new_contents: import sys
  sys.path.append('/home/jwalker/dynamics/python/atmos-tools')
  sys.path.append('/home/jwalker/dynamics/python/atmos-read')
  
  import os
  import numpy as np
  import matplotlib.pyplot as plt
  import merra
  import atmos as atm
  from merra import load_daily_season
  
  datadir = '/home/jwalker/eady/datastore/merra/daily/'
  savedir = datadir
  years = np.arange(1979, 2015)
  season = 'ann'
  lon1, lon2 = 40, 120
  lat1, lat2 = -60, 60
  nperday = 8
  
  def pathstr(var):
      return datadir + 'merra_' + var + '200_'
  
  def outfile(year):
      lats = atm.latlon_labels([lat1, lat2], 'lat', '%.0f', deg_symbol=False)
      lons = atm.latlon_labels([lon1, lon2], 'lon', '%.0f', deg_symbol=False)
      subset = '%s-%s_%s-%s' % (lons[0], lons[1], lats[0], lats[1])
      return datadir + 'merra_uv200_%s_%d.nc' % (subset, year)
  
  for year in years:
      print('Loading U')
      u = load_daily_season(pathstr('u'), year, season, 'U', lat1, lat2, lon1,
                            lon2)
      print('Loading V')
      v = load_daily_season(pathstr('v'), year, season, 'V', lat1, lat2, lon1,
                            lon2)
      print('Calculating vorticity and Rossby number')
      rel_vort, _ , _ = atm.vorticity(u, v)
      Ro = atm.rossby_num(u, v)
  
      print('Calculating daily means from 3-hourly data')
      days = np.arange(1, u.shape[0]/nperday + 1)
      u = atm.daily_from_subdaily(u, nperday, dayname='Day', dayvals=days)
      v = atm.daily_from_subdaily(v, nperday, dayname='Day', dayvals=days)
      rel_vort = atm.daily_from_subdaily(rel_vort, nperday, dayname='Day',
                                         dayvals=days)
      Ro = atm.daily_from_subdaily(Ro, nperday, dayname='Day', dayvals=days)
  
      print('Saving to ' + outfile(year))
      atm.save_nc(outfile(year), u, v, rel_vort, Ro)
  
subject: Combine uv200 from all years and calculate Rossby numbers