Downloading model data with opendap

These examples use the get_metocean_dap.

The xray package can probably be used for the same thing.

HYCOM Global

from get_metocean_dap import get_metocean_dap


# Set the time-space domain here
xrange = [118.0,127.0]
yrange = [-19.0,-11.0]
zrange = [0.,6000.]
trange = ['20140401.000000','20140501.000000']
vars = ['temp','salt','u','v','ssh']

outfile = 'DATA/HYCOM_ScottReef_Apr2014.nc'
#gridfile = 'DATA/HYCOM_Global_grid.nc' # Set to None
gridfile = None


# Call the function
get_metocean_dap(xrange, yrange, zrange, trange, outfile,\
    name='HYCOM', gridfile=gridfile, oceanvars = vars)

GFS

Getting the Global Forecasting System data is a little more tricky because each time step is stored in a differnt opendap file. See the get_gfs_function in get_metocean_dap for tips on how to modify this.

from get_metocean_dap import get_gfs_tds

xrange = [118.0,127.0]
yrange = [-19.0,-11.0]
zrange = [0.,0.]
#trange = ['20150113.000000','20150120.000000']
trange = ['20150318.000000','20150326.000000']

outfile = 'DATA/GFS_ScottReef_March2015.nc'

get_gfs_tds(xrange,yrange,zrange,trange,outfile)

Arbitrary ocean model opendap server

Note that this has not been fully tested.

The code should work for any ocean model (or other dataset). Simply replace the url and variable names.

# Dictionary contains the important information
oceandict = {\
    'ncurl':'http://tds.hycom.org/thredds/dodsC/glb_analysis',\
    'type':'ocean',\
    'u':'u',\
    'v':'v',\
    'temp':'temperature',\
    'salt':'salinity',\
    'ssh':'ssh',\
    }

    get_metocean_dap(xrange, yrange, zrange, trange, outfile,\
    oceanvars = vars, oceandict=oceandict)

ROMS

This example downloads ROMS data from a Texas A&M opendap server. This code was written prior to the get_metocean_dap code so is slightly different.

"""
Download a subset of the Tx-La shelf ROMS model output
"""
from romsio import roms_subset

#ncfiles = ['http://barataria.tamu.edu:8080/thredds/dodsC/txla_nesting6/ocean_his_%04d.nc'%i for i in range(100,196)]
ncfiles = ['http://barataria.tamu.edu:8080/thredds/dodsC/NcML/txla_nesting6.nc']
bbox = [-95.53,-94.25,28.3,30.0]
grdfile = '../DATA/txla_grd_v4_new.nc'

###
# 2007
timelims = ('20140101000000','20140701000000')
outfile = '../DATA/txla_subset_HIS_2014.nc'

# Writes the data file
roms = roms_subset(ncfiles,bbox,timelims,gridfile=grdfile)
roms.Writefile(outfile)
roms.Go()