The cloud of gasses and suspended particles surrounding earth Becomes less dense as altitude increases Made up of layers Protective bubble that gives UV protection, breathable air, and moisture 78% N2, 21% O2, .9% Ar, and .033% CO2 Water Vapor runs from almost 0% in deserts to nearly 4% in tropical rain forests
5 layers Identified by Thermal characteristics Composition Air movement Density
Starts at earths surface and runs to between 4 and 12 miles thick depending on latitude 11-12 miles thick at the equator and thins to 4 miles thick at the poles Temperature decreases as altitude increases Transitional zone between layers is called a ______pause (tropopause)
From the tropopause to 31 miles above earth’s surface Holds 19% of atmosphere’s gases UV radiation is absorbed by O2 molecules making O3 Causes temperature to go up as altitude increases Divided by the stratopause
From stratopause to 53 miles above earth’s surface Less dense than stratosphere As altitude increases, temperature decreases Slows down meteorites, leaving a trail in the night sky
From mesopause to 430 miles above earth’s surface Exposed to very high amounts of UV radiation and X-rays As altitude increase, temperature increases Feels cold because of very low density Contains ionosphere – causes radio waves to reflect back to earth Also causes aroras
From thermopause to 6200 miles above earth Area where satellites orbit
Air has mass and therefore exerts pressure as it piles up above us As the density of air increases, the pressure of the air increases As the temperature of air increases, the density of the air decreases Air pressure is exerted in all directions at once Standard air pressure at sea level is 14.7 lbs/in2
As elevation increases, air pressure decreases, because there is less atmosphere above you. Due to this variation, air pressure at two different locations cannot be compared. We use sea level as the basis for a standard conversion for each location. Measure air pressure in inches of mercury or millibars. Standard air pressure at sea level is 29.92 inches of mercury or 1013.2 millibars.
Pressure systems are labeled as high or low High pressure is associated with clear skies Low pressure is associated with cloudy skies Because cold air is more dense than warm air, the highest air pressure readings are found on cold, clear days.
Heat energy is transferred through: Radiation Conduction Convection The Sun’s heat is what fuels our planet’s weather.
Heat transferred through electromagnetic energy. (excited atoms) This is how the sun heats our planet Dark objects absorb more radiation that light colored objects
Transfers heat through two solid objects touching Metal spoon on a hot surface gets hot
Heat is transferred through moving fluids Air in the atmosphere acts as a fluid Hot air masses rise causing mixing of the atmosphere Also causes winds Land heats up by radiation which heats air byconduction, which heats atmosphere by convection
We have incoming energy from the sun and outgoing energy reflected by earth’s surface The air molecules trap some reflected heat, creating a warming “blanket” around earth This stabilizes our temperature Cloud cover traps even more of the reflected heat closer to the earth’s surface Cloudy nights cool off less that clear nights
The ocean absorbs, stores, and releases heat and moisture into our atmosphere driving much of our weather. The top 10 feet of ocean contains more heat that the entire atmosphere.
Epipelagic – sunlight zone – surface to 660 ft Wind causes mixing and therefore even temp dist At end of layer is the thermocline – rapid decrease in temp with relation to depth Mesopelagic – twilight zone – 660 ft to 3,300 ft Bathypelagic - midnight zone - 3,300 ft to 13,100 ft Only light comes from bioluminescence Constant temperature of 39o F Abyssopelagic – 13,100 ft to 19,700 ft Little to no life, pitch black, extreme pressure Hadalpelagic – 19,700 ft to 35,000+ ft trenches
Ocean water is salty. Most of the salt is NaCl, but some is MgCl or KCl. Different areas of the earth’s oceans are saltier than others. Around the equator and the poles are the least salty because of high rain fall and ice melt. The Atlantic, Persian Gulf, and Red Sea are the most salty due to high evaporation. Salinity is measured in grams of salt per liter. Normal salt levels are around 35 g/l
The density of water increases as temperature decreases up to about 40o F. Between 40o F and 32o F, the molecules begin locking together and decreasing the density. As a result, ice floats and expands. About 9% expansion by volume. However, salt decreases the temperature at which water freezes. Sea water freezes around 28o F
The temperature and salinity of the water impacts is density. The density of ocean water directly impacts ocean circulation patterns. Ocean circulation patterns influence most of our weather patterns in one way or another.
Surface currents along the west coasts flow toward the equator and bring cold water from the poles to the equator. California Current that keeps San Francisco cool. Surface currents along the east coasts flow toward the poles and bring warm water to the poles. Gulf Stream that keeps England warmer. The deep ocean currents that circulate the global oceans is called the great ocean conveyor.
Themohaline Circulation – Thermo (tempurature) & Haline (salt) Water takes about 1000 years to complete Sinking Up welling
Because the land heats up and cools off more quickly than the ocean, the difference in the air temperature over these bodies, also heats up/cools off correspondingly. Warm air masses rise above land pulling in cool ocean breezes during the day. Warm air masses over water rise and pull cool land breezes during the night.