matlab_class/gcmfaces_smooth/diffsmooth2Drotated.m

function [FLD]=diffsmooth2Drotated(fld,dxLarge,dxSmall,fldRef);
%
%object: slanted diffusive smoother (after Weaver and Courtier 2001)
%
%input: fld                  field to be smoothed (masked with NaN)
%       dxLarge,dySmall  smoothing scale in direction of 
%                        weak,strong fldRef gradient
%       fldRef           tracer field which gradient defines 
%                        directions of strong,weak smoothing
%output:FLD                  smoothed field
%
%asumption: dxLarge/dxSmall are given at tracer points (not U/V points)

global mygrid;

dxC=mygrid.DXC; dyC=mygrid.DYC; 
dxG=mygrid.DXG; dyG=mygrid.DYG; 
rA=mygrid.RAC;

%scale the diffusive operator:
tmp0=dxLarge./dxC; tmp0(isnan(fld))=NaN; tmp00=nanmax(tmp0);
tmp0=dxLarge./dyC; tmp0(isnan(fld))=NaN; tmp00=max([tmp00 nanmax(tmp0)]);
nbt=tmp00;
nbt=ceil(1.1*2*nbt^2);

dt=1;
T=nbt*dt;

%diffusion operator:
kLarge=dxLarge.*dxLarge/T/2;
kSmall=dxSmall.*dxSmall/T/2;
[Kux,Kuy,Kvx,Kvy]=diffrotated(kLarge,kSmall,fldRef);

%setup problem:
myOp.dt=1;
myOp.nbt=nbt;
myOp.Kux=Kux;
myOp.Kuy=Kuy;
myOp.Kvx=Kvx;
myOp.Kvy=Kvy;

%time step problem:
FLD=gcmfaces_timestep(myOp,fld);

1	function [FLD]=diffsmooth2Drotated(fld,dxLarge,dxSmall,fldRef);
2	%
3	%object: slanted diffusive smoother (after Weaver and Courtier 2001)
4	%
5	%input: fld field to be smoothed (masked with NaN)
6	% dxLarge,dySmall smoothing scale in direction of
7	% weak,strong fldRef gradient
8	% fldRef tracer field which gradient defines
9	% directions of strong,weak smoothing
10	%output:FLD smoothed field
11	%
12	%asumption: dxLarge/dxSmall are given at tracer points (not U/V points)
13
14	global mygrid;
15
16	dxC=mygrid.DXC; dyC=mygrid.DYC;
17	dxG=mygrid.DXG; dyG=mygrid.DYG;
18	rA=mygrid.RAC;
19
20	%scale the diffusive operator:
21	tmp0=dxLarge./dxC; tmp0(isnan(fld))=NaN; tmp00=nanmax(tmp0);
22	tmp0=dxLarge./dyC; tmp0(isnan(fld))=NaN; tmp00=max([tmp00 nanmax(tmp0)]);
23	nbt=tmp00;
24	nbt=ceil(1.12nbt^2);
25
26	dt=1;
27	T=nbt*dt;
28
29	%diffusion operator:
30	kLarge=dxLarge.*dxLarge/T/2;
31	kSmall=dxSmall.*dxSmall/T/2;
32	[Kux,Kuy,Kvx,Kvy]=diffrotated(kLarge,kSmall,fldRef);
33
34	%setup problem:
35	myOp.dt=1;
36	myOp.nbt=nbt;
37	myOp.Kux=Kux;
38	myOp.Kuy=Kuy;
39	myOp.Kvx=Kvx;
40	myOp.Kvy=Kvy;
41
42	%time step problem:
43	FLD=gcmfaces_timestep(myOp,fld);
44