MURSYS - North Sea and Baltic Sea - Report 1 2007





the emblem of the BSH
   
 

MURSYS - North Sea and Baltic Sea - Report 1 2007

   
 
 

Marine Environmental Reporting System - Abstract - Reporting Period: 1 January - 30 June 2007

North Sea

Weather

January 2007 started very mild and windy in the North Sea region, with monthly mean temperatures of 6 to 7 °C, about 5 K above the long-term mean. A series of low-pressure systems brought 95 to 140 mm precipitation, about twice as much as expected during this month. Some snow fell at the end of January. A number of strong low-pressure systems caused gale force winds of 8 Bft or more in the German Bight in 25 % of the time, mostly (80 %) from southwesterly to northwesterly directions. 40 to 50 hours of sunshine were recorded, which was 10 % below normal in most places but about 10 % above normal in the area of the North Frisian islands and coast.
February marked the end of the mildest winter in over 100 years, with monthly mean temperatures of 4 to 5 °C, exceeding the long-term mean by 3 K. Precipitation, in the first ten days of the monthly locally as snow, was 60 to 80 mm, about twice the normal amount. Only 30 to 40 hours of sunshine were recorded, which was 40 to 60 % below normal. Moderate winds prevailed most of the time.
Average temperatures of 7 bis 8 °C in the spring month of March were about 4 K above the long-term means. Rainfall of mostly 45 to 55 mm was on the order of the long-term means, exceeding them only in a few places by up to 20 %; only Sylt (30 mm) was too dry. The number of sunshine hours was 5 times that of February; with 175 to 220 hours, normal values were exceeded by 60 - 80 %. Frequent strong winds occasionally reached gale force.
With mean temperatures of 10 - 12 °C, the dry and sunny month of April was the eighth month in series that was definitely too warm, with long-term April mean values exceeded by 4 K. Only 3 - 8 mm rain was recorded. The 250 to 265 hours of sunshine in April constituted a record value, with long-term means exceeded by 50 %. Weak winds prevailed, and 19 April was the only day with some stormy gusts.
Monthly mean temperatures in May reached 12 to 14 °C, which was only 1 - 2 K above the reference values. With rainfall of 60 - 75 mm in many areas, mean values were exceeded by up to 50 %. East Friesland and Helgoland even recorded 100 mm, which was about twice the normal quantity. The duration of sunshine, at 200 to 245 hours, was on the order of the long-term means. Winds were often fresh, gusting up to 8 - 9 Bft.
June was exceptionally warm and wet, with average monthly temperatures of 16 to 18 °C, which was 2 K above the values of the 1961 - 1990 reference series. In spite of a dry first half of the month, total rainfall still reached 70 - 130 mm, or 130 to 180 % of the monthly means. With cloudy weather prevailing in the second half of June, the 160 - 220 hours of sunshine were 10 - 20 % below normal. Winds were mostly weak, with some gale force gusts at the end of the month.

Water temperatures

The monthly mean value of sea surface temperatures (SST) is compared to the so-called climatological value (1971 - 1993). The ranking among the highest SST monthly mean values since 1971 is given in brackets.

The monthly mean SST in January 2007 was 8.3 °C, which was 1.7 K above the climatological mean (rank 1 among the highest January mean SST since 1971).
The mean SST in Februar, at 7.2 °C, was 1.5 K above the climatological mean (rank 4).
In March, the mean SST was 7.1 °C, which was 1.4 K above the climatological mean (rank 2).
The monthly mean SST in April was as high as 8.4 °C, exceeding the climatological mean by 1.7 K (rank 1).
SST in May averaged 10.2 °C, 1.1 K above the climatological mean (rank 4).
In June, the mean sea surface temperature rose to 13.2 °C and exceeded the climatological mean by 1.2 K (rank 4).

Surface runoff

During the first half of 2007, Elbe runoff (Neu-Darchow gauge station) was somewhat higher than the monthly runoff means of the years 1926 - 2004 in February, and slightly lower in March. Runoff in the other months was below the long-term means (much lower in April and May).
Also the river Weser (Intschede gauge station) had lower-than-average runoff in April and May, while in the other months the 1951 - 2004 runoff means were exceeded slightly (January and Juni) or markedly (February, March).
Ems runoff (Versen gauge station) was below the long-term mean of 1951 - 2004 in April; the other months had runoff volumes exceeding the mean reference values.
The Rhein runoff means (Rees gauge station) in January, February and June were on the order of the 1931 - 2004 reference means. They clearly exceeded the long-term means in March but were lower in April and May.

Ice conditions

No ice formed on the German North Sea coast in the first half of 2007 due to mild weather.

Baltic Sea

Weather

An unusually mild and windy January 2007 led to monthly mean temperatures of 5 - 6 °C in the Baltic Sea region, which was 5 - 6 K above the mean values of the 1961 - 1990 reference period. Rainfall ranging from 65 mm on the coast of Vorpommern to 150 mm on the east coast of Schleswig-Holstein was about twice the normal quantity. There was some local snow at the end of the month. W - SW winds, often with gale-force gusts, blew in more than 80 % of the time. The 30 - 45 hours of sunshine recorded in the western Baltic region were below the mean values in most areas, and 20 % above the mean values in the southern Baltic Sea region. On the island of Rügen, the sun shone on 58 hours, which was 55 % above normal.

Also in the Baltic region, February marked the end of the mildest winter in more than 100 years. With monthly mean temperatures of 2 - 3 °C, this winter was generally 2 - 3 K too warm. 50 - 70 mm rainfall was recorded in many areas, which was 2 - 3 times the monthly average (exceptions were the Pomeranian coast and Rügen, with about 34 mm). This month's 40 - 55 hours of sunshine was 10 - 40 % below normal. Winds generally were moderate, with occasional gusts.
With spring-like monthly mean temperatures of 6 - 7 °C, March was 3 - 4 K warmer than the long-term means. Rainfall around 40 mm in most areas slightly exceeded the mean values, but the island of Rügen was too dry (28 mm) and the Greifswalder Bodden region too wet (more than 60 mm). This month's 160 - 190 hours of sunshine was 25 to 75 % above normal. The wind freshened up sometimes and occasionally reached gale force in the second half of the month.
In the exceptionally dry, warm and sunny month of April, the monthly mean temperatures of 8 - 10 °C exceeded long-term means by 3 - 4 K. Rainfall in the entire month generally was as low as 3 mm, in some places 6 mm. This month's 260 to 299 hours of sunshine was 50 - 70 % above the mean values. Weak winds prevailed, with a few local gale-force gusts on 19/20 April.
May reached monthly mean temperatures of 12 - 14 °C, about 2 K above the reference values. Rainfall was above average: 65 - 110 mm in many areas, which was locally twice the monthly mean. The duration of sunshine, at 230 to 246 hours, was slightly below normal in most areas. Gusty winds occurred in areas affected by low-pressure systems.
Also the month of June was warmer and wetter than normal: the monthly mean temperatures of 16 - 17 °C were 1 - 2 K above the reference values. Although the first half of the month was nearly dry, total precipitation in June was 100 - 170 mm, about 180 - 280 % of the normal monthly means. The 190 - 235 hours of sunshine recorded in June was 10 - 20 % below normal. Winds were predominantly weak, but strong winds occurred toward the end of the month.

Water temperatures

Water temperatures (at 3 m depth) on the Baltic coast of Mecklenburg-Vorpommern off Warnemünde and Koserow in January 2007 averaged 6.2 °C and 4.6 °C, respectively, which was about 3 K higher than the values of the reference series (1997 - 2007 in Warnemünde; 1999 - 2007 in Koserow).
In February, water temperatures at Warnemünde exceeded the values of the long-term reference series by 2.7 K, with an average temperature of 5.1 °C which is unprecedented since the beginning of regular measurements. In Koserow, an average temperature of 2.2 °C was reached (0.7 K above the reference values).
Also in March, the mean temperatures of 5.9 °C in Warnemünde and 3.7 °C in Koserow were 2.7 K and 1.2 K, respectively, above the values of the reference series.
Im April, mean water temperatures of 8.4 °C in Warnemünde and 8.2 °C in Koserow were measured, which was 2.7 K and 2.2 K, respectively, above the reference series.
In May, the mean water temperatures of 12.1 °C in Warnemünde and 12.8 °C in Koserow were 1.6 K and 1,2 K, respectively, above the values of the reference series.
The mean water temperatures in June reached 15.2 °C and 18.0 °C, respectively, which was 0.2 K and 2.3 K above the reference values.

Water levels

Water levels on the Baltic Sea coasts of Schleswig-Holstein and Mecklenburg-Vorpommern in January 2007 reached monthly mean values that were 15 cm (Kiel) and 32 cm (Koserow) above the values of the reference series (1991 - 2000 in Schleswig-Holstein; 1996 - 2005 in Mecklenburg-Vorpommern). Extreme values were the minimum level of 387 cm recorded in Eckernförde on 1 January, and the maximum level of 629 cm in Koserow on 19 January.
Also February brought mean water levels exceeding those of the reference series by 23 cm in Kiel and 13 cm in Koserow. The highest water level was 617 cm, recorded in Schleswig on 9 February, and the lowest value was 448 cm in Flensburg on 28 February.
Also in March, the monthly mean values exceeded the reference means, in Schleswig-Holstein (Kiel) by 12 cm, and in Mecklenburg-Vorpommern (Warnemünde) by 9 cm. The minimum level of 410 cm was recorded in Flensburg on 18 March, and the maximum level of 636 cm in Lübeck on 22 March.
Mean water levels in April were 4 cm (Travemünde) and 8 cm (Koserow) above the reference values. The highest level of 571 cm on 30 April and the lowest level of 417 cm on 19 April were recorded In Flensburg.
In May, the monthly means were again higher than the reference means: in Travemünde by 13 cm, and in Warnemünde by 12 cm. The highest (554 cm on 27 May) and lowest levels (448 cm on 10 May) were again recorded in Flensburg.
Also in June, the mean water levels exceeded the reference means: in Schleswig-Holstein by 8 cm (Travemünde), and in Mecklenburg-Vorpommern by 1 cm (Warnemünde). The lowest water level (375 cm on 27.06.) and the highest water level (573 cm on 15 June) were once again measured at the Flensburg gauge station.

Surface runoff

Runoff of the river Odra (Hohensaaten-Finow gauge station) in January, April, May, and June was below the runoff means of the reference period from 1941 to 2004; in February and March, runoff exceeded the long-term means.

Ice conditions

New ice formation, which had begun in the northernmost part of the Baltic Sea in early November, was interrupted by a warm spell in late November and did not continue until the last week of December. In January, ice growth continued slowly, became more intensive in February, and reached its maximum extent of about 120,000 km² in the first decade of March. This corresponded to a mild ice winter. At this time in early March, the northern parts of the Gulfs of Finland and Riga, the Bay of Bothnia, Norra Kvarken, and the Archipelago Sea were covered with ice. Coastal ice extended to southern Sweden, and in the Sea of Bothnia thin ice occurred also in relatively large sea areas. One week later, the ice began to retreat in the southern part of the northern Baltic Sea. Also in April and May, the weather continued to be too warm for the season. This year's ice season ended on 21 May. Based on the number of ice reports issued, this was the shortest ice season since the winter of 1960/61in all areas of the northern Baltic Sea.
On the German coasts, the ice winter of 2006/07 was very weak due to unusually mild weather. On the German Baltic Sea coast, short cold spells in late January and early February led to insignificant ice formation in the waters of the inner Schlei and in the sheltered, shallow bodden waters of Mecklenburg-Vorpommern.

back

 
 © 2016 Bundesamt für Seeschifffahrt und Hydrographie Last Update: 19.04.2013 18:00:10  
 Print Version Home • Deutsche Version • Contact • Help • Federal Freedom of Information Act • Imprint