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.