Air Quality

Carvings on the exterior of an old limestone building are decaying due to acid rain.Carvings on the exterior of an old limestone building are decaying due to acid rain.
Denver, Colorado, on a day with good air quality with clear skies (top) and on a day with poor air quality with hazy skies (bottom).
Carbon Dioxide molecule
Carbon Monoxide molecule
These two maps show typical nitrogen dioxide levels over China from January 1-20, 2020, and then show decreased nitrogen dioxide levels over the same area from February 10-25, 2020.
Air pollution creates harmful yellow dust storms over the Korean Peninsula.
Diagram illustrating relative abundances of gases in Earth's atmosphere
Smokestacks from an oil refinery in Commerce City, Colorado, are shown pumping black smoke into the atmosphere.
Smoke rising from a forest fire over the mountains of Idaho.
Pie chart showing the gases that make up the atmosphere: Nitrogen (78%), Oxygen (21%), Inert Gases- mostly Argon (.96%), and Carbon Dioxide (0.04%).
Air pollution in Mexico City causes hazy skies that block sunlight from reaching the ground.
A picture of a thermal inversion over Boulder, Colorado, appears as a brown layer in the sky.
Methane molecule
Nitric oxide molecule
Nitrogen Dioxide molecule
Nitrogen molecule
Multiple smokestacks releasing pollutants into the air in the form of white smoke, burning natural gas, and black smoke.
Oxygen molecule
Brown patches scattered across the surface of three leaves of a potato plant are evidence of ozone damage.
A view of the Earth showing the ozone hole as recorded in 2019.
Ozone molecule
Heavy traffic in Mexico City causes air pollution.
Propane molecule - example hydrocarbon
Sizes of Aerosols, Raindrop and Cloud Droplets
Smog over Denver, Colorado, appears as a hazy sky above the city.
The top image shows normal conditions when warm air rises from the surface, carrying pollutants from industry and homes up into the atmosphere where the air temperature is cooler. The bottom image shows thermal inversion, or when cool air and pollutants from the surface are inhibited from rising by a layer of warm air.
A graphic showing ways you can help to reduce air pollution: wind turbines as an example of renewable energy, driving low pollution vehicles, taking the bus or riding your bike, refuel at gas stations in the evening, compost yard waste instead of burning it, mow grass in the evening, avoid using the fireplace or wood stoves when air quality is poor, use low VOC cleaners and paints, and in general use less energy.

Earth as a System

Air masses in and around North America
Carbon cycle diagram
Carbon Cycle diagram from NASA
Carbon Cycle Diagram
Carbon Cycle diagram from the DOE with numbers
Carbon Cycle Diagram from the IPCC
Earth viewed from space
Global Atmospheric Circulation
Heat transfer diagram
Map of Ocean Circulation
Radiation Budget Diagram for Earth's Atmosphere
Diagram of the water cycle

How Weather Works

Air masses in and around North America
Side view (A) and weather map representation (B) of a cold front
Dropsonde in Flight
Foggy forest
Heat transfer diagram
Diagram of how air moves in high (left) and low (right) pressure systems
Diagram of how clouds form
Weather map representation of an occluded front
Rainbow
Dropsonde beneath parachute
Weather map representation of a stationary front
Side view (A) and weather map representation (B) of a warm front
Scientist launching weather balloon

Clouds

Altocumulus clouds
Altostratus clouds
Cirrocumulus clouds over a forest
Cirrostratus clouds
Cirrus clouds over a winter landscape
Diagram of cloud types. High in the atmosphere are cirrocumulus and cirrus. In the middle of the atmosphere are altocumulus and altostratus. In the lower atmosphere are stratocumulus, stratus and cumulus. Cumulonimbus clouds can be found from near the ground up to above 50,000 feet.
Contrails
Cumulonimbus cloud
Cumulus clouds
Diagram of how clouds form
Kelvin-Helmholtz cloud
Lenticular clouds
Mammatus Clouds
Marine Stratocumulus Clouds
Nimbostratus clouds with a rainbow
A cloud floating in the middle of a museum room
Noctilucent clouds glowing on the horizon just after sunset
Polar Stratospheric Clouds
Stratocumulus clouds at sunset
Stratus clouds

Layers of the Atmosphere

Atmosphere of Jupiter in December 2000
Aurora viewed from space
Chemical Composition of Earth's Atmosphere
Layers of Earth's Atmosphere
Dropsonde in Flight
Diagram illustrating relative abundances of gases in Earth's atmosphere
Heat transfer diagram
Regions of the Ionosphere diagram
Mesosphere diagram
Dropsonde beneath parachute
Stratosphere Diagram
Troposphere Diagram
Scientist launching weather balloon

Storms and Other Weather

Process of a blizzard. In the first image (top), a house is clearly seen. In the middle image, a house is partially obscured by blowing snow. In the bottom image, the house is almost completely obscured by blowing snow.
Diagram of how hurricanes form
Diagram of how tornadoes form
Hurricane Alex viewed from space
Hurricane damage to houses
Ice-covered powerlines
Lightning
Microscope image of a snowflake
Fence covered in deep snow
Storm Front Over Lake Superior
Supercell Thunderstorm
Storm clouds fill the sky above the grassy plains.
Diagram of a thunderstorm forming
A crowd watches as a tornado form in Wyoming in June of 2009
Trees laid flat from a microburst

How Climate Works

Carbon cycle diagram
Carbon Cycle Diagram
Radiation Budget Diagram for Earth's Atmosphere
The Year Without a Summer

Sun and Space Weather

Compare Sun Images - Visible Light and Ultraviolet
Coronal Holes in Ultraviolet Image of the Sun
Coronal Loops in UV TRACE image
Coronal Mass Ejection on January 4, 2002
Sketch of the Earth and Sun (not to scale)
Layers of Earth's Atmosphere as seen from space
Earth's Dipole Magnetic Field
Earth's Magnetosphere
Graph of Sunspot Counts from 1975 to 2016
Photosphere - Sunspots and Granulation
H-alpha View of the Sun
Diagram of the regions of the Sun
Solar Active Regions: Sunspots on the left and UV image of the Sun on the right
Solar chromosphere during eclipse
Sun's corona - during eclipse (top) and UV image (bottom)
Solar eclipse on July 11, 1991 as seen from Hawaii
Solar Filament in H-alpha Light
Ultraviolet image of a solar flare from November 2003
Red sunspots on orange sun
Sun with Sunspots - Solar Max 2001 and Solar Min 2005
Sun's Atmosphere - Corona and Chromosphere
Sun's Corona at Solar Min & Solar Max
Visible Light Spectrum of the Sun
Two views of sunspots
Two views of sunspots
Ultraviolet image of a solar flare from November 2003
Ultraviolet Sun with Coronal Loops

Impacts of Climate Change

Cracks in Dry Mud
Farmland affected by draught
Map of coastal Bangladesh showing current sea level (left), one meter rise in sea level (center) affecting 15 million people, and 1.5 meter rise in sea level (right) affecting 18 million people.
Map of United States farms by county, showing the majority of farms in the center of the U.S.
Diagram showing what happens to carbon dioxide. Forty percent stays in the atmosphere, thirty percent is taken up through land cover, and thirty percent ends up in the ocean.
changes in soil moisture and dry days in the US

How We Study Climate

How Models Simulate 20th Century Climate With (top) and Without (bottom) the Imp
Tree Rings

How Climate Changes

Effects of an Increase on Mean Temperature