BIOL-208 Lecture Notes - Lecture 23: North Atlantic Oscillation, Habitat Fragmentation, Gilgit-Baltistan
17 Dec 2016
School
Department
Course
Professor
Global ecology
- Introduction
- Rapid global changes produces challenges
- Require principles from many disciplines
- Multidisciplinary teams
- Biologists, physicists, chemists, earth scientists
- Economists, sociologists, political scientists
- Atmospheric envelope and the greenhouse earth
- Clean dry air at the earth’s surface
- 78% Nitrogen
- 21% Oxygen
- 1% Argon
- 0.0038% Carbon Dioxide
- 0.00005% Ozone
- Earth’s magnetic field was born by 3.45 billion years ago, shielding “life”
from deadly solar radiation. Earth occupied by anaerobes
- Then cyanobacteria created the world’s largest pollution event: oxygen
- Troposphere
- Earth's surface to 9-16 km
- Constant oscillation fluctuates how far it extends
- Atmospheric gases most concentrated
- Stratosphere
- Troposphere to about 50 km
- Ozone most concentrated
- Mesosphere and Thermosphere
- Extended above the stratosphere
- Greenhouse effect
- Earths surface: heat is trapped by greenhouse gases
- H2O, CO2, CH4, O3, nitrous oxide, CFCs
- -18℃ average temperature without vs 15℃ average temperature
with
- 30% incoming solar radiation reflected into space
- Clouds, particulates
- 70% solar energy absorbed by atmosphere or earth’s surface
- Reemitted as infrared radiation
- Absorbed by greenhouse gases
- Radiated back to earth
- Of the incoming solar energy, some is reflected by clouds or the earth’s
surface
- If the solar energy absorbed, some is radiated into space as infrared light,
and some is absorbed by greenhouse gases
- Some is absorbed by the earth’s surface or by the atmosphere
- Greenhouse gases radiate some of the heat they absorb back to earth’s
surface
find more resources at oneclass.com
find more resources at oneclass.com
- Key influences on Biosphere
- Habitat loss
- Habitat fragmentation
- Overexploitation of natural populations
- Invasive species
- Altered nutrient cycling and nutrient inputs
- Climate change
- A Global System
- Large scale atmospheric and oceanic phenomena
- Southern oscillation: oscillation in atmospheric pressure that extends
across the pacific ocean
- North atlantic oscillation and northern hemisphere annular mode:
oscillations in atmospheric pressure that affect northern areas
- Southern Oscillation
- British mathematician Walker (1924) first to recognize patterns in
barometric pressure across pacific ocean
- Barometric pressure is negative; when it changes, ocean
temperature changes
- Termed pattern the southern oscillation
- Positive values indicate higher barometric pressure in the eastern pacific
ocean; large spikes are called La Ninas
- Negative values indicate lower barometric pressure in the eastern pacific
ocean; large spikes are called El Nino
- El Nino
- Strongly negative values of southern oscillation
- Circulation system moves in plane of equator
- Air over warmer western pacific rises
- Sinks as it reaches eastern pacific
- Moves west again, gathering moisture and rising as it
warms again
- La Nina
- Periods of lower sea surface temperature
- Higher than average barometric pressure in eastern tropical
pacific
- Walker circulation
- During a La Nina, the location of storm generation in the Pacific
moves westward
- During an El Nino, the location of major storm generation moves
eastward
- Walker circulation moves in the plane of the equator
- Meridional air circulation
- Climate effects
- Strong El Ninos bring exceptionally wet or exceptionally dry
conditions to a large part of the planet
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Clean dry air at the earth"s surface. Earth"s magnetic field was born by 3. 45 billion years ago, shielding life from deadly solar radiation. Then cyanobacteria created the world"s largest pollution event: oxygen. Constant oscillation fluctuates how far it extends. Earths surface: heat is trapped by greenhouse gases. H2o, co2, ch4, o3, nitrous oxide, cfcs. 18 average temperature without vs 15 average temperature with. 30% incoming solar radiation reflected into space. 70% solar energy absorbed by atmosphere or earth"s surface. Of the incoming solar energy, some is reflected by clouds or the earth"s surface. If the solar energy absorbed, some is radiated into space as infrared light, and some is absorbed by greenhouse gases. Some is absorbed by the earth"s surface or by the atmosphere. Greenhouse gases radiate some of the heat they absorb back to earth"s surface. Southern oscillation: oscillation in atmospheric pressure that extends across the pacific ocean.
