# Compute heat transport as cp*VT + L*VQ + VZ?

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tom.kilpatrick@...
Compute heat transport as cp*VT + L*VQ + VZ?

This is a related question to Jing's from a few months ago; I am trying to compute atmospheric heat transport and am wondering whether this is the correct equation:

AHT = cp*VT + L*VQ + VZ.

When I compute the heat transport this way, the results look different from the inferred transport that I obtain from the radiative and surface heat fluxes (see plot). It looks like using the above equation misses the eddy contribution or something.

tom.kilpatrick@...

Here is the figure.

Attachment:
tom.kilpatrick@...

Nevermind, this is explained in Yang et al. (2015). VT, VQ, and VZ include the eddy contributions; the issue is the influence of a "spurious" v on the transport. Apparently this is related to the interpolation from model sigma-coordiantes to p-coordinates (see Eq. 29 in the reference). Big shout to the authors for their responses to my email queries.

Yang, H., Q. Li, K. Wang, Y. Sun and D. Sun (2015): Decomposing the meridional heat transport in the climate system. Climate Dynamics 44, 2751–2768, doi:10.1007/s00382-014-2380-5.

bowen.zhao@...

Do you think you missed g0 in VZ? I'm calculating the same problem but got even worse results...

tom.kilpatrick@...

I'm not sure. My notes say that "VZ" includes the factor of g0, but the netcdf file metadata implies VZ does not include the g0 factor:

float VZ(time, lev, lat, lon) ;

VZ:mdims = 1 ;

VZ:units = "m2/s" ;

VZ:long_name = "Meridional transport of geopotential energy" ;

VZ:cell_methods = "time: mean" ;