temperature and insolation

Slide 1: 

Insolation: The Sun is at the centre of the Solar system. The Sun isthe source of heat to all planets and satellites of the solar system. So theSun is the main source of heat and light for the Earth also.Earth is 150 million km away from the Sun. The furnace that melts hard iron has a temperature of 1100ºc. Only when we are very near to the furnace we feel the heat. But evenat a distance of 150 million km we are unable to bear the heat of themid-day Sun. Therefore to emit light and heat over such a distance, what would be the temperature of the Sun? 5000degreeC &150,000degreeC at its core

Insolation is…… : 

Insolation is…… IN = incoming SOL = solar ATION = radiation Def: radiation from the sun

We receive only one 2 billionth (1/2,000,000,000) of all the suns energy! Solar radiation consists of two types of rays. They are;1. The visible Sunrays that consists of seven colours2. The invisible Sunrays consisting of Gama rays, X rays, Ultravioletrays, Infra red rays and Radio waves.Since the temperature of the Sun is very high, it emits heat inthe form of short wave radiation. This short wave radiation can travel a distance of 150 million km to reach and heat the Earth : 

We receive only one 2 billionth (1/2,000,000,000) of all the suns energy! Solar radiation consists of two types of rays. They are;1. The visible Sunrays that consists of seven colours2. The invisible Sunrays consisting of Gama rays, X rays, Ultravioletrays, Infra red rays and Radio waves.Since the temperature of the Sun is very high, it emits heat inthe form of short wave radiation. This short wave radiation can travel a distance of 150 million km to reach and heat the Earth

Slide 4: 

All areas of the Earth get the same amount of sunlight! Why are some area’s cold and others hot?

Some area’s have greater intensity then others : 

Some area’s have greater intensity then others Intensity of Insolation is correlated to the average surface temperature. As intensity goes up, so does temp.

#1 Factor affecting Insolation : 

#1 Factor affecting Insolation Angle of Insolation or the angle of the sun ray’s hitting the earth. The greater the angle, the greater the temperature. 00 is cold – 900 is hot

How does angle affect intensity? : 

How does angle affect intensity?

What affects angle? : 

What affects angle? Time of day When is the sun highest in the sky? 12 pm, noon As the sun gets higher in the sky, what happens to the shadow length? Shadow Video

Slide 9: 

Higher angle = small shadow = High temps What determines the angle of insolation is…

When does hottest/coldest times of day/year occur? Why? : 

When does hottest/coldest times of day/year occur? Why?

Warmest Times : 

Warmest Times Temp. rises = incoming energy>outgoing energy Temp. drops = incoming<outgoing

Slide 12: 

Radioactive Balance = Incoming energy is the same as Outgoing energy Hottest times occur after maximum insolation because incoming=outgoing energy

Latitude : 

Latitude Dictates the angle and duration of insolation (# of daylight hours)

Intensity due to tilt of the Earth : 

Intensity due to tilt of the Earth The earth is tilted 23 1/2o to the sun which causes changes in intesity Higher latitude = Less intense Low latitude = more intense Equator is most intense on average.

Some more factors …………… : 

Some more factors …………… Slope of the mountains Condition of the atmosphere

Heating and cooling of the atmosphere : 

Heating and cooling of the atmosphere There are four ways by which the atmosphere or air gets heated and cooled. They are conduction, convection, radiation and Advection the latent heat of water-vapour also responsible

Slide 17: 

Conduction: The molecules of air lying in contact with the Earth’s surface get heated up. These molecules in turn heat up the adjoiningmolecules and so on. This process of heat transfer from one molecule to another is known as conduction

Slide 18: 

Convection: The air nearer to the Earth’s surface gets heated, expands,becomes lighter and moves upwards. The cool, heavier, upper air sinksdownward to take its place. When the cool air reaches the Earth’ssurface it gets heated, expands and rises up. This process continues and is known as convection

Slide 19: 

Radiation: When heat is transferred from one body to another without the help of any medium (e.g. solids, liquids or gas) it is called radiation. Incoming solar radiation heats the Earth. The heated Earth re-radiates this heat to the atmosphere in the form of long wave radiation

Slide 20: 

Advection The transfer of heat through horizontal movement of air is called advection In middle latitudes, most of diurnal variation in daily weather are caused by advection only.In tropical regions particularly in northern India during summer season local winds called loo is the out come of advection process.

Slide 21: 

Latent heat of water-vapour: Evaporation takes place continuously from the hydrosphere, biosphere and lithosphere. Much energy is needed to convert water into water-vapour. The energy, which is absorbed by water to become water-vapour is hidden in the vapour. This hidden heat energy is known as ‘latent heat’. The water-vapour,mixes with the air and rises up along with the air. As it rises up, it cools and begins to condense, when condensation takes place, the watervapour present in the atmosphere becomes water particles there byreleasing its latent heat. The latent heat released during the process of condensation heats the air column.

Heat balance of the Earth : 

Heat balance of the Earth Now we understand that the Sun heats the Earth and the Earth passes the heat to the atmosphere. So both the Earth and the atmosphere get their heat from the Sun. This process of heating of the Earth by the Sun occurs everyday, for millions of years. But the temperature of the Earth is maintained at a particular level because there is a balance between the heat that comes from the Sun to the Earth and that which goes from the Earth back to space

Net Radiation and the Planetary Energy Balance heat balance of the earth : 

Net Radiation and the Planetary Energy Balance heat balance of the earth

Slide 24: 

Shortwave radiation from the Sun enters the surface-atmosphere system of the Earth and is ultimately returned to space as longwave radiation (because the Earth is cooler than the Sun). A basic necessity of this energy interchange is that incoming solar insolation and outgoing radiation be equal in quantity

Global longwave radiation cascade. : 

Global longwave radiation cascade.

Inversion of Temperature: : 

Inversion of Temperature: Under special circumstances, there is an increase in temperature with an increase in elevation. This state of affairs of known as Temperature Inversion.During calm cool nights (winter), the sinking cold air collects in hollows and valleys causing a decrease of temperature. In mountain areas, the valley floors are colder than the places at a higher level. It happens in winter and spring nights.

Slide 27: 

The ideal conditions of temperature inversion are: 1. Absence of winds;2. Clear skies;3. Long winter nights;4. Cold dry air; and5. Snow covered earth.

Spatial distribution of insolation at the earth’s surface Balance between average net shortwave and longwave radiation from 90° North to 90° South. : 

Spatial distribution of insolation at the earth’s surface Balance between average net shortwave and longwave radiation from 90° North to 90° South.

"aphelion" and "perihelion" : 

"aphelion" and "perihelion"

Slide 30: 

The planets in our Solar System orbit the Sun. The orbits of some planets are almost perfect circles, but others are not. Some orbits are shaped more like ovals, or "stretched out" circles. Scientists call these oval shapes "ellipses". If a planet's orbit is a circle, the Sun is at the center of that circle. If, instead, theorbit is an ellipse, the Sun is at a point called the "focus" of the ellipse, which is not quite the same as the center. Since the Sun is not at the center of an elliptical orbit, the planet moves closer towards and further away from the Sun as it orbits. The place where the planet is closest to the Sun is called perihelion. When the planet is furthest away from the Sun, it is at aphelion. The words "aphelion" and "perihelion" come from the Greek language. In Greek, "helios" mean Sun, "peri" means near, and "apo" means away from. When Earth is at perihelion, it is about 147 million km (91 million miles) from the Sun. When it is at aphelion, it is 152 million km (almost 95 million miles) from the Sun. Earth is about 5 million km (more than 3 million miles) further from the Sun at aphelion than at perihelion

Why do we experience seasons? : 

Why do we experience seasons? Seasons are the result of earths tilt and revolution. Tilt = 23.5 degrees, increased tilt = hotter summers and colder winters.

Seasons are opposite in Southern Hempisphere : 

Seasons are opposite in Southern Hempisphere What if tilt were more/less? There would be greater differences in temperatures for the latitudes.

Greenhouse Effect : 

Greenhouse Effect Warming trend due to absorption of terrestrial (land) radiation (infrared) by greenhouse gases (CO2 + H2O vapor)

Slide 37: 

Without greenhouse gases, the average temp of 59oF, would drop to 0o F CH4 (Methane), water vapor, CO2, as well as Other gases If all ice were to melt on Earth seal level would reach 75m.! ! Seal level is rising 2.5 mm/yr

Sky Dome Model : 

Sky Dome Model