80 
Air temperatures in the area of the boundary waters briefly dropped below 0 °C during the first days 
of December (Figure 8.1). Until 20 December, the temperatures were mostly just above 0 °C, with the 
exception of two 2-day periods with light frost. This led to continuous cooling of the water in the inner 
fairways and Pomeranian Bay (Figures 8.2 and 8.3). On 22/23 December, all monitoring stations at 
Szczecin Lagoon simultaneously reported the first ice. From 4 to 6 January, water temperatures in the 
southern part of the Pomeranian Bay also dropped to near zero (Figure 8.3). From 17 January until the 
end of the winter season, the air temperatures were mostly positive. The sum of coldness (sum of nega 
tive daily means of air temperature) at the Ueckermunde station in the winter of 2001/02 was 57.5 °C. 
This value was mostly reached as early as mid-January (Figure 8.5). 
Characteristics of the 2001/02 ice season in the Szczecin Lagoon and Pomeranian Bay 
In the Szczecin Lagoon, the 2001/02 ice season began on 22 December and lasted until the third dec 
ade of January, without major interruptions (Figure 8.4). In the waters investigated, the long-term mean 
of first ice formation during mild winters is 23 December (Sztobryn et al, 1999). 
December January 
2001/02 .3° f. )i 1 
Szczecin, harbour 
Trzebiez, Roztoka Odranska (river mouth) 
Zalew Szczecinski 
Ueckermunde, harbour 
Ueckermunde, harbour to river mouth 
Ueckermunde. Stettiner Haff 
Kamin. Stettiner Haff 
Kamminke, harbour and vicinity 
Swinoujscie - Szczecin, fairway 
Swinoujscie, harbour 
Swinoujscie, sea area 
l'" —’ M ‘ П 
1 -U-i- 
10 ' 20 "Jo lü 20 io 
December January 
Figure 8.4. Ice concentration and thickness in the Szczecin Lagoon during the winter of 2001/02 
4 5 
4 
3 
ЛЛЛЛЛЛЛ 
3 A 
a b с а 
A - Ice thickness: length of period 
1: < 5 cm 2: 5-10 cm 
3: 11-15 cm 4: 16-30 cm 
5: 31-50 cm 
В - Ice concentration: length of period 
a: <7/10 b: 7/10-8/10 
c: 9/10-10/10 
ЛЛЛЛЛЛ - Ridged ice 
In mild winters, the last ice in the Szczecin Lagoon is normally observed on 16 February. In the ice 
winter of 2001/02, it disappeared 3 weeks earlier. The extreme values for this parameter are between 27 
November and 11 March. 
The length of the ice season in Szczecin Lagoon and in the harbours in its vicinity varies between 17 
and 38 days. In the season under review, 13 days with ice were recorded in the area between 
Ueckermunde harbour and the mouth of the river Uecker, and 38 days in the harbour of Kamminke. The 
mean value for mild ice winters in Szczecin Lagoon is 29 days. In the near-shore zone of the Lagoon, ice 
may be present on maximally 57 days during a mild winter. 
A complete ice cover was only observed for a short period in the eastern part of Szczecin Lagoon. In the 
near-shore region of Kleines Haff, the ice did not form a complete fast-ice cover until early January. 
Toward the middle of the month, the thickness of level ice reached maximally 7 to 15 cm (Figure 8.5). 
Rafting of ice occurred temporarily in the fairways to Ueckermunde and Szczecin - Swinoujscie. There 
were several days on which low-powered vessels had difficulties navigating in Szczecin Lagoon: in the 
near-shore zone of the Lagoon in the period between 4 and 26 January, and in its central part between 9 
and 25 January.