绘制metpy SkewT时获取错误消息

Question

我正在使用WRF输出数据绘制SkweT，这里是代码：

import wrf
from netCDF4 import Dataset
import matplotlib.pyplot as plt
import numpy as np
import metpy.calc as mpcalc
from metpy.plots import SkewT
from metpy.units import units
wrfin = Dataset(r'wrfout_d02_2022-06-19_00_00_00')
lat_lon = [25.0803, 121.2183]
x_y = wrf.ll_to_xy(wrfin, lat_lon[0], lat_lon[1])
p1 = wrf.getvar(wrfin,"pressure",timeidx=0)
T1 = wrf.getvar(wrfin,"tc",timeidx=0)
Td1 = wrf.getvar(wrfin,"td",timeidx=0)
u1 = wrf.getvar(wrfin,"ua",timeidx=0)
v1 = wrf.getvar(wrfin,"va",timeidx=0)
p = p1[:,x_y[0],x_y[1]] * units.hPa
T = T1[:,x_y[0],x_y[1]] * units.degC
Td = Td1[:,x_y[0],x_y[1]] * units.degC
u = v1[:,x_y[0],x_y[1]] * units('m/s')
v = u1[:,x_y[0],x_y[1]] * units('m/s')
skew = SkewT()
skew.plot(p, T, 'r')
skew.plot(p, Td, 'g')
my_interval =  np.arange(100, 1000, 50) * units('mbar')
ix = mpcalc.resample_nn_1d(p, my_interval)
skew.plot_barbs(p[ix], u[ix], v[ix])
skew.plot_dry_adiabats()
skew.plot_moist_adiabats()
skew.plot_mixing_lines()
skew.ax.set_ylim(1000, 100)
skew.ax.set_xlim(-60, 40)
skew.ax.set_xlabel('Temperature ($^circ$C)')
skew.ax.set_ylabel('Pressure (hPa)')
plt.savefig('SkewT.png', bbox_inches='tight')

但运行错误消息，尤其是在块中：

    **raise DimensionalityError(
pint.errors.DimensionalityError: Cannot convert from 'dimensionless' (dimensionless) to 'millibar' ([mass] / [length] / [time] ** 2)**

mpcalc.resample_nn_1d似乎不起作用。

我该怎么解决？

python版本：3.9.7

metpy版本：0.12.0

Answer 1

我的猜测是wrf.getvar()返回NumPy掩码数组，与Pint Quantity实例相比(与普通数组相比(，它们的行为有点奇怪。我建议尝试这种语法；附上"；单位：

p = units.Quantity(p1[:,x_y[0],x_y[1]], 'hPa')
T = units.Quantity(T1[:,x_y[0],x_y[1]], 'degC')
Td = units.Quantity(Td1[:,x_y[0],x_y[1]], 'degC')
u = units.Quantity(v1[:,x_y[0],x_y[1]], 'm/s')
v = units.Quantity(u1[:,x_y[0],x_y[1]], 'm/s')

此外，提醒一下MetPy0.12有点过时了，我建议您尽快更新到最新版本(目前为1.3.1(。