Chapter 2 - The Physical Environment Flashcards
relating to fish that migrates back to the river to spawn. Salmon have a life cycle of starting in rivers, growing up traveling to the sea, then coming back to the river to spawn again.
Anadromous
Suggested by Steven Hare and Robert Francis to explain the declining salmon population
Suggested that changes in the environment of habitat (where salmon spawn) could be contributing to the population decrease
Hypothesized that shift in salmon production were associated with long-term climate variation in the North Pacific
Suggestion by Nathan Mantua & Colleagues to explain the salmon decline
Noted that when fishing was poor in Washington and Oregon, it was good in Alaska
Ultimate determinant of where organisms can live, the resources available to them, and the rate at which their population can grow
Understanding of this is the key to understand all the ecological phenomena
Physical Environment
long-term trends in temperature, wind, and precipitation
Climate
Drives climate system and biological energy production
Radiation
Influences the availability of critical resources: water & nutrients
Soil
Current temperature, humidity, precipitation, wind, and cloud cover
Weather
Long-term description of weather at a given location, based on averages, and variation measured over decades
Climate
Includes daily, and seasonal cycles associated with changes in solar radiation as Earth rotates and revolves
Changes over years or decades
Climate Variation
Climate Variation occurs as a result of
changes in the intensity, and distribution of solar radiation reaching the Earth’s surface, and changes in the overall energy balance
Determines the rates of biochemical reactions, and physiological activity for all organisms
Temperature
Supplies water that is an essential resource for terrestrial organisms
Where freshwater organisms depend on
Precipitation
Where marine organisms depend on
Influence the temperature, and chemistry of waters they live in
Ocean Currents
Usually used to characterize climate or physical environment at a given location
Average Conditions
Why can’t average conditions characterize geographic distributions?
because it is influenced by extreme conditions more than average conditions
Driven by energy that is derived from solar radiation
Global Climate System
Heat loss due to evaporation
Latent Heat Flux
How many watts of solar radiation per square meter each year is received by the top of earth’s atmosphere?
342 watts, 1/3 reflected back out by atmosphere, 1/5 absorbed by ozone
When energy is transferred through exchange of kinetic energy by molecules in direct contact with each other
Conduction
Transfer of energy via wind and water
Convection
Energy transfer from the warm air immediately above the Earth’s surface to the cooler atmosphere by both convection and conduction
Sensible Heat Flux
Several gases contained in the atmosphere that absorb, and reradiate infrared radiation
Greenhouse gasses
Force exerted by molecules of air on the air, and surface below it
Atmospheric Pressure
Steps of Storm Formation
Uplift of air → formation of bands of low atmospheric pressure relative to zones to the north and south → flows toward the poles when it reaches troposphere, and stratosphere → cools (exchange heat with surrounding air) → reaches the same temperature as the surrounding air → descends to the surface via subsidence
Large-scale pattern of atmospheric circulation created by the tropical uplift of air
Hadley cell
Named after George Hadley
Creates regions of high atmospheric pressure, which inhibit cloud formation
Where majority of deserts are found
Subsidence
Large-scale pattern of atmospheric circulation near the poles
Polar cell
Exists at mid-latitudes between Hadley and Polar Cells
Ferrell Cell
Named after William Ferrell
These cells establish the major climate zones on Earth which are:
Tropical zone - between 30° N and S
Temperate zone - between 30° and 60° N and S
Polar zone - above 60° N and S
Ferrell Cells are driven by?
Driven by:
Movement of the polar and hadley cells
Exchange of energy between tropical and polar air masses in region called polar front
Deflection associated with earth’s rotation resulting into surface winds blowing toward the equator from high-pressure zones at tropic zone are deflected to the west
Coriolis Effect
above 75-200m; warmer and less saline = less dense
Surface Water
Zones where deep ocean currents connect with surface currents again, where deep ocean water rise to the surface
Occurs when prevailing winds blow nearly parallel to a coastline
Occurs in westward-flowing equatorial Pacific Ocean
Upwelling
Layer of surface water where there is enough light to support photosynthesis
Photic Zone
large system of interconnected surface and deep ocean currents linking the Pacific, Indian, and Atlantic oceans
Great ocean conveyor belt
decrease in temp. with increase in height in elevation above sea level
Lapse Rate
Climate with little variation in daily and seasonal temperatures; higher humidity; on coastal regions
Maritime Climate
Climate with greater variation in daily and seasonal temperatures; on continental land masses
Continental Climate
Slopes facing into the prevailing winds
Windward Slopes
Slopes facing away from the prevailing winds
Leeward Slopes
Results in lower precipitation and soil moisture in leeward slopes
Rain-shadow effect
The amount of solar radiation that a surface reflects and is influenced by: type of vegetation, soil, topography
Albedo
Sum of water loss by transpiration and by evaporation
Evapotranspiration
Earth closest to the sun
Earth farthest from the sun
Perihelion and Aphelion respectively
Layering of water in oceans and lakes
Stratification
Areas in the ocean where cold, nutrient-rich waters from deeper
layers rise to the surface.
○Occurs due to movement of surface currents away from coastline
○ Allows deeper, cold water to rise and replace the displaces surface water
○ Driven by a combination of wind patterns and Coriolis effect (Earth’s rotation)
○ Upwelling = ↓ temperature
Upwelling Zones
surface layer = warmest and supports active population of
phytoplankton and zooplankton
Epilimnion
zone of rapid temperature decline found below the surface layer; separates epilimnion from hypolimnion
Thermocline
stable layer of the densest and coldest water
Hypolimnion
Mixing of the surface and deep layers of lake
Turnover
warming of the central and eastern equatorial Pacific Ocean
El Nino
cooling of the central and eastern equatorial Pacific Ocean
La Nina
An oscillation in atmospheric pressures and ocean currents in the North Atlantic Ocean that affects climatic variation in Europe, in northern Asia, and on the east coast of North America.
North Atlantic Oscillation
A long-term oscillation in sea surface temperatures and atmospheric pressures in the North Pacific Ocean that has widespread climatic effects.
Pacific Decadal Oscillation (PDO)
periods during the Earth’s history when glaciers and ice sheets reached their maximum extent or coverage
Glacial Maxima
refer to warmer intervals or phases between the glacial maxima when glaciers and ice sheets retreat or melt
Interglacial Period
cause of the regularity of glacial and interglacial cycles
Milankovitch cycles
refers to the concentration of dissolved salts in water
Salinity
A process by which high rates of evapotranspiration in arid regions result in a progressive buildup of salts at the soil surface.
Salinization
