THE WATER CYCLE

-THE SUPPLY OF WATER ON EARTH IS CONSTANTLY BEING RECYCLED BETWEEN THE OCEANS, ATMOSPHERE AND LAND

HOW WATER ENTERS THE ATMOSPHERE:

1) EVAPORATION2)TRANSPIRATION:THE PROCESS BY WHICH LIVING PLANTS RELEASE WATER VAPOR INTO THE ATMOSPHERE

“EVAPOTRANSPIRATION”

HOW WATER LEAVES THE ATMOSPHERE:

1) WATER VAPOR CONDENSES ON A CONDENSATION NUCLEI

2) DROPLETS BECOME BIG ENOUGH TO FALL TO THE SURFACE AS PRECIPITATION

WHAT HAPPENS TO THE PRECIPITATION AFTER IT FALLS OUT OF THE SKY?

-50% RETURNS TO THE ATMOSPHERE BY EVAPORATION

-18% INFILTRATES (SINKS) INTO THE GROUND.

-32% IS SURFACE RUNOFF THAT ENTERS LAKES AND RIVERS

GROUNDWATER

-WATER THAT INFILTRATES (SINKS) THE EARTH’S SURFACE

-ONLY 0.6% OF THE EARTH’S WATER EXISTS WITHIN THE GROUND AS GROUNDWATER

-GROUNDWATER IS FRESH WATER

GROUNDWATER ZONES

-AFTER INFILTRATING THE GROUND, GROUNDWATER OCCUPIES DISTINCT ZONES

-ZONE OF SATURATION-

-ALL SPACES, CRACKS AND OTHER OPENINGS IN THE SOIL AND ROCK GRAINS BECOME COMPLETELY FILLED WITH WATER

-WATER WILL STOP SINKING INTO THE SOIL ONCE IT HAS REACHED A LAYER OF SOLID ROCK “IMPERMEABLE BEDROCK” UNDERNEATH THE SATURATED ZONE

-THE WATER TABLE-

THE UPPERMOST SURFACE OF THE SATURATED ZONE

-SOIL AND ROCK ACT AS A NATURAL FILTER ALLOWING GROUNDWATER TO BE A GOOD SOURCE OF DRINKING WATER

-WELLS MUST REACH BELOW THE WATER TABLE IN ORDER TO YIELD A GOOD SUPPLY OF WATER

POROSITY:

THE PERCENTAGE OF EMPTY SPACE , THAT DETERMINES HOW MUCH AIR OR WATER A SAMPLE OF ROCK CAN HOLD MOST POROUS

1) SOILS CONTAINING ROUND PARTICLES THAT ARE ALL THE SAME SIZE2) PARTICLES THAT ARE NOT CLOSELY PACKED

LEAST POROUS1) FLATTENED OR ANGULAR

SOIL PARTICLES

2) MIXTURE OF PARTICLE SIZES IN A SOIL. SMALLER PARTICLES CAN FIT INTO LARGER PARTICLE SPACES

PERMEABILITY

*ABILITY OF A SOIL TO TRANSMIT WATER

-RATE OF PERMEABILITY

-HOW FAST WATER CAN PASS THOUGH A SOIL

-DEPENDS ON SIZE OF THE PORES AND HOW WELL THEY ARE CONNECTED

MOST PERMEABLE

-LARGE PORES

-WELL CONNECTED PORES

SURFACE RUNOFF

1) WHEN RAINFALL EXCEEDS THE PERMEABILITY RATE OF THE SOIL

2) WHEN A SOIL IS SATURATED

3) WHEN THE SLOPE OR GRADIENT OF A SOILS SURFACE IS TOO GREAT FOR INFILTRATION TO OCCUR

4) IF THE GROUND IS BELOW 0OC

CAPILLARITY

ABILITY OF THE SOIL TO DRAW WATER UPWARD INTO TINY SPACES BETWEEN SOIL GRAINS

-SOILS COMPOSED OF VERY SMALL PARTICLES SHOW THE GREATEST CAPILLARY UPTAKE

-PULLS WATER UP AGAINST GRAVITY BECAUSE OF THE ATTRACTION BETWEEN THE WATER AND THE SURFACE OF THE SOIL MOLECULES

GREATEST CAPILLARITY

-DURING AND IMMEDIATELY AFTER PRECIPITATION, STREAMS RECEIVE WATER FROM OVERLAND FLOW

-STREAMS FLOW DURING DRY PERIODS BECAUSE OF WATER COMING FROM THE GROUND

RAINFALL AND STREAM FLOW-STREAMS AND RIVERS DO NOT

RESPOND IMMEDIATELY TO RAINFALL-MOST PRECIPITATION FALLS ON THE GROUND AND THEN MUST FLOW OVER THE LAND AS RUNOFF TO REACH A STREAM-A LAG TIME EXISTS BETWEEN MAXIMUM PRECIPITATION AND MAXIMUM STREAM DISCHARGE

HOW QUICKLY DOES A STREAM RESPOND TO PRECIPITATION?1)LARGE RIVERS RESPOND

SLOWLY-MOST RUNOFF MUST FLOW A GREAT DISTANCE TO REACH THE RIVERS2) SMALL RIVERS AND STREAMS IN MOUNTAIN AREAS RESPOND QUICKLY-SURFACE RUNOFF IS QUICKLY

DISTRIBUTED

WATERSHEDS

-GEOGRAPHIC AREA THAT DRAINS INTO A PARTICULAR STREAM OR BODY OF WATER

INSOLATION

“Incoming SOlar radiATION

-THE SUN’S ELECTROMAGNETIC ENERGY THAT REACHES THE EARTH

INTENSITY “STRENGTH” OF INSOLATION DEPENDS ON SEVERAL FACTORS

1) ANGLE OF INSOLATTION

2) DURATION OF INSOLATION

3) TYPE OF SURFACE THE INSOLATION STRIKES

ANGLE OF INSOLATION

-MEASURE OF HOW HIGH THE SUN IS IN THE SKY.

-THE ANGLE IS MEASURED FROM THE HORIZON UP TO THE POSITION OF THE SUNEX:-THE NOON SUN HAS THE

GREATEST ANGLE OF INSOLATIONNOON HAS THE GREATEST INTENSITY OF INSOLATION PER UNIT AREA

EX:

IN THE MORNING AND THE AFTERNOON WHEN THE SUN IS LOWER IN THE SKY, SUNLIGHT IS LESS DIRECT AND LESS INTENSE

THE ANGLE OF INSOLATION CHANGES SEASONALLY.

IN THE NORTHERN HEMISPHERE:HIGHEST INSOLATION= SUMMER

SOLSTICE (JUNE 21)

LOWEST INSOLATION=WINTER SOLSTICE(DEC 21)

BECAUSE THE EARTH IS SPHERICAL, EACH LATITUDE RECEIVES A DIFFERENT ANGLE OF INSOLATION

BETWEEN 23 ½ N AND 23 ½ S LATITUDE-RECEIVE VERTICAL RAYS (90o OF INSOLATION) EACH DAY AT NOON-THIS EXPLAINS SUCH WARM

TEMPERATURES AROUND THE EQUATOR

MOVEMENT FARTHER N AND S OF THE EQUATOR

THE ANGLE OF INSOLATION BECOMES LESS (LESS ANGLE BETWEEN THE HORIZON AND THE SUN.)

SLANTING RAYS ARE WEAKER IN INTENSITY BECAUSE THEY DISTRIBUTE THEIR ENERGY OVER A LARGER AREA

DURATION OF INSOLATION

-LENGTH OF TIME FROM SUNRISE TO SUNSET

-AT ANY LOCATION ON EARTH, THE TOTAL TIME THE SUN IS ABOVE THE HORIZON IS 6 MONTHS A YEAR.

EQUATOR=12 HOURS DAYLIGHT, 12 HOURS NIGHT

NORTH POLE=6 MONTHS OF SUNLIGHT, 6 MONTHS DARKNESS

ABSORPTION OF INSOLATION

WATER:-NEEDS MORE ENERGY TO RAISE THE TEMPERATURE. THAN LAND -HEATS UP AND COOLS OFF MORE SLOWLY THAN LAND

-REFLECTS INSOLATION BETTER THAN LAND

-INSOLATION CAN PENETRATE DEEPER THAN LAND BECAUSE WATER IS TRANSPARENT

-CONVECTION IN WATER CAN CARRY HEAT ENERGY DEEP IN THE HYDROSPHERE.

THE SAME AMOUNT OF INSOLATION CAN TRAVEL THROUGH A GREATER VOLUME OF WATER THAN LAND

REFLECTION OF INSOLATION

-LIGHT COLORED OBJECTS REFLECT INSOLATION BETTER

SNOW

ICE

WATER

-CAUSES COOLER TEMPERATURES IN THESE AREAS

TERRESTRIAL RADIATION

-ENERGY WAVES EMITTED BY THE SUN ARE SHORTER IN WAVELENGTH THAN THOSE RELEASED AS INFRARED FROM THE SURFACE OF THE EARTH

GREENHOUSE EFFECT

-LONG INFRARED WAVES ARE ABSORBED BY GASSES AND ARE TRAPPED IN THE ATMOSPHERE, SIMILAR TO A GREENHOUSE

THE INSOLATION-TEMPERATURE LAG

-A TIME LAG EXISTS BETWEEN THE TIME OF MAXIMUM INSOLATION AND MAXIMUM TEMPERATURE

CLIMATE:

-BASED ON ATMOSPHERIC CONDITIONS OVER A LONG PERIOD OF TIME

-THE AVERAGE TEMPERATURE AND PRECIPITATION OF AN AREA DETERMINES THE CLIMATE OF A PARTICULAR GEOGRAPHIC LOCATION

UNITED STATES CLIMATE

-GENERALLY GETS COOLER THE FARTHER NORTH YOU TRAVELPRECIPITATION

TEMPERATURE

-THERE IS NOT ENOUGH PRECIPITATION TO SATISFY WHAT COULD EVAPORATE UNDER THE HOT AND DRY CONDITIONS THERE

-MOST OF SOUTHWEST US IS CONSIDERED AN ARID CLIMATE

FACTORS THAT AFFECT CLIMATE

LATITUDE:-IMPORTANT TO DETERMINE

AVERAGE LOCAL TEMPERATURES-AS THE DISTANCE FROM THE EQUATOR INCREASES, THE AVERAGE ANNUAL TEMPERATURE DECREASES

-LOCATIONS IN THE MID LATITUDES EXPERIENCE LARGE SEASONAL CHANGES IN TEMPERATURES

ALTITUDE:

-HIGH ALTITUDE LOCATIONS HAVE COOL CLIMATES BECAUSE AIR COOLS AS IT REACHES HIGHER ELEVATIONS

AIR RISESAIR EXPANDS DUE TO LESS PRESSUREAIR COOLS

ADIABATIC COOLINGADIABATIC COOLING

MOUNTAIN RANGES:

-CAN MODIFY TEMPERATURE AND PRECIPITATION PATTERNSEX: WARM, MOIST AIR FROM THE PACIFIC OCEAN IS OFTEN FORCED TO RISE DUE TO A MOUNTAIN BARRIER.

THE AIR UNDERGOES ADIABATIC COOLING AND MAY COOL BELOW DEW POINT AND CAUSE PRECIPITATION

LOCATIONS ON THE WINDWARD SIDE OF THE MOUNTAIN WILL BE MORE MOIST

LOCATIONS ON THE LEEWARD SIDE OF THE MOUNTAIN WILL BE WARMER AND DRIER

OCEANS AND LARGE BODIES OF WATER:

-BECAUSE OF WATER’S HIGH SPECIFIC HEAT, IT WARMS UP AND COOLS OFF MUCH MORE SLOWLY THAN LAND-LOCATIONS NEAR LARGE BODIES OF WATER HAVE MORE MODERATE CLIMATES-WARMER WINTERS AND COOLER SUMERS -LOCATIONS INLAND HAVE GREATER SEASONAL TEMPERATURES

OCEAN CURRENTS:

THE TEMPERATURE OF A CURRENT OF WATER WILL AFFECT THE AIR TEMPERATURE ABOVE IT

EX: THE GULF STREAM

WARM WATER COMES UP FROM THE GULF OF MEXICO AND BRINGS WARM AIR WITH IT