Chapter 15 Flashcards
insolation
incoming solar radiation and energy input which varies by latitude and where the subsolar point is located
subsolar point
the point at which the sun is directly overhead
How much of the sun’s energy is absorbed by earth’s surface?
70%. It reflects the rest into space.
What kind of energy bounces off earth’s surface?
Infrared radiation.
Greenhouse effect
greenhouse gases absorb a portion of radiation emitted from earth’s surface and trap it in the atmosphere.
Low pressure air
warm air rises, leading to low pressure at the surface, resulting in rainy, cloudy, or snowy weather.
High pressure air
When air cools, it descends, leading to high pressure at the surface, resulting in clear weather.
Equatorial low-pressure trough
warming near the equator creates warm (less dense) rising air which creates low pressure at the surface and it creates the Intertropical Convergence Zone (ITCZ) where trade winds converge.
Subtropical high-pressure cells
dry air near the equator is heated as it compresses towards the surface of the atmosphere, it creates high pressure when it cools and sinks in the subtropics
Subpolar low-pressure cells
confrontation between the warm westerlies and colder dry air from the poles. This pushes up the bulk of air towards the equator, creating a low pressure belt.
Polar high pressure cells
relatively weak
What is albedo?
A measurement of the reflective properties of surfaces
5 greenhouse gases
co2, water vapor, methane, nitrous oxide, and chloroflourocarbons.
Temperature
controlled by latitude, altitude, land-water heating differences, and cloud cover.
how does the thermohaline circulation moderate climate? Scientists are concerned about it slowing - why?
It warms Europe, rapid melting of Greenland’s ice sheet could interrupt the flow of heat and cause Europe to cool dramatically.
What is the concept of sea level rise?
sea levels rise because water expands as it warms, glaciers and ice sheets and melting, and groundwater we extract eventually reaches the ocean
Proxies
records that give us data about temperature, ice cover, or rain, like tree rings, ice cores, and sediments.
1st phase of the Milankovich cycles
an axial wobble that occurs every 19-23,000 years.
2nd phase of the Milankovich cycles
a 3 degree shift in the tilt of earth’s axis that occurs every 41,000 years.
3rd phase of the Milankovich cycles
A variation in earth’s orbit from almost circular to more elliptical which happens every 100,000 years.
Radiative forcing
a measure of the influence that a climatic factor has in altering the balance of incoming and outgoing energy like ice albedo or tropospheric aerosols.
Cooling agents
negative forcing factors like low lying clouds, snow and ice, volcanoes, sulfate aerosols.
warming agents - positive forcing factors
1 kg of fossil fuel burned produces 3 kg of co2, other greenhouse gases.
Climate forcing strength
the cfs of different greenhouse gases is described relative to that of carbon dioxide (global warming potential = gwp)
co2 has a gwp of 1. Lifetime in atmosphere is 100 years.
What happens when the jet stream goes into a blocking pattern?
It gets slowed by arctic warming, departs from its normal configuration and stalls weather systems in place.
What is the difference between climate change and global warming?
A change in climate is defined by changes in the average or variability of its temp, or rain, and lasts for a decade or longer. Global warming is the rise in global temps due to the increase in greenhouse gases
What is the primary anthropogenic source of greenhouse gases?
Fossil fuels
What is the leading cause of methane?
Livestock and rice cultivation
How many emissions do we produce annually?
7.2 billion metric tons
