Meteorology

1. Meteorology

2. METEOROLOGY THE STUDY OF THE ENTIRE ATMOSPHERE, INCLUDING ITS WEATHER

3. THE ATMOSPHERE • •AIR IS A MIXTURE OF MANY GASES IN EARTH’S LOWER ATMOSPHERE • •NITROGEN AND OXYGEN TOGETHER FORM ABOUT 99% OF DRY AIR BY VOLUME • •THE REMAINING 1 % IS MAINLY • ARGON AND CARBON DIOXIDE

4. STRUCTURE OF THE ATMOSPHERE TROPOSPHERE- IS THE LOWEST LAYER OF THE ATMOSPHERE (0-12 km) IN WHICH ALL OF EARTH’S WEATHER OCCURS. •GRADUALLY DECREASES IN TEMP. WITH AN INCREASE IN ALTITUDE. •CONTAINS ALL WATER VAPOR. •THE JET STREAM IS LOCATED BETWEEN 6-12 km.

5. TROPOPAUSE-THE TOP OF THE TROPOSPHERE WHERE THE DECREASE IN TEMP. STOPS • STRATOSPHERE- REACHES FROM THE TROPOPAUSE TO ABOUT 50 KM ABOVE EARTH •STEADY WINDS AND FEW WEATHER CHANGES (PLANES FLY HERE!) •STEADY INCREASE IN TEMP. WITH THE INCREASE OF ALTITUDE, WHICH IS CAUSED BY ABSORPTION FROM THE OZONE

6. OZONE – ULTRAVIOLET RAYS MAKE OXYGEN O3. THE OZONE LAYER ABSORBS SUN’S UV RAYS AND PROTECTS US FROM BURNING. STRATOPAUSE- THE TOP OF THE STRATOSPHERE WHERE THE TEMP. STOPS RISING. MESOSPHERE- TEMPERATURE DROPS AGAIN THERMOSPHERE- TEMPERATURE RISES AGAIN ABOUT 500 KM FROM EARTH

7. WHAT IS THE WEATHER LIKE OUTSIDE?

8. WEATHER- IS THE STATE OF THE ATMOSPHERE AT A GIVEN TIME AND PLACE TO TRY TO PREDICT WEATHER YOU NEED TO OBSERVE THE CLOUDS, WIND, TEMP., HUMIDITY, AIR PRESSURE AND PRECIPITATION OVER A PERIOD OF TIME.

9. HEATING OF THE ATMOSPHERE ENERGY FROM THE SUN RESULTS IN CHANGES IN THE WEATHER. HEAT MOVES THROUGH THE ATMOSPHERE IN THREE WAYS • •CONDUCTION- AN OBJECT RECIEVES HEAT WHEN IT COMES INTO CONTACT WITH A HOTTER OBJECT. (EX. A PAN ON A HOT STOVE)

10. •RADIATION- HOT BODIES RADIATE ENERGY IN SHORT WAVES (SUN); COLD BODIES RADIATE ENERGY IN LONGER WAVES (EARTH) •CONVECTION- MOST EFFECTIVE; THE RISING OF HOT AIR AND SINKING OF COLD AIR RESULTS IN A STEADY FLOW. CONVECTION IS VERY IMPORTANT IN MOVING HEAT THROUGH THE ATMOSPHERE.

11. INSOLATION SOLAR ENERGY THAT REACHES THE EARTH; WE RECIEVE ONE TWO-BILLIONTH OF THE SUN’S RAYS

12. GREENHOUSE EFFECT SHORT ULTRA VIOLET WAVES FROM THE SUN ARE ABLE TO REACH THE EARTH’S SURFACE, THEN LONGER INFRARED WAVES RE-RADIATED BY THE EARTH’S SURFACE ARE TRAPPED BY GREENHOUSE GASSES. (CFC’S AND CO2)

13. NORMAL LAPSE RATE – THE RATE OF COOLING WITH ALTITUDE (1C FOR EVERY 160 METERS) TEMPERATURE INVERSION - WHEN THE AIR IS ESPECIALLY STILL COOLER AIR, BECAUSE OF ITS GREATER DENSITY, SETTLES CLOSE TO THE GROUND, AND THE WARMER AIR FORMS A BLANKET ABOVE IT IN A TEMPERATURE INVERSION. POLLUTANTS IN THE AIR, SUCH AS SMOKE AND SOOT, ARE ALSO TRAPPED CLOSE TO THE GROUND .

14. SPECIFIC HEAT THE AMOUNT OF HEAT REQUIRED TO RAISE THE TEMP. OF SOMETHING 1ºC ** WATER HAS A HIGH SPECIFIC HEAT COMPARED TO SOIL. **

15. ABSORPTION TO TAKE IN ENERGY AND HEAT UP. REFLECTION TO BOUNCE BACK ENERGY. TO ABSORB SHORT WAVE ENERGY AND GIVE OFF LONG WAVE ENERGY. RE-RADIATION

16. GOOD ABSORBERS POOR ABSORBERS DARK-COLORED LIGHT COLORED ROUGH SURFACE SMOOTH SURFACE DRY SOIL WET SOIL

17. HEATING OF LAND AND WATER WHICH HEATS UP FASTER?? WATER WARMS MUCH MORE SLOWLY THAN LAND • IN WATER, THE SUN’S RAYS GO TO A DEPTH OF MANY METERS. ON LAND, THE SUN’S RAYS HEAT ONLY THE TOP FEW CENTIMETERS OF SOIL

18. • WATER CAN SPREAD HEAT EASILY BECAUSE IT IS A FLUID • SOME SOLAR ENERGY IS USED IN THE PROCESS OF EVAPORATION. THUS, LESS SOLAR ENERGY IS AVAILABLE TO RAISE THE TEMPERATURE OF THE WATER.

19. • WATER COOLS MORE SLOWLY THAN LAND BECAUSE ITS HEAT IS SPREAD THROUGH A GREATER DEPTH

20. TEMPERATURE TEMPERATURE IS A MEASURE OF THE ENERGY OF MOLECULES. THE MORE ENERGY THE MOLECULES IN AIR HAVE, THE HOTTER IT FEELS. • TEMPERATURE IS MEASURED IN DEGREES (CELSIUS, FAHRENHEIT, KELVIN)

21. THERMOMETERS ARE THE INSTRUMENTS USED TO MEASURE TEMPERATURE • THE ALCOHOL EXPANDS WHEN HEATED THERMOGRAPHS ARE SELF-RECORDING THERMOMETERS

22. ISOTHERMS ARE LINES DRAWN ON MAPS CONNECTING PLACES WITH THE SAME TEMPERATURE

23. EVAPORATION • • THE CHANGE FROM LIQUID WATER TO WATER VAPOR WATER VAPOR IS SPREAD THROUGHOUT THE TROPOSPHERE BY CONVECTION CURRENTS AND WINDS.

24. HUMIDITY THE CAPACITY OF AIR FOR HOLDING WATER VAPOR • AS AIR TEMPERATURE INCREASES SO DOES THE AMOUNT OF WATER VAPOR IT CAN HOLD SPECIFIC HUMIDITY- THE AMOUNT OF WATER VAPOR ACTUALLY PRESENT IN THE AIR.

25. RELATIVE HUMIDITY- COMPARES THE ACTUAL AMOUNT OF WATERVAPOR IN THE AIR(SPEC. HUMIDITY) WITH THE MAXIMUM AMOUNT OF WATER VAPOR THE AIR CAN HOLD AT THAT TEMPERATURE PSYCHROMETER- IS THE INSTRUMENT USED TO DETERMINE RELATIVE HUMIDITY

26. CONDENSATION THE CHANGE FROM WATER VAPOR TO A LIQUID. THIS OCCURS WHEN THE TEMPERATURE DROPS LOW ENOUGH THAT THE CAPACITY FOR WATER VAPOR IN THE AIR DROPS BELOW THE SPECIFIC HUMIDITY.

27. EXAMPLES DEW- WATER VAPOR WHICH CONDENSES ON SURFACES, SUCH AS GRASS, IN THE FORM OF A LIQUID. •DEW POINT- TEMPERATURE AT WHICH SATURATION OCCURS. CLOUDS OR FOGS- FORM WHEN THE WATER VAPOR CONDENSES INTO DROPLETS

28. AIR MAY BE COOLED BELOW ITS DEW POINT IN MANY WAYS: •CONTACTING A COLDER SURFACE •RADIATING HEAT •MIXING WITH COLDER AIR •EXPANDING WHEN IT RISES

29. WATER VAPOR NEEDS TO CONDENSE ON SOMETHING!! CONDENSATION NUCLEI- TINY PARTICLES, SUCH AS SALT, SULFATE, OR NITRATE PARTICLES, ON WHICH WATER VAPOR CONDENSES • •WHEN COOLING OCCURS BY CONTACT WITH A COLDER SURFACE, THE WATER VAPOR CONDENSES DIRECTLY ON THAT SURFACE • >0C = DEW • <0C = FROST

30. FOGS SURFACE LAYERS OF AIR A FEW HUNDRED METERS THICK WHICH ARE COOLED BELOW THE DEW POINT. AS WATER VAPOR CONDENSES TINY DROPLETS STAY SUSPENDED IN THE AIR BY THE LIGHTEST AIR MOVEMENT.

31. RADIATION FOGS - AT NIGHT THE GROUND LOSES HEAT RAPIDLY. LIGHT WINDS MIX THE COLD BOTTOM AIR WITH THE AIR A SHORT DISTANCE FROM THE SURFACE. WHEN THE WHOLE LAYER OF AIR IS COOLED BELOW THE DEW POINT, A FOG FORMS. (COMMON IN HUMID VALLEYS AND NEAR RIVERS AND LAKES)

32. ADVECTION FOGS – RESULT WHEN WARM, MOIST AIR BLOWS OVER COOL SURFACES (EX. COASTAL CALIFORNIA)

33. CLOUDS CLOUDS FORM WHEN AIR ABOVE THE SURFACE COOLS BELOW THE DEW POINT

34. PRECIPITATION IS THE FALLING OF ANY FORM OF WATER FROM THE AIR TO THE EARTH’S SURFACE. • OCCURS WHEN CLOUD DROPLETS GROW INTO DROPS HEAVY ENOUGH TO FALL TO EARTH.

35. RAINDROPS FORM FROM TINY DROPLETS AND THEN GROW BY BUMPING INTO AND COMBINING WITH OTHER DROPLETS. SLEET FORMS WHEN RAINDROPS FALL THROUGH THE FREEZING AIR AND FALL TO THE GROUND AS PELLETS OF ICE HAILSTONES BEGIN AS A FROZEN RAINDROP AND GROWS BY COLLECTING SMALLER ICE PARTICLES OR LIQUID CLOUD DROPLETS ACID RAIN FORMS WHEN WATER CONDENSES ON SULFATE AND NITRATE

36. AIR PRESSURE THE WEIGHT OF THE ATMOSPHERE PER UNIT AREA DIFFERENCES IN AIR PRESSURE CAUSE THE EARTH’S WIND AND WEATHER CHANGES **PRESSURE DECREASES WITH ALTITUDE**

37. BAROMETER MERCURY BAROMETER IS AN INSTRUMENT USED TO MEASURE AIR PRESSURE ANEROID BAROMETER MEASURES PRESSURE WITH A THIN METAL CAN

38. MILLIBAR- IS A METRIC UNIT OF PRESSURE **STANDARD SEA-LEVEL PRESSURE IS 1013.2 MB ** ISOBAR – LINES THAT JOIN POINTS HAVING THE SAME AIR PRESSURE AT A GIVEN TIME •EACH LINE IS WORTH 4 MB

39. HIGH PRESSURE AREA (HIGH) – THE AREA OF THE LARGEST PRESSURE. THE PRESSURE IN A HIGH IS GREATER THAN THE SURROUNDING AIR L LOW PRESSURE ARE (LOW) – THIS AREA HAS LOWER PRESSURE THAN THE SURROUNDING AREA H PRESSURE GRADIENT – THE RATE OF CHANGE FOR AIR PRESSURE BETWEEN TWO POINTS

40. RISING BAROMETER- GREATER PRESSURE USUALLY MEANS COOLER, DRIER WEATHER (SINKING AIR) FALLING BAROMETER – LESS PRESSURE BECAUSE THE AIR IS WARM AND MOIST AND RISES. THIS CAN BE A SIGN OF PRECIPITATION

41. WIND THE HORIZONTAL MOVEMENT OF AIR FROM AREAS OF HIGH AIR PRESSURE TO AREAS OF LOW AIR PRESSURE. THE CLOSER THE SPACING BETWEEN ISOBARS THE STRONGER THE WINDS WINDS BLOW ACROSS ISOBARS, FROM HIGH TO LOW AIR PRESSURE.

42. GLOBAL WIND BELTS WIND FLOWS FROM HIGH PRESSURE AT THE POLES TO LOW PRESSURE AT THE EQUATOR • THE WIND IS DEFLECTED BY THE EARTH’S ROTATION, CALLED THE CORIOLUS EFFECT

43. Air Masses AN AIR MASS IS A HUGE SECTION OF THE LOWER TROPOSPHERE THAT HAS THE SAME KIND OF WEATHER (TEMPERATURE AND MOISTURE PROPERTIES) THROUGHOUT THE BEST SOURCE REGIONS FOR AIR MASSES ARE LARGE FLAT AREAS WHERE AIR CAN BE STAGNANT LONG ENOUGH TO TAKE ON THE CHARACTERISTICS OF THE SURFACE BELOW

44. AIR MASSES HAVE TWO CHARACTERISTICS: TEMPERATURE DEPENDS ON WHETHER IT COMES FROM THE TROPICS OR POLAR REGIONS THE HUMIDITY OF THE AIR MASS DEPENDS ON WHETHER IT COMES FROM LAND OR SEA AIR MASSES ARE NAMED FROM THEIR SOURCE REGION c - CONTINENTAL T – TROPICAL m – MARITIME P – POLAR A - ARCTIC

45. BOUNDARIES BETWEEN AIRMASSES ARE CALLED FRONTS

46. Cold Front 1) COLD AIR IS ADVANCING AND REPLACING WARM AIR 2) COLD FRONTS ARE STEEPER AND MOVE FASTER THAN WARM FRONTS 3) THE AIR RISES UPWARD RAPIDLY FORMING CUMULONIMBUS

47. Cold Front 4) HEAVY PRECIPITATION AND THUNDERSTORMS WHICH START AND END QUICKLY ARE ASSOCIATED WITH COLD FRONTS 5) PRECIPITATION COVERS 75 – 100 MILES AND OCCURS BOTH BEFORE AND AFTER A COLD FRONT PASSES AT THE SURFACE 6) COLD FRONTS TRAVEL AT SPEEDS BETWEEN 25- 30 MPH

48. Cold Front 7) AS SOON AS THE FRONT PASSES THE TEMPERATURE WILL DECREASE AND THE WIND SPEED MAY RISE. The Weather Channel Map Symbol

49. Warm Front 1) WARM AIR IS ADVANCING AND REPLACING COLD AIR 2) WARM FRONTS MOVE SLOWER; WARM AIR MOVES UP A GENTLE FRONTAL SURFACE 3) WARM AIR MAY TRAVEL 1000 KM BEFORE RISING 2 OR 3 KM

50. Warm Front 4) FIRST CIRRUS AND CIRROSTRATUS CLOUDS FORM AND THEN THERE ARE ALTOSTRATUS CLOUDS. FINALLY, STEADY RAIN FALLS FROM NIMBOSTRATUS CLOUDS 5) PRECIPITATION CAN OCCUR FOR 225 – 275 MILES AHEAD OF WHERE THE FRONT TOUCHES THE GROUND