Dataset: Research data for "Sensitivities of warm conveyor belt ascent, associated precipitation characteristics and large-scale flow pattern - insights from a perturbed parameter ensemble"

This archive contains warm conveyor belt (WCB) trajectory data from a perturbed parameter ensemble (PPE) presented in the manuscript "Sensitivities of warm conveyor belt ascent, associated precipitation characteristics and large-scale flow pattern - insights from a perturbed parameter ensemble" published in the Quartely Journal of the Royal Meteorological Society.

The study presents a 70-member perturbed parameter ensemble (PPE) built with the Icosahedral Nonhydrostatic (ICON) modelling framework and analyses sensitivities of WCB ascent and its characteristics to perturbations of cloud microphysical parameters and environmental conditions. WCB ascent behaviour and associated properties are quantified based on online trajectories which are included in this archive. Details about parameter perturbations and variables stored along WCB trajectories are provided in the original publication.

The data set includes the following: (i) Lagrangian air parcel trajectories of WCB airstreams and respective properties from each PPE member (ID000-ID069), and (ii) values for the parameter perturbations.

(i) WCB trajectories and respective properties
Each file (PPE_WCB_trajs_ID*nc; in netcdf format) contains WCB trajectory data from one PPE member, representing the path in space (3D coordinates) and time (time step) of air parcels identified to belong to a WCB as well as characteristics in terms of variables at each time step; data are available 1-hourly and centered relative to the start of the WCB ascent phase at time = 0 h. WCB trajectory information is extended to time = -10 h to time = 58 h relative to the start of the ascent. The following variables are available (see Oertel et al., 2025 for more details):
(1) Basic WCB characteristics (longitude, latitude, pressure, altitude, temperature, potential vorticity, specific humidity, simulation lead time)
(2) Hydrometeor mass mixing ratios for cloud droplets, rain drops, ice, snow, and graupel
(3) Along flow integrated diabatic heating rates (ADH, in K; ADH for first and second saturation adjustment, vapor deposition on snow, ice, and sum of all frozen hydrometeors, riming, CCN activation, evaporation of rain and of melting ice hydrometeors, melting of frozen hydrometeor, freezing of rain, homogeneous freezing of cloud droplets, homogeneous and heterogeneous ice nucleation, long- and shortwave radiation, convection and turbulence parameterisations)
(4) Along flow integrated diabatic PV rates (APV, in PVU; APV for first and second saturation adjustment, vapor deposition on sum of all frozen hydrometeors, riming, evaporation of rain, melting of frozen hydrometeors, as well as total radiation, convection and turbulence parameterisations)

(ii) Values for the parameter perturbations
Both text files, EmulatorInputsDesign.csv and ValidationInputsDesign.csv, include the values for the parameter perturbations for each PPE member for the training (EmulatorInputsDesign.csv; PPE members ID000-ID049) and the validation (ValidationInputsDesign.csv; PPE members ID050-ID069) data sets, respectively. The training data set includes the first 50 members and the validation data set includes 20 additional members. The PPE includes five perturbed parameters, which are sea surface temperature (SST), cloud condensation nuclei (CCN), ice nucleating particles (INP), capacitance of ice and snow (CAP), and maximum supersaturation (SAT). Each column lists one perturbed parameter for the respective simulation: V1 (SST), V2 (CCN), V3 (INP), V4 (CAP), and V5 (SAT). The perturbed parameter values are explained in more detail in Oertel et al. (2025).