now chapter one was introduction the atmosphere the basic guesses uh what's around the earth how do we look at different spheres and what's happening above the earth those different layers the stratosphere the troposphere the tropopause what is the warmest layer what's the coldest layer so again go back and look at chapter one so you can get familiar with some of the questions that may be on test one chapter two is about heating the earth's surface in the atmosphere so how do we warm things up at the ground how do we warm things up above the ground and that's what we're going to be looking at in chapter two and all this heat generally is produced by the sun so first the earth has two different types of principles one is rotation one is revolution rotation is the spinning of the earth at its axis and don't forget it's tilted at twenty three and a half degrees revolution refers to the movement of the earth in its orbit around the sun remember the earth goes around the sun so with that tilt and the way the sun um sits in the the universe and the way the earth goes around that's how we start to develop our seasons and also it determines on how much daylight we get on the earth different spots where's the sun uh where's the earth relationship sun going throughout the year so the two most important features for the variation in solar energy reaching particular location the seasonal changes in the angle at which the sun rays strike the earth which in the northern hemisphere that is towards summer which is june 21st 22nd that time frame and then the length of daylight so you'll notice that when we talk about this chapter and also even now currently that during the summer or sunset around 8 30 now the sun is starting to set on long island at around seven to 702 so that's one thing you need to take note of the less daylight the less energy the cooler we're going to be during the winter we only get around nine and a half hours of daylight during the summer we get about 15 and a half hours of daylight so there's a big variation that's why the summer is warmer than the winter so we're going to be looking at the seasonal changes and also the length of daylight so the four days throughout the year that's really important to us that everyone looks forward to is the summer solstice which is in june okay the autumnal equinox or fall which comes up in september which is actually coming up next week then we have the winter solstice which is in december right around december 20th to 22nd and also um the vernal equinox which is coming up in march of next year roughly around march 19th to the 22nd it does vary sometimes year to year and one of the reasons for that is when we talk about the timing is that it's based on greenwich mean time in europe and we're you know four to five hours behind them so if it occurs at you know 1 a.m greenwich mean time our season will be on a different day here in the united states so we're going to be looking at where the sun's direct rays hit during our seasonal times summer winter spring and fall all right so some very important pages you need to look at the smart figures on page 23 29 through 34 figures 2.2 2.5 2.6 2.9 and basically they look like this they're going to show you where the sun's rays are hitting so when you're looking at this one of the important things you want to notice is right here for december the sun's direct rays are hitting down here during our summer the sun's direct rays are hitting here so that's one of the things that kind of determines the season when we're going to be warm okay and you can see the revolution okay and the rotation going around how that we have a tilt and how the earth is moving around the sun so you're going to be looking at these key points here these dates and where is the sun's direct rays hitting okay you can see these different white lines on the earth those are latitude lines and those latitude lines that we're going to look at the tropic of cancer the equator and the tropic of capricorn so those are things we have to look at when we're looking at different seasons because where the sun's rays are hidden hitting on the earth we'll get a very good idea on what season it is so notice the tilt of the earth and the location of the sun's rays hitting the earth okay so let's take a look at this in june so we're past june now but notice up here where where long island is it says roughly about 15 hours of daylight that's because when we're in our summer solstice the sun's direct rays are hitting this line right here 23.5 degrees north so the sun's direct rays are hitting the tropic of cancer around june 20th 21st and 22nd as opposed to during the winter solstice okay this is northern hemisphere the sun's direct rays are hitting down here which is around 23.5 degrees south so you can see in the northern hemisphere we're around nine hours near long island so different seasons will give us different hours then in spring and fall the equinox means equal so we get 12 hours of daylight 12 hours of darkness okay so those are things we really need to pay attention to where the sun's direct rays are going to hit on the earth so some of the important ones are right here tropic of cancer the equator entropic of capricorn so when we look at these weather maps look where the sun's direct rays are hitting so let's get the naming of some of these okay first at 23.5 degrees north this is known as the tropic of cancer the tropic of cancer is at 23.5 degrees north the equator is at zero the tropic of capricorn is at 23.5 degrees south tropic of cancer is 23.5 degrees north these three lines are going to be very important to understand what season we are in okay and you can see how this is split half the earth is lit half the earth is dark that's what we mean by the equinox equal daylight equal darkness and that is 12 hours so that circle of illumination goes right through the north pole where half the earth is dark and half the earth is lit so we're going to be focusing on where these sun's rays hitting during what time of the year so let's start out with spring and fall okay during spring and fall march and september the sun's direct rays will hit the equator okay and that is allowing us to have unilateral 12 hours of daylight and 12 hours of darkness so during spring and fall okay the autumnal equinox or fall equinox the vernal equinox or spring equinox the sun's direct rays hit the equator we get 12 hours of daylight 12 hours of darkness by the way farmingdale is roughly latitude line around 40 degrees north okay so these are latitude lines 40 degrees north 23.5 degrees south zero 20 um 23.5 degrees north zero 23.5 degrees south 40 degrees south you have the arctic circle at 66.5 degrees north and you have the antarctic circle which is down at 66.5 degrees south so let's look at summer the sun's direct rays are hitting into the northern hemisphere okay so that's why we have longer days in our summer or in when the sun's rec rays are hitting the northern hemisphere so right here are 23.5 degrees north this is the tropic of cancer the sun's rays are hitting here long island is roughly around 40 degrees north so during june we get about 15 hours of daylight where our sun will rise at around 5 25 in the morning and our sun will set roughly around 8 25 in the evening now when we're in our summer okay this is the northern hemisphere summer the north pole gets about 24 hours of daylight the south pole gets zero so this is very important to understand so if you've ever been to miami okay or through texas the sun actually sets later the further north you go in the summer so around maine they get about 16 to 17 hours long island 15 but down towards miami they're only getting about 13 and a half to 14 hours in the summer now that's kind of reversed as we go into the winter so as we head into the winter you can see now where the sun's direct rays are hitting so now they're hitting in the southern hemisphere so right along 23.5 degrees south which is right here this is the tropic of capricorn long island which is up around 40 degrees north is roughly getting around 9 hours so our winter solstice december is when we have our shortest daylight hours notice the north pole is now dark the south pole is now lit 24 hours so you can see how we have decreasing sunshine from south to north from the southern hemisphere to northern hemisphere and during the winter solstice which is roughly around december 20th 21st and 22nd the sun's direct rays are hitting the tropic of cancer i'm sorry tropic of capricorn tropic of capricorn is 23.5 degrees south tropic of cancer is 23.5 degrees north so when the sun's rays hit tropic of cancer which is 23.5 degrees north that is our summer when the sun's direct rays are hitting 23.5 degrees south that is our winter and when the the sun's direct rays are hitting zero or the equator that is our spring or fall so understand where the sun's direct rays are hitting during what time of the year right now we are approaching our equinox and the sun's rays okay are generally just north of the equator right now okay we're roughly around two to three degrees north okay sunrise for today is roughly around 6 30 sun sets roughly around 7 p.m so we're getting real close to that equinox so right now during your class we're going to get close to the winter solstice but we're going to go from summer solstice to the fall equinox with the autumnal equinox and we'll get real close to the this point come uh late in our semester so by the time we get towards december when you're taking your final your sum will set between 4 30 and 5 pm so understand where the sun's direct rays are hitting during certain times of the year you can see as we go back here right now our orbit around the sun is allowing we're tilting slightly still towards the sun in the northern hemisphere the sun's direct rays are approaching the equator so that will give us 12 hours of daylight 12 hours of darkness and that circle of illumination is right through the poles now as we go towards december you can see as we tilt away in the northern hemisphere we're getting less daylight and less energy so as we're tilted towards more energy more daylight summer is warmer tilted away less energy less daylight colder conditions and those seasons will change as the earth goes around the sun and the tilt changes so our warmest time of the year most daylight most energy is summer least amount of energy least amount of sun is towards our winter okay so those what we're going to be looking at understand where the tropic of cancer is the equator and the tropic of capricorn so again you can see there's going to be a couple different diagrams here of how the earth goes around the sun how the sun is tilted towards the earth and that will give us an idea of what season we are in so you can see september spring south of the equator fall north of the equator sun shines equally on the southern and northern equator once we're at the equinox equinox daylight 12 hours night time 12 hours understanding the sun angle you're not going to have to know how to calculate this for the test but just getting an idea during the summer okay our newton's angle is roughly around 73.5 degrees so that's a lot of energy hitting the earth we never get a full 90 degree angle that happens at 23.5 degrees south so we never get full income acceleration from the sun so in our summer our highest sun angle will give us the most energy and then notice in our winter roughly around december 21st our noon sun angle is around um 23.5 degrees south uh where the sun's hitting so when you add all that in the noon sun angle in winter is 26.5 degrees so you go from a high angle high energy a lot of incoming energy from the sun to a very small energy that's why we're so cold in the winter and that's why we're so warm in the center in the summer so again understand the latitude lines what it represents the tropic of cancer the equator and tropic of capricorn and just a reminder the sun's direct rays hitting the tropic of cancer when we're in our summer in the northern hemisphere in our equator during our march in spring march spring and fall in september and tropic of capricorn 23.5 degrees south when we are in our winter now the seasons are opposite from the northern hemisphere to the southern hemisphere so if we're in summer southern hemisphere is in winter if we're in fall southern hemisphere is in spring so we have opposite seasons so there's a lot more diagrams here and again these are the same diagrams our nose page 29 through 34 so make sure you take a look at the diagrams in the book and obviously they're here in the notes as well here's our almanacs to give you an idea of when we're looking at the information of when the sun rolls set what the record should be by the way daylight saving time goes through november 1st after that we fall back we turn the clocks back and that's one of the reasons why the sun sets roughly around 4 25 in december our fall officially begins september 22nd at 9 31 in the morning eastern daylight time winter will begin monday december 21st at 502 am eastern standard time so we have the clocks that move forward and backwards so how do we know when the seasons actually start when the sun's direct rays hit that location 23.5 degrees north tropic of cancer the equator and 23.5 degrees south tropic of capricorn what the time is at greenwich mean time that's what time it is and we're roughly about four to five hours behind that time frame so the sun's direct rays are hitting the earth and we can pinpoint when the actual seasonals will start now in weather terms meteorological seasons are a little bit different they're broken down into three months so we can get better averages and they represent more when it's actually warm cold or kind of cool or mild so fall for me meteorologist or meteorological start was september 1st and that goes september october november december 1st is when winter starts for meteorological situations astronomical is when the sun's direct rays hit a certain par portion of the earth and again our fall will start tuesday september 22nd at 9 31 am that's when the sun's direct rays are hitting the equator our winter monday december 21st at 502 am that's when the sun's direct rays will hit the tropic of capricorn which is 23.5 degrees south and as we go back towards next summer roughly around june 20th that's when the sun's rays will hit tropic of cancer at 23.5 degrees north so you can read more about why the seasons change to follow up with what i just went over understanding where the sun's direct rays are hitting during a certain time of year now as the sun's rays come in and we're tilted towards the sun we get a lot more energy coming in so what is energy energy is the ability to do work there are two major categories of energy one is kinetic energy and one is potential energy so kinetic energy is thought to be the energy of motion things are moving around the atmosphere think about little if you've ever seen a little ball pit that kid's playing all the balls are moving around that is kinetic energy the molecules in the atmosphere those are kinetic energy they're moving all around okay potential energy is the ability to do work okay that i'm sitting here right now doing nothing but if i get up and start talking and moving that would be kinetic energy in the atmosphere water droplets suspended in a cloud that's not falling from the sky that's potential energy little water droplets hanging out in the clouds suspended there that's potential and then as it actually starts to rain that's the kinetic energy and when there's a lot of kinetic energy we get thunderstorms and we can get tornadoes we can get hurricanes so those are the differences between potential which is the ability to do something kinetic is the actual movement of all the little motions and molecules in the atmosphere so there's a heat transfer heat is the transfer of energy okay into and out of an object because of temperature difference between that object and it's surrounded go read uh to follow up again on page 35-38 so basically what we're going to do is how is heat going from one object to another okay and this is one a lot of people are familiar with because you can kind of touch it conduction if you ever boiled water if you ever cook pasta okay and you have a metal handle and you're cooking that pasta you turn the flames on high if you go to touch that metal handle you're going to burn yourself that's conduction that's why we have mittens or if you ever put a metal spoon into boiling water it's going to move from that water into that metal spoon metal spoon is going to get hot if you touch it you're going to burn yourself convection see those little water molecules moving up and down that's in the atmosphere as well the movement of air upward and downward is convection convection air going upward and downward so when you boil water that's convection that's how the atmosphere is working you heat the ground and the air rises so convection is when you boil water or in the atmosphere heat rises and the air molecules go up and down there's another word advection which is not part of the three mechanisms of heat transfer advection not part of the tree three mechanisms heat transfer but it's the horizontal movement of energy or heat okay advection is horizontal not part of three mechanisms the main mechanisms but you have convection which is vertical horizontally is advection so convection conduction and then we have radiation that's the energy that's coming in from the sun or you can see here flames off of a fire pit maybe logs or your stove that's radiation all objects give off some sort of radiation and radiation can be very deadly depending on what type of radiation for example an x-ray is dangerous radiation if you get enough x-rays that radiation can make your bones a little brittle so three mechanisms of heat transfer conduction a transfer of heat through matter by molecular motion activity or motion so it's going to go from one object to another convection and transfer of heat by mass movement or circulation within a substance air going up and down or water bubbles going up and down radiation and transfer mechanism by which solar energy reaches the planet that's the sun's rays coming in into our atmosphere that's what's going to heat us so if we don't have the sun we're looking at much cooler conditions a much cooler climate so that's why in our summer as we're facing towards the sun we're warmer in the northern hemisphere so if we got rid of the sun we have more darkness and we would be much much cooler so we're going to understand radiation okay i'm going to end the video here please look at chapter one chapter two go over the first part understand the seasons if you have any questions let me know