Earth and Space Science TEK 14 a 14) Fluid Earth. The student knows that Earth’s global ocean stores solar energy and is a major driving force for weather and climate through complex atmospheric interactions. The student is expected to: (a) analyze the uneven distribution of solar energy on Earth’s surface, including differences in atmospheric transparency, surface albedo, Earth’s tilt, duration of insolation, and differences in atmospheric and surface absorption of energy. The student understands that atmospheric transparency is the extent to which the Earth’s atmosphere transmits light from celestial objects. Students know that the atmosphere’s clarity varies widely, depending upon the amount of absorbing material such as water vapor, dust, aerosols, and polluting gases.

Atmospheric Transparency The more clear the sky, the more solar energy makes it to the surface of the Earth. Clouds, aerosols, and debris can block some of the sun’s rays. Above the clouds Below the clouds When something is transparent, you can see through it. Atmospheric transparency is the is the extent to which the Earth’s atmosphere transmits light from celestial objects. Aerosols are minute particles suspended in the atmosphere. When these particles are sufficiently large, we notice their presence as they scatter and absorb sunlight. Their scattering of sunlight can reduce visibility Debris from volcanoes includes aerosols, ash, rocks, water vapor, and other gases, along with dust.

The cloud patterns in Earth’s atmosphere are constantly changing, but there are areas on Earth where clouds persist, and other areas where clear (transparent) is also the norm. As you can see in this image of clouds on Earth, which was taken over a series of decades, it shows well over 67% of the surface is usually covered with clouds. Most of the clouds occur over the oceans. Any surprises there? Where do you notice a lack of clouds? Any surprises there ?

1.Summarize how atmospheric transparency influences the distribution of solar energy on Earth. 2.What are aerosols, and how can they influence atmospheric transparency? 3.Where on Earth are clouds most persistent? 4.Where on Earth is a lack of clouds the norm?

Uneven Distribution of Solar Energy Surface Albedo How much of the sun’s energy is absorbed or reflected, depends on what surface the sunlight falls on. High Albedo = reflective Low Albedo = absorptive

Uneven Distribution of Solar Energy Earth’s Tilt Earth’s tilt: Seasonal differences can also account for the uneven distribution of solar energy. Angle of Insolation

5. Describe a place on Earth that has a high albedo. 6. Describe a place on Earth that has a low albedo. 7. How does albedo influence the distribution of thermal energy on Earth? 8. Why are there seasonal differences in the amount of sunlight that reaches the Earth’s surface? 9. Where on Earth are the most direct rays of the Sun hitting? 10. What global locations typically get the lowest angle of insolation? 11. At what angle does the Earth’s axis of rotation lie from the plane of the ecliptic?

Uneven Distribution of Solar Energy Duration of Insolation Solar radiation received by the Earth is known as INSOLATION (for incoming solar radiation). It is the main source of energy on our planet. The seasonal variations in temperature that we experience are due to fluctuations in insolation. Two major solar factors are at work to determine the Earth’s energy budget, that of angle of insolation, and duration of daylight. Therefore, a location on Earth will receive more insolation if the Sun shines more directly, or the Sun shines longer, or BOTH. We already know where the angle of insolation is greatest, but where does the sun shine longer?

12. What two solar factors determine Earth’s energy budget most? 13. What do you notice about the length of daylight at every location on Earth during the spring and fall equinox? 14. In which hemisphere is the length of daylight hours longer on June 21 st ? December 21 st ? 15. How does this data correlate to seasons on Earth?

Uneven Distribution of Solar Energy Differences in Atmospheric and Surface Absorption The energy entering, reflected, absorbed, and emitted by the Earth are the components of the Earth's radiation budget. Based on the law of conservation of energy, this radiation budget represents the balance between incoming radiation, which is almost entirely solar radiation, and outgoing radiation, which is partly reflected solar radiation and partly radiation emitted from the Earth, including the atmosphere. Entering: Ultraviolet and visible (short wave radiation) Leaving: o Reflected: Ultraviolet (short-wave radiation) o Emitted: Infrared radiation (long-wave radiation) A budget that's out of balance can cause the temperature of the atmosphere to increase or decrease and eventually affect our climate.

16. What energies are the components of the Earth’s radiation budget? 17. How is the energy received by the Earth (entering), different from the energy given off by the Earth? 18. What types of surfaces reflect more energy? 19. What types of surfaces absorb more energy? 20. What happens when the Earth’s energy budget is out of balance?