数据源

# 数据环境配置：使用本地数据目录（可用环境变量 CEDARKIT_NOTEBOOK_DATA_ROOT 覆盖）
from cedarkit_notebook.data import get_data_root, get_dataset_query

DATA_CLASS = "cmadaas"
STORAGE_BASE = str(get_data_root())

import pandas as pd
from reki.data_finder import find_local_file
from reki.format.grib.eccodes import load_field_from_file

# 起报时次与预报时效固定为本地已下载数据（见 data/metadata/cma-meso-3km.yaml）
query = get_dataset_query("cma-meso-3km")
start_time = pd.to_datetime(query["start_time"], format="%Y%m%d%H")
forecast_time = pd.to_timedelta(query["forecast_time"])

file_path = find_local_file(
    "cma_meso_3km/grib2/orig",
    start_time=start_time,
    forecast_time=forecast_time,
    data_class=DATA_CLASS,
    storage_base=STORAGE_BASE,
)

t_2m_field = load_field_from_file(
    file_path,
    parameter="2t",
) - 273.15
t_2m_field