################# Radiosonde data sources

This file documents the original radiosonde datasets used in this study.
It describes the data sources, access procedures, and variables used.

Derived datasets used to generate the figures presented in the paper are provided
separately as frozen datasets (DATA_FigX.csv), together with the associated
Python plotting scripts.

###Contents

Météo-France operational radiosonde data
Operational radiosonde observations at Nîmes and Trappes.
ECMWF ERA5 reanalysis

GRUAN radiosonde data (Trappes)
Reference radiosonde observations from the GRUAN network.

1. Météo-France operational radiosonde data

Stations :
Nîmes (France) : ID station 07645
Trappes (France) : ID station 07145

## Official data source

Météo-France public data portal:
https://donneespubliques.meteofrance.fr/?fond=produit&id_produit=97&id_rubrique=33

Data access procedure: 
1. Access the Météo-France public data portal
2. Select “Téléchargement de données archivées”.
3. Choose the year and month of interest.
4. Download the radiosonde data files.
5. Keep the files starting by 07145 for the Trappes Station and 07645 for the Nimes-Courbessac station and ending by "_complet.csv".

### Variables used

The following variables are used in this study:

p_niv : pressure (Pa)
altitude : altitude (m)
t : air temperature (K)
td : dew point temperature (K)
dd : wind direction (°)
ff : wind speed (m/s)
dur_dep : elapsed time since balloon launch (s)
dep_lat : balloon latitudinal displacement from launch site (°)
dep_lon : balloon longitudinal displacement from launch site (°)



2. GRUAN radiosonde data — Trappes
Station :
Trappes (France)

###Data source

GRUAN (GCOS Reference Upper-Air Network) radiosonde data,
accessed via the Climserv platform (IPSL).

###Data access

Access to GRUAN data requires a user account.

Account request form:
https://mesocentre.ipsl.fr/account-opening/

After account approval, GRUAN radiosonde datasets can be accessed and
downloaded through the Climserv services.

GRUAN data are not freely redistributable.
Users must download the data directly from the Climserv platform and comply
with GRUAN data use policies.

###Variables used

The following variables are used in this study:
date : sounding date and time
rh : relative humidity (%)
level : pressure (hPa)
alt : altitude (m)
t : air temperature (K)
arl_lat : balloon latitude along the ascent (°)
arl_lon : balloon longitude along the ascent (°)



3. ECMWF ERA5 reanalysis

## Data source

ECMWF ERA5 reanalysis data portal:
https://cds.climate.copernicus.eu/datasets/reanalysis-era5-complete?tab=overview

Data resolution : 
horizontal resolution:  0.125°
temporal resolution: 1 hour

### Variables used

The following variables are used in this study:
q : specific humidity (kg/kg)
pressure
t : temperature (K)
latitude (°)
longitude (°)
time (UTC)