CLOUD FORMATION A STUDY IN METEOROLOGY Created by Joshua Toebbe NOHS 2015

WHAT ARE CLOUDS? WELL, WHAT ARE THEY? ITS SIMPLE… WATER! BUT ITS NOT QUIT THAT SIMPLE. Created by Joshua Toebbe NOHS 2015

CLOUD RECIPE TO HAVE A CLOUD YOU NEED THREE THINGS: WATER (IN VAPOR FORM) NUCLEATION SITES A DROP IN PRESSURE Created by Joshua Toebbe NOHS 2015

CLOUD RECIPE OKAY LETS MAKE A CLOUD…REALLY… WATER VAPOR (FROM HOT WATER) NUCLEATION SITES (SMOKE) AND A CHANGE IN PRESSURE (SQUEEZING A BOTTLE) Created by Joshua Toebbe NOHS 2015

WATER VAPOR FOR CLOUDS TO FORM THEIR MUST BE WATER VAPOR IN THE AIR. FOR THIS TO OCCUR THEIR MUST BE ENOUGH ENERGY IN WATER PARTICLES TO BREAK FREE FROM THE SURFACE AND ENTER THE ATMOSPHERE (JUST LIKE WE TALKED ABOUT LAST TIME). Created by Joshua Toebbe NOHS 2015

WATER VAPOR THERE IS ALWAYS A SMALL AMOUNT OF MOISTURE IN THE AIR. BUT FOR CLOUDS TO FORM THEIR MUST BE AN EXCESS OF THIS MOISTURE. THE RELATIVE HUMIDITY MUST BE SO HIGH THAT THE WATER VAPOR IS FORCED TO CONDENSE INTO TINY WATER DROPLETS. Created by Joshua Toebbe NOHS 2015

WATER VAPOR Created by Joshua Toebbe NOHS 2015

WATER VAPOR SO FOR THE HUMIDITY TO RISE, THE TEMPERATURE MUST FALL. AND WITHIN THE TROPOSPHERE WHAT HAPPEN TO THE TEMPERATURE AS ALTITUDE INCREASES? THAT’S RIGHT, IT DROPS! TEMPERATURE FALLS AS ALTITUDE INCREASES. Created by Joshua Toebbe NOHS 2015

WATER VAPOR HAVE YOU EVER NOTICED THAT CLOUDS GENERALLY HANG OUT AT THE SAME ALTITUDE (OR AT LEAST IN ALTITUDE GROUPS)? Created by Joshua Toebbe NOHS 2015

WATER VAPOR THAT’S BECAUSE THE ALTITUDE AT WHICH THEY FORM, IS THE ALTITUDE AT WHICH THE PRESSURE AND TEMPERATURE PERSUADE WATER VAPOR TO CONDENSE. Created by Joshua Toebbe NOHS 2015

WATER VAPOR THIS ALTITUDE IS KNOWN AS THE LIFTED CONDENSATION LEVEL. IT CHANGES FROM DAY TO DAY, AND SOMETIMES EVEN DURING THE DAY, BUT IT IS WHERE ALL THE CLOUDS LIKE TO HANG OUT. Created by Joshua Toebbe NOHS 2015

WATER VAPOR WHY IS THIS? BELOW THE LCL, WATER DOES NOT CONDENSE, SO THERE ARE NO CLOUDS AT LOWER ALTITUDES. ABOVE IT THE WATER HAS ALREADY CONDENSED, SO THERE IS NO MORE WATER TO MAKE CLOUDS. AS A RESULT, THE CLOUDS CLUSTER AROUND THE LCL. Created by Joshua Toebbe NOHS 2015

WATER VAPOR THERE CAN BE MULTIPLE LCLS IN A SINGLE DAY. THE RELATIONSHIP BETWEEN TEMPERATURE, PRESSURE, ALTITUDE AND HUMIDITY IS A COMPLICATED ONE. AND THE CONDITIONS ARE ALWAYS CHANGING. THIS IS WHY WE CAN HAVE CLOUDS AT DIFFERENT ALTITUDES. Created by Joshua Toebbe NOHS 2015

WATER VAPOR BUT EVEN THEN, THE CLOUDS GROUP AROUND THEIR PERSPECTIVE LCL. Created by Joshua Toebbe NOHS 2015

NUCLEATION WATER DOESN’T JUST CONDENSE ON ITS OWN. AT LEAST NOT WITHOUT A MUCH GREATER DROP IN TEMPERATURE ANY WAY. SO THE WATER VAPOR MOLECULES NEED SOMETHING TO HANG ON TO AS THEY JOIN TOGETHER. THESE ARE KNOWN AS NUCLEATION SITES. Created by Joshua Toebbe NOHS 2015

NUCLEATION NUCLEATION SITES GIVE THE MOLECULES A MEETING PLACE SO THEY CAN FORM DROPLETS. THESE COULD BE SMALL PARTICLES OF DUST, SEA SALT BEING BLOWN ABOUT IN THE AIR, SMOKE, SAND PARTICLES, ANYTHING REALLY. THEY JUST HAVE TO BE SMALL ENOUGH TO BE CARRIED BY THE WIND INTO THE ATMOSPHERE. Created by Joshua Toebbe NOHS 2015

PRESSURE FINALLY WE REACH OUR LAST INGREDIENT: A DROP IN PRESSURE. DO YOU RECALL WHAT CAUSES ATMOSPHERIC PRESSURE? Created by Joshua Toebbe NOHS 2015

PRESSURE PRESSURE IS A MEASURE OF FORCE PER AREA. THE FORCE IS BEING GENERATED (IN THIS CASE), BY THE WEIGHT OF THE ATMOSPHERE ABOVE GROUND LEVEL. Created by Joshua Toebbe NOHS 2015

PRESSURE THE MORE AIR THAT IS THERE, THE GREATER THE PRESSURE, THE LESS AIR THAT IS THERE, THE LOWER THE PRESSURE. SINCE THE THICKNESS OF THE ATMOSPHERE DOESN’T REALLY CHANGE. THIS “EXTRA AIR” COMES FROM THE CONVECTION CURRENTS IN OUR ATMOSPHERE. Created by Joshua Toebbe NOHS 2015

PRESSURE UNEVEN HEATING OF THE EARTHS SURFACE PRODUCES CONVECTION CURRENTS. THESE REGIONS OF RISING AND FALLING AIR HAVE THE SAME THICKNESS. BUT THEY GENERATE DIFFERENT PRESSURES. Created by Joshua Toebbe NOHS 2015

PRESSURE FALLING AIR IS BEING PUSHED BACK TOWARD THE GROUND AND THUS GENERATES A HIGHER PRESSURE ZONE. RISING AIR IS CHARACTERIZED BY A LOW PRESSURE REGION. THE AIR IS BEING LIFTED OFF THE GROUND, REDUCING ITS (WEIGHT) FORCE ACTING ON THE EARTH. Created by Joshua Toebbe NOHS 2015

PRESSURE RECALL THAT FOR CLOUDS TO FORM THE AIR MUST GET COOLER. THIS IS MOST OFTEN ACHIEVED BY INCREASING ALTITUDE WITHIN THE TROPOSPHERE. IF THE PRESSURE IS HIGH, THE AIR CAN NOT RISE. RATHER IT IS FORCED BACK TOWARD EARTH. IF THE PRESSURE IS LOW, THE AIR CAN RISE, AND CLOUDS CAN FORM. Created by Joshua Toebbe NOHS 2015

PRESSURE THIS RELATIONSHIP PRODUCES A NICE BUT COUNTERINTUITIVE WAY OF PREDICTING WEATHER. IF BAROMETRIC PRESSURE IS FALLING, PRECIPITATION IS PROBABLY COMING (SINCE CLOUDS ARE FORMING IN THE RISING AIR) IF BAROMETRIC PRESSURE IS RISING, THE SKY WILL BE CLEAR AND NO PRECIPITATION OCCURS (SINCE THE AIR IS FALLING AND CLOUDS CANNOT FORM). Created by Joshua Toebbe NOHS 2015

WEATHER PREDICTION BAROMETRIC PRESSURE IS EASILY MEASUREABLE, AND PROVIDES A WONDERFUL TOOL FOR PREDICTING WEATHER. NOTE: IT DOESN’T REALLY MATER WHAT THE PRESSURE IS, JUST THE DIRECTION ITS GOING IN (UP OR DOWN). Created by Joshua Toebbe NOHS 2015

WEATHER PREDICTION SO LETS TAKE A LOOK AT A SPECIFIC SITUATION. THE MEASUREMENTS FROM LAST WEEK. (2/1-2/7, 2015) DATA FROM LOCALCONDITIONS.COM DaySundayMondayTuesdayWednesdayThursdayFridaySaturday Pressure (in-Hg) Trend (Arrow) Created by Joshua Toebbe NOHS 2015

CLOUD FORMATION Sunday Monday Saturday Tuesday Wedensday Thursday Friday Created by Joshua Toebbe NOHS 2015

CLOUD FORMATION Sunday Monday Saturday Tuesday Wedensday Thursday Friday Created by Joshua Toebbe NOHS 2015

SOURCES NEWMAN, L. (DEC. 15, 2006) MOISTURE, STABILITY AND PRECIPITATION. RETRIEVED FEB. 7, 2015 FROM ISTURE/MOISTURE_STABIL_PREC/MOISTURE_STABIL_PREC2.HTML ISTURE/MOISTURE_STABIL_PREC/MOISTURE_STABIL_PREC2.HTML RIEBEEK, H. (MARCH 15, 2004) WILL RUNAWAY WATER WARM THE WORLD? RETRIEVED FEB. 7, 2015 FROM PRINTALL.PHP PRINTALL.PHP Created by Joshua Toebbe NOHS 2015