Tuchen et al. 
Moored Velocity Observations at 0°N, 23°W 
TABLE 1 | List of the subsurface moorings at 0°N, 23°W as well as the deploying and recovering research cruises, and the start and end dates of the individual 
mooring periods. 
Mooring ID Deploying cruise Deployment date Recovering cruise Recovery date 
Moored observations/ 
LADCP measurements 
(recovering cruise) 
2611 (FO) 
9612 {F1} 
9613 {F2) 
KPO-1001 
RV L’Atalante PI RATA-FR10 
RV L’Atalante PIRATA-FR12 
RV Le Suroit PIRATA-FR13 
RV Meteor M68/2 
14.12.2001 
12.02.2004 
RV Le Suroit PI RATA- FRI 1 
RV Le Suroit PIRATA-FR13 
53V Meteor M68/2 
3V L’Atalante IPMGEOMAR4 
3V Meteor M80/1 
21.12.2002 
29.05.2005 
19.06.2006 
01.03.2008 
10.1594/PANGAEA.924689 
10.1594/PANGAEA.924690 
10.1594/PANGAEA.924692 
29.05.2005 
10.1594/PANGAEA 924693 
10.1594/PANGAEA. 811565 
10.1594/PANGAEA 924780 
10.1594/PANGAEA 811718 
10.1594/PANGAEA 924781 
10.1594/PANGAEA 846777 
10.1594/PANGAEA 923604 
10.1594/PANGAEA. 846763 
10.1594/PANGAEA.923986 
10.1594/PANGAEA. 869634 
10.1594/PANGAEA.908544 
0.1594/PANGAEA. 877351 
10.1594/PANGAEA.924247 
0.1594/PANGAEA.915871 
10.1594/PANGAEA 904026 
10.1594/PANGAEA 915873 
10.1594/PANGAEA.924782 
10.1594/PANGAEA.941181 
10.1594/PANGAEA.941190 
10.1594/PANGAEA.941186 
Moored current velocity data from the subsurface mooring and LADCP measurements (fram the 2008 cruise onward) can be accessed through their individual links in the PANGAEA 
reD0sSItOory. 
subsampled to a temporal resolution of 12 hours. The vertical 
gap that occurs between adjacent ADCPs was filled by 
linear interpolation. 
Current velocity data from the upward-looking ADCP of the 
most recent Kiel Physical Oceanography (KPO) mooring KPO- 
1210 is still under examination since the instrument compass was 
found to have not worked properly. Consequently, these data are 
not included in the data set presented here, but will potentially be 
included in a future update, once a satisfactory solution is found. 
As part of a case study to investigate the transfer of wind 
momentum across the air-sea interface and the diurnal cycle of 
the upper ocean, a downward-looking 600-kHz ADCP was 
attached to the PIRATA moored surface buoy for eight 
months between October 2008 to June 2009 (Wenegrat et al., 
2014; Wenegrat and McPhaden, 2015). This ADCP covered a 
depth range between about 4 to 35 m with vertical resolution of 
0.75 m and hourly temporal resolution. Since data from the 
upward-looking KPO ADCP is generally limited to data below 
20 m due to reflection at the ocean surface, the shallow ADCP 
provides a valuable addition. 
depths. The first moorings were usually equipped with three to 
four mechanical Rotor Current Meters (RCMs) which have been 
gradually replaced by acoustic current meters such as Argonauts 
or Aquadopps. Mechanical current meters occasionally failed 
and are generally more vulnerable to physical obstructions than 
acoustic current meters. Consequently, since February 2018, only 
Aquadopps are being installed in the subsurface mooring 
providing reliable records of horizontal current velocity with a 
high temporal resolution of 1 or 2 hours. During the first three 
deployments, current meters were used more extensively to cover 
depths between 800 to 1500 m (Bunge et al., 2008). 
For the final data product, only quality-controlled current 
meter data were included leading to an exclusion of five RCMs 
between 2006 to 2014. Analogously to ADCP data, current meter 
velocities were 40-hour low-pass filtered to remove tidal 
velocities and then interpolated to a 12-hour temporal 
resolution. Several current meters were equipped with a 
pressure sensor. If pressure was recorded, the temporal mean 
of the pressure time series sets the equivalent depth at which the 
current meter data were included in the final data product. 
Otherwise, the nominal depth/pressure was used. Furthermore, 
current meter data were excluded if they substantially intersected 
with ADCP data. This was the case for one RCM, three 
Argonauts, and three Aquadopps all located between 750 to 
Current Meter Measurements 
An efficient way to complement long-range current velocity 
measurements is the deployment of current meters at discrete 
Zrontiers in Marine Science | www frontiersin oru 
une 2022 | Valume 9 | Article 91097