Lec 1 - Intro + Climate Data Flashcards
What is weather?
short-term statistical descriptions of the state of the atmosphere at a given time/place
What are the parts of the E-A system?
- Lithosphere
- Biosphere
- Hydrosphere
- Atmosphere
What is climate the result of?
a place’s location!
What is climate?
Study of long-term averages/variability of weather conditions for place/region/globe
What are the two things to focus on in any climatic change?
- Forcing
- Responses
What climate components respond the fastest to changes?
- atmosphere
- land surface
What climate components respond very slowly to changes?
- mountain glaciers
- deep ocean
- ice sheets
How do feedbacks alter climate changes?
- amplifying them (positive feedback)
- suppressing them (negative feedback)
Name 4 types of climate archives
- sediments
- ice
-coral
-trees
What is the major climate archive on Earth, and how does it form?
sediments
- continuous deposition at water bottom OR rainfall/runoff eroding/transporting it OR carried by wind
- physical/granular OR chemical/dissolved form
What is a moraine?
long, curving ridges made of jumbled mix of unsorted debris
- sediment archive = jumbled, pushed around
What is a Loess?
rock(?) formation made by winds continuously bringing and dropping grains of sediment in undisturbed areas
What timescale are ice archives formed on?
Antarctica - 700ky
Greenland - 120ky
Mountain glaciers - 10ky
When are tree ring archives useful?
- when looking at 10s-100s of years in past
- when they grew somewhere with many seasons (growing period/dormant period)
How can corals act as a climate archive?
- CaCO3 bands form annually
- useful looking at 10s to 100s of years in the past
What is a more recently-emerged climate archive?
human records!
How does radiometric dating work?
- a certain portion of an element exists as an unstable/radioactive isotope
- these parent isotopes decay at a known rate into stable isotope of another element
- using the known half-life, we can figure out how long it’s been since the thing died
How does radiocarbon dating work, and when is it useful?
- 14C decays into 14N
- half life is 5780yrs, so only useful in 10s of ky
What are the two types of climate proxies?
- biotic proxies
- geological/geochemical proxies
What are some types of biotic climate proxies?
- pollen
- plankton
- macrofossils (historical ecology/distribution)
Why are plankton so useful as climate proxies?
- ubiquitous
- well-defined climate preferences
- have been around for a long time in geologic history
What types of geological/geochemical data are useful as climate proxies?
- sediment textures tell us about erosion/conditions
- sediment types tell us where it came from (physical weathering, chemical weathering)
