Weather and climate Flashcards
1
Q
What is palaeoclimatology?
A
The study of the climate prior instrumental measurements
2
Q
Methods of palaeoclimatology
A
- Archives
- Chronology
- Proxies
- climate modelling
3
Q
Uniformitariarnism
A
The same natural laws and processes that operate on Earth as they have in the past
4
Q
Observed changes since 1950AD
A
- Earth, ocean and atmosphere has warmed
- Snow diminishing
- Earth, ocean and atmosphere has been
increasing 0.5 degrees Celsius since 1850 - 90% of accumulated energy since 1971-2010
is stored in oceans - Temperature is influenced by surface
temperature - People are measuring sea levels as
temperatures are causing oceans to expand
5
Q
Observed changes in the Cryosphere
A
- sea ice is reducing
- Greenland and Antarctica ice sheets are
reducing in mass - Glaciers worldwide is reducing
- Antarctic sea ice and Northern Hemisphere Spring snow fall is decreasing
6
Q
Observations in sea level rise
A
- The rate of sea level since 1850 was the
largest than anytime in the previous 2,000
years - From 1901-2010, sea level rose by 0.19m
- Sea levels were 5.5-9m higher than current
levels in the last interglacial period, Eemian
7
Q
Atmospheric Greenhouse Gas
A
- CO2 concentrations have increased 40%
since pre-industrial times - CO2, CH4 and N2O have increased to levels
that has not been experienced in 800,000
years - CO2 = most abundant man made
greenhouse gasp that is increasing every
year
8
Q
Observations in Ocean pH
A
- Declining and so more acidic - influenced by
CO2 dissolving in the ocean - About a 0.1 unit decrease
- 26% increase in H+
9
Q
Climate change
A
- It’s happening more rapidly than any other event in the past ~55Myr
- Palaeoclimatology focuses on the climate
change in the cenozoic - Climate is long term
10
Q
Controls on weather and climate
A
- plate tectonics = internal heating alters the
surface geography - Orbital changes = the earths path around the
sun influences the level of radiation the earth
receives - main source of energy to earth = sun
- where you are on earth affects the level of
radiation you receive - equator = more =
lower level of incident - earth tilt is important
11
Q
Global energy balance
A
- Solar irradiative input is short wave radiation
- Earth’s output is long wave radiation
12
Q
Global energy balance - processes
A
- Reflection = no temperature change
- Absorption = radiative energy is converted to
heat - Scattering = diffuse energy and lowers the
intensity caused by small particles in the
atmosphere
These influences the earths temperature
13
Q
Reflection
A
No temperature change
14
Q
Climate drivers
A
Natural and anthropogenic substances and processes that alters the earth energy balance
15
Q
Radioactive forcing
A
The changes in energy fluxes caused by changes in climate drivers
