AP Environmental Study Session 6

Tropical Storms When moisture laden air blows over warm ocean water a low pressure system forms Winds will spiral around the depression What’s the difference between a hurricane and a typhoon? – Location Location Location As the systems moves over the warm water: – Pulls water vapor up into the air – Vapor condenses and adds energy

El Nino / La Nina Occurs every 3 – 7 years Normal: – Trade Winds move warm water off the coast – Keeps coastal water cool and with lots of nutrients During El Nino: – Trade Winds are weakened or reversed – Moves warm water to the coast – Water contains less oxygen and nutrients During La Nina: – Coastal waters are colder than normal

Upwelling and Redtides Upwelling: – Seasonal movement of cold, deep, nutrient rich water to the surface – Large influx of nutrients causes exponential increases in algae populations Redtide: – Dinoflagellate blooms which produce toxins

The Hydrosphere

Salt Water and Oceans Ocean’s salinity varies, but it about 3.5% – For every 1 liter of sea water there are 35 grams of salt Barrier Islands: – Created by deposited sediments – Continually shifting – Act as a buffer zone to shorelines behind them

Coral Reefs A type of barrier island Built by cnidarians – Secrete a hard calciferous shells Diversity Reserviors – Corals provide homes and food for numerous species – An Oasis in the Desert

Ocean Zones Coastal: – Area between the shore and the edge of the continental shelf Euphotic: – Has the highest levels of dissolved oxygen – Most sunlight, >>>photosynthesis – Warmest region Bathyal: – Below Euphotic Zone, < sunlight – Not enough light for photosynthesis – Cooler than Euphotic

Abyssal: – Deepest region of the ocean – Extremely cold temps – Very low dissolved oxygen levels – Lots of nutrients – >>> Pressure

Ocean Currents Thermohaline Conveyor – Large circulation of sea water – Contributes to the climates throughout the world – Driven by differences in temp, salinity, density and Earth’s rotation

Freshwater Contains small amounts of salts, not near the extent of the ocean ( < 1.0% salt ) Formed by the accumulation of liquid atmospheric moisture and melted snow Lakes, rivers, streams, ground water

Vocab regarding Freshwater Watershed: – An area that drains an area of land into a particular river or stream Estuaries: – Freshwater with increased nutrients, salts, and sediments – ‘arms’ of the ocean that extend inland – Salt water marshes, mangrove forests, bays, inlets Wetlands: – Areas where excess water sits on the surface of the Earth – Marshes, swamps, bogs, prairie potholes, flood plains Deltas: – Areas of rivers/streams that meet the ocean – Significantly slowed flow velocity causes sediments to fall to the bottom

Freshwater Stratification Epilimnion: – Upper most, photosynthetic, warmer, less dense, most oxygenated Hypolimnion: – Lower, more dense, less oxygenated, cooler Thermocline – The transition between the Epi- and Hypo-limnion where a dramatic temperature shift is experienced Pycnocline – The transition between different layers of water which have differing densities

Freshwater Stratification Littoral Zone: – From the shoreline to the point where rooted plants stop growing – Abundant sunlight and photosynthesis Limnetic Zone: – Surface of open water – Abundant sunlight and photosynthesis Profundal Zone: – Aphotic zone = no sunlight Benthic Zone: – Deepest layer of water – Low temps, low oxygen

Human Water Use Key Words Riparian Right – People have legal rights to use a riparian area Prior Appropriation – Water is given to people who have traditionally used it in the past Interbasin Transfer – Water moved long distances away from their original source Confined/Unconfined Aquifer – No water is readily transported / water can freely move vertically or horizontally Water-stressed – Annual supply of 1,000 – 2,000 cubic meters per person Water-scarce – < 1,000 cubic meters of water per person

Human Uses