WRF_out文件绘制降水空间填色图时出现白线

taiyang · 发表于 2022-4-12 09:58:42

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使用ERA5作为初始场，运行WRF模式，对输出的文件进行处理绘制，使用python降水填色空间场。出现以下问题：
- 当指定levels时，在赤道以北3°左右会出现一条白线，已经检测了该范围内的数据结果，并没有异常值
- 只有使用python提取数据绘制填色图时出现此问题；
- ncl、ncview、xarray.plot()都没有该问题
微信图片_20220412095409.png

绘图code如下：

from wrf import getvar,get_cartopy
import xarray as xr
import numpy as np
import matplotlib.pyplot as plt
import cartopy.crs as ccrs
import cartopy.feature as cfeature
from cartopy.mpl.ticker import LongitudeFormatter,LatitudeFormatter
from netCDF4 import Dataset as nc
import cmaps
ncfile=nc(r'D:/wrf/wrfout_d01_2004-06-25_04_00_00.nc')

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希望大家提提建议

taiyang · 发表于 2022-4-12 10:01:18

from wrf import getvar,get_cartopy
import xarray as xr
import numpy as np
import matplotlib.pyplot as plt
import cartopy.crs as ccrs
import cartopy.feature as cfeature
from cartopy.mpl.ticker import LongitudeFormatter,LatitudeFormatter
from netCDF4 import Dataset as nc
import cmaps
ncfile=nc(r'D:/wrf/wrfout_d01_2004-06-25_04_00_00.nc')
slp=getvar(ncfile, "slp")
rain_exp=np.array(getvar(ncfile, "RAINNC"))
rain_con=np.array(getvar(ncfile, "RAINC"))
rain_tot=np.array(rain_exp+rain_con)
rain1=getvar(ncfile, "RAINNC")
rain2=getvar(ncfile, "RAINC")
lon=getvar(ncfile, "XLONG")
lat=getvar(ncfile, "XLAT")
rain=(rain1+rain2)
fig = plt.figure(figsize=(10, 14),dpi=100)
box=[0,180,-30,30.5]
scale='50m'
xstep, ystep = 40, 15
#######plot####################
def make_map(ax, title):
# set_extent set crs
ax.set_extent(box, crs=ccrs.PlateCarree())
land = cfeature.NaturalEarthFeature('physical',
'land',
scale,
edgecolor='grey',
facecolor='none',zorder=1
)
ax.add_feature(land) # set land color
ax.coastlines(scale) # set coastline resolution
# set coordinate axis
ax.set_xticks(np.arange(box[0],box[1], xstep),crs=ccrs.PlateCarree())
ax.set_yticks(np.arange(box[2], box[3]+ystep, ystep),crs=ccrs.PlateCarree(central_longitude=0))
ax.xaxis.set_major_formatter(LongitudeFormatter(zero_direction_label =False))#经度0不加标识
ax.yaxis.set_major_formatter(LatitudeFormatter())
ax.set_title(title, fontsize=15, loc='left',pad=10)
ax.tick_params(which='major',
direction='out',
length=8,
width=0.99,
pad=3,
labelsize=15,
bottom=True, left=True, right=False, top=False)
return ax
ax0=fig.add_subplot(311,projection=ccrs.PlateCarree())
ax0=make_map(ax0,'2004-06-25_04--RAINC(set levels(0,5.1,0.1))')
cb0=ax0.contourf(lon,lat,rain2,transform=ccrs.PlateCarree(),levels=np.arange(0,5.1,0.1))
c0=fig.colorbar(cb0,ax=ax0,shrink=0.8,pad=0.05,aspect=13)
ax1=fig.add_subplot(312,projection=ccrs.PlateCarree())
ax1=make_map(ax1,'2004-06-25_04--RAINNC(set levels(0,5.1,0.1))')
cb1=ax1.contourf(lon,lat,rain1,transform=ccrs.PlateCarree(),levels=np.arange(0,5.1,0.1))
c1=fig.colorbar(cb1,ax=ax1,shrink=0.8,pad=0.05,aspect=13)
ax2=fig.add_subplot(313,projection=ccrs.PlateCarree())
ax2=make_map(ax2,'2004-06-25_04--RAINNC+RAINC(set levels(0,5.1,0.5))')
cb2=ax2.contourf(lon,lat,rain,transform=ccrs.PlateCarree(),levels=np.arange(0,5.1,0.5))
c2=fig.colorbar(cb2,ax=ax2,shrink=0.8,pad=0.05,aspect=13)
plt.show()

复制代码

taiyang · 发表于 2022-11-11 10:12:15

问题解决了，原因是，模式中的lon的排列是（0-180,-180-0）导致的，将负的那一部分加上360.使得lon的排列范围是0-360，就解决该问题啦~

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