Query on transport computations

[Dianne Deauna]

Good day! I would like to inquire about the use of the commands transp_mn3 and meantspt. I used it for different straits from the same model with differing bottom depths, and the results show a transport value per layer. Do these values take into account the difference in layer thickness between different locations? Could I compare transport across the same layers for different locations? Or do I still have to account for variations due to bottom depth. Thank you! 

[Alan]

Transport is dx*thickness*velocity, so it does allow for layer thickness.

You can compare transports in the same layer at different straits, providing that layer "represents" the same water mass at both locations.  For example if the layer is isopycnal at both locations it represents a (near) constant potential density and if it is in fixed coordinates at both locations it represents a fixed depth range.  Sometimes the same layer can represent different water masses - either in time or in space - making comparision difficult.  What is certain is that you can compare the total flow (all layers) in both straits, providing your sections cover the entire strait.   It is also the case that ranges of consequtive layers may be more easy to compare than individual layers, particularly if you can associate them with an identifiable water mass.

If you are using hycomproc to make plots, then plotting vertical sections at your strait locations gives a good indication of the layer structure.  Setting 'vstep ' to 1.0 (stairstep) shows the layers best.

Alan.