Vertical profiles of air temperature, humidity, pressure, and the horizontal wind vector measured by dropsondes (type RS904) released from Polar 5 during ACLOUD 2017. The profiles cover altitudes between the flight level of Polar 5 (typically 3-4 km) and the surface. Observations during ACLOUD cover a range of cloud-free and cloud covered situations over open ocean and closed sea ice west and north of Svalbard. The ASPEN software package was used to correct the raw data for the slow time response of the temperature sensor and to remove the known humidity bias. Data close to the aircraft, where the sensors still did not adjust to the outside temperature, and invalid measurements were removed by the quality check of ASPEN. To resolve temperature and humidity changes at cloud top the time response of the sensors has been corrected by an alternative method following (Miloshevich et al. 2004)

PLEASE NOTE On 2019-11-07 a corrected version 2 was added to this dataset containing one flight more, please use V2.