lec 1- Flashcards
proxy
a variable that had a strong correlation to a certain event or condition in the past.
an indirect measurement
what are the 2 pieces to measure for an environmental proxy
the climate
age/ time
what factors might change the energy balance of the earth?
GHG composition/abundance
cloud cover
historically, what was the cause of the Ice Age
the introduction of cyanobacteria (phytoplankton) introducing oxygen into the atmos
2.4 billion years ago
what are ice ages
long periods when large glaicer are presnece
how many ice ages have occurred
at least 5
methanogen hypothesis
microbes that feed on H2 and CO2 (anoxic) to make CH4 which allowed the earth to be warm, pre-oxygen
when oxygen-producing bacteria evolved, the atmosphere was littered with O2, killing the methanogens gas CO2 and methane (cooling!)
surface radiation balance equation
Q*= Ki+Ko+Li+Lo
how is heat transferred in the atmosphere?
via convection in/ across Hadley cells
warmed air rises and cool dense air sinks to replace it, causing a cycling effect
why does the Q* value change as dramatically with high energy inputs
because water can absorb a lot of energy before changing temp (High heat capacity). further, most of the energy causes a state change and water in lost to evaporation