Contain many glacial and interglacial periods.
occur every 40-110,000 years. Cools slowly for 10,000s then warms rapidly for 100,000s
last 10-20,000 years
ice age 1.8 million years to today. current ice age.
Solar radition let in by gases, but keeps it from reflecting back into space, trapping heat within the atmosphere, warmer.
average weather over time (personality)
short term phenomenon. (mood)
measurement of how much light is reflected. greater albedo= means less light absorbed, more reflected, cooled temperatures.
positive feedback mechanism
self-perpetuating change in some parameter.
Albedo of Glacial Ice, Water vapor as a GHG more evaporates when it's warm,Warm oceans absorb less CO2 than cold oceans.
large continental glaciers
Isotope, heavier and harder to evaporate than O16. warmer heat allows more O18 to evaporate. More O18 present in ice during warmer periods.
lake sediments in glacial lakes that only form when the lake unfreezes part of the year. thicker layer= lake unfrozen for longer=past warmer weather.
Vostok Ice cores
Antartica, location ice cores came from that give us evidence about past climate. Bubbles, time, air trapped. concentration of past GHG, O18, and pollen.
How do glacial periods and interglacial periods relate to ice ages?
multiple glacial and interglacial periods within an ice age.
What is the most recent (or current) ice age?
Pleistocene Ice Age
What are the major greenhouse gases (GHG 4)?
water vapor, methane, carbon dioxide, and ozone
How are changes in sea level related to climate?
when ice builds on land, sea level drops. When ice melts, sea level rises.
What are the factors that may lead to an ice age?
-decrease of GHG effect
-more ocean surface to absorb CO2
-major volcanic eruptions
-positions of continents
What factors may lead to glacial periods?
changes in the earths obliquity (tilt), eccentricity (orbit around sun), and percession (orientation of axis). Milankovich cycles. natural cycles may work together to create climate fluctuations on Earth.
Difference between climate and weather?
climate=personality over time, stable measurement
What are factors that effect today's climate (7)?
latitude, altitude, albedo, closeness to water, wind direction, variations in solar energy, amount of plants for photosynthesis.
-All months warm, precipitation, vegetation, day/night temperatures more extreme than seasonal
water deficiency, more evaporation than precipitation.
Humid Mid-latitude- mild winters
WARM-distinct seasons, mild winters
Humid Mid-latitude- severe winters
COLD- distinct seasons, severe winters
average below 50 in summer, extreme cold in winters.
low varying temperatures, high precipitation.
Short term climate change
1 historical photos: size of glaciers, sea level, types of vegitation then and now.
3 tree rings:thicker rings=more precipitation/warmer temp.
4 Ice cores: previously trapped GHGs, presence of O18, pollen trapped reveals types of plants, climate needed for them.
Long term climate change
Milankovich cycles: obliquity (aixal tilt), percession (change in tilt orientation), eccentricity (orbit around sun). patterns/overlapping cause change in climate.
What information do ice cores give us?
-trapped air bubbles show previous presence of GHG and concentrations
-presence of isotope O18- warmer weather, more O18. cooler-less.
-pollen trapped in ice layers-types of plants and climate needed for them.
Where is climate headed? How is sea level responding?
2. sea level rising- thermal expansion of water & glacial melting
3. connection between CO2 levels and global temps. both increasing.