosphere you need to define:
- solar radiation;
- cloud cover or sun hours (there are 2 formulations to compute climatological solar radiation);
- air temperature;
- relative humidity;
- wind velocity X;
- wind velocity Y;

Note: wind velocity X and Y can be computed from wind modulos and wind direction.

At the water-air interface you need to define:

- surface radiation (this is solar radiation times (1. - ALBEDO);
- non solar flux (this is the sum of infrared radiation, sensible heat, latent heat. You can specify this from a file, let the model compute the fluxes or let them be constant. If you want to define just the more important you can define them as being contant in time and with a value of zero.)
- infrared radiation;
- sensible heat;
- latent heat;

A \"almost\" complete text describing how to initialize and use some of the keywords I talked about can be found in ftp://ftp.mohid.com/read_write/Documentation/ in a file named FillMatrix.doc .

Hope this helps. Best regards,
Luis

[nuno@fis.ua.pt]

Hi again,

I’m having some problems with the transport module. I’m calibrating the heat transport in Ria de Aveiro. There are two situations: with or without imposing surface fluxes.
When I don’t impose surface fluxes the model time series of temperature show an acceptable mean value but no amplitude. When I use surface fluxes the amplitude of the model series improve and the mean value increases (I don’t want that!!). I have a maximum of ~38 ºC in the water temperature in the North of the lagoon (quite tropical!!). I don’t know if this anomaly is due to the size of the water column in intertidal areas or not. I don’t know what I’m doing wrong. If anybody have some ideas please talk to me.

Best regards,
Nuno

[luis_at_mohid.com]

Hi Nuno!

How do you compute the surface fluxes? Do you compute them or do you impose a surface flux? If you impose you can have some troubles in the shallow areas, as the imposed flux surely is not accounting for water depth. Best regards,
Luis

[nuno@fis.ua.pt]

Hi,

I would like to get Mohid's outputs (time series) of latent heat, sensible heat, etc. Is the keyword TIME_SERIE active (or not) in the module InterfaceWaterAir?

Nuno

[paulo.chambel.maretec@taguspark.pt]

Hi,
Nuno I check the source code and the Time Serie Option is active. The ModuleInterfaceWaterAir creates time series with extensions \".sri\". In the block property you want to do a output with the time serie format you need to define the follow keyword.

<beginproperty>
TIME_SERIE : 1
<endproperty>

TIME_SERIE_LOCATION : d:\\file where\\the time series location\\is defined .dat

[luis_at_mohid.com]

Hi Pedro,

Yes, this is true and it is a bug. I'll try to change this soon.
Regards,
Luis

[luis_at_mohid.com]

Hi Pedro,

I've corrected the bug. You can update your source code version, compile and the problem is solved.
Best regards,
Luis