Fig. 6: Lagrangian time evolution of atmospheric variables along DI trajectories.

Relative to the start of descent (0 h): a pressure level (hPa), b potential temperature (K), c specific humidity (g kg⁻¹), d relative humidity (%), e ocean evaporation (W m⁻²), and f equivalent potential temperature (K). Note the atmospheric variables are traced along the three-dimensional location of the DI, while surface ocean evaporation (being a two-dimensional variable) is taken by considering the DI airmass horizontal location. The solid black line connects the mean from each time step, and the cyan and gray shadings represent the 5–95th and 25–75th percentile range, respectively. The coherent descent is diagnosed within the 0–48 h window, with an increase in pressure of more than 400 hPa.