Glass eel catches and FAO (Food and Agricultural Organization) landings of the European freshwate... more Glass eel catches and FAO (Food and Agricultural Organization) landings of the European freshwater eel (Anguilla anguilla) show a decrease over the past 20 years. The long-term trends in the time series mask an interannual fluctuation, which becomes apparent on the application of a high-pass filter and autocorrelation analysis. Both the FAO landings and the glass eel catches show interannual fluctuations with a repeat period of 6-8 years, similar to the period of the North Atlantic Oscillation (NAO). Most glass eel catch monitoring stations are in phase. The glass eel catches show a significant negative correlation with the NAO lagged by 0-2 years, consistent with the hypothesis that the positive NAO phase has an adverse impact on the larval survival in and migration from the Sargasso Sea spawning location, one year prior to the arrival of the glass eels in Europe and North Africa. The FAO landings can be divided into two groups of different phase that have an approximate correspondence to the NAO dipole in winter rainfall in Europe and North Africa. One group (P) comprises Denmark, Ireland, Morocco, Netherlands, Norway, Sweden, Tunisia, and the United Kingdom, and the other group (N) comprises France, Germany, Italy, Poland, Portugal, Spain, and Turkey. At least for the interannual fluctuations, the success of the glass eel fishery (and eel recruitment) may be coupled with the number of migrating silver eels from the N group of countries and uncoupled with the P group of countries.
<p>January 2007 was a remarkably stormy period in Europe with impacts on so... more <p>January 2007 was a remarkably stormy period in Europe with impacts on societal infrastructure and implications for energy meteorology.  A series of cyclones tracked across the North Atlantic and into Europe during the two week period 8-22 January 2007.  For many parts of Europe, Storm Kyrill on 18 January 2007 was the most important of these for the infrastructure damage that it caused.  It had the highest European storm-related insurance losses in recent history.  The storm spawned a high intensity derecho that started in western Germany and travelled into eastern Europe. It was associated with severe convection, lightning, several tornadoes, and strong wind gusts.  The storm caused over 50 fatalities, widespread disruption of transport and power networks, and a lot of forest damage.   Storm Hanno on the 14 January 2007 was the second most severe storm of the period with serious impacts in Norway and southern Sweden.  Wind gusts reached the level of the 20-50 year event.  There were 6 fatalities in southern Sweden, some building damage, power cuts, and forest damage.  Storm Franz on 12 January 2007 caused the highest surge in the southern North Sea for January.  However, its flooding impact was reduced because the monthly cycle of spring and neap tides was near a minimum.  By contrast, astronomical tides were highest near the end of the period on 20-22 January 2007.  The highest absolute water levels for the month for many tide gauge stations were registered during Storm Kyrill on 18 January 2007 and also during Storm Lancelot on 20 January 2007.  This contribution takes a closer look at the North Sea surge of two important storms of the period: Storm Franz and Storm Kyrill.  An analysis is presented of tide gauge data to elucidate the storm surge and wave field around the North Sea and to assess possible links with shipping accidents and offshore incidents.  An unusually large wave sequence had been registered at the FINO1 offshore wind energy research platform only a couple of months previously on 1 November 2006.  The water level data is analyzed to ascertain if there may have been a repeat of the wave event during the storm sequence on 8-22 January 2007.</p>
The Britta storm of 31 October-1 November 2006 was a severe autumn storm that was particularly da... more The Britta storm of 31 October-1 November 2006 was a severe autumn storm that was particularly damaging for shipping and coastal flooding from storm surge effects along the southern North Sea. The main low pressure of the storm propagated from Scotland to southern Norway on 31 October, leading to a system of strong north winds that moved southward across North Sea over an 18 h period. A progression of ship and offshore platform difficulties were registered from the northern part of the North Sea from late on 31 October and culminated near the coasts of Germany and the Netherlands early on 1 November with a series of ship emergencies linked with large waves. In two separate incidents, unusually high waves broke the bridge windows of ships and necessitated emergency rescues, and a Dutch motor lifeboat experienced a triple capsize. In the southern North Sea, several gas production and research platforms experienced wave impact damage. The FINO1 offshore research platform, near the Dutch-German border, experienced some of the worst storm conditions with some structural damage. Its meteorological and oceanographic instrumentation give a unique profile of the severe met-ocean conditions during the storm. Two Waverider buoys at FINO1 and the nearby Dutch coastal site of Schiermonnikoog recorded groups of large waves at different times during the storm. These reports give insight into a little-reported rogue wave phenomenon that sometimes accompanies the "ground sea" conditions of the worst storms of the area.
<p>Storm Xaver impacted the northern Europe on 5-6 December 2013. &... more <p>Storm Xaver impacted the northern Europe on 5-6 December 2013.  It developed southeast of Greenland and passed north of Scotland and across southern Norway on a trajectory that led to a cold air outbreak across the North Sea and intense convection activity in northern Europe.  Strong sustained north winds led to a high storm surge that impacted all countries bordering the North Sea.  Storm Xaver was a century scale event with certain locations around the North Sea reporting their highest ever water levels since the start of modern records.  Media reports from the time of the storm chronicle the scale of the disruptions, including many cancelled flights, interrupted rail networks, closed bridges and roads, coastal building collapses, and power blackouts across northern Europe.  Much of this was due to the strong winds, but coastal storm surge flooding was important in the UK, and it led to interrupted port operations around the North Sea.</p><p>The storm was important for energy infrastructure and particularly for wind energy infrastructure.  In the northern North Sea, petroleum platforms were evacuated and operations closed ahead of the storm as a precautionary measure.  A number of onshore wind turbines were badly damaged by high winds and lightning strikes in the UK and Germany.  Over the North Sea, wind speeds exceeded the turbine shutdown threshold of 25 m/s for an extended period of time, with economic impacts from the loss of power generation.   In the German Bight, the FINO1 offshore wind energy research platform was damaged at the 15 m level by large waves.  This was the third report of storm damage to this platform after Storm Britta in 2006 and Storm Tilo in 2007.  Researchers have highlighted the need to reassess  the design criteria for offshore wind turbines based on these kinds of extreme meteorological events.  For the offshore wind industry, an important element of energy meteorology is to characterize both the evolving wind and wave fields during severe storms as both elements contribute to turbine loads and potential damage.</p><p>The present conference contribution presents a literature review of the major events during Storm Xaver and impacts on energy infrastructure.  Tide gauge records are reanalyzed to trace the progress of the storm surge wave around the North Sea.  A spectral analysis is used to separate the long period storm surge component, diurnal/semidiurnal tide, and short period components in the original water level record.  The short period component of the tide gauge record is important as it may be linked with infragravity waves that have been implicated in certain cases of offshore infrastructure damage in addition to coastal erosion.  Discussion is made of offshore wave records during the storm.  Storm Xaver is compared with two damaging offshore storms in 2006 and 2007.</p>
Offshore energy infrastructure, including the petroleum and wind energy sectors, are susceptible ... more Offshore energy infrastructure, including the petroleum and wind energy sectors, are susceptible to damage and interruption by extreme meteorological events. In northwest Europe and especially the North Sea, these extreme meteorological events are mostly associated with severe storms in the autumn and winter seasons. In the North Sea, storm surges have an impact on the offshore energy sector mainly from the flooding of port facilities and from strong ocean currents causing extra structural loading and bottom scouring. Storm Britta on 31 October-1 November 2006 was an important North Sea storm with a high surge along the coast of the Netherlands and Germany and a significant number of high wave reports. The paper presents an analysis of the national tide gauge records of the United Kingdom, the Netherlands, Germany, and Denmark to spectrally isolate and reconstruct time series components corresponding to the storm surge, semi-diurnal tide, and short period contribution. The semi-diurnal tides and storm surge during Storm Britta are tracked counter-clockwise around the North Sea from Scotland to northern Denmark. The storm surge was remarkable for its pronounced peak in the coastal area between the Netherlands and Germany with no precedent in the ∼ 100 year measurement record. The short period component of the tide gauge records show large oscillations during the height of the storm that may correspond with reports of unusually high waves at nearby coastal locations.
This contribution reviews the dynamics in the marine atmospheric boundary layer (MABL) with a dia... more This contribution reviews the dynamics in the marine atmospheric boundary layer (MABL) with a diagnostic diagram: wind speed versus air-sea temperature difference or U-ΔT. The diagram was first used by Alfred Woodcock in a series of observational studies from the early 1940s of gull flight patterns, and it was revisited in later decades to illustrate the dynamic and thermodynamic controls of fog formation, mesoscale convective clouds, surface fluxes of heat and momentum, whitecap formation, and vessel icing. The present report uses the figure to compare recent met-ocean conditions for a series of Norwegian offshore production platforms in northern Europe.
This contribution reviews the dynamics in the marine atmospheric boundary layer (MABL) with a dia... more This contribution reviews the dynamics in the marine atmospheric boundary layer (MABL) with a diagnostic diagram: wind speed versus air-sea temperature difference or U-ΔT. The diagram was first used by Alfred Woodcock in a series of observational studies from the early 1940s of gull flight patterns, and it was revisited in later decades to illustrate the dynamic and thermodynamic controls of fog formation, mesoscale convective clouds, surface fluxes of heat and momentum, whitecap formation, and vessel icing. The present report uses the figure to compare recent met-ocean conditions for a series of Norwegian offshore production platforms in northern Europe.
14 Specifcations for Complex I small-scale CTD profier (MHI 8101) . 15 Combined Table of Measurem... more 14 Specifcations for Complex I small-scale CTD profier (MHI 8101) . 15 Combined Table of Measurements with Complex MHI 4206 16 Time and Location of Experiments 17 List of Files with Maps (Images)
Storm Tilo on 8-9 November 2007 ranks among the serious winter storms in northern Europe over the... more Storm Tilo on 8-9 November 2007 ranks among the serious winter storms in northern Europe over the past 30 years. Its low pressure centre passed across the northern North Sea, and this led to a cold air outbreak in northwest Europe. Strong north winds across the North Sea contributed to a high storm surge that was serious for coastal regions in eastern England, the Netherlands and Germany. Storm winds and unusually high waves caused shipping accidents and damage to some offshore energy infrastructure. This report presents an outline of the met-ocean conditions and a short overview of storm impacts on societal and energy infrastructure. The progress of the storm surge around the North Sea is analysed using data from the national tide gauge networks. A spectral analysis of the water level data is used to isolate the long period storm surge and short period oscillations (i.e., < 4.8 h) from the tidal signal. The calculated skew surge is compared with literature reports for this storm and also with another serious North Sea storm from 31 October-1 November 2006 (Storm Britta). The short period oscillations are compared with the platform and shipping incident reports for the 2 d storm period. The results support previous reports of unusual wave and water level dynamics during some severe regional winter storms.
&amp;lt;p&amp;gt;January 2007 was a remarkably stormy period in Europe with impacts on so... more &amp;lt;p&amp;gt;January 2007 was a remarkably stormy period in Europe with impacts on societal infrastructure and implications for energy meteorology. &amp;amp;#160;A series of cyclones tracked across the North Atlantic and into Europe during the two week period 8-22 January 2007. &amp;amp;#160;For many parts of Europe, Storm Kyrill on 18 January 2007 was the most important of these for the infrastructure damage that it caused.&amp;amp;#160; It had the highest European storm-related insurance losses in recent history.&amp;amp;#160; The storm spawned a high intensity derecho that started in western Germany and travelled into eastern Europe. It was associated with severe convection, lightning, several tornadoes, and strong wind gusts. &amp;amp;#160;The storm caused over 50 fatalities, widespread disruption of transport and power networks, and a lot of forest damage. &amp;amp;#160; Storm Hanno on the 14 January 2007 was the second most severe storm of the period with serious impacts in Norway and southern Sweden.&amp;amp;#160; Wind gusts reached the level of the 20-50 year event. &amp;amp;#160;There were 6 fatalities in southern Sweden, some building damage, power cuts, and forest damage. &amp;amp;#160;Storm Franz on 12 January 2007 caused the highest surge in the southern North Sea for January.&amp;amp;#160; However, its flooding impact was reduced because the monthly cycle of spring and neap tides was near a minimum.&amp;amp;#160; By contrast, astronomical tides were highest near the end of the period on 20-22 January 2007. &amp;amp;#160;The highest absolute water levels for the month for many tide gauge stations were registered during Storm Kyrill on 18 January 2007 and also during Storm Lancelot on 20 January 2007. &amp;amp;#160;This contribution takes a closer look at the North Sea surge of two important storms of the period: Storm Franz and Storm Kyrill. &amp;amp;#160;An analysis is presented of tide gauge data to elucidate the storm surge and wave field around the North Sea and to assess possible links with shipping accidents and offshore incidents.&amp;amp;#160; An unusually large wave sequence had been registered at the FINO1 offshore wind energy research platform only a couple of months previously on 1 November 2006. &amp;amp;#160;The water level data is analyzed to ascertain if there may have been a repeat of the wave event during the storm sequence on 8-22 January 2007.&amp;lt;/p&amp;gt;
&amp;lt;p&amp;gt;Storm Xaver impacted the northern Europe on 5-6 December 2013. &amp;... more &amp;lt;p&amp;gt;Storm Xaver impacted the northern Europe on 5-6 December 2013. &amp;amp;#160;It developed southeast of Greenland and passed north of Scotland and across southern Norway on a trajectory that led to a cold air outbreak across the North Sea and intense convection activity in northern Europe.&amp;amp;#160; Strong sustained north winds led to a high storm surge that impacted all countries bordering the North Sea. &amp;amp;#160;Storm Xaver was a century scale event with certain locations around the North Sea reporting their highest ever water levels since the start of modern records.&amp;amp;#160; Media reports from the time of the storm chronicle the scale of the disruptions, including many cancelled flights, interrupted rail networks, closed bridges and roads, coastal building collapses, and power blackouts across northern Europe. &amp;amp;#160;Much of this was due to the strong winds, but coastal storm surge flooding was important in the UK, and it led to interrupted port operations around the North Sea.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;The storm was important for energy infrastructure and particularly for wind energy infrastructure.&amp;amp;#160; In the northern North Sea, petroleum platforms were evacuated and operations closed ahead of the storm as a precautionary measure.&amp;amp;#160; A number of onshore wind turbines were badly damaged by high winds and lightning strikes in the UK and Germany.&amp;amp;#160; Over the North Sea, wind speeds exceeded the turbine shutdown threshold of 25 m/s for an extended period of time, with economic impacts from the loss of power generation.&amp;amp;#160;&amp;amp;#160; In the German Bight, the FINO1 offshore wind energy research platform was damaged at the 15 m level by large waves. &amp;amp;#160;This was the third report of storm damage to this platform after Storm Britta in 2006 and Storm Tilo in 2007. &amp;amp;#160;Researchers have highlighted the need to reassess&amp;amp;#160; the design criteria for offshore wind turbines based on these kinds of extreme meteorological events. &amp;amp;#160;For the offshore wind industry, an important element of energy meteorology is to characterize both the evolving wind and wave fields during severe storms as both elements contribute to turbine loads and potential damage.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;The present conference contribution presents a literature review of the major events during Storm Xaver and impacts on energy infrastructure.&amp;amp;#160; Tide gauge records are reanalyzed to trace the progress of the storm surge wave around the North Sea.&amp;amp;#160; A spectral analysis is used to separate the long period storm surge component, diurnal/semidiurnal tide, and short period components in the original water level record. &amp;amp;#160;The short period component of the tide gauge record is important as it may be linked with infragravity waves that have been implicated in certain cases of offshore infrastructure damage in addition to coastal erosion. &amp;amp;#160;Discussion is made of offshore wave records during the storm.&amp;amp;#160; Storm Xaver is compared with two damaging offshore storms in 2006 and 2007.&amp;lt;/p&amp;gt;
Glass eel catches and FAO (Food and Agricultural Organization) landings of the European freshwate... more Glass eel catches and FAO (Food and Agricultural Organization) landings of the European freshwater eel (Anguilla anguilla) show a decrease over the past 20 years. The long-term trends in the time series mask an interannual fluctuation, which becomes apparent on the application of a high-pass filter and autocorrelation analysis. Both the FAO landings and the glass eel catches show interannual fluctuations with a repeat period of 6-8 years, similar to the period of the North Atlantic Oscillation (NAO). Most glass eel catch monitoring stations are in phase. The glass eel catches show a significant negative correlation with the NAO lagged by 0-2 years, consistent with the hypothesis that the positive NAO phase has an adverse impact on the larval survival in and migration from the Sargasso Sea spawning location, one year prior to the arrival of the glass eels in Europe and North Africa. The FAO landings can be divided into two groups of different phase that have an approximate correspondence to the NAO dipole in winter rainfall in Europe and North Africa. One group (P) comprises Denmark, Ireland, Morocco, Netherlands, Norway, Sweden, Tunisia, and the United Kingdom, and the other group (N) comprises France, Germany, Italy, Poland, Portugal, Spain, and Turkey. At least for the interannual fluctuations, the success of the glass eel fishery (and eel recruitment) may be coupled with the number of migrating silver eels from the N group of countries and uncoupled with the P group of countries.
&amp;lt;p&amp;gt;January 2007 was a remarkably stormy period in Europe with impacts on so... more &amp;lt;p&amp;gt;January 2007 was a remarkably stormy period in Europe with impacts on societal infrastructure and implications for energy meteorology. &amp;amp;#160;A series of cyclones tracked across the North Atlantic and into Europe during the two week period 8-22 January 2007. &amp;amp;#160;For many parts of Europe, Storm Kyrill on 18 January 2007 was the most important of these for the infrastructure damage that it caused.&amp;amp;#160; It had the highest European storm-related insurance losses in recent history.&amp;amp;#160; The storm spawned a high intensity derecho that started in western Germany and travelled into eastern Europe. It was associated with severe convection, lightning, several tornadoes, and strong wind gusts. &amp;amp;#160;The storm caused over 50 fatalities, widespread disruption of transport and power networks, and a lot of forest damage. &amp;amp;#160; Storm Hanno on the 14 January 2007 was the second most severe storm of the period with serious impacts in Norway and southern Sweden.&amp;amp;#160; Wind gusts reached the level of the 20-50 year event. &amp;amp;#160;There were 6 fatalities in southern Sweden, some building damage, power cuts, and forest damage. &amp;amp;#160;Storm Franz on 12 January 2007 caused the highest surge in the southern North Sea for January.&amp;amp;#160; However, its flooding impact was reduced because the monthly cycle of spring and neap tides was near a minimum.&amp;amp;#160; By contrast, astronomical tides were highest near the end of the period on 20-22 January 2007. &amp;amp;#160;The highest absolute water levels for the month for many tide gauge stations were registered during Storm Kyrill on 18 January 2007 and also during Storm Lancelot on 20 January 2007. &amp;amp;#160;This contribution takes a closer look at the North Sea surge of two important storms of the period: Storm Franz and Storm Kyrill. &amp;amp;#160;An analysis is presented of tide gauge data to elucidate the storm surge and wave field around the North Sea and to assess possible links with shipping accidents and offshore incidents.&amp;amp;#160; An unusually large wave sequence had been registered at the FINO1 offshore wind energy research platform only a couple of months previously on 1 November 2006. &amp;amp;#160;The water level data is analyzed to ascertain if there may have been a repeat of the wave event during the storm sequence on 8-22 January 2007.&amp;lt;/p&amp;gt;
The Britta storm of 31 October-1 November 2006 was a severe autumn storm that was particularly da... more The Britta storm of 31 October-1 November 2006 was a severe autumn storm that was particularly damaging for shipping and coastal flooding from storm surge effects along the southern North Sea. The main low pressure of the storm propagated from Scotland to southern Norway on 31 October, leading to a system of strong north winds that moved southward across North Sea over an 18 h period. A progression of ship and offshore platform difficulties were registered from the northern part of the North Sea from late on 31 October and culminated near the coasts of Germany and the Netherlands early on 1 November with a series of ship emergencies linked with large waves. In two separate incidents, unusually high waves broke the bridge windows of ships and necessitated emergency rescues, and a Dutch motor lifeboat experienced a triple capsize. In the southern North Sea, several gas production and research platforms experienced wave impact damage. The FINO1 offshore research platform, near the Dutch-German border, experienced some of the worst storm conditions with some structural damage. Its meteorological and oceanographic instrumentation give a unique profile of the severe met-ocean conditions during the storm. Two Waverider buoys at FINO1 and the nearby Dutch coastal site of Schiermonnikoog recorded groups of large waves at different times during the storm. These reports give insight into a little-reported rogue wave phenomenon that sometimes accompanies the "ground sea" conditions of the worst storms of the area.
&amp;lt;p&amp;gt;Storm Xaver impacted the northern Europe on 5-6 December 2013. &amp;... more &amp;lt;p&amp;gt;Storm Xaver impacted the northern Europe on 5-6 December 2013. &amp;amp;#160;It developed southeast of Greenland and passed north of Scotland and across southern Norway on a trajectory that led to a cold air outbreak across the North Sea and intense convection activity in northern Europe.&amp;amp;#160; Strong sustained north winds led to a high storm surge that impacted all countries bordering the North Sea. &amp;amp;#160;Storm Xaver was a century scale event with certain locations around the North Sea reporting their highest ever water levels since the start of modern records.&amp;amp;#160; Media reports from the time of the storm chronicle the scale of the disruptions, including many cancelled flights, interrupted rail networks, closed bridges and roads, coastal building collapses, and power blackouts across northern Europe. &amp;amp;#160;Much of this was due to the strong winds, but coastal storm surge flooding was important in the UK, and it led to interrupted port operations around the North Sea.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;The storm was important for energy infrastructure and particularly for wind energy infrastructure.&amp;amp;#160; In the northern North Sea, petroleum platforms were evacuated and operations closed ahead of the storm as a precautionary measure.&amp;amp;#160; A number of onshore wind turbines were badly damaged by high winds and lightning strikes in the UK and Germany.&amp;amp;#160; Over the North Sea, wind speeds exceeded the turbine shutdown threshold of 25 m/s for an extended period of time, with economic impacts from the loss of power generation.&amp;amp;#160;&amp;amp;#160; In the German Bight, the FINO1 offshore wind energy research platform was damaged at the 15 m level by large waves. &amp;amp;#160;This was the third report of storm damage to this platform after Storm Britta in 2006 and Storm Tilo in 2007. &amp;amp;#160;Researchers have highlighted the need to reassess&amp;amp;#160; the design criteria for offshore wind turbines based on these kinds of extreme meteorological events. &amp;amp;#160;For the offshore wind industry, an important element of energy meteorology is to characterize both the evolving wind and wave fields during severe storms as both elements contribute to turbine loads and potential damage.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;The present conference contribution presents a literature review of the major events during Storm Xaver and impacts on energy infrastructure.&amp;amp;#160; Tide gauge records are reanalyzed to trace the progress of the storm surge wave around the North Sea.&amp;amp;#160; A spectral analysis is used to separate the long period storm surge component, diurnal/semidiurnal tide, and short period components in the original water level record. &amp;amp;#160;The short period component of the tide gauge record is important as it may be linked with infragravity waves that have been implicated in certain cases of offshore infrastructure damage in addition to coastal erosion. &amp;amp;#160;Discussion is made of offshore wave records during the storm.&amp;amp;#160; Storm Xaver is compared with two damaging offshore storms in 2006 and 2007.&amp;lt;/p&amp;gt;
Offshore energy infrastructure, including the petroleum and wind energy sectors, are susceptible ... more Offshore energy infrastructure, including the petroleum and wind energy sectors, are susceptible to damage and interruption by extreme meteorological events. In northwest Europe and especially the North Sea, these extreme meteorological events are mostly associated with severe storms in the autumn and winter seasons. In the North Sea, storm surges have an impact on the offshore energy sector mainly from the flooding of port facilities and from strong ocean currents causing extra structural loading and bottom scouring. Storm Britta on 31 October-1 November 2006 was an important North Sea storm with a high surge along the coast of the Netherlands and Germany and a significant number of high wave reports. The paper presents an analysis of the national tide gauge records of the United Kingdom, the Netherlands, Germany, and Denmark to spectrally isolate and reconstruct time series components corresponding to the storm surge, semi-diurnal tide, and short period contribution. The semi-diurnal tides and storm surge during Storm Britta are tracked counter-clockwise around the North Sea from Scotland to northern Denmark. The storm surge was remarkable for its pronounced peak in the coastal area between the Netherlands and Germany with no precedent in the ∼ 100 year measurement record. The short period component of the tide gauge records show large oscillations during the height of the storm that may correspond with reports of unusually high waves at nearby coastal locations.
This contribution reviews the dynamics in the marine atmospheric boundary layer (MABL) with a dia... more This contribution reviews the dynamics in the marine atmospheric boundary layer (MABL) with a diagnostic diagram: wind speed versus air-sea temperature difference or U-ΔT. The diagram was first used by Alfred Woodcock in a series of observational studies from the early 1940s of gull flight patterns, and it was revisited in later decades to illustrate the dynamic and thermodynamic controls of fog formation, mesoscale convective clouds, surface fluxes of heat and momentum, whitecap formation, and vessel icing. The present report uses the figure to compare recent met-ocean conditions for a series of Norwegian offshore production platforms in northern Europe.
This contribution reviews the dynamics in the marine atmospheric boundary layer (MABL) with a dia... more This contribution reviews the dynamics in the marine atmospheric boundary layer (MABL) with a diagnostic diagram: wind speed versus air-sea temperature difference or U-ΔT. The diagram was first used by Alfred Woodcock in a series of observational studies from the early 1940s of gull flight patterns, and it was revisited in later decades to illustrate the dynamic and thermodynamic controls of fog formation, mesoscale convective clouds, surface fluxes of heat and momentum, whitecap formation, and vessel icing. The present report uses the figure to compare recent met-ocean conditions for a series of Norwegian offshore production platforms in northern Europe.
14 Specifcations for Complex I small-scale CTD profier (MHI 8101) . 15 Combined Table of Measurem... more 14 Specifcations for Complex I small-scale CTD profier (MHI 8101) . 15 Combined Table of Measurements with Complex MHI 4206 16 Time and Location of Experiments 17 List of Files with Maps (Images)
Storm Tilo on 8-9 November 2007 ranks among the serious winter storms in northern Europe over the... more Storm Tilo on 8-9 November 2007 ranks among the serious winter storms in northern Europe over the past 30 years. Its low pressure centre passed across the northern North Sea, and this led to a cold air outbreak in northwest Europe. Strong north winds across the North Sea contributed to a high storm surge that was serious for coastal regions in eastern England, the Netherlands and Germany. Storm winds and unusually high waves caused shipping accidents and damage to some offshore energy infrastructure. This report presents an outline of the met-ocean conditions and a short overview of storm impacts on societal and energy infrastructure. The progress of the storm surge around the North Sea is analysed using data from the national tide gauge networks. A spectral analysis of the water level data is used to isolate the long period storm surge and short period oscillations (i.e., < 4.8 h) from the tidal signal. The calculated skew surge is compared with literature reports for this storm and also with another serious North Sea storm from 31 October-1 November 2006 (Storm Britta). The short period oscillations are compared with the platform and shipping incident reports for the 2 d storm period. The results support previous reports of unusual wave and water level dynamics during some severe regional winter storms.
&amp;lt;p&amp;gt;January 2007 was a remarkably stormy period in Europe with impacts on so... more &amp;lt;p&amp;gt;January 2007 was a remarkably stormy period in Europe with impacts on societal infrastructure and implications for energy meteorology. &amp;amp;#160;A series of cyclones tracked across the North Atlantic and into Europe during the two week period 8-22 January 2007. &amp;amp;#160;For many parts of Europe, Storm Kyrill on 18 January 2007 was the most important of these for the infrastructure damage that it caused.&amp;amp;#160; It had the highest European storm-related insurance losses in recent history.&amp;amp;#160; The storm spawned a high intensity derecho that started in western Germany and travelled into eastern Europe. It was associated with severe convection, lightning, several tornadoes, and strong wind gusts. &amp;amp;#160;The storm caused over 50 fatalities, widespread disruption of transport and power networks, and a lot of forest damage. &amp;amp;#160; Storm Hanno on the 14 January 2007 was the second most severe storm of the period with serious impacts in Norway and southern Sweden.&amp;amp;#160; Wind gusts reached the level of the 20-50 year event. &amp;amp;#160;There were 6 fatalities in southern Sweden, some building damage, power cuts, and forest damage. &amp;amp;#160;Storm Franz on 12 January 2007 caused the highest surge in the southern North Sea for January.&amp;amp;#160; However, its flooding impact was reduced because the monthly cycle of spring and neap tides was near a minimum.&amp;amp;#160; By contrast, astronomical tides were highest near the end of the period on 20-22 January 2007. &amp;amp;#160;The highest absolute water levels for the month for many tide gauge stations were registered during Storm Kyrill on 18 January 2007 and also during Storm Lancelot on 20 January 2007. &amp;amp;#160;This contribution takes a closer look at the North Sea surge of two important storms of the period: Storm Franz and Storm Kyrill. &amp;amp;#160;An analysis is presented of tide gauge data to elucidate the storm surge and wave field around the North Sea and to assess possible links with shipping accidents and offshore incidents.&amp;amp;#160; An unusually large wave sequence had been registered at the FINO1 offshore wind energy research platform only a couple of months previously on 1 November 2006. &amp;amp;#160;The water level data is analyzed to ascertain if there may have been a repeat of the wave event during the storm sequence on 8-22 January 2007.&amp;lt;/p&amp;gt;
&amp;lt;p&amp;gt;Storm Xaver impacted the northern Europe on 5-6 December 2013. &amp;... more &amp;lt;p&amp;gt;Storm Xaver impacted the northern Europe on 5-6 December 2013. &amp;amp;#160;It developed southeast of Greenland and passed north of Scotland and across southern Norway on a trajectory that led to a cold air outbreak across the North Sea and intense convection activity in northern Europe.&amp;amp;#160; Strong sustained north winds led to a high storm surge that impacted all countries bordering the North Sea. &amp;amp;#160;Storm Xaver was a century scale event with certain locations around the North Sea reporting their highest ever water levels since the start of modern records.&amp;amp;#160; Media reports from the time of the storm chronicle the scale of the disruptions, including many cancelled flights, interrupted rail networks, closed bridges and roads, coastal building collapses, and power blackouts across northern Europe. &amp;amp;#160;Much of this was due to the strong winds, but coastal storm surge flooding was important in the UK, and it led to interrupted port operations around the North Sea.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;The storm was important for energy infrastructure and particularly for wind energy infrastructure.&amp;amp;#160; In the northern North Sea, petroleum platforms were evacuated and operations closed ahead of the storm as a precautionary measure.&amp;amp;#160; A number of onshore wind turbines were badly damaged by high winds and lightning strikes in the UK and Germany.&amp;amp;#160; Over the North Sea, wind speeds exceeded the turbine shutdown threshold of 25 m/s for an extended period of time, with economic impacts from the loss of power generation.&amp;amp;#160;&amp;amp;#160; In the German Bight, the FINO1 offshore wind energy research platform was damaged at the 15 m level by large waves. &amp;amp;#160;This was the third report of storm damage to this platform after Storm Britta in 2006 and Storm Tilo in 2007. &amp;amp;#160;Researchers have highlighted the need to reassess&amp;amp;#160; the design criteria for offshore wind turbines based on these kinds of extreme meteorological events. &amp;amp;#160;For the offshore wind industry, an important element of energy meteorology is to characterize both the evolving wind and wave fields during severe storms as both elements contribute to turbine loads and potential damage.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;The present conference contribution presents a literature review of the major events during Storm Xaver and impacts on energy infrastructure.&amp;amp;#160; Tide gauge records are reanalyzed to trace the progress of the storm surge wave around the North Sea.&amp;amp;#160; A spectral analysis is used to separate the long period storm surge component, diurnal/semidiurnal tide, and short period components in the original water level record. &amp;amp;#160;The short period component of the tide gauge record is important as it may be linked with infragravity waves that have been implicated in certain cases of offshore infrastructure damage in addition to coastal erosion. &amp;amp;#160;Discussion is made of offshore wave records during the storm.&amp;amp;#160; Storm Xaver is compared with two damaging offshore storms in 2006 and 2007.&amp;lt;/p&amp;gt;
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