Plotting Wind magnitude and direction

Hello, I need to plot hourly wind maps with magnitude as its background and direction arrows above it. I have 2 nc file which contains hourly data of wind magnitude i.e., u component and Wind direction i.e., v component for a month. how can I plot these based on different time interval. hereby i am attaching my both nc file named uwnd and vwnd. Please help me out. Thanks in advance. netcdf file

Answer 1

[KSSV]

YOu can read the data from ncfile using ncread.

Let u, v be your wind matrices. And X, Y be your locations.

M = sqrt(u.^2+v.^2) ;  % magnitude 
figure
hold on
pcolor(X,Y,M) ; 
shading interp 
quiver(X,Y,u,v)

[shravani banerjee]

But how can I extract my u wind and v wind variables based on time and lat/long. I am mainly stuck in this issue. Thanks in advance.

[KSSV]

YOu can read all the variables at once..this will be a 3d matrix..from here extract the each time data and plot.

Or

Using ncread you can read variables in a loop of time. Read about ncread

[shravani banerjee]

Can you give me a sample code to extract each time and plotting. It will be a great help as i am new to this software.

[KSSV]

No issues..attach your file...

[shravani banerjee]

netcdf file It consist both the u wind and v wind file. Thanks in advance.

[KSSV]

ncfile1 = 'uwnd.nc'; 
ncfile2 = 'vwnd.nc'; 

lon = ncread(ncfile1,'longitude') ; nx = length(lon) ; dx = min(diff(lon)) ;
lat = ncread(ncfile1,'latitude') ; ny = length(lat) ; dy = min(diff(lat)) ;
[X,Y] = meshgrid(lon,lat) ;

t = ncread(ncfile1,'time') ; nt = length(t) ;
pivot = datenum('1900-01-01 00:00:0.0') ;
thedates = datetime(datestr((double(t)/24+pivot))) ;

for i = 1:nt
    u = ncread(ncfile1,'u',[1,1,i],[nx,ny,1]) ;
    v = ncread(ncfile2,'v',[1,1,i],[nx,ny,1]) ;
    s = sqrt(u.^2+v.^2) ;
    pcolor(X,Y,s') ;
    hold on
    quiver(X,Y,u',v',1,'r') ;
    title(sprintf('%s',thedates(i)))
    hold off

      drawnow
  end

[shravani banerjee]

Thank you a lot! I'll try this code and get back to you.

[shravani banerjee]

is this command correct? %

    thedates = datetime(datestr((double(t)/24+pivot))) ;

as i am getting an error in this line.

    Error using date2time (line 55)
    Not enough input arguments

[KSSV]

It is working fine in my version......YOu can comment that line and title line...and check.

Answer 2

[Bijay Guha]

This kind of wind vector plots are possible in MATLAB?? Kindly help!

The attached image shows the wind vector plots in the vertical axis. I need the help regarding the arrows only!

Thanks in Advance

Regards

[KSSV]

Read about quiver. It should help you.