This painting thus portrays Amsterdam as it must have been around 1538, and not the enlarged Amsterdam of 1652.
The urban design work of the Dutch architect Hendrik Petrus Berlage (1856-1934) focused on finding sustainable concepts to cope with the strong population growth of Dutch cities in the 1930s
Amsterdam North up view in the GeoGarage platform (NLHO nautical chart)
Mapping the UK's Exclusive Economic Zone provides data used by offshore industries, including aquaculture and fisheries information, as well as the energy sector.
UK Government aims to support autonomous navigation and map over 6 million square kilometres of the world’s oceans
The UK Hydrographic Office (UKHO) has welcomed the publication of the UK government’s ‘Maritime 2050’ strategy paper, which sets out the vision for the future of the UK maritime sector.
A real vision for the future of the UK maritime sector
The strategy, which has been developed in consultation with agencies including the UKHO and the wider public and private sectors, sets out a series of detailed recommendations to help the UK maintain its position as a leading global maritime nation.
These recommendations span themes including the environment, international trade, security and resilience, infrastructure, people and technology.
A marine geospatial opportunity
A focus on the positive impact that smart shipping and use of autonomous vessels could have on the environment, as well as safety and efficiency across the maritime industry, forms a key part of the paper.
In recognition of these benefits, the strategy supports collaboration between the UKHO, Maritime & Coastguard Agency, industry experts and the wider government to develop navigation and safety data requirements that enable the use of these technologies in the future.
The strategy also recognises the value of marine geospatial data in unlocking economic potential for maritime-related industries, with further recommendations to not only fully map the seabed in the UK’s Exclusive Economic Zone (spanning 6,805,586 sq. km) to modern standards, but also play a key role in international efforts to chart the world’s seabed.
This aim will be key to helping government and the wider industry improve our understanding of how we can protect and sustainably benefit from the global marine environment.
Commenting on the Maritime 2050 paper, Cathrine Armour, Director of Customer Division, said:
The UK Hydrographic Office welcomes the publication of Maritime 2050, which sets out a compelling vision for the future of the UK maritime sector. The UK has the world’s fifth largest Exclusive Economic Zone and the better we understand our oceans, the better placed we will be to ensure its prosperity whilst capitalising on the opportunities that exist.
As the government’s hydrographic and marine geospatial data experts, we are proud of the part we play in mapping the UK’s seabed and enabling the future of maritime navigation. At the same time, we can only meet the ambitions of Maritime 2050 through a collaborative approach that brings together the expertise and insights of all our partners across government, industry and academia. We look forward to working closely with these partners to fulfil these goals.
The so-called "Draupner wave" was recorded by an oil drilling platform in 1995.
In 1995, a powerful rogue wave slammed into an offshore gas pipeline platform operated by Statoil in the southern tip of Norway.
Dubbed the "Draupner wave," it generated intense interest among scientists, since the platform's various sensors and instruments provided precise details about the wave's dynamics.
Rogue waves had long been considered a myth, so those readings—combined with damage to the platform consistent with a wave some 84 feet high—provided crucial evidence for the phenomenon
The phenomenon of rogue waves, which researchers have recreated in testing tanks, can now be predicted for the first time and has been found to be triggered by two waves crossing over at the key angle of 60 degrees source : FloWave Ocean Energy Research facilty (Edimburg Univ)
It wasn't long before scientists were attempting to recreate rogue waves in the laboratory, the better to understand the mechanisms behind how they form in the first place.
Now a team at the University of Oxford in England has successfully recreated the "Draupner wave" in a circular water tank, according to a new paper in the Journal of Fluid Mechanics, shedding further light on the mechanisms that produced it.
Bonus: the wave profile bears a striking resemblance to The Great Wave off Kanagawa, a famous 19th-century woodblock print by Japanese artist Katsushika Hokusai.
Close-up of the event, taken from Paul Taylor's paper.
"The measurement of the Draupner wave in 1995 was a seminal observation initiating many years of research into the physics of freak waves and shifting their standing from mere folklore to a credible real-world phenomenon," said co-author Mark McAllister of the University of Oxford.
"By recreating the Draupner wave in the lab, we have moved one step closer to understanding the potential mechanisms of this phenomenon."
A rogue wave is usually defined as a wave that is 2.2 times taller than the average waves around it.
They are notoriously difficult to predict and can appear quite suddenly, making them very dangerous to ships and deep-sea drilling platforms.
In 1978, a supposedly "unsinkable" cargo ship called the MS München was lost at sea.
Analysis of the floating wreckage that was recovered indicated a powerful rogue wave (possibly more than one) was the most likely culprit.
Rogue waves can also form in lakes, like Lake Superior's "Three Sisters" phenomenon (three large waves hitting a ship one after the other before the first wave can clear).
This is believed to have caused the sinking of the SS Edmund Fitzgerald, immortalized in a 1975 ballad by Gordon Lightfoot.
The Great Wave off Kanagawa, a 19th-century woodcut print by Japanese artist Katsushika Hokusai
versus simulated Draupner freak wave
Despite numerous anecdotal eyewitness accounts about rogue waves, there wasn't any hard scientific evidence for them, so such claims were dismissed as myths or legends.
In fact, a French naval officer in 1826, Jules Dumont d'Urville, reported seeing a 108-foot-high wave in the Indian Ocean and was roundly ridiculed by physicist François Arago for his trouble.
At the time, scientists didn't think waves could be higher than 30 feet.
In the early 1960s, the National Institute of Oceanography reported measuring a 67-foot wave, cited in a seminal 1964 paper by Laurence Draper on the subject.
"Modern research has confirmed that such monsters can occur, and that wave heights can exceed by an appreciable amount the maximum values which have been accepted in responsible circles," Draper wrote.
But scientific evidence was still mostly lacking, until a rogue wave was recorded slamming into a platform in the North Sea in 1984.
Satellite and radar imagery over the past few decades further confirmed that rogue waves are very real.
Rogue waves are a combination of the energy of several ordinary waves focused into one spot.
Early lab attempts to recreate rogue waves used long, straight wave tanks and relied on paddles or similar mechanical means to create different kinds of waves.
Those experiments revealed that not just any chance combination of multiple waves is sufficient to produce a rogue wave.
Rather, the waves start out with roughly the same dominant wavelength, but a small perturbation will make one wave a bit higher than the others.
This causes the waves behind it to speed up, while the waves in front slow down.
Energy piles up in a positive feedback loop until the wave with the initial perturbation "goes rogue."
Still images of the reconstruction of the Draupner wave,
showing plunging breaking that gives an upper limit to how high a wave can get.
Reconstructed Draupner wave shown breaking from an upward projected jet.
This does not limit wave crest height.
Reconstruction of the Draupner wave, this time shown breaking along the confluence of the crossing waves, producing a jet with both plunging and upward motion.
The black lines denote real measurements from the Draupner platform in 1995. The red dashed lines are the final experimental results in the lab. DOI: Journal of Fluid Mechanics, 2019. 10.1017/jfm.2018.886 (About DOIs).
But ocean waves are not produced by mechanical means; they're the result of wind interacting with the surface of the water.
And it's tough to recreate those precise dynamics with long, straight water tanks. So in 2017, physicists built at large, ring-shaped water tank (5 meters in diameter) at the University of Turin in Italy, using fans to blow air over the surface to simulate wind. They observed the same "self-focusing" effect in the rogue waves produced in the tank.
In this latest experiment, the Oxford scientists generated two sets of waves in a circular water tank at the University of Edinburgh and made sure they crossed each other at various angles, the better to recreate the conditions under which the Draupner wave had formed.
In these conditions, the wave doesn't break like you'd normally expect.
Wave breaking usually serves to limit a wave's maximum height, but that limiting factor doesn't occur when waves cross each other at large angles.
The sweet spot turned out to be an angle of 120 degrees: when the groups of waves crossed at that angle, they formed a wave that scaled neatly with the height and length of the Draupner wave (albeit at 1/35th the size of the original).
This rare photo of a rogue wave was taken by first mate Philippe Lijour aboard the supertanker Esso Languedoc, during a storm off Durban in South Africa in 1980.
The mast seen starboard in the photo stands 25 metres above mean sea level.
The wave approached the ship from behind before breaking over the deck, but in this case caused only minor damage.
The mean wave height at the time was between 5-10 metres.
All this research matters, because a better understanding of how powerful rogue waves form could help scientists make better predictions as to when they are likely to occur.
That means ships and offshore drilling platforms can be better prepared for such an event.
"Not only does this laboratory observation shed light on how the famous Draupner wave may have occurred, it also highlights the nature and significance of wave breaking in crossing sea conditions," said co-author Ton van den Bremer.
I saw an article this morning that said something to the effect that the "Polar Vortex" was coming to the United States to blah, blah, blah.
This characterization of the Polar Vortex as this "storm-like thing" that comes to get us periodically is somewhat mischaracterized.
I promise you it is not like the boogeyman hiding under our bed.
I realized that it was probably time to revisit four things about weather that still confuse the public.
I could have certainly included more, but these are the ones that I notice in my personal spaces and on social media.
The polar vortex (also sometimes called the circumpolar vortex) is a large, persistent, upper-atmospheric, cyclonic circulation that forms and exists over the winter pole...
The polar vortex is perfectly normal, and has been known about for at least 70 years.
It is not a winter storm, or a storm of any kind.
It's just a natural part of Earth's circulation 10 to 30 miles up in the atmosphere.
There is one at both poles, and other planets have them too.
McNoldy goes on to point out that recently the Polar Vortex recently split allowing very cold Arctic air to intrude into the eastern half of the continental United States.
source : NOAA
European vs American Model
This is one that honestly amuses me.
Monitor social media enough, and it's almost like there are fan clubs or cheering sections.
The American Global Forecast System (GFS) model and the European Center For Medium-Range Weather Forecast (ECMWF) model (often referred to as the "Euro") are global forecast models often used by meteorologists. There are other models by the way, and they all are used by our community.
However, these two seem to get headlines for weather events 7 to 14 days out.
You've probably seen social "media-rologists" or your Aunt Clara share an "loooooongggg-range" hurricane or snowstorm prediction.
It probably came from one of these models.
Scientific studies and meteorological experience tells us that the "Euro" model has typically been more accurate, on average, than the GFS model.
This prompted Congress, after Hurricane Sandy, to have a sense of urgency about providing NOAA with the tools to catch or surpass the European model.
Candidly, we need to be more proactive when it comes to these things rather than reactive, but I digress. I wrote in Forbes two years ago about some of those changes to the GFS after this mandate was issued.
I find that the constant "GFS vs Euro" banter gives some people the impression that the Euro is light-years beyond the GFS.
In fact, they both have their moments of "good" and "bad" performance.
I have even noticed that in recent weeks.
NOAA's GFS model is still a world-class model.
Weather vs Climate
Certain people consistently tweet snarky comments when it is cold or snowing as if that refutes the notion of global warming.
Here is a pro-tip: Resist the urge to do that because an informed reader will immediately recognize that you do not know the difference between weather and climate.
Even as our climate warms, we will always have winter, snowstorms, blizzards, and cold outbreaks.
More importantly, it is not called "East Coast Warming," it is called Global Warming.
Even if one tiny corner of the planet is experiencing extreme cold (or warmth), it is more intelligent to assess what the broader planet is doing before typing out that Tweet.
Accuracy of Forecasts
I write about this ad nauseam, but it just will not go away.
I saw a post recently asking what our "guess" was for the weather this week.
I have been fascinated by this public tendency to perceive forecasts to be wrong.
As I have written before, there are several reasons this happens.
First, sometimes the forecast is wrong.
However, it is right far more often.
People tend to remember the less frequent event, the missed forecast.
I am sure Chicago Bears fans remember the missed field goal in the playoffs far more than all of the kickers made field goals this past year.
It is human nature especially if the missed forecast impacted their lives in some way.
Second, many people do not understand what probabilistic forecasts or uncertainty is trying to convey.
There are people that actually interpret a 20% chance of rain as meaning it is not going to rain.
Wouldn't that be 0%.
Rainfall forecasts are presented in a probabilistic sense.
I also notice the same struggle with things like the "hurricane cone of uncertainty." During Hurricane Irma, some people evacuated from one part of the cone to another part of Florida that was still in the cone.
I think the successes of weather forecasts have also given the public the illusion that we can also do things we cannot.
When that doesn't happen, they complain.
Our models are not robust enough to tell you that it is going to rain at 4:32 pm directly over your dog's water bowl in the backyard by the tomato plant.
This is why we have to keep educating about math, statistics, weather, and overall science literacy with "teachable moments" like the Polar Vortex.
I will bring this to a close.
I could have more by digging deeper on these topics:
Hurricanes and typhoons are basically the same type of storm but in a different part of the world.
Climatologists really do know that climate also changes naturally.
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