7 
NS "Rossiva" cruise to the North Pole 
During August 1990 the Soviet nuclear icebreaker "Rossiya" took a party of tourists from 
Murmansk to the North Pole and return. As the vessel was not fully booked, Detlev 
Quadfasel from the Institut für Meereskunde der Universität Hamburg, with the support 
of the BSH, took the opportunity to join the trip and performed XBT measurements 
using T-7 and T-5 probes. A Bathy Systems SA-810 controler and a Compaq SLT286 
laptop computer was used for data acquisition. Our assumption was confirmed that XBT 
drops in ice-covered areas would be challenging. The regular speed of the vessel is 14 
knots, but even in ice cover as thick as 2 m, the "Rossiya" proceeded with a speed of 
more than 10 knots. The probes had to be launched in open water, i.e. leads or small 
polynias. The size of these patches of open water varied between one and several 
hundred meters and only rarely exceeded a kilometer in size. Because broken ice in the 
wake of the vessel immediately destroyed the XBT wire, the sampling depth was limited 
by the length of the leads. Thus, of 170 probes launched in the ice regime, only half 
reached a depth of more than 350 m. Arctic Ocean conditions permitted calibration of 
the XBT record by providing a surface temperature at the freezing point or a subsurface 
temperature minimum in the halocline, which also lies close to the freezing point. In the 
case of temperatures recorded below the freezing point, therefore, the profiles have been 
adjusted by adding an offset to prevent unrealistically low temperatures. The scientific 
results of this cruise have been published by Quadfasel et al. (1991, 1993). 
Presentation of data 
An overview of the XBT measurements during 13 voyages of CMS "Köln Atlantic" and 
3 voyages of CMS "Monte Rosa" is summarized in Table 1, and the positions of all XBT 
drops are presented in Fig. 4. A presentation of all data is given separately in Tables, 
track plots, profile plots, and section plots for each vessels’ voyages. In addition to our 
regular ship-of-opportunity data, five transects measured by D. Quadfasel on board the 
Soviet nuclear icebreaker "Rossiya" (call sign: UPIG) are presented at the end of this 
report.