Lesson 17: Moisture, Cloud Formation, and Precipitation PDF

UNIT IV. MOISTURE, CLOUDS, PRECIPITATION, AIR PRESSURE AND WIND LESSON 17. MOISTURE, CLOUD FORMATION, AND PRECIPITATION Mr. Angelo Tucay Mr. Carl Fermil Aguinaldo Ms. Shella Cabal  LEARNING OBJECTIVES: AT THE END OF THE LESSON, THE LEARNERS SHOULD BE ABLE TO: 1.EXPLAIN...

UNIT IV. MOISTURE, CLOUDS, PRECIPITATION, AIR PRESSURE AND WIND LESSON 17. MOISTURE, CLOUD FORMATION, AND PRECIPITATION Mr. Angelo Tucay Mr. Carl Fermil Aguinaldo Ms. Shella Cabal  LEARNING OBJECTIVES: AT THE END OF THE LESSON, THE LEARNERS SHOULD BE ABLE TO: 1.EXPLAIN HOW WATER CHANGES IN THE ATMOSPHERE AND HOW IT IS MEASURED; 2.Describe how clouds are formed; and 3.Identify various forms of precipitation.  TASK 1. RECALL TIME Give an example of greenhouse gases and its sources. TASK 1. RECALL TIME Carbon dioxide Methane Nitrous oxide Water vapor Ozone Fluorinated gas  TASK 1. RECALL TIME How do we benefit from greenhouse effect and how does greenhouse effect become harmful?  TASK 1. RECALL TIME Positive side: The greenhouse effect keeps the planet warm enough for life to exist. Without it, Earth would be frozen and uninhabitable.  TASK 1. RECALL TIME Negative side: Human activities like burning fossil fuels for energy have increased the amount of greenhouse gases in the atmosphere, which has made the greenhouse effect stronger.  TASK 2. 4 PIC 1 WORD INSTRUCTION: UNLOCK THE MYSTERY WORD USING THE PROVIDE IMAGE AS CLUE. TASK 2. 4 PIC 1 WORD _ U_I_IT_ TASK 2. 4 PIC 1 WORD HUMIDITY TASK 2. 4 PIC 1 WORD D_ _ __IN_ TASK 2. 4 PIC 1 WORD DEW POINT TASK 2. 4 PIC 1 WORD M_I_T_R_ TASK 2. 4 PIC 1 WORD MOISTURE  UNLOCKING OF WORDS Humidity Humidity is the amount of water vapor in the air. If there is a lot of water vapor in the air, the humidity will be high. The higher the humidity, the wetter it feels outside.  UNLOCKING OF WORDS Dew point The dew point refers to the temperature at which the air becomes saturated with water vapor. When the rate of evaporation equals the rate of condensation, the dew point is reached.  UNLOCKING OF WORDS Moisture Water in liquid form or traces of water in a substance. Moisture content is the amount of water in a substance WHAT DO YOU KNOW? What do you know about moisture? WHAT DO YOU KNOW? What do you know about cloud? WHAT DO YOU KNOW? What do you know about precipitation? DIFFERENT STATE OF WATER WATER IN THE ATMOSPHERE EXIST IN THREE PHASES. SOLID LIQUID GAS  WATER CHANGES ITS PHASE WHEN ENERGY IS ABSORBED OR RELEASED BY IT IN TERMS OF HEAT.  EVAPORATION MOLECULES OF LIQUID ABSORBS ENERGY CAUSING THEIR BONDS TO BREAK AND TURN INTO GAS.  CONDENSATION MOLECULES OF WATER VAPOR RELEASES ENERGY AND TURNS TO LIQUID STATE.  MELTING ABSORPTION OF ENERGY TRANSFORMING FROM SOLID TO LIQUID  FREEZING RELEASING OF ENERGY TRANSFORMING FROM LIQUID TO SOLID  SUBLIMATION SOLID TO GAS (ABSORBS ENERGY) - Dry ice used as smoke during plays  DEPOSITION GAS TO SOLID (RELEASE OF ENERGY) - frost in freezer compartments  ANALYSIS IN WHICH PHASE CHANGE moisture is connected? clouds? precipitation?  HUMIDITY AMOUNT OF MOISTURE (WATER VAPOR) IN AIR. Hygrometer (hygro – moisture, metron – measuring) Psychrometer (a type of hygrometer) HUMIDITY  HUMIDITY WHEN WATER EVAPORATES, COOLING OCCURS AT THE WATER BELOW SURFACE AND, VAPOR PRESSURE INCREASES. RATE OF EVAPORATION IS DETERMINED BY THE TEMPERATURE OF AIR.  HUMIDITY WHEN VAPOR PRESSURE INCREASES, RATE OF CONDENSATION INCREASES.  HUMIDITY WHEN RATE OF EVAPORATION AND CONDENSATION IS EQUAL, AIR IS SAID TO BE SATURATED. TEMPERATURE AT WHICH RATE OF EVAPORATION AND CONDENSATION IS EQUAL IS DEW POINT.  HUMIDITY ABSOLUTE HUMIDITY – MEASURES HOW MUCH HUMID IS A PARCEL OF AIR. SINCE VOLUME OF AIR CHANGES FREQUENTLY, THIS IS HARD TO MEASURE.  HUMIDITY MIXING RATIO (mass of water vapor)/(mass of dry air)  HUMIDITY RELATIVE HUMIDITY– RATIO OF ACTUAL WATER VAPOR CONTENT COMPARED WITH THE AMOUNT REQUIRED FOR SATURATION. IF THE ACTUAL WATER VAPOR CONTENT OF THE 1KG OF AIR AT 25°C IS 18 G/KG OF AIR, WHAT IS ITS RELATIVE HUMIDITY? IF THE ACTUAL WATER VAPOR CONTENT OF THE 1KG OF AIR AT 25°C IS 18 G/KG OF AIR, WHAT IS ITS RELATIVE HUMIDITY? 90% HOW MANY GRAMS OF WATER VAPOR IS PRESENT IN 1KG OF AIR AT 25°C IF IT HAS A RELATIVE HUMIDITY OF 20%? HOW MANY GRAMS OF WATER VAPOR IS PRESENT IN 1KG OF AIR AT 25°C IF IT HAS A RELATIVE HUMIDITY OF 20%? 4g HOW MANY GRAMS OF WATER VAPOR IS NEEDED TO SATURATE A ONE KILOGRAM OF AIR AT 25°C? HOW MANY GRAMS OF WATER VAPOR IS NEEDED TO SATURATE A ONE KILOGRAM OF AIR AT 25°C? 20g IF A 1KG OF AIR AT 25°C IS SAID TO HAVE A RELATIVE HUMIDITY OF 50%, HOW MANY GRAMS OF WATER VAPOR IS PRESENT IN THE AIR? IF A 1KG OF AIR AT 25°C IS SAID TO HAVE A RELATIVE HUMIDITY OF 50%, HOW MANY GRAMS OF WATER VAPOR IS PRESENT IN THE AIR? 10g  BY HOW MUCH °C SHOULD A 1KG AIR AT 25°C COOLDOWN FOR IT TO BECOME SATURATED IF THE CURRENT WATER VAPOR CONTENT OF THE AIR IS 14G?  BY HOW MUCH °C SHOULD A 1KG AIR AT 25°C COOLDOWN FOR IT TO BECOME SATURATED IF THE CURRENT WATER VAPOR CONTENT OF THE AIR IS 14G? 5°C  CLOUD HOW ARE CLOUDS FORMED? CLOUD GENERALLY, CLOUDS ARE FORMED THROUGH ADIABATIC COOLING OF WATER VAPOR. COOLING PROCESS WHEN AIR IS COOLED OR WARMED BECAUSE OF EXPANSION OR COMPRESSION NOT DUE TO THERMAL ENERGY TRANSFER. AS AIR RISES, ATMOSPHERIC PRESSURE DECREASES, THUS EXPANSION CAN TAKE PLACE. EXPANSION CAUSE THE AIR TO LOWER ITS TEMPERATURE. (10℃/1000METERS) DRY ADIABATIC RATE – RATE OF COOLING OF UNSATURATED AIR. WET ADIABATIC RATE – RATE OF COOLING OF AIR DURING CONDENSATION OF MOISTURE. (SLOWER THAN DRY ADIABATIC) TYPES OF CLOUDS  TYPES OF CLOUDS CLOUDS ARE CLASSIFIED ACCORDING TO FORM AND HEIGHT. Low Clouds – Stratus, stratocumulus, nimbostratus Stratus (stratum = layers) sheets or layers that covers the sky. TYPES OF CLOUDS  TYPES OF CLOUDS CLOUDS ARE CLASSIFIED ACCORDING TO FORM AND HEIGHT. Middle Clouds – (alto prefix) altostratus, altocumulus Sun or moon is visible as a bright spot. TYPES OF CLOUDS  TYPES OF CLOUDS CLOUDS ARE CLASSIFIED ACCORDING TO FORM AND HEIGHT. High Clouds – cirrus, cirrostratus, cirrocumulus. Cirrus (cirrus = a curl of hair) high white and thin. TYPES OF CLOUDS  TYPES OF CLOUDS CUMULUS (CUMULUS = A PILE) – CLOUDS CONSISTS OF GLOBULAR INDIVIDUAL CLOUD MASSES (CAULIFLOWER STRUCTURE). Nimbus (rain clouds) – dark, grey clouds associated with precipitation. Fogs – clouds near the ground (mostly due to cooling of water vapor near the surface. TYPES OF CLOUDS  PRECIPITATION PRECIPITATION – ANY FORM OF MOISTURE THAT FALLS FROM AIR TO EARTH  PRECIPITATION COALESCENCE – PROCESS WHICH LARGE DROPLETS OF WATER COMBINE WITH SMALLER DROPLETS TO PRECIPITATE AND REACH THE GROUND.  PRECIPITATION SUPERCOOLING – FORMATION OF ICE CRYSTAL DUE TO FREEZING NUCLEI. PRECIPITATION  PRECIPITATION RAIN – LIQUID PRECIPITATION  PRECIPITATION SNOW – SOLID PRECIPITATION (ICE CRYSTALS)  PRECIPITATION SLEET – RAIN FALLS INTO FREEZING AIR (CLEAR ICE PELLETS) SLEET FORMS WHEN SNOW MELTS SLIGHTLY AND THEN REFREEZES AS IT FALLS THROUGH A COLDER LAYER OF THE ATMOSPHERE.  PRECIPITATION HAIL – LARGE ICE PELLETS WITH IRREGULAR SHAPE. HAIL FORMS WHEN WATER FREEZES ONTO A HAILSTONE'S SURFACE  ANY QUESTION? THANK YOU