Ecology Exam 3

What is climate?

long-term averages and variability in weather patterns measured over decades

What is weather?

current conditions - temp., precipitation, humidity, cloud cover

What are the determinants of Climate?

temperature and precipitation

What is global temp. influenced by?

topography

greenhouse gases

solar radiation

ocean currents

The Green Sun Orbits

What is Global precipitation influenced by?

atmospheric circulation cells

ocean currents

topography (rain shadow)

Apples on Trees

What is Global Energy balance influenced by?

• greenhouse gases regulate how much outgoing heat is retained in Earth’s atmosphere

• balance between incoming solar radiation and outgoing heat

• distance of Sun from Earth

How does the Sun give rise to Earth’s climate?

• sun is ultimate source of energy that drives Earth’s climate

• solar radiation is strongest at equator and weaker towards poles - creating uneven heating

• uneven heating makes atmospheric circulation cells, causing warm air to rise and cool air to sink

• atmospheric circulation influences precipitation and prevailing winds

• winds drive ocean currents, which redistribute heat

Define Rain-Shadow Effect?

mountain ranges block moist air, creating a dry leeward side and a wet windward side

Process of Rain-Shadow Effect

1. moist air meets a mountain and is forced upward

2. the air cools and releases precipitation as it rises

• windward side: faces winds - high precipitation

• Leeward side: low precipitation

T/F : Climate impacts global distribution of animals

T

What percentage of the Earth’s atmosphere do greenhouse gases take up?

.1%

Why warmer on equator than poles?

sun rays are the strongest, warming the air

Uplift

process where warm air molecules rise and expand becoming less dense while cool air falls and contract becoming more dense

Atmospheric Circulation Cell

1. warm air rises and begins to cool

2. air loses moisture and condenses into clouds

3. once air is dry enough it falls back to surface: subsidence

subsidence

once warm air dries enough it falls back to surface

Coriolis Effect

deflection of wind caused by Earth’s rotation

• northern hemi: winds curve right

• southern hemi: winds curve left

Thermohaline circulation

driven by temp and salt, not wind

Great Ocean Conveyor Belt

links oceans and redistributes heat from tropics to poles

What does the Hockey Stick figure show? What are the primary drivers of the Hockey Stick figure?

shows stable temps followed by a rapid increase in recent decades; primary driver: human activties increasing greenhouse gases

What are the Milankovitch cycles? How do the Milankovitch cycles influence long-term climate variation?

changes in Earth's orbit and orientation that affect how solar energy is distributed; orbital shape, axis tilt, and orientation angle relative to stars, wobble

Interpret the Keeling Curve:

1. Why do CO2 concentrations fluctuate annually?

2. Why are CO2 concentrations trending positively?

1. seasonal photosythesis causes annual flunctuations 2. Human CO2 emmissions cause the long term increase

Misconception

a view or opinion that’s incorrect as its based on incorrect facts, faulty thinking, or understanding

Main causes of global warming

cars, trucks, burning fossil fuels for electricity, ozone hole, toxic wastes, deforestation, sun, cows, aerosol spray, volcanic eruptions, acid rain

Climate change misconceptions

Climate has always changed, recent change is no diff. than in the past

volcanoes emit more CO2 than humans

aerosols capture heat and are responsible for warming

depletion of the stratospheric ozone layer is causing warming

humans emit a tiny fraction of CO2

we are too far gone

T/F: greater earth tilt toward the sun= warmer summers, colder winters

True

How does chemical weathering remove CO2 from the atmosphere?

formation of calcite, settling and compaction, and formation of limestone

What causes seasonal climate variation?

Earth’s wobble

T/F: Aerosols tend to scatter radiation back into space or can brighten clouds, decreasing reflectivity and warming climate

F; aerosols tend to scatter radiation back into space or brightening clouds by increasing reflectivty and cooling climate

Function of the ozone

• absorbs ultraviolet from the sun protecting us high in the stratosphere

• a pollutant and contributor to smog w/ GHG characteristics near the ground

Why does CO2 increase in Nov-May and decrease in June-Oct?

• more land in the nothern hemi which increases carbon uptake in summer and carbon loss in winter

• plants release more CO2 through respiration during winter and absorb less through photosynthesis

What influences climate?

where species can survive

how species interact

how communities assemble

how ecosystems function

how ecosystems feed back to the climate system