データを描画してみよう！

インポート

import numpy as np
import xarray as xr

import matplotlib.pyplot as plt
import cartopy.crs as ccrs
import cartopy.feature as cfeature
from cartopy.mpl.ticker import LatitudeFormatter,LongitudeFormatter

データの描画

nc = xr.open_dataset('D:\\APP/progress/data/data/sst/cobesst.nc')
nc

C:\Users\kaiyo\anaconda3\lib\site-packages\xarray\coding\times.py:123: SerializationWarning: Ambiguous reference date string: 1-1-1 00:00:00. The first value is assumed to be the year hence will be padded with zeros to remove the ambiguity (the padded reference date string is: 0001-1-1 00:00:00). To remove this message, remove the ambiguity by padding your reference date strings with zeros.
  warnings.warn(warning_msg, SerializationWarning)

<xarray.Dataset>
Dimensions:  (time: 1557, lon: 360, lat: 180)
Coordinates:
  * time     (time) datetime64[ns] 1891-01-01 1891-02-01 ... 2020-09-01
  * lon      (lon) float64 0.5 1.5 2.5 3.5 4.5 ... 355.5 356.5 357.5 358.5 359.5
  * lat      (lat) float64 -89.5 -88.5 -87.5 -86.5 -85.5 ... 86.5 87.5 88.5 89.5
Data variables:
    t        (time, lat, lon) float32 ...
Attributes:
    CDI:          Climate Data Interface version 1.9.8 (https://mpimet.mpg.de...
    Conventions:  CF-1.6
    history:      Wed Nov 11 09:56:10 2020: cdo -f nc import_binary cobesst.c...
    CDO:          Climate Data Operators version 1.9.8 (https://mpimet.mpg.de...

### 変数を定義 ###
lon = nc["lon"]
lat = nc["lat"]
sst = nc['t']

### 特定の日付のみ取り出す ###
year = sst['time'].dt.year
month = sst['time'].dt.month
sst_april = sst[(year==1998)&(month==4)]

### 不要な次元を削除 ###
sst_april = np.squeeze(sst_april)

fig = plt.figure()
ax = fig.add_subplot(1,1,1,projection=ccrs.PlateCarree(central_longitude= 180))
ax.add_feature(cfeature.LAND) ### 地形を塗る
ax.coastlines(resolution='50m',lw=0.5)
ax.set_title('SST (April 1998)',fontsize=20)

### 目盛を描く緯度経度の値を設定 ###
ax.set_xticks(np.arange(0,360.1,60),crs=ccrs.PlateCarree())
ax.set_yticks(np.arange(-90,90.1,30),crs=ccrs.PlateCarree())
    
### 目盛の表示形式を度数表記にする ### 
latfmt = LatitudeFormatter()
lonfmt = LongitudeFormatter(zero_direction_label=True)
ax.xaxis.set_major_formatter(lonfmt)
ax.yaxis.set_major_formatter(latfmt)
ax.axes.tick_params(labelsize=16)

### 描画範囲を指定 ###
ax.set_extent([120,270,10,70],ccrs.PlateCarree())

### 等値線 ###
clevs = np.arange(0,35,5)
im = ax.contour(lon,lat,sst_april,clevs,transform=ccrs.PlateCarree(),colors='k',extend='both')
im.clabel(fmt='%1.0f',fontsize=14)

### Shade ###
im = ax.contourf(lon,lat,sst_april,clevs,transform=ccrs.PlateCarree(),cmap="Spectral_r",extend="both")

### Colorbar ###
cb = plt.colorbar(im, pad=0.15, aspect=20, shrink=0.7,orientation="horizontal")
cb.set_label("[$^\circ$C]",labelpad=5,size=16)
cb.ax.tick_params(labelsize=16)

plt.show()

### 複数枚書いてみる ###
sst_98 = sst[(year==1998)]

def main():
    title = ['Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec']

    fig = plt.figure(figsize=(30,5))
    
    for i in range(0,12):
        ax = fig.add_subplot(2,6,i+1,projection=ccrs.PlateCarree(central_longitude= 195))
        ax.add_feature(cfeature.LAND)
        ax.set_title(title[i],fontsize=18)
        ax.coastlines(resolution='50m',lw=0.5)
        
        ### 目盛を描く緯度経度の値を設定 ###
        ax.set_xticks(np.arange(0,360.1,60),crs=ccrs.PlateCarree())
        ax.set_yticks(np.arange(-90,90.1,30),crs=ccrs.PlateCarree())
    
        ### 目盛の表示形式を度数表記にする ### 
        latfmt = LatitudeFormatter()
        lonfmt = LongitudeFormatter(zero_direction_label=True)
        ax.xaxis.set_major_formatter(lonfmt)
        ax.yaxis.set_major_formatter(latfmt)
        ax.axes.tick_params(labelsize=15)

        ### 描画範囲を指定 ###
        ax.set_extent([120,270,10,70],ccrs.PlateCarree())
        
        clevs = np.arange(0,35,5)
        im = ax.contourf(lon,lat,sst_98[(i)],clevs,transform=ccrs.PlateCarree(),cmap="Spectral_r",extend="both")

    cax = plt.axes([0.26,0.05,0.5,0.05]) #[左下のx位置,左下のy位置,図に対する横の長さの比,図に対する縦の長さの比]
    cb = plt.colorbar(im,cax=cax,orientation="horizontal")
    cb.set_label("[$^\circ$C]",labelpad=5,size=15)
    cb.ax.tick_params(labelsize=15)

    fig.suptitle('SST in 1998',fontsize=20,y=0.95)
    plt.subplots_adjust(hspace=0.2)
    plt.subplots_adjust(wspace=0.5)
    
    plt.show()
    
if __name__ == '__main__':
    main()