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Video 1.1.1. From perception to data

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Strategies for winning. Meteorology in a round the world regatta

Universitat de Barcelona

4.5 (47 calificaciones) | 1.8K estudiantes inscritos

In this course you can learn about the mechanics of global weather, the foundations of ocean meteorology, predictive modeling and how sailors receive data via satellite and use high-performance navigation software. This course looks at oceanic meteorology and climatology through the lens of the sport of sailing. You will gain a basic knowledge of meteorology needed by sailors to take part in a regatta such as the Barcelona World Race, the only double-handed, round the world regatta with no stops. You will learn about the strategies employed during a round the world regatta and how these are put to use on board the latest ocean racing yachts.

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De la lección

Understanding maritime meteorology

In this module you will learn the foundations for an understanding of general and in particular maritime meteorology. What are the factors and engines powering the weather? What do we need to know to understand the weather phenomena we experience every day? What do ocean sailors need to know to predict the weather? Instructors: Tomàs Molina, Santi Serrat

Video 1.1.1. From perception to data13:47

Video 1.1.2. Towards numerical models21:47

Video 1.1.3. The evolution of meteorological information in ocean regattas13:58

Impartido por:

Tomàs Molina

Transcripción

[MUSIC]

In this first lesson we are going to make a brief review

of the history of meteorology.

Brief because we will map out only the most important milestones

in this science, and we have titled it "From intuition to supercomputers".

Because everything started without science, with intuition, simply with perception,

and everything has evolved toward the present day.

All the meteorology and especially the meteorology associated to the

navigation, depends on supercomputers, and powerful

systems that allow us to do calculations.

Let's start by talking about the Ancient times,

Fundamental thing that must be taken into account for this period is

the concept of the world people had back then.

Let us focus on the European concept, the Greek concept of the world,

and look at this map of Anaximadre, a Greek philosopher,

from 5th century BC.

He drew what was considered the world for his time.

Look at one very important thing on this map.

The Mediterranean, which is this sea here, was the center of the world.

Here is the Mediterranean, the Black Sea, then there were Europe, Asia, Libya.

It was not called Africa but it is called Libya.

Then there was this flat disk shape, all surrounded by water,

an ocean, which was called the Mar Ignoto - Unknown Sea.

This marked the way to understand the first meteorology.

Everything started to happen in the Mediterranean,

meteorological phenomena were perceived in the Mediterranean.

The development of climatology began in the Mediterranean.

Those was where the bases

from which the meteorological knowledge was

developed later.

The boats that sail at that time were rowing and sailing boats,

but already adapted to the characteristics of the Mediterranean.

And it is during this time that the word meteorology is born, although not science.

The word meteorology was developed by Aristotle, because he wrote a treatise,

he wrote a book called Meteorology.

Meteorologica, which dealt with the perception,

the description of phenomena occurring in nature.

The cartographic knowledge of the Mediterranean,

began to develop in the Middle Ages.

Mapping began to develop,

entirely for the purpose of navigation.

Look at this map,

it is a chart from the Catalan Atlas, developed in Majorca,

one of the most famous works, and still considered as

the main source of medieval knowledge.

Navigation routes are described, bearing and leading lines.

There is no climate knowledge associated with these charts.

That was coming later.

During the Middle Ages, in the Mediterranean, what they did basically,

the sailors were the ones who accumulated this knowledge.

At that time sailors were Arabs, Byzantines, Venetians, Genoan,

Catalans and Majorcan.

They were basically merchants and military, but mainly

merchants were the ones who were developing the navigation routes.

They were collecting data on wind types, current types,

the types of waves.

Which were the best times of year to travel from one place to another, etc.

While this occurred in the Mediterranean, in northern Europe,

the Vikings began to develop ocean navigation.

In fact the Vikings were the first ocean navigators.

They set off from Scandinavia

to Iceland and even arrived in North America, before Columbus.

However, the knowledge of the Vikings has not come to us systematized,

because they had no records.

They did not keep records on climate and weather data of what they were

discovering, the areas where they were sailing.

So Northern Europe, the Vikings.

In China, during the Yuan Dynasty, there was a navigator who began to cross

that whole area, the seas that surrounded China.

This navigator, Wang Dayuan, was the first who systematically,

logged in a series of climatic data, on the Indian Ocean and the Arabian Sea.

So you can see how things were in the Middle Ages,

the meteorological and climatic knowledge of the Middle Ages.

Mediterranean, Northern Europe,

Vikings and in China, ocean sailors who traded with Arabia.

Everything began to change with the discoveries.

The discovery routes were

the first experiences that the European navigators had

beyond the Mediterranean,

in terms of sea voyage.

The first that merits the mention,

but there were many others before, was Christopher Columbus.

Cristobal Colón, in 1492, threw himself into the trade winds, set out to find Zipango.

Because he did not really look for America, but for Zipango, he was looking for Japan.

Columbus knew very well that the trade winds existed, because he had sailed

Madeira, through the Canaries and knew that those winds were always constant.

Columbus quite rightly thought, that if he positioned himself in a latitude,

around 28 degrees North, according to his calculations, if he maintained that latitude,

and always keep the trade wind, he would reach Japan.

That was his initial idea.

This is a map of the voyage that Columbus took, he left Palos,

went to the Canaries and remained practically in constant latitude,

28 degrees north, all the time.

Here he climbed slightly,

but kept following more or less constant latitude, here down a little,

under the recommendation of Pinzón brothers.

During this whole voyage he sailed with trade winds.

But the most interesting thing to observe on this map is, on the return trip, Columbus,

did not return to the same place, logically, because he knew that the winds were against,

but he took a route towards the north looking for the westerlies.

This established the first circuit, lets say Atlantic crossing,

which become known, the first oceanic wind circuit

known and used to travel, the route of the trade winds,

to sail from Europe to America and the route of the westerlies,

higher up north of the Azores anticyclone,

north of the Azores, with the zone of the westerlies.

This is the circuit that was then used throughout the colonization of America,

by the Spanish galleons, by the French and by the English.

This is a representation of Columbus, from the museum near Cadiz (Spain).

At that time, all climate knowledge was recorded.

Columbus is pictured writing down in the sailing charts,

the wind he was encountering, and all the

climate conditions that he came across on his voyage.

He was a great sailor and a great connoisseur of meteorology.

The second, I would say even more interesting than Columbus, was Vasco da Gama.

Vasco da Gama was the Portuguese who opened the route to India.

The Portuguese had already sailed in Africa, and Vasco da Gama

set off towards India on a journey, during which at first he wanted to to follow

the route by his compatriot Bartolomeu Dias, so set off around African coast.

However, Vasco da Gama, made a first stop in Cape Verde.

And then, instead of continuing along the coast, to round the Cape of Good Hope

what he did was to turn southwest, and arrived almost to Brazil.

In fact, if they had sailed about 100 miles further,

they would had seen the coasts of Recife.

And then he began to sail south, skirting the prevailing winds,

what we now know to be the anticyclone of St. Helena.

He did not know,

but had an intuition, because he knew that there was a very strong wind here,

that had been reported by earlier Portuguese explorers.

And he knew that to avoid those winds,

he already had the first intuition of that anticyclonic circulation,

the same that Columbus had back north with the anticyclone of the Azores.

Vasco da Gama, risking even a riot, because he was about to have a

mutiny on board because the crew did not understand why he was heading

so much to the west when in fact what they wanted was to go east,

toward the Cape of New Hope.

Vasco da Gama was the first, let's say he took a risk,

to really trust his intuition about that South Atlantic atmospheric circulation.

This route is precisely what all ships now do,

the Barcelona World Race and the Vendée Globe Boats.

All the round the world regattas that go the three capes route,

from West to East.

they do not take the direct route, as it will be explained later by

Marcel van Triest and Tomás Molina, when explaining the climatic conditions

special for the Barcelona World Race.

They do not go directly to the shortest route,

but skirt the Azores anticyclone, sorry, skirt the St. Helena High.

Vasco de Gama already knew that, five centuries before.

In the Renaissance, it really is when all things began to change.

Until then, meteorology was intuition,

recording, and a discerning eye of the sailor.

Renaissance brought a very important change of conception of the world,

one Copernicus gave us.

You know that before Copernicus people believed that the Earth was the

center of the world and everything revolved around the Earth.

Copernicus was the first to say no, the center of the Solar system was the Sun.

The Earth revolves around the Sun along with all the planets.

This seems to be a purely astronomical question,

but was actually also of enormous meteorological importance.

Because it changed the way people perceived the weather.

Seasons became another concept,

the way in which the Sun heated the Earth.

They begun to study the inclination of the Earth,

it was already known the Earth was round.

But they started to study

its axes, the ways in which it was oriented towards the Sun.

That allowed them to completely change the mental paradigm

and began to think of another concept, and that gave birth to meteorological science.

Another important milestone in the history of meteorology.

The first measuring instruments.

The first measuring instrument that emerged was the thermometer,

by Galileo.

Galileo, in 1607, devised a thermometer.

Here is a modern Galilean thermometer, which is called Galileo.

That you can find online, in any online store.

It is not evidently the thermometer of Galileo,

But it represents, explains how Galileo made his thermometer.

What he did was to place several solids with different densities inside a fluid.

And according to the temperature

these solids dilated more or less, rose and fell.

This thermometer had no scale.

It was only a relative perception of temperature.

It was about more or less temperature,

and it served little to science.

Instead, what another disciple of Galileo developed was extremely important for the

science - the barometer, which was invented by Evangelista Torricelli.

That barometer, look here, I don't know if you can see it well...

it was graduated with a scale, a mercury tube.

With this you could give objective data on measures.

That is, on one variable that was the pressure,

comparable objective measures could be taken with other instruments.

This is a very important step.

And the barometer became the basic instrument

to predict the weather, because you could see that the pressure varied with time.

They did not known why but they could see that it happened.

These data led to the possibility of comparing them

and that was when the empirical science begun to develop.

The first attempt to create a scientific method around these data

being obtained with the measuring instruments, was carried out in Italy.

Medici organized a network of observatories, basic ones at that time,

where temperature and pressure data were taken,

systematized and then compiled.

At that time there was no telecommunication,

everything was done on horseback, that was the fastest.

Thus, a lot of information was complied later.

It can be considered that these data of pressure, temperature,

humidity, wind direction and sky conditions,

were the first attempt at synoptic meteorology in history.

More important instruments, the most important of all that really,

that gave scientific rigor to measurements, was made by Fahrenheit.

Fahrenheit developed the first mercury thermometer

and the most important thing about that thermometer is that it had a scale.

That scale allowed the same as allowed the barometer before Torricelli,

to give objective data,

systematic, which could then be compared, could be mass produced.

Here you see Fahrenheit with his first thermometer,

and here there is a scale.

It was not very precise, but nevertheless

it was a measuring instrument that could then be manufactured in series

and then distributed to take measures in different places.

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