EARTH 10 Lecture Notes - Lecture 14: Marine Isotope Stage, Weddell Sea, Little Ice Age
Document Summary
Isotope: variants of same element that has same # of protons & electrons but differing # of neutrons in nuclei. Marine isotope stage: periods of alternating warm and cool periods in earth"s paleoclimate, variations in oxygen isotopes used as proxy for global temp change. Important analogue for current day climate: 120000 years ago, analogy for global warming scenarios, sea levels were 6-9m higher than today. W antarctica? (some say it collapsed ~3. 3m to 6-9m. Ice loss = ocean rise globally: solar output changes. Sunspot cycles: ~11 yr (more sunspots, more solar energy released: early and mid-holocene: warmer in antarctica. El nino: periods of warmer ocean temps along equatorian coast; brings changes in antarctic weather too, high pressure over amundsen & bellingshausen seas. Reduced sea ice & warmer conditions: weddell sea: colder & more ice. Casing warming across parts of antarctica: wind pattern changes. Circum-antarctic winds have increased 15-20% over last 30 years: greenhouse gases: co2.
