Sruise Report, RV ATAIR, Cruise 0671013-1, Bremerhaven —- Skagen - Aberdeen, 19 Jul — 11 Aug 2022 | 35

7.

Underway Measurements

A variety of routine underway measurements were carried out during cruise 067/073-1. Among
the acquired data of interest were navigational information, near surface hydrography (temperature,
 conductivity, and thus salinity) measured by the vessel's thermosalinograph (TSG),
near-surface fluorescence and turbidity obtained from a dual-wavelength ECO sensor attached
to the TSG system, as well as meteorological parameters and water temperature recorded by
the weather station operated by the German Weather Service (DWD) under the identifier
CVTKCAL. Navigational and meteorological data was recorded from the beginning of the
zruise on, recording of additional underway data was interrupted during the port stay in Skagen,
 Denmark, when transiting through the Dutch EEZ, and while operating within the Swedish
territorial waters. It was resumed afterwards. Data was logged in time steps of 1 second by the
vessel’s DSHIP system. All underway data relevant to this cruise were exported from the
DSHIP database on a daily basis. Water depths were measured by a single-beam echosounder
 along the cruise track and on hydrographic stations. Depths provided by the vessel’s
acho-sounding device result in water depths when the vessels’s draft of 5 m is added. Any
further processing or quality control of water depth data was not carried out.

7.1

Ship’s Meteorological Staticn

The autonomous weather station installed aboard RV ATAIR and operated by the DWD automatically
 records every second all meteorological standard parameters like wind speed and
direction, air temperature and air pressure, relative humidity and surface water temperature
and others. While corresponding data is sent directly to the Global Telecommunication System
(GTS), it is also fed into the DSHIP database. Figure 7.1 provides an overview on the metearological
 conditions encountered during cruise 067/073-1. Raw data was smoothed by applying
 a moving median filter.

The average air temperature throughout the cruise was 16.1°C, temperatures ranged from
10.7°C to 30°C, the latter at the very beginning of the cruise. Maximum water temperatures
axceeded 20°C right at the beginning of the cruise, minum water temperatures were 11.7°C,
the average was 15.9°C. Average air pressure was 1017.2 hPa, and pressures ranged from
1004.2 hPa to 1027.9 hPa. Notable periods of absolute wind speeds exceeding 7 Bf were
observed on 21 July 2022, 26 July 2022, 02 August 2022, and on 05/06 August 2022. The
average wind speed throughout the cruise was 7.82 m/s, which corresponds to a wind strength
of 4 Bf. The maximum wind speed was 20.5 m/s, corresponding to 8 Bf. Figure 7.2 displays
the spatial distribution of absolute wind speeds and directions (15 min average values) along
the cruise track.