environ 331 exam review

Earth's warming since ~1850

+1.5°C

UNFCCC

UN Framework Convention on Climate Change, international treaty to combat "dangerous human interference with the climate system", conference of the parties in the governing body, goal approved by 192 countries

Solar activity

more sunspots, more northern lights, more solar storms

Characteristics of LW and SW radiation

LW - low frequency, near infrared to IR, Earth's radiation, lower temp and energy; SW - high frequency, UV and visible, sun's radiation, higher temp and energy

Solar constant

energy per unit area at a given distance from the sun, S = POWER OF THE SUN / AREA OF IMAGINARY SPHERE OF Re,orbit (W/m^2)

Blackbody temperature calculation

energy flux in = energy flux out, S*piR^2 = sigma(o)T^4 * 4piR^2

Earth temperature

about 15°C

Earth's reflectivity

30%

Albedo

reflectivity change from surface (snow, ice, grass, deserts) and atmosphere (clouds, aerosols)

Greenhouse gases

GHG - water vapor, CO2, CH4, nitrous oxide, ozone, CCl2F2;

Earth geometry and radiative balance

radiation-in is received over area, radiation-out occurs over sphere

Greenhouse layer model of radiative transfer

understand how to calculate and fill in red question marks in a sketch

Venus vs Earth

qualitatively different (numbers provided if needed)

Why do GH gas molecules interact with radiation?

Wavelength-specific aspect of GH absorption

window region, saturation, broadening

Nonlinear relationship between CO2 concentration and radiative forcing; climate sensitivity

Residence time

Characteristics of different GHGs

concentrations for CO2, CH4, N2O; global warming potential; lifetimes; primary sources and sinks

Forcing

A primary cause of change, typically an energy imbalance

Natural forcing

Changes in sun, volcanoes

Anthropogenic forcing

emissions of atmospheric greenhouse gases and atmospheric pollutants, albedo change form land use

Feedback

Process triggered by an initial change, which either amplifies or weakens initial change

First layer of the atmospheric structure

Troposphere 0-10 km, the region where T increases with height

Third layer of the atmospheric structure

Stratosphere 10 - 45 km the region where T increases with height

Second layer of the atmospheric structure

Tropopause - boundary between troposphere and stratosphere

How long is the atmosphere mixing time?

A few weeks

What are CO2 equivalents?

Radiative forcings that when of ten expressed in units have the equivalent of CO2, N2O, CH4

What are the significant health impacts of the tropospheric ozone?

• Aggravates lung tissue

• Sore throat, coughing

• Aggravates respiratory ailments

• makes lungs susceptible to infection

What are the significant impacts on plant growth from the tropospheric ozone?

• Inhibits photosynthesis

• Reduces leaf longevity and accelerates senses

• Decreases the efficiency of water use

• Inhibits pollen tube growth

Plants include crops

agricultural productivity where O3 is high

Aerosols have both

natural and anthropogenic sources

Residence time

days to weeks in troposphere, few years in stratosphere

Scattering

short wave radiation strikes aerosol and bounces off in all directions

What are some examples of scattering?

Sulfate (cooling), Black carbon (warming), Organic carbon (cooling), Mineral dust

Increase albedo (cloud radiative effect today)

increase reflection (cooling)

Absorbs longwave (cloud radiative effect today)

due to vapor (warming)

Spatial variability

depends on climatology

Net effect

clouds cool planet

Net radiation imbalance at the top atmosphere

Downward at low latitudes, Upwards at high latitudes

Poleward energy transport

Heat is transferred in a northward direction throughout the atlantic

What shape is Earths orbit?

An ellipse where the degree to which the orbit departs from a circle is measured by its eccentricity

What is dependent on the change of the season?

The tilt of the axis and the change of it is when seasons change. when the axis is tilt closer to the sun, its summer, when its away its winter

Summer solstice

the sun is directly overhead at it’s furthest northern point (tropic of cancer N)

Winter solstice

the sun is directly overhead at its furthest southern point

Zenith angle

The angle between the sun and the vertical (90 - elevation)

How is air warmed?

Longwave radiation from the earths surface

When can air hold more water?

When moist air is warmed

What’s a Hadley cell? What is ItCZ?

A type of 6 cell patern, ItCZ is part of the hadley cell

What are trade winds?

The wind that flows towards the equator from the North-East in NH or South-East in SH

What is the IPCC?

Organized by the World Metrological Organization and the United Nations, it brings together climate sciences and issues regular (5-7 yrs) reports on the stare of the climate, they do not advocate for policies or act as activists

What are the groups within the IPCC?

• Group 1: Physical science

• Group 2: Impacts

• Group 3: Mitigation and Adaption

Who is in the IPCC?

234 authors, plus hundreds of reviewers, and only peer-reviewed science

What are some of the US - IRA actions?

Falling costs of wind and solar, new electricity is mostly renewable

Actions – local: strong goals for carbon emissions cuts

Solar activity is high now – what does this mean (high spots, high energy, etc.) 

more sunspots, more northern lights, more solar storms,

Basic characteristics of LW radiation

 low frequency, near infrared to IR, the Earth's radiation, lower temp and energy

Basic characteristics of SW radiation

high frequency, UV and visible, the sun's radiation, higher temp and energy

What is blackbody radiation?

An idealized set of assumptions about how objects interact with EMR, and re-emits the radiation as a function of its temperature

What makes Earth not a blackbody

reflectivity is 30%

What gasses are not GHG

N,O,argon,Ne, He

Radiation-in

is received over area

radiation-out

 occurs over sphere

How is radiation-in distributed?

over the sphere: need to balance radiation in and radiation  out over the entire planet’s area, so we correct Rad-in for spherical area (divide by 4