User:ZacharyFranciscoOSU/sandbox
Article 1: Climate Proxies Notes
- Defined as preserved physical characteristics of the past that can be utilized to indicate past climate conditions
- Examples: ice cores, tree rings, corals, sub-fossil pollen etc.
- Proxies are cross-verified to improve accuracy
- Not all proxies are uniform, more in the Northern hemisphere
- Ice cores - cylindrical samples from within ice sheets
- Isotopes of ice cores indicate temperature
- Can reveal the climate records for the past 650,000 years
- Tree rings
- Reveals climate for past thousands of years
- Fossil leaves
- CO2 content of past atmospheres for leaves
- Boreholes
- Do not require calibration
- Record the surface temperature
- Potential risk of contamination by groundwater
- Corals
- Ocean coral skeletal rings
- Cooler temps, corals used heavier isotopes
- Warmer temps, coral used more normal oxygen isotopes
- Pollen grains
- Found in sediments
- Measure layers of varve
- Water isotopes and temp reconstruction
- Imply glacial-interglacial temp changes were twice as large than previously believed
- Hydrogen and oxygen isotopes
- Isotope fractionation - the vapour pressure of heavier isotopes is lower, so the vapour contains more of the lighter isotopes and when precipitation occurs heavier isotopes are present
- Pseudoproxies - the skill of combing proxy data
- Proxy records are compared with the known temperature of the model