fastmeteo 0.2.1

Fast interpolation for ERA5 data with Zarr

Fast Meteo

A super-fast Python package to obtain meteorological parameters for your flight trajectories.

Data

fastmeteo uses Analysis-Ready, Cloud Optimized (ARCO) ERA5 data from Google's Public datasets, which in turn is derived from Copernicus ERA5. Copernicus ERA5 data span from 1940 to present.

Beware that Google's ARCO ERA5 may not include more recent months.

You can discover the time interval covered as follows:

import xarray as xr
from fastmeteo.grid import arco_era5_url

dd = xr.open_zarr(arco_era5_url, chunks={"time": 48}, consolidated=True)
dd.coords

Checklist

Here are a few things you should know first:

• Synchronization of the data from the Google ARCO ERA5 store can be a little slow, as each hour of data is about 250MB.

• Once the data is available locally, the code is blazing fast.

• To share access for your group, a good practice is to set up fastmeteo on a server and use it in Server-Client mode.

• You can pre-sync the data using fastmeteo-sync command

Install

stable version

pip install fastmeteo

development version

pip install git+https://github.com/open-aviation/fastmeteo

or, if you prefer poetry:

git clone https://github.com/open-aviation/fastmeteo
cd fastmeteo
poetry install

Usage

Local mode

You can get the weather information for a given flight or position with the following code. Basic information on time, latitude, longitude, and altitude is needed.

import pandas as pd
from fastmeteo import Grid

flight = pd.DataFrame(
    {
        "timestamp": ["2021-10-12T01:10:00", "2021-10-12T01:20:00"],
        "latitude": [40.3, 42.5],
        "longitude": [4.2, 6.6],
        "altitude": [25_000, 30_000],
    }
)

fmg = Grid(local_store="/tmp/era5-zarr")

# Obtain weather information.
flight_new = fmg.interpolate(flight)

Server-client mode

When running the tool in a server-client mode. The following script can be used to start a FastAPI service on the server. It handles the flight date request and obtains Google ARCO data if the partition is not on the server. After that, it will perform the interpolation of weather data and return the final data to the client.

fastmeteo-serve --local-store /tmp/era5-zarr

At the client side, the following code can be used to submit and get the process flight with meteorology data.

import pandas as pd
from fastmeteo import Client

flight = pd.DataFrame(
    {
        "timestamp": ["2021-10-12T01:10:00", "2021-10-12T01:20:00"],
        "latitude": [40.3, 42.5],
        "longitude": [4.2, 6.6],
        "altitude": [25_000, 30_000],
    }
)

# define the client object
client = Client()

# send the flight and receive the new DataFrame
flight_new = client.submit_flight(flight)

Pre-sync your data

You can use the following command to pre-sync the data:

fastmeteo-sync --local-store /tmp/era5-zarr/ --start 2022-01-01 --stop 2022-02-01

Above example will download the data for January 2022 to your /tmp/era5-zarr/ folder.

Options

Meteorological features

If you want more or different meteorological features than wind, temperature and humidity, specify the desired feature list as follows:

features = [
    "u_component_of_wind",
    "v_component_of_wind",
    "convective_available_potential_energy",
]

fmg = Grid(local_store="/tmp/era5-zarr", features=features)

flight_new = fmg.interpolate(flight)

All available parameters can be found at: https://codes.ecmwf.int/grib/param-db/

You should use feature names in lower case with underscores for the list of features in fastmeteo.

Pressure levels

By default, fastmeteo extracts features for the following pressure levels (hPa), out of all available levels:

100, 125, 150, 175, 200, 225, 250, 300, 350, 400, 450,
500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000

You can also customize the desired levels (sorted), for example, as follows:

levels = [500, 600, 700, 800, 900, 1000]
fmg = Grid(local_store="/tmp/era5-zarr", levels=levels)

flight_new = fmg.interpolate(flight)