Download Global Climates and biomes

GLOBAL CLIMATES AND
BIOMES
APES Unit 2
Friedland and Relyea
Global weather and climate

Weather vs. Climate
 Weather:
Short term
 Climate: Long term

Biomes are primarily characterized according to
climate
 Precipitation
 Temperature

What determines weather and climate?
Earth’s Atmosphere

Made of 5 layers of gasses:
Earth’s Atmosphere





Troposphere: where we live; weather
Stratosphere: ozone layer, UV protection
Mesosphere
Thermosphere: aurora borealis; satellites
Exosphere
Unequal Heating of the Earth
Albedo: Earth’s avg 30% Reflected
How would tropical regions with dense
green foliage differ in albedo values
to snow-covered polar regions?
Atmospheric Convection Currents


Uneven heating drives the circulation of air in the atmosphere
Properties of air that influence this movement

Density



Warm air, less dense, rises
Cool air, more dense, sinks
Water vapor capacity

Warm air, high capacity



Cool air, low capacity
Adiabaitc heating or cooling



Humidity
Heating: as air sinks, pressure increases, volume decreases, temp increases
Cooling: as air rises, pressure decreases, volume increases, temp decreases
Latent heat release

Water vapor condenses and releases heat and in doing so, the warm air begins
to rise
Convection Currents


Global patterns of air movement that are initiated by the
unequal heating of the earth
Hadley Cells form At the Tropics:

Density?


Adiabatic (cooling or heating) occurs



Result:
Condensation and clouds are formed


Result:
Result:
A continuous stream of warm air rises into the troposphere, is
cooled at the top of the troposphere, contains very little water
vapor and is displaced north and south as warmer air rises from
below.
The displaced, cooler, dryer air then sinks back to earth around
30*N&S, experiences high pressures and heating dry climates
Hadley Cells

Also see Figure
4.6 in your
textbook
Intertropical Convergence Zone

Dense clouds, high thunderstorm activity, follows the
most direct sun throughout the year.
Polar Cells

Similar to Hadley Cells
 Warm
air, rises and condenses at 60* N&S and cool,
dry air is displaced and sinks at the poles
Earth’s Rotation…


The rotation of the earth on it’s axis also plays a
huge role in climate
Rotation is faster at the equator than the poles
 Why?


Because of this rotation, a deflection occurs from
north to south (think about drawing a line from the
top to bottom of a beach ball while the beach ball
spins…)
This deflection is called the Coriolis effect
Prevailing Winds

Occur due to a combination of atmospheric
convection currents and the Coriolis Effect
What causes seasonal changes?

https://www.youtube.com/watch?v=82p-DYgGFjI
9




min description of earth’s tilt and seasonal changes
Summer Solstice
Fall Equinox
Winter Solstice
Spring Equinox
Mind Engagement

With your neighbor, discuss and explain how the
earth’s climate is determined by global circulation
patterns.
Ocean currents influence weather

Driven by
 Temperature
 Gravity
 Prevailing
winds
 Coriolis effect
 Locations of contienets
Gyres




Patterns of water circulation
Northern Hemisphere: clockwise
Southern Hemisphere: counterclockwise
Redistribute heat in the ocean
Upwelling




Upward movement of water toward the surface
Deep waters bring nutrients towards the surface
that are necessary for large populations of
producers
These producers support large populations of
consumers
Upwelling is important for supporting highly
productive ecosystems
Thermohaline Circulation



Drives the mixing of surface water and deep water
and is crucial for moving heat and nutrients around
the globe
Driven by salinity of the water
Graphic Representation of the TC:
https://www.youtube.com/watch?v=3niR_-Kv4SM
Is the thermohaline in trouble?



What would happen if air temperatures increase?
Al Gore Explains:
https://www.youtube.com/watch?v=02NRKzemXYE
How is the thermohaline linked to the next possible
ice age?
El Nino-Southern Oscillation

Approx every 3-7 years, surface currents in the
tropical pacific reverse direction
 Weaker
trade winds near S. America
 Warm water moves eastward
 Upwelling stops  decrease in productivity

Global Impact of El Nino
 Cooler
wetter conditions in SE US
 Dry weather in SE Asia and S Africa
Rain Shadow Effect
Climate determines terrestrial biomes









Tundra
Boreal Forest
Temperate Rainforest
Temperate Seasonal Forest
Woodland/Shrubland
Temperate Grassland/Cold Desert
Tropical Rainforest
Tropical Seasonal Forest/Savanna
Subtropical Desert
Biomes


Have a particular
combination of
average annual
temperature and
annual precipitation
and contain distinctive
plant growth that
have adapted to the
climate
Animal populations
can also aid in the
characterization of
biomes.
Climatogram (Climate Diagrams)
See also,
page 101
in your
textbook
Biomes Webquest Activity
Climatogram Activity

Using the provided data, create a climatogram for
each biome, analyze the graphs and answer the
discussion questions provided.
Aquatic Biomes

Characterized by
 Salinity
 Depth
 Water

Flow
Freshwater vs. Marine Aquatic Biomes
Describing Aquatic Ecosystems
• Salinity: the amount of dissolved salt
present in water. Ecosystems are
classified as salt water, fresh water, or
brackish depending on salinity.
• Photosynthesis tends to be limited by
light availability, which is a function of
depth and water clarity.
• Aquatic ecosystems are either flowing or
standing.
• Aquatic ecosystem zones: photic, aphotic,
benthic
Freshwater Ecosystems:
Ponds, Lakes, Inland Seas
• Salinity is less than 0.5 ppt (parts per thousand)
• Ponds and lakes are
similar, except in size,
but inland seas contain
organisms adapted for
open water.
• Ponds and lakes are
divided horizontally
into zones: littoral
and limnetic
Freshwater Ecosystems:
Wetlands
• Areas of land flooded with water at least part of the year
• Include freshwater marshes, swamps, bogs, and fens
• Wetlands prevent flooding, recharge aquifers, filter pollutants, and
provide habitats.
Freshwater Ecosystems:
Rivers and Streams
• Bodies of surface water that flow
downhill, eventually reaching an ocean
or inland sea
• Watershed: The area of land drained
by a river and its tributaries
• Characteristics, such as dissolved
oxygen, temperature, water speed,
organisms, and others, change from
source to mouth.
Estuaries
• Occur where a river flows into the ocean or
an inland sea
• Coastal estuaries are brackish ecosystems;
organisms must tolerate wide salinity and
temperature ranges.
• Coastal estuaries are home to salt marshes
and mangrove forests.
• Like wetlands, estuaries help prevent
flooding and soil erosion as well as provide
habitats.
Everglades, Florida, wetlands
Did You Know?Salt marshes and mangrove forests are two of the
most productive ecosystems on Earth.
Oceans
• Currents are driven by water temperature and density differences,
wind, and gravity.
• Surface winds and heating generate vertical currents that transport
nutrients and oxygen.
• Horizontal ocean zones:
intertidal, neritic, open ocean
• Vertical ocean zones: photic,
aphotic, benthic
Did You Know?If the water in the oceans
evaporated, a 60 m (200 ft) deep layer of salt
would be left behind.
Ocean Ecosystems
• Intertidal: Highly diverse; extreme range of temperature, moisture,
and salinity
• Neritic: Productive kelp forests and coral reefs provide habitats and
help protect shorelines from erosion.
• Open ocean: Low
productivity due to low
light penetration;
phytoplankton base of
food chain; deep sea
organisms and
hydrothermal vent
communities
Did You Know?Over 90% of ocean water on
Earth is in the open ocean zone.
Coral Reefs




Earth’s most diverse marine biome
What are corals? Are they living or non-living?
Coral Bleaching: occurs when algae inside the coral
die and thus the coral die.
Ted Talk:
https://www.ted.com/talks/jeremy_jackson/transcript
Open Ocean