[MUSIC] This module deals with ocean chemistry, chemical oceanography. We have titled it "Chemical industry, with pipes without walls". Let's explain why this title. There will be five sessions in five days. The first day we are going to try to compose sea water and there will be a small presentation of the documents that will be later posted on the course, which should be read, which will carry more information. And in the introduction we are going to address some basic issues which make it easier to read. The first day we are going to discuss the subject of what is the chemical composition of sea water that interests us. On the second day we are going to dedicate ourselves to see what the main processes that make this marine chemistry. This great industry that processes materials and uses energy. How is it organized and what are the main axes of this organization? The third day we are going to devote to something very important that is carbon. Carbon is not only important for life. It is also very important, as everyone knows, for all relative to climate change and in which we humans play an important role. And we have to make decisions on aspects that affect the whole globe. And finally we will see how, at the global level, all chemical elements are redistributed in all oceans. Obviously the last session will be a working session of the students reviewing all the documents. And trying to answer a questionnaire to see how far they have learned, have understood what we intend to communicate. So let's see what the subject of oceanic chemistry is about. First, maybe say that generally when people think chemistry, think of an academic chemistry, those who have studied chemistry in school. And it is usually a laboratory chemistry, in which we see a flask, an Erlenmeyer. In which we put substances in the middle, for example, liquid typically and let them react, for example cover a little. And then we mix it up and we have what would be a chemistry of a thing that can be quite complex but well mixed. This is the chemistry that had great success and is also a very important part of chemistry. All the thermodynamics applied to chemistry gave some fantastic fruits at the level of knowledge, in modern science. However this chemistry generally explains a reaction dynamics. And this reaction is working until finally it is in a state of equilibrium. That is to say, it is finished, it is like throwing a rocket, it explodes many things, and in the end it is turned off, turned off and finished. It is the thermodynamic equilibrium is in the same energy. Of course marine chemistry, this part of the chemistry for marine chemistry is very important but marine chemistry, chemical oceanography studies the chemistry of nature. And the chemistry of nature is not what we we imagine of a chemical treatment plant, of chemical processing. Where it is a system obviously open, out of balance, where we put energy, we draw energy, refrigerate, filter, catalyze, etc., whatever. All this is what one imagines when the chemistry becomes something more complex or when chemistry thinks more about chemical engineering or industry. obviously this is a complicated process, which generally has some targets, has some waste products, etc .; But what does this look like oceanic chemistry is that it is an open and out of balance system. But generally, here in the industry it's about controlling all the processes and therefore there are pipes, containers, tanks, transportation. Here could be a truck or a tube that would take things back to the beginning, but at sea the question is not this. There are no pipes at sea, but there are complex processes. In the sea we have water, we have the atmosphere, we have solar radiation. We even have chemical and heat energy coming from the Earth's mantle. We have both rain and inland water inlets. That is, we have a complex system, one of the important parts is just water. And water has a role not only of solvent, but plays an important role in the dynamics of fluid surroundings. Both the atmosphere and the ocean. Water is fundamental, but it is fundamental not only as support, but as transport for example of heat. When water evaporates, heat is transported into the atmosphere and when the water condenses releases this heat into the atmosphere. And this is the machine, a thermodynamic machine that works, in the atmosphere works very well. And at sea it does not work so well because the system goes a little against against nature, that is, against what would be a good thermodynamic machine. Because the sea has to be heated and cooled by the same site. As the atmosphere cools at low pressure and heated by the lower part of the atmosphere at high pressure. Logically apart from the water exchanges that are very mechanical operation of fluid casings, we have the chemical composition. Of course, water is a major component at sea, and in the atmosphere we have nitrogen, oxygen and argon as the major gases. There is also water, logically, In the variable proportion, and there are gas exchanges. That is, atmospheric gases dissolve, too, in part in the water and therefore, there are also dissolved gases in the water. But chemical composition, we are interested in thinking of other things that there are in much lower concentrations but they are very important. For example, you know that ozone is important in certain atmospheric layers, we know that ozone is a filter for ultraviolet radiation, for example. And CO2, the carbon dioxide we also know is a greenhouse gas and that is very important. And in the sea, what if there are mostly as substances, as dissolved compounds, are the salts, the sea salt. and sea salt has a few compounds that are major, and also has a regular concentration everywhere which would be the ones we put here. And the basic composition of the air, is formed by nitrogen, oxygen and argon that form almost 100%. There are other gases like CO2, ozone, important, water. This would be a percentage of dry air, without water. This is important to say because water is a component that can vary widely and is important in the atmosphere. And the other major components of marine water, sea salt, these represent here 99.30% of all sea salt. But marine chemistry is something more, and if we look inside the sea. and we take samples of water, for example, we analyze them. There are things we can analyze because they are dissolved. The question is whether this will be representative of this water, or an important part of the sea or the ocean. But there are also other things, there are particles, and there are organisms. There are organisms, such as these copepods that have an activity, but these copepods are not alone. There are these copepods but they are there, but in general are small marine crustaceans. But they play an important role in marine chemistry. Why? Because they are small processors. All organisms are in turn like small industries. As open systems that process energy matter, but they are also particles, that is, are not dissolved, and also have an activity, we could say organized. That is, chemically clever. Chemistry, dissolved is one, marine chemistry has to have all these particles. That if we are seeing that this is a millimeter, this is a millimeter, and let's get going until we get to the smallest, these would be bacteria and this would be bacteria, this would be viruses. That is, if we go down, then from here we have organic molecules, or non-organic, but large molecules, up to the simplest inorganic molecules. They could be, for example, carbon dioxide, sulphate, etc. Therefore it is a not only complex chemistry, because the elements or substances that exist are complex. But because there are processors that are working particles, Which act in a way, let's say, organized. Therefore, we have that the organisms themselves are processors, but in addition, all this happens in a medium. In which we have to think that there are processes that have what we would call simple activity or biological relations. But that in the background are always chemical, have a chemical characteristic and we can also treat them as chemistry. Because it gives rise to the processes and operations of this whole industry which we have said about marine chemistry, without walls. That is to say with pipes, with pipes but which have no walls in the sense that there is no way to control it. That there is an organization, which is the organization of the marine circulation, of the structuring of the column of water, of the winds, of tectonic movements, etc. All this, would be the external energy that organizes the transport in a medium where there is gravity, solar radiation and other sources of energy which are say the auxiliary part that organizes all marine chemistry. Therefore, and in conclusion, marine chemistry is much more that the chemistry that we sometimes think is the chemistry, which is that of chemistry games. We put one reagent, another, a different color or bubbles, no. Chemistry is organized chemistry.