• 在nc数据处理时，以ERA5的小时数据为例，使用的时间为UTC，不同时区存在时间上的差异，如何将其转化为北京当地的时间呢?

• https://confluence.ecmwf.int/display/CKB/ERA5%3A+data+documentation
  

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Mon Aug  7 20:53:05 2023

@author: xpji
"""



import xarray as xr
import numpy as np
import pandas as pd
from datetime import datetime
from dateutil import tz


def convert_time_zone(input_path, output_path, start_time, end_time):
    # 设置时区
    from_zone = tz.gettz('UTC')
    to_zone = tz.gettz('Asia/Shanghai')

    # 打开NetCDF文件
    pre = xr.open_dataset(input_path)

    # 获取时间变量
    time_str = pd.date_range(start=start_time, end=end_time, freq='1H').strftime('%Y-%m-%d %H:%M:%S')

    result = []
    for t in time_str:
        dt = datetime.strptime(t, '%Y-%m-%d %H:%M:%S').replace(tzinfo=from_zone)
        dt = dt.astimezone(to_zone)
        print('原始时间:', t, '北京时间：', dt)
        result.append(dt)

    result_formatted = []
    for dt in result:
        dt_beijing = dt.strftime('%Y-%m-%d %H:%M:%S')
        result_formatted.append(dt_beijing)

    # 将result_formatted转换为与pre数据集的维度相同的DataArray
    time_beijing = xr.DataArray(result_formatted, dims='time')

    # 创建新的数据集
    pre_beijing = pre.copy(deep=True)
    pre_beijing['time'] = time_beijing

    # 保存为新的NetCDF文件
    pre_beijing.to_netcdf(output_path)

    print("数据已保存为:", output_path)


convert_time_zone('./wind_850hpa_hourly.nc', 
                  './wind_850hpa_hourly_beijing.nc', 
                  '2004-06-15 00:00:00', '2004-06-30 18:00:00')