This repository contains references to the atmospheric measurements and their post-processing steps of the cruise *Atlantic Transit * with the identifier PS147 on the RV Polarstern.
The cruise started March 12, 2025 in Stanley, Falkland, and ended April 14, 2025 in Bremerhaven, Germany.
Further general information about the cruise can be found in the expedition programme and the cruise report.
The data from the different instruments have been standardised with the shipspy package to simplify the comparison between different instruments and campaigns as much as possible. For reprocessing the data run reprocess.sh.
The continuous measurements (Ship integrated sensors, PAMOS, and IWV) contain data of the time period from 2025-03-13 10:00 until 2025-04-13 22:00 with some data gaps specified in shipspy_settings/PS147_sections.txt. The start point is at 49.99˚S and 56.69˚W, the end point is at 53.86˚N and 7.77˚W. Radiosondes were launched once a day at 11 UTC except from the moist tropics where the launch frequency was 3 hours. The data is divided in three sections by the coordinate section: section 0 is the first part until the moist tropics, section 1 is the crossing of the moist tropics, and section 2 is the last part until Bremerhaven.
Here we show how to plot the radiosonde data within the ITCZ using the section coordinate to select the period.
fig, axs = plt.subplots(5,2,figsize=(12,12),sharex=True)
radio_level2 = xr.open_dataset("ps147_radiosondes_level2.nc")
itcz = radio_level2.groupby("section")[1]
vars_to_plot = ["t_air", "dp", "theta", "p_air", "u_air", "v_air", "wspd", "wdir", "rh", "mr"]
for v, ax in zip(vars_to_plot,fig.get_axes()):
itcz[v].plot(x = "start_time", ax = ax)
ax.set_xlabel("")
plt.tight_layout()