Lecture 14 Flashcards
(18 cards)
Where does Earth get its energy budget from?
From the sun
What regions receive more solar energy than?
Equatorial regions receive more solar energy than the poles
How is the energy redistributed to counter the imbalance?
By the coupled atmospheric and ocean circulation- the heat engine of the earth
How much of the incoming solar radiation is reflected back? How?
29%; primarily by clouds but also by bright surfaces such as ice
What helps balance net incoming radiation absorbed at the surface?
By outgoing energy through evaporation, convection, and thermal infrared radiation
What absorbs outgoing thermal infrared radiation? How much?
Water vapor and greenhouse gases; about 5%
What is a natural forcing?
changes in Sun’s brightness, Milankovitch cycles, large volcanic eruptions, and changes in surface albedo due to ice cover
What are Anthropogenic forcings?
Particle pollution, greenhouse gas concentrations and deforestation
What 3 components make up the Milankovitch cycles?
- Eccentricity- shape of the orbit
- Obliquity- tilt of the Earth’s axis
- Precession- Earth’s slow wobble
What wouldn’t we have without the tilt of the Earth?
Seasons
What is the basic physics of greenhouse effect?
gases in the atmosphere absorb infrared radiation that warms up the surface of the earth
What did Savante Arrhenius provide?
the first estimates of temperature change expected from increasing CO2 in the atmosphere
What accounts for the majority of greenhouse fas emissions?
CO2
What is Phenology?
study of temporal aspects of recurrent natural (biological) phenomenon and their relation to climate
Why is it difficult to study long term trends in Phenology?
because Phenology does not leave a record so cannot be studied in the fossil or archeological record
What must we rely on to study phenology?
On past observations that are lacking for most species
What phenologies are not expected to change because of warming?
Phenologies on some temperate species are controlled by photoperiod rather than temperature
What is Disrupted Synchrony?
mismatches in the timing of phenological shifts can disrupt interactions between species
