UNIT OBJECTIVES • EXPLAIN THE EFFECTS OF THE EARTH-SUN RELATIONSHIP ON LIFE ON EARTH. • IDENTIFY THE FACTORS THAT CONTRIBUTE TO EARTH’S CLIMATES. • DESCRIBE THE MAJOR CLIMATE PATTERNS FOUND ON EARTH. EARTH-SUN RELATIONSHIPS
OBJECTIVES • DESCRIBE HOW EARTH’S POSITION IN RELATION TO THE SUN AFFECTS TEMPERATURES ON EARTH. • EXPLAIN HOW EARTH’S ROTATION CAUSES DAY AND NIGHT. • DISCUSS THE RELATIONSHIP OF THE EARTH TO THE SUN DURING EACH SEASON. • IDENTIFY HOW GLOBAL WARMING MIGHT AFFECT EARTH’S AIR, LAND, AND WATER. EARTH-SUN RELATIONSHIPS TERMS TO KNOW PLACES TO LOCATE CLIMATE SEASONS TROPIC OF CANCER AXIS ECLIPTIC TROPIC OF CAPRICORN TEMPERATURE ENERGY EQUATOR REVOLUTION ROTATION POLES EQUINOX CONDUCTOR SOLSTICE CONVECTION GREENHOUSE EFFECT ADVECTION GLOBAL WARMING RADIATION WEATHER PERIHELION APHELION EARTH-SUN RELATIONSHIPS
THE SUN, THE BRIGHTEST STAR IN OUR SKY, IS A MAJOR FACTOR IN CREATING EARTH’S CLIMATES. THE SUN, COMPOSED OF HYDROGEN, HELIUM, AND OTHER GASES, ROTATES ON AN AXIS AT ABOUT THE SAME ANGLE AS THE EARTH’S AXIS. ONLY A TINY FRACTION OF THE POWER GENERATED BY THE SUN REACHES THE EARTH. OUR SOLAR SYSTEM DIMENSIONS AND DISTANCES
• EARTH’S ORBIT • AVERAGE DISTANCE FROM EARTH TO THE SUN IS 150,000,000 KM (93,000,000 MI). • PERIHELION • CLOSEST AT JANUARY 3. • 147,255,000 KM (91,500,000 MI). • APHELION • FARTHEST AT JULY 4. • 152,083,000 KM (94,500,000 MI). • EARTH IS 8 MINUTES 20 SECONDS FROM THE SUN. • PLANE OF EARTH’S ORBIT IS THE PLANE OF THE ECLIPTIC. EARTH’S TILT AND ROTATION
• EARTH IS CURRENTLY TILTED AT AN ANGLE OF ABOUT 23½°. BECAUSE OF THE TILT OF THIS AXIS, NOT ALL PLACES ON EARTH RECEIVE THE SAME AMOUNT OF DIRECT SUNLIGHT AT THE SAME TIME. AXIAL TILT AND PARALLELISM EARTH’S REVOLUTION • EARTH TRAVELS IN AN ORBIT AROUND THE SUN, COMPLETING ONE TRIP ABOUT EVERY365 DAYS. • THE SEASONS ARE CAUSED BY THE EARTH’S REVOLUTION AROUND THE SUN AND THE EARTH’S TILT. • THE EQUATOR DIVIDES EARTH INTO THE NORTHERN AND SOUTHERN HEMISPHERES. WHEN ONE HEMISPHERE EXPERIENCES WINTER, THE OTHER EXPERIENCES SUMMER. REVOLUTION AND ROTATION THE POLES • THE NORTH POLE AND THE SOUTH POLE ARE LOCATED AT EITHER END OF THE EARTH’S AXIS. • EACH POLE RECEIVES CONTINUOUS INDIRECT SUNLIGHT SIX MONTHS EACH YEAR. • WHILE ONE RECEIVES CONTINUOUS SUNLIGHT, THE OTHER RECEIVES LITTLE TO NO SUNLIGHT. - UNEVEN DISTRIBUTION OF INSULATION. - INTENSITY IS SEASONAL & LATITUDINAL. - MOST INTENSE AT THE SUB-SOLAR POINT THE TROPICS OF CANCER AND CAPRICORN
• THE LINE OF LATITUDE AT 23½°N IS CALLED THE TROPIC OF CANCER – THE NORTHERN MOST LATITUDE ON THE EARTH TO RECEIVE THE SUN’S DIRECT RAYS.
• THE LINE OF LATITUDE AT 23½°S IS CALLED THE TROPIC OF CAPRICORN – THE SOUTHERN MOST LATITUDE TO RECEIVE THE SUN’S DIRECT RAYS. SEASONALITY
• SEASONAL CHANGES. – SUN’S ALTITUDE – ANGLE ABOVE HORIZON. – DECLINATION – LOCATION OF THE SUB-SOLAR POINT. – LENGTH OF DAYLIGHT. REASONS FOR SEASONS
• REVOLUTION. • ROTATION. • TILT OF EARTH’S AXIS. • AXIAL PARALLELISM. • SPHERICITY. REASONS FOR SEASONS • REVOLUTION – EARTH REVOLVES AROUND THE SUN. – VOYAGE TAKES ONE YEAR. – EARTH’S SPEED IS 107,280 KMPH (66,660 MPH) • ROTATION – EARTH ROTATES ON ITS AXIS ONCE EVERY 24 HOURS. – ROTATIONAL VELOCITY AT EQUATOR IS 1,674 KMPH (1,041 MPH) • TILT OF EARTH’S AXIS – AXIS IS TILTED 23.5° FROM PLANE OF ECLIPTIC. • AXIAL PARALLELISM – AXIS MAINTAINS ALIGNMENT DURING ORBIT AROUND THE SUN. – NORTH POLE POINTS TOWARD THE NORTH STAR(POLARIS) • SPHERICITY
ANNUAL MARCH OF THE SEASONS • WINTER SOLSTICE – DECEMBER 21 OR 22. – SUBSOLAR POINT, TROPIC OF CAPRICORN. • SPRING EQUINOX – MARCH 20 OR 21. – SUBSOLAR POINT, EQUATOR. • SUMMER SOLSTICE – JUNE 20 OR 21. – SUBSOLAR POINT, TROPIC OF CANCER. • FALL EQUINOX – SEPTEMBER 22 OR 23. – SUBSOLAR POINT, EQUATOR
ANNUAL MARCH OF THE SEASONS
EARTH-SUN RELATIONSHIPS
• KEY POINTS • THE EARTH’S POSITION IN RELATION TO THE SUN AFFECTS TEMPERATURES ON EARTH. • THE ROTATION OF THE EARTH CAUSES DAY AND NIGHT. • THE EARTH’S REVOLUTION AND ITS TILT IN RELATION TO THE SUN PRODUCE THE SEASONS. • GLOBAL TEMPERATURES MAY BE INCREASING AS A RESULT OF HUMAN ACTIVITY EARTH’S REVOLUTION
• DISCUSSION QUESTION • HOW DOES THE REVERSAL OF SEASONS IN THE NORTHERN AND SOUTHERN HEMISPHERES AFFECT THE LIVES OF PEOPLE ON EARTH? • POSSIBLE ANSWER: FOOD CROPS CAN BE PRODUCED YEAR-ROUND BECAUSE OF THE REVERSAL OF SEASONS, SO FRESH FRUITS AND VEGETABLES GENERALLY ARE AVAILABLE ALL YEAR LONG CRITICAL THINKING
Q: DRAWING CONCLUSIONS WHAT EFFECTS DOES THE EARTH’S TILT ON ITS AXIS HAVE ON YOUR DAILY LIFE?
A: THE TILT CAUSES TEMPERATURE VARIATIONS AND AFFECTS ANY DAILY ACTIVITIES THAT ARE DEPENDENT ON WEATHER OR TEMPERATURE(CHOICE OF CLOTHING, OUTDOOR ACTIVITIES, INDOOR HEATING OR COOLING, AND SO ON). CRITICAL THINKING
Q: ANALYZING INFORMATION WHAT WOULD YOU PACK IF YOU WERE VISITING ARGENTINA IN DECEMBER?
A: YOU WOULD PACK CLOTHING FOR WARM WEATHER (IN LOW ELEVATIONS) AND WARM CLOTHING FOR MOUNTAINS OR EXTREME SOUTHERN LATITUDES IF YOU WERE VISITING ARGENTINA IN DECEMBER. ANALYZING DIAGRAMS
Location Study the diagram of the seasons below. In what months do the sun’s rays strike the Equator directly? The Tropics of Cancer and Capricorn? ANALYZING DIAGRAMS
The sun’s rays strike the Equator directly in March and September. They strike the Tropics of Cancer and Capricorn in December or June. EARTH’S TILT AND ROTATION
DISCUSSION QUESTION
Q: WHICH PLACES ON EARTH RECEIVE THE MOST DIRECT SUNLIGHT? HOW DOES THIS PHENOMENON AFFECT THEIR CLIMATES?
A: REGIONS IN THE TROPICS RECEIVE THE MOST DIRECT SUNLIGHT. THESE REGIONS ARE GENERALLY WARM OR HOT YEAR-ROUND, DEPENDING ON THEIR ELEVATION. CLIMATE AND WEATHER
DISCUSSION QUESTION
Q: THINK ABOUT YOUR LOCATION AND THE EARTH’S RELATIONSHIP TO THE SUN. HOW DOES THE EARTH-SUN RELATIONSHIP AFFECT YOUR LIFE? ASSIGNMENT: EARTH/SUN RELATIONSHIPS (TEAM PROJECT)
• SEASONAL WEATHER AND CLIMATE ARE RELATED TO EARTH/SUN RELATIONSHIPS. FOCUS YOUR EFFORTS ON THE OKLAHOMA CITY METROPOLITAN REGION, AND GATHER CLIMATE STATISTICS AND SEASONAL EARTH/SUN RELATIONSHIPS. ESTABLISH THE LATITUDE/LONGITUDE FOR WILL ROGERS INTERNATIONAL AIRPORT. COLLECT CLIMATE STATISTICS (DAILY HIGH AND LOW TEMPERATURES AND MONTHLY MEAN HIGH AND MEAN LOW TEMPERATURES) FOR THIS STATION FOR ONE YEAR. ALSO COLLECT SEASONAL DATA SUCH AS THE DAILY CHANGES IN THE LENGTH OF DAYLIGHT HOURS, THE DAILY LENGTH OF DARKNESS HOURS, AND MAXIMUM AND MINIMUM DAILY SUN ANGLES (HEIGHT AT SOLAR NOON) AND COMPASS AZIMUTHS (POSITIONS OF THE SUN). DETERMINE THE RANGE OF THESE VALUES FOR EACH OF THE THREE SEASONS. CREATE A TABLE FOR ALL VARIABLES YOU HAVE COLLECTED.