During the RV Senckenberg cruise in the German Bight near Helgoland, the autonomous research catamaran HALOBATES collected data on Essential Climate Variables (ECV), including sea surface temperature (SST) and salinity (SSS) and meteorological variables. The catamaran recorded SST and SSS at seven depths. Measurements covered the near-surface layer (NSL) from 30 to 100 cm with a high vertical resolution of approximately 10 cm and the first millimeter of the ocean, the sea-surface microlayer (SML), also known as the ocean's skin layer. Conductivity, temperature, and depth (CTD) sensors measured temperature and conductivity via a flow-through system on HALOBATES. Additional temperature sensors were mounted below the catamaran to measure the water temperature in situ at six depths in the NSL. Salinity was corrected with reference data from discrete samples, and biases between the sensors were removed for salinity and temperature, respectively. Two weather stations on the catamaran recorded relevant meteorological variables such as wind speed, wind direction, air temperature, humidity, and solar radiation. Additional meteorological sensors (optical laser disdrometer and two pyrgeometers) were mounted on RV Senckenberg, monitoring precipitation and incoming and outgoing longwave irradiance. The dataset consists of two HALOBATES operations conducted on 21 and 22 September 2022.

Quality Flag: Name - Implication0: Unknown - No information on data quality1: Good data - Certainly good data point2: Probably good data - Likely good data3: Questionable data - Data point needs extra attention4: Bad Data - Do not use