Lecture #6 (Atmosphere) Flashcards
What are the 4 different layers of the atmosphere?
Thermosphere (>85km); Mesosphere (50-85km); Stratosphere (10-50km); Troposphere (0-10km)
When UV interacts with ozone & other molecules what happens to the air density? Which leads to a(n) ____ in temperatures in the upper stratosphere
Air density starts to increase; increase
Which ozone layer is key?
Stratosphere
What is a jet stream?
A narrow (250-500 km wide; several km deep) band of strong horizontal winds in the atmosphere at altitudes of 30,000 to 40,000 ft. Winds in this band are stronger than those adjacent to it
What happens after air is heated in the tropics-equator?
The air gets sent up and towards the poles. In turn air in the poles move toward the equator, but due to a few reasons, including rotation of planet, there is an intermediate cell.
How does a subtropical jet stream form?
As a result of the principle of the conservation of angular momentum.
What is the conservation of angular momentum?
Air is heated and rises over the area with the strongest solar radiation (equator). At the top of the troposphere, this rising air moves toward the poles. As it moves toward the poles, the distance between it & the Earth’s axis decreases. As this distance decreases, the air accelerates toward the west. The air reaches its maximum westward velocity between 20’ & 40’ from the equator & then starts sinking
What are the 3 main “cells” in global circulation patterns?
- Hadley cell (Equator to 30’ N/S)
- Ferrel (mid-latitude) cell (30’ to 60’ N/S)
- Polar cell (60’ to 90’ N/S)
What is the Coriolis force?
Creates the patterns of winds in the cells (‘trade’ winds)
Rossby waves are also known as what?
Long waves
How do Rossby waves form?
Due to the earth’s geography:
1. Differential heating of Earth’s surface (heating from the sun is uneven due to the different shapes & sizes of land masses)
2. Major mountains deflect the jet stream since air can’t travel through a mountain so it must rise up & over or go around
What are short waves?
They’re embed within the long wave pattern forming smaller cycles or troughs such as a “pocket of cold air” moving down from polar areas in winter
How many general planetary waves are in the Rossby (long) wave pattern?
5
What is the El Nino-Southern Oscillation (ENSO)?
A quasi-periodic fluctuation in winter ocean temperatures in equatorial Pacific: warmer than normal central & eastern equatorial Pacific
El Nino has major effects on ______ weather conditions affecting ecosystems & species
trans-Pacific
El Nina is associated with ___ than normal central & eastern equatorial Pacific.
cooler
Easterly trade winds results in ___ upwelling in east
cold
Weakened east trade winds results in ___ upwelling in east
less
During a strong El Nino, how are Galapagos penguins effected?
The cycle slows or is shut down leading to a massive decline in penguins, since they rely on fish that rely themselves on phytoplankton
How does an El Nino effect North American weather?
Causes the Pacific jet stream to move south & spread further east. During winter it leads to wetter conditions than usual in the Southern US & warmer and drier conditions in the Northwestern side of the continent
How does an El Nina effect North American weather?
Causes the jet stream to move northward and to weaken over the eastern Pacific. During La Nina winters, the South sees warmer and drier conditions than usual. The North and Canada tend to be wetter and colder
What is the orographic effect (lift) of mountains?
When an air mass moves from low to high elevation (over mountains), and as the air mass gains altitude it cools adiabatically, increasing relative humidity (to 100%) & thus creates clouds or under the right conditions precipitation
What does orographic lifting affect?
Precipitation, rain shadowing, leeward winds, & associated cloud patterns
Define Adiabatic
The change in temperature caused by the expansion (cooling) or compression (warming) of a body of air as it rises or descends in the atmosphere, with no exchange of heat with the surrounding air
What are Fohn (Chinook) winds?
Dry, warm, downslope winds that occur in the lee (downward) side of a mountain range. Occurs because of orographic lift, as a result the leeward slopes becomes warmer (air compresses) than elevations on the windward slopes.
What does the numerical weather prediction (NWP) do?
Solves a complex set of equations based on the physics of how the air moves & how heat and moisture are exchanged in the atmosphere
_____ ________ are key to parameterizing the model for future predictions
Initial conditions
What are the 2 scales of models?
1) Global - covers entire Earth
2) Regional - covering part of the Earth
What are some variables of the NWP at the surface?
Temperature; humidity; pressure; moisture fluxes; heat fluxes; radiation fluxes
What are some variables of the NWP in the atmospheric column?
Wind vectors; humidity; clouds; temperature; height; precipitation; aerosols
How much of the nitrogen on Earth is being stored in the atmosphere?
80%
Is atmospheric nitrogen in useable form?
No
What create useable forms of nitrogen as nitrate for plant growth?
Bacteria and lightening
What happens to nitrogen when plants & animals decompose?
It converts inorganic ammonium salts via mineralization that is fixed with clay or converted by bacteria to nitrites & then nitrates back to plants & the atmosphere
Nitrogen is a ____ factor
limiting
When was the Guano age?
1800s
What was the Guano age?
When agriculture was expanding but lacked extra fertilizer
What was/is the purpose of the Haber process?
To address the shortage of available nitrogen fertilizer
Why did Haber develop the Haber process?
To produce ammonia from air by reaction with hydrogen & a metal catalyst under high temperatures & pressures - process is still used today to make chemical fertilizers reliant on the agricultural industry (together without plant breeding)
What are some of the ways that carbon moves in the carbon cycle?
Atmosphere to plants via photosynthesis to make simple sugars for growth; plants to animals via food chains; plants & animals to soil through decay; living things to the atmosphere via respiration; fossil fuels to the atmosphere when fuels are burned; atmosphere to oceans
The Summit of Mauna Loa Hawaii has been recording ____ in the air since ___.
CO2; 1958
The Summit of Mauna Loa, Hawaii shows a long-term trend up & seasonal variation due to what?
Plant growth
Who is started this project?
Keeling
The curve of this is known as what?
Keeling Curve
Why is Mauna Loa an ideal location?
It is so remote & prevailing winds blow from the land out to sea at night bringing clean, well-mixed air from high in the atmosphere to the observatory - removing interference
Who first proposed the greenhouse gas concept?
Arrhenius
What are some common sources of air pollution?
Natural; stationary; area (small stationary sources combined; mobile
What are 6 common pollutants
1) Ground level ozone
2) Particulate matter
3) Carbon monoxide & dioxide
4) Nitrogen dioxide
5) Sulfur dioxide
6) Lead
Where in Banff National Park had the highest organochlorine contaminant concentrations of any trout in western Canadian lakes?
Bow Lake
What is Ozone?
A gaseous molecule occurring in different parts of the atmosphere. It is chemically reactive & dangerous to plant & animal life when in the lower atmosphere (ground-level ozone from vehicle exhaust & anthropogenic emissions)
What are CFCs?
Carbon, chlorine, & fluorine chemicals synthesized in the 1920s & used as refrigerants, solvents & in aerosol sprays
Who discovered that the “haze” in the sky was due to CFCs & in the 1980s that led to the destruction to the atmospheric ozone layer?
Lovelock
What did the Hubbard Brook study find?
That rainwater pH of initial samples averaged a pH of 4.1 (often much lower), which was up to 100 times more acidic than unpolluted rain despite being isolated from nearby human activity.
Who was the primary scientist in the Hubbard Brook study?
Gene Likens
What did Likens discover?
Acid rain
Sulfur dioxide & nitrogen oxides from the burning of fossil fuels leads to precipitation that is more ____.
acidic (~4.3 pH)
What is one ecological impact of acid rain?
Number of fish species drops from an average of 6 in lakes at normal levels of acidity to 1 or 0 fish species at very high acidity. – Reduces biodiversity
Lichens are very good ____. (show signs of pollutants easily)
bioindicators
What is vanadium?
An obscure metal that is associated with bitumen so a good indicator of bitumen pollution
What is fugitive dust?
Very small particles suspended in the air (primarily mineral dust) that originates from the soil of Earth’s pedosphere
