heat flux or heat convergence?

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zhongyf01@...
heat flux or heat convergence?

Hi there,

What are the terms UET,VNT,WTT in pop history file? Are they heat flux or convergence/divergence of heat flux? They have unit degC/s like heat convergence, but their longnames sound like heat flux across a face.

Thanks.

njn01

It is the latter. For example, UET is obtained using

UET(i,j) = 0.5*(u(i,j)*dyu(i,j)+u(i,j-1)*dyu(i,j-1)) * 0.5*(T(i,j) + T(i+1,j))
UET(i,j) = UET(i,j)/TAREA(i,j)

Also, the magnitude of it is meaningless by itself. It needs to be differenced from something as in convergence/divergence computations.

bzhao@...

Just a follow up of this, I don't think these terms are meaningless by themselves. They represent advective heat flux through the given face if corrected by a length scale. For example, the WTT term in POP is calculated as below,

FLUX_T(:,:,n) = dz2r(k)*WTK*(TRACER(:,:,k-1,n,curtime) +
& TRACER(:,:,k ,n,curtime))

if FLUX_T is multiplied by 2*dz(k), you get vertical advective heat flux through the top face of the tracer cell.

Please correct me if I am wrong.

Bin

bowen.zhao@...

I'm confused by the same question on the dimension of "heat flux" however the orginal question and answer is not displayed any more (may be it's too long ago). Could you please repost the answer again? Thanks very much!

As a reminder, the question is about "is VNT a heat advection v*dT/dy or heat convergence d(V*T)/dy?"

Best,

Bowen

bowen.zhao@...

After digging into the code, it seems to me that VNT=T*V*dx/(dx*dy). Thus to get back to the traditional VT, we simply need VT=VNT*HTE, where HTE=dy. Please correct me please if I were wrong.

liufukaiouc@...

Is UET -> u*dT/dx , VNT -> v*dT/dy, WTT-> w*dT/dz ?