Properties of identified ship tracks

The ship track database of is used, which used "day microphysics" images comprised of a composite of visible, near and thermal infrared channels were used to manually locate likely positions of ship tracks. Identification was assisted by examining the CDNC, calculated from the MYD06 level 2 cloud retrieval products from Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua satellite. The CDNC is calculated based on the adiabatic assumption, using the cloud optical depth and cloud effective radius from the MODIS MYD06 level 2 product. Ship locations were sourced from their automatic identification system (AIS) data, allowing an observed ship track to be linked to the generating ship. Local meteorology was gathered from the European Centre for Medium-Range Weather Forecasts ERA5 reanalysis data, and ships mass emission rates were calculated using their specific fuel consumption and estimated drag. Data labels: trackno: Ship track identifier (-) sox: SO emission rate (kg s^-1) cbh: Cloud base height (m) blh: Boundary layer height (m) cth: Cloud top height (m) spd_res: Relative velocity between ship velocity and wind velocity (m s^-1) nd_cln: Background cloud droplet number concentration (cm^-3) nd_pol: Ship track cloud droplet number concentration (cm^-3) cf_liq: Liquid cloud fraction (-) lwp: Liquid water path (g m^-2) t1000: Temperature at 1000 hPa (K) LTS: Low tropospheric stability (K) ctt: Cloud top temperature (K) ctrc: Cloud top radiative cooling (W m^-2) is_coupled: Flag for cloud coupling according to cloud base height indicator (cbh<1000 m)