Astronomy Exam One

What does the term “environmental” refer to?

aspects that focus on the relationship between people and the natural environment

Hypothesis vs Theory vs Paradigm

tentative or untested explanation

vs

tested multiple times and confirmed hypothesis (describes a specific phenomena, like natural selection)

vs

a theory that explains a large number of interrelated aspects of the natural world (a general assumption about the world, like evolutionary biology)

What hypothesis is the generally accepted idea of how our solar system formed around the same time?
What does this hypothesis say the solar system evolved from?
When and how did the solar system assume a flat disc shape with the protosun (pre-Sun) at the center?
What did inner planets begin to form from?
What did outer planets begin to form from?

Solar Nebula Hypothesis

Solar nebula (enormous rotating cloud containing mostly hydrogen and helium)

5 billion years ago, the solar nebula contracted

metallic rocky clumps

fragments with high percentage of ices

What is the approximate age of the Earth?

4.5 billion years

As the Earth formed, what caused temperatures to increase?
What is differentiation?
As a result of differentiation, what materials sunk towards the center of the Earth and what materials rose toward the surface?
What formed the Earth’s primitive atmosphere?

the decay of radioactive elements and heat from high-velocity impacts

the process where a planet’s materials separate by density to form its internal structure

iron and nickel melted and sunk towards center (forming the cores); lighter rocky components floated up (forming the crusts)

gaseous material that escaped from Earth’s interior

What is a system?
What are the different systems of the Earth?

any size group of interacting parts that form a complex whole

• hydrosphere

• atmosphere

• biosphere

• solid earth

What is the most prominent feature of the hydrosphere?
How much of the Earth’s surface (what percentage) does the ocean cover?
How much of the Earth’s water does the ocean contain?
What does the hydrosphere also include other than the ocean?

ocean

71% (mid-to-low seventies; number may be different on test)

97%

• streams

• lakes

• glaciers

• groundwater

What system is the smallest of the spheres? What is this system characterized as? One half of this system lies below what distance?

atmosphere

thin, tenuous blanket of air

below 5.6 kilometers (3.5 miles)

What does the biosphere include? Where is the biosphere mainly concentrated at?

all life forms

near the surface in a zone that extends from ocean floor to several kilometers into the atmosphere

What is the solid earth sphere based on?
What does it consist of?
What are the divisions of the outer portion based on?
What is considered the rigid outer layer?
How is the Earth’s surface divided by?

compositional differences

crust, mantle, and core

how materials behave

lithosphere

continents and ocean basins

Open systems vs Closed systems

both energy and matter flowing into and out of the system (e.g. a river system, climate, plant/animal system)

vs

self-contained; nothing permanently leaves the system (e.g. hydrologic cycle, carbon cycle, nitrogen cycle)

Negative feedback mechanisms vs Positive feedback mechanisms

resist change and stabilize the system (e.g. friction)

vs

enhance the change to the system (greenhouse gasses)

What are the two sources of energy for the Earth?
Which source of energy drives external processes (weather, ocean and erosional processes)?
Which source of energy drives internal processes (volcanoes, earthquakes, and mountain building)?

(1) the Sun and (2) Earth’s radioactive interior

the Sun

radioactivity

Renewable resources vs Nonrenewable resources

can be replenished “rapidly” (e.g. plants and energy from water and wind)

vs

cannot be replenished “rapidly” (e.g. metals and fuels)

What are some reasons as to why Earth Science is important?

• rate of mineral and energy usage has climbed more rapidly than overall growth of population

• environmental problems that are either human-induced or humans accentuated

• understanding natural disasters

Human-induced environmental problems vs Human-accentuated environmental problems

problems that are actually caused by humans (e.g. urban air pollution and ozone depletion)

vs

problems that humans contribute to but don’t directly cause (e.g. acid rain and global warming)

Weather vs Climate

what is going on in atmosphere over a short period of time and is constantly changing

vs

over a long period of time; generalized, composite of weather

What is an air parcel?

an imaginary blob of air that contains different gases

What is the most abundant gas in the atmosphere?

Second most abundant?

Third most abundant?

How much of atmosphere consists of carbon dioxide?

What does carbon dioxide help do?

Nitrogen (N) - 78%

Oxygen (O₂) - 21%

Argon

0.036%

absorbs heat energy from Earth

What is an aerosol (AKA particulates or condensation nuclei)?

What can aerosols do/affect?

Why are aerosols important?

What sources do aerosols originate from?

tiny solid or liquid particles (e.g. dust or water droplets)

• can reflect light (cool atmosphere) or absorb light (warm atmosphere)

• color sunrise and sunsets

without them, you cannot form clouds (you can’t allow water vapor to condense)

dust storms, volcanic eruptions, urban air pollution, etc.

Why is water vapor considered a “perfect criminal”?

What percent does it take up the air’s volume?

Why is water vapor important?

it is the most efficient greenhouse gas because it doesn’t leave a measurable chemical trace

4%

• forms clouds and precipitation

• absorbs heat energy from Earth

What is an ozone?

Where is ozone concentrated at above the surface?

Why is ozone important?

How does human activity deplete the ozone?

Three atoms of oxygen (O₃)

10-15 kilometers above surface

absorbs harmful UV radiation

humans add chlorofluorocarbons (CFCs)

What is atmospheric pressure?

What is the average sea level pressure?

What does pressure decrease with?

One-half of the atmosphere is below how many miles?

What percent of the atmosphere is below 10 miles (16 km)?

How much of the atmosphere is below jets when they fly?

the weight of the air above

slightly more than 1000 millibars; about 14.7 pounds per square inch

altitude

3.5 miles (5.6 km)

90%

2/3

What is the bottom layer of the atmosphere called?

What usually occurs in this layer?

What happens to temperature as altitude increases (and what is this phenomena called)?

What is the average temperature difference between altitude (Celsius to kilometer, Fahrenheit to feet)?

What is the average height/thickness of this layer (and what is the height varied with)?

What is the outer boundary called?

troposphere

weather

temperature decreases (called environmental lapse rate)

• 6.5˚C per kilometer (average) 

• 3.5˚F per 1000 feet (average)

12 km (varies with latitude)

tropopause

What is the second layer (from bottom to top) of the atmosphere called?

What is the range of height this layer occupies?

What happens to temperature as altitude increases?

What is the outer boundary called?

stratosphere

12 km - 50 km

temperature increases

stratopause

What is the third layer (from bottom to top) of the atmosphere called?

What is the range of height this layer occupies?

What happens to the temperature as altitude increases?

What is the outer boundary called?

mesosphere

50 km - 80 km

temperature decreases

mesopause

What is the last layer (from bottom to top) of the atmosphere called?

What is the upper limit of this layer?

How much does this layer take up the atmosphere’s mass (in general)?

Are gases moving at high or low speeds?

thermosphere

no well-defined upper limit

makes only a fraction of atmosphere’s mass

high speeds

Conduction vs Convection vs Radiation

• heat transfer through molecular activity

• happens in solids

• faster vibrating molecules have more energy and therefore give off more heat, which can be transferred to cooler objects (requires direct touch)

vs

• mass movement of heat within a fluid (liquid/air)

• usually vertical motions

• hot fluid molecules move up, cold molecules move down, forming circulatory flow of heat

vs

• heat transfer through electromagnetic waves

• consists of different wavelengths

• can travel through a vacuum (needs no medium to carry it) at 300,000 km (186,000 miles) per second
  

  

Heat is always transferred from ___ to ___ objects.

warmer; cooler

What are the different wavelengths that radiation can travel through?

• gamma (very short waves)

• X-rays

• Ultraviolet (UV)

  • Three levels: A, B, and C

• Visible

  • ROYGBIV

• Infrared

• Microwaves and radio waves (radio is longest waves)
  

  

As wavelength decreases (for radiation), what happens to the energy carried per wave?

According to basic laws of radiation, do all objects, at whatever temperature, emit radiation?

According to basic laws of radiation, which radiates more totaled energy per unit area: hotter or cooler objects?

According to basic laws of radiation, the hotter a radiating body gets, what happens to the wavelength of maximum radiation?

According to basic laws of radiation, objects that are good absorbers of radiation are also good at what?

energy carried per wave decreases

yes

hotter objects emit more radiation

the wavelength gets shorter

emitting radiation

Atmosphere is largely ___ to incoming solar radiation.

transparent

What are the three different ways the atmosphere affects incoming radiation from the Sun?

What is albedo?

• Reflection (light bounces back from a surface at the same angle it hit)

• Scattering (light is bounced out at different angles due to interactions with small particles)

• Absorption (light energy is taken in by a material and converted into another form, like heat)

percent that is reflected (objects that don’t reflect a lot of light have a low albedo [like black shirts], while objects that reflect a lot of light have a high albedo [like white shirts])

What is terrestrial radiation?

What is terrestrial radiation absorbed by?

How is the lower atmosphere heated?

What is the heating of the atmosphere called?

the long-wavelength radiation coming from the planet due to its temperature

Carbon dioxide and water vapor in the atmosphere

from the Earth’s surface

Greenhouse effect

How does the greenhouse effect work? (List three key steps).

What characterizes a greenhouse gas?

1. visible light passes through atmosphere

2. surface absorbs visible light and emits thermal radiation in infrared

3. greenhouse gases absorb and re-emit infrared radiation, thereby heating the lower atmosphere

• any gas that absorbs infrared

• must contain molecules with two different types of elements (CO₂, H₂O, CH₄)

• it CANNOT be a molecule with one or two atoms of the same element (O₂, N₂)

What is air temperature a measure of?

How do molecules move in a cold volume of air? Warm volume?

What are some of the measurements that can be taken of temperature?

What are some important factors that influence the rate of heat loss from the body (consequently influences the human sensation of temperature)?

average speed of molecules

cold volume—molecules move more slowly and crowd closer together; warm volume—molecules move faster and farther apart

Measurements of temperature:

• daily maximum and minimum

• daily/monthly/annual mean

• daily/monthly/annual range

Factors that influence sensation of temperature:

• air temperature

• relative humidity

• wind speed

• sunshine

What is the boiling and freezing point of water in Fahrenheit?

What is the boiling and freezing point of water in Celsius?

What is the boiling and freezing point of water in Kelvin?

• Freezing: 32°F

• Boiling: 212°F

• Freezing: 0°C

• Boiling: 100°C

• Freezing: 273.15 Kelvin

• Boiling: 373.15 Kelvin

What is the most important control of temperature?

What are other important controls?

solar radiation

• differential heating of land and water (land heats and cools more rapidly than water; land also gets hotter and cooler than water)

• altitude

• geographic position

• cloud cover

• albedo

What is an isotherm?

What do isotherms show?

How are temperatures adjusted on temperature maps?

What two months are used for analysis because they represent temperature extremes?

a line connecting places of equal temperature

ocean currents

adjusted to sea level

January and July

What does heat index measure?

How is heat index calculated?

Why are heat indexes important?

how hot it feels outside by comparing air temperature and humidity

uses a table with a formula that takes into account relative humidity and dry bulb temperature

it indicates how dangerous the heat can be than just the air temperature by telling people how much heat their bodies can handle

What do wind chills measure?

How are wind chills calculated?

Why are wind chills important?

how cold it feels outside due to wind and temperature

uses a table with a formula that takes into account the temperature and wind speed

it can be a major factor in health hazards like frostbite and hypothermia