Skip to content

Instantly share code, notes, and snippets.

Embed
What would you like to do?
LOCA, 16th degree downscaled climate data (2016-04-02) S3 data Peek
# A simple example showing how to extract and plot some of the LOCA downscale
# climate projections data; data downloaded from the LOCA S3 cache copy.
# This example does spatial and temporal plots, for entertainment and
# coding educational purposes only. See http://loca.ucsd.edu for the official
# distribution and general information about the data.
import sys, os
import random, urllib2
import pprint
import requests
import matplotlib.pyplot as plt
from matplotlib.dates import DateFormatter
import numpy
NIST_NET_ZERO_RESIDENCE_LOC = (39.138356, -77.219574)
# google maps view: https://goo.gl/maps/PfHsAJH8iZx
# An Assessment of Typical Weather Year Data Impacts vs. Multi-year
# Weather Data on Net-Zero Energy Building Simulations
# http://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.1204.pdf
# Comparing the Energy and Economic Performance of the NIST NZERTF
# Design across the Mixed-Humid Climate Zone
# http://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.1603.pdf
try:
import netCDF4
except ImportError, e:
sys.stderr.write(str(e)+"\n\nYou need to install\nhdf5 (https://www.hdfgroup.org/HDF5/),\n"+\
"netcdf (http://www.unidata.ucar.edu/software/netcdf/),\n"+\
"netCDF4 (https://pypi.python.org/pypi/netCDF4)\nfor this example to run.\n\n")
sys.exit(1)
def plot_data_temp_spatial(dat, data_min, data_max, fnameout, datlab):
plt.rcParams['figure.figsize'] = (12, 8)
plt.imshow(data, vmin=data_min, vmax=data_max, origin='lower', cmap=plt.cm.get_cmap('jet',18))
plt.colorbar(drawedges=True, ticks=numpy.linspace(data_min,data_max,10), orientation='horizontal', extend='both', pad=0.05, shrink=0.8).set_label(u'\N{DEGREE SIGN}C')
plt.title('Temp '+str(datlab))
plt.savefig(fnameout)
def plot_data_temp_time(dat, tms, fnameout):
plt.rcParams['figure.figsize'] = (12, 8)
monthsFmt = DateFormatter("%b '%Y")
fig, ax = plt.subplots()
ax.plot_date(tms, dat, '-')
ax.xaxis.set_major_formatter(monthsFmt)
ax.autoscale_view()
fig.autofmt_xdate()
plt.title('Temp')
plt.savefig(fnameout)
if __name__ == '__main__':
# stage a local copy (for simplicity)
remote = 'http://nasanex.s3.amazonaws.com/LOCA/CESM1-BGC/16th/rcp85/r1i1p1/tasmax/tasmax_day_CESM1-BGC_rcp85_r1i1p1_20500101-20501231.LOCA_2016-04-02.16th.nc'
localfnm = os.path.split(remote)[1]
if not os.path.exists(localfnm):
localfd = open(localfnm, "w")
r = requests.get(remote)
localfd.write(r.content)
localfd.close()
# open the local file
ncfd = netCDF4.Dataset(localfnm)
# print some metadata
pprint.pprint(ncfd.variables)
pprint.pprint(ncfd.dimensions)
# probe (convert to python datetimes) and print the available time steps for this file
dtms = netCDF4.num2date(ncfd['time'][:], units=ncfd['time'].units, calendar=ncfd['time'].calendar)
for i,d in enumerate(dtms):
print "[%d] %s" % (i, d)
# randomly choose a time step
step = random.choice(range(len(dtms)))
print 'selected step', step, dtms[step]
# get variables handle
var = ncfd.variables['tasmax']
# get the fill value/no data value
na = float(var._FillValue)
rawdata = var[step,:,:]
# convert var units (kelvin to Celsius)
print 'var units', var.units
data = numpy.ma.masked_where(rawdata==na, rawdata-273.15)
print 'plotting map...'
plot_data_temp_spatial(data, -10.0, 40.0, localfnm+".%04d.png" % step, dtms[step].strftime("%Y-%m-%d"))
# now look through the time dimension, but we need to find the location index we're interested in (convert coords)
latidx = (numpy.abs(ncfd['lat'][:] - NIST_NET_ZERO_RESIDENCE_LOC[0])).argmin()
lonidx = (numpy.abs(ncfd['lon'][:] - (360.0 + NIST_NET_ZERO_RESIDENCE_LOC[1]) )).argmin()
# get the data at y,x over all time steps in this file (convert units)
rawdatat = var[:,latidx, lonidx]
data = numpy.ma.masked_where(rawdatat==na, rawdatat-273.15)
print 'plotting time series...'
plot_data_temp_time(data, dtms, localfnm+".%04d_%04d.png" % (latidx, lonidx))
ncfd.close()
#__main__
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.