5

1.  GENERAL  DESCRIPTION  OF  STORM  SURGES

This  monograph  on  the  most  important  storm  surges  in  the  western  and  central  parts  of  the
southern  Baltic  Sea  coast  in  the  period  from  1976  to  2000  was  prepared  in  co-operation
between  the  Federal  Maritime  and  Hydrographic  Agency  of  Germany  (Bundesamt  für
Seeschifffahrt  und  Hydrographie,  Rostock  -  Hamburg)  and  the  Institute  of  Meteorology  and
Water  Management  (Instytut  Meteorologii  i  Gospodarki  Wodnej  -  Oddziat  Morski,  Gdynia)
following  the  conclusion  of  the  Polish/German  treaty  on  water  management  in  the  boundary
waters.  On  the  basis  of  this  treaty,  the  forecasting  and  warning  services  of  the  two  countries
co-operate  closely  within  the  framework  of  a  Polish/German  working  group  W-1  for  hydrology
and  hydrogeology  in  the  boundary  waters.  This  includes  the  exchange  of  hydrological  data,
information  about  coastal  defence  measures,  sea-ice  service,  and  joint  scientific  studies.
Because  of  the  separation  of  meteorological  and  hydrological  competences  in  Germany,  the
main  work  on  the  preparation  of  this  monograph  was  carried  out  by  the  maritime  branch  of
IMGW.
1.1  Brief  review  of  scientific  contributions
The  catalogue  of  storm  surges  on  the  Polish  coasts  in  the  years  1951-1975  (Majewski  ed.,
Dziadziuszko  and  Wisniewska  1983)  occupies  an  important  position  in  the  oceanographic
literature  of  Poland.  It  describes  sea  level  variations  at  three  Polish  gauges  -  Kotobrzeg,
Ustka  and  Wtadystawowo  -  during  75  of  the  most  interesting  surges  and  also  provides
descriptions  of  the  atmospheric  conditions,  e.g.  pressure  pattern,  wind  speeds  and  directions
(this  monograph  is  a  continuation  of  the  study  published  in  1983).  A  comparable  paper
discussing  storm  surges  on  the  German  Baltic  Sea  coast  does  not  exist.  The  only  similar
publication  is  „Untersuchungen  über  Sturmflutwetterlagen  an  der  deutschen  Ostseeküste“
(Investigation  of  weather  conditions  causing  storm  surges  on  the  German  Baltic  coast)  by
Erich  Kohlmetz  (1964),  which  covers  the  events  from  1872  to  1961.
Among  other  German  and  Polish  contributions,  Wielbihska  (1966)  gave  some  examples  of
the  dominant  influence  of  strong  onshore  wind  on  coastal  surges.  The  atmospheric
circulation  patterns  accompanying  storm  surges  on  the  Polish  coast  were  also  investigated
by  Wisniewska  (1978).
Both  the  Polish  and  German  bibliographies  of  the  second  half  of  the  20th  century  contain  a
series  of  studies  on  storm  surges,  which  were  published  in  various  journals,  as  conference
papers,  or  at  relevant  institutions.  Relevant  papers  were  published,  e.g.,  by  Kostrzewa  et  al.
(1983),  Majewski  (1989),  Malicki  and  Wielbihska  (1992),  Baerens  et  al.  (1994),  Hupfer  et  al.
(1994),  Neemann  (1994),  Dziadziuszko  and  Malicki  (1995),  Sztobryn  et  al.  (1995),  MBLU
(1996),  Beckmann  (1997),  Meinke  (1998),  Sztobryn  (2000),  Kowalska  (2001),  Stanistawczyk
(2001,2002)  and  Hupfer  et  al.  (2003).  Many  of  these  papers  focus  on  physics  and  statistics
without,  however,  providing  detailed  descriptions  of  individual  storm  surges.  Adequate
documentation  is  only  available  on  a  few  exceptional  events.  This  ongoing  loss  of  information
has  not  been  markedly  reduced  until  the  end  of  the  20th  century,  following  the  introduction  of
electronic  archiving  of  meteorological  and  hydrological  records.  In  this  respect,  the  present
study  closes  a  gap  in  the  available  descriptions  of  Baltic  storm  surges.
1.2  Definition  of  a  storm  surge
A  storm  surge  (after  Hydrological  Aspects  of  Combined  Effects  of  Storm  Surges  and  Heavy
Rainfall  on  River  Flow,  WMO  -  No.  704,  Geneva  1988)  has  been  defined  as  a  rapid  change
of  sea  level  above  the  level  that  would  be  observed  at  the  same  time  and  place  without  the
impact  of  stormy  winds.  In  the  International  Glossary  of  Hydrology  (WMO  -  Geneva  1992),  a
storm  surge  has  been  defined  as  an  elevation  of  the  sea  level  caused  by  the  passage  of  a
low  pressure  centre.
The  exact  definition  of  storm  surges  is  a  function  of  probability,  but  on  the  German  Baltic
coast  a  more  common  definition  of  a  storm  surge  is  the  occurrence  of  a  water  level  at  least
1m  above  the  generalized  mean  sea  level.  In  terms  of  tide  gauge  data,  this  means  at  least