After School Review Commack High School Meteorology & Climate After School Review Commack High School

Ozone layer is in the stratosphere The Atmosphere Page 14 ESRT’s Thermosphere Mesosphere Ozone layer is in the stratosphere Stratosphere Troposphere Troposphere K. Corbisiero 2010

Weather: Atmospheric conditions at a specific location for a short period of time (days) NOTE: this differs from climate because climate is the conditions over a large area over a long period of time (years) K. Corbisiero 2010

Weather Variables and Instruments Temperature Pressure Wind Speed Precipitation Humidity, Dew Point How much the air is pushing down (also called barometric pressure) How fast the wind is moving (faster when isobars are closest) Rain, hail, sleet, or snow falling to the ground How warm or cool the air is Amount of moisture in the air (water vapor) Psychrometer Thermometer Barometer Anemometer Rain Gauge K. Corbisiero 2010

Winds blow from high to low! Land & Sea Breezes Has to do with specific heat. Water has highest specific heat so takes longer to heat up and longer to cool down. Land heats and cools quickly. L H Blows from land to sea LAND BREEZE Remember: warm rising air is low pressure and cooler sinking air is high pressure. Winds blow from high to low! L H Blows from sea to land SEA BREEZE K. Corbisiero 2010

Dew Point & Relative Humidity – page 12 ESRT’s Dew Point – the point at which condensation occurs. The air is full, and when the temperature lowers to the dew point, the moisture is forced to leave the air and condense into a liquid. Humidity – how much moisture is in the air. 100% relative humidity mean that the air is full, no more moisture can ‘fit’ in. 0% humidity means the air is very dry. K. Corbisiero 2010

Wet Bulb & Dry Bulb The wet bulb temperature is usually cooler than the dry bulb temperature. The closer they are, the more moisture there is in the air (the more humid it is) K. Corbisiero 2010

2°C 33 % Dew Point = ___________ Relative Humidity = ___________ Using the charts: (ESRT’s page 12) X axis = (dry bulb – the wet bulb) = the difference between them. Y axis = the dry bulb (dry bulb is normal air temperature) 2°C 33 % Determine the dewpoint and relative humidity for the readings on the sling psychrometer to the left: Dew Point = ___________ Relative Humidity = ___________ #1 Mistake Students Make – They use the wrong chart! K. Corbisiero 2010

High and Low Pressure Systems Clear (no clouds) Dry air Cooler air Righty Tighty CW Wind blows out Sinking air mass Cloudy Moist humid air Warmer air Lefty Loosey CCW Wind blows in Rising air mass H L K. Corbisiero 2010

Pressure Gradient Calculations – pg 1 ESRT’s Distance (use map scale) Cloud Formation Clouds form when warm, moist air rises and cools to a temperature below the dew point. This forces the moist air to condense. There must be condensation nuclei present (dust etc). Pressure Gradient Calculations – pg 1 ESRT’s Change in field value distance Change in air pressure Distance (use map scale) Gradient = = K. Corbisiero 2010

Fastest wind speed because isobars are closest together The wind is strongest between points _____ and _____ because the isobars are the __________________ together. This means there is a __________________ gradient. A Fastest wind speed because isobars are closest together B Closest Steep Wind blows from HIGH to LOW! Calculate the gradient between points A & B: 1008 – 992 mb 35 miles Change in air pressure Distance (use map scale) G = = = 0.46 mb/mile K. Corbisiero 2010

Temperature & Moisture Content Air Masses: Large body of air that gets its temperature and moisture content from the location it formed over. Page 13 ESRT’s Temperature & Moisture Content Dry and very cool Dry and cool Dry and warm Moist and warm Moist and cool Note: A = Arctic – forms near the poles P = Polar – forms in the north T = Tropical – forms near the equator c = Continental – forms over a continent m = Maritime – forms over an ocean K. Corbisiero 2010

NOTE: cA is NOT on this map mP mP cP cT mT mT NOTE: cA is NOT on this map K. Corbisiero 2010

West Coast East Coast General Direction of Air Movement Across the US: General Direction of Weather in NYS is Northeast K. Corbisiero 2010

cP cP mT Fronts Page 13 ESRT’s Fronts are boundaries between two different air masses. At frontal boundaries clouds form and precipitation occurs (rain in shaded area). Page 13 ESRT’s cP cP mT On the diagram to the left: Label the cP and mT air masses. Draw an arrow showing the direction the system is moving. K. Corbisiero 2010

cP cP mT Warm (mT) Cold (cP) Cold (cP) Rain at the fronts K. Corbisiero 2010

Drop the decimal and keep the last three digits. Air Pressure Encoding 1020.1 mb = 201 Drop the decimal and keep the last three digits. Air Pressure Decoding 088 = 1008.8 Put the decimal in the tenths place. Add either a 10 or a 9 to the front. It must be a pressure on the conversion chart! See that there is no such pressure as 908.8? So you know you have to use 10. K. Corbisiero 2010

Station Models Page 13 ESRT’s K. Corbisiero 2010

Temp = _______________ Dewpoint = ____________ Pressure = ____________ Cloud cover = __________ Wind Speed = __________ Wind Direction = ________ Winter (temp is low) Temp = 87F Dewpoint = 78F Pressure 1015.0 mb Cloud cover 25% Wind Speed = 5 knots Wind Direction = SW Summer (temp is high) 87 150 996 78 Best chance of precipitation: 100% Cloud Cover Temperature and Dewpoint are very close (30 and 29!) Low pressure! 30°F 29°F 999.6 mb 100% 20 knots NE BONUS: Which station is summer and which is winter? Which one has the best chance of precipitation (give three reasons why!) K. Corbisiero 2010

Long term weather conditions over a large area (year to year) Climate Long term weather conditions over a large area (year to year) Weather Short term conditions over a small area and a short time (day to day) K. Corbisiero 2010

Factors Affecting Climate Latitude – The most important factor! The coldest climates are located near the ______________ while the warmest climates are located near the _______________. Poles Equator Warm Cold K. Corbisiero 2010

Even at the equator there is snow on the top of the mountains! Elevation – The height of a location above sea level. Locations with a high elevation above sea level are __________________. This is why you can find snow on the tops of mountains! Cold Even at the equator there is snow on the top of the mountains! Cold at the tops of mountains Equator – hot at surface K. Corbisiero 2010

Rising air that expands, cools, and condenses Windward Side Topography – Mountains – Mountains are barriers that can block circulation. They have the ability to modify climate patterns. The side the wind comes from is the windward. Rising air that expands, cools, and condenses Windward Side Lush vegetation Leeward side deserts Rain on windward side only K. Corbisiero 2010

Rainforests near equator Planetary Wind & Moisture Belts – When rising air is cooled by adiabatic expansion, moisture is released. These latitudes, such as the equator, have a lot of precipitation. These areas have very humid climates (rain forests) At latitudes of about 20 to 30 degrees, there are sinking high pressure systems being warmed. This is where many (not all) deserts are located. These areas are arid (deserts) Deserts at 30°N Rainforests near equator Deserts at 30°S K. Corbisiero 2010

Ocean Currents – An ocean current is a stream of water that circulates through the ocean. Air above the ocean current is affected by the temperature of the water – cooler currents cool the air while warm currents warm the air. The East coast of the USA has a warm current and the West coast has a cool current. At the same latitude, the East coast will have warmer temperatures than the West coast. K. Corbisiero 2010

Nearness to Large bodies of Water (Inland vs. Coastal) – Because of waters specific heat, it cools down slowly and heats up slowly. This causes locations near the ocean or other bodies of water to have a more moderate (small temperature range – cooler in summer and warmer in winter) than inland (continental) locations. Continental locations will experience large seasonal temperature variations. Note – Inland means far away from the coastline where oceans are Coastal means next to oceans or large bodies of water like the Great Lakes Inland location Warmer summers And cooler winters (larger temp range) Coastal location Cooler summers And warmer winters (small temp range) K. Corbisiero 2010

(shortwave) Radiation Climate Change Global Cooling Caused by pollutants, dust, or ash in the atmosphere blocking the infrared radiation from reaching the Earth. A volcanic eruption can cause this. Global Warming Caused by the gases carbon dioxide and methane in the atmosphere. They absorb the infrared radiation. The are released by burning fossil fuels. Greenhouse Effect Incoming Infrared (shortwave) Radiation Shortwave infrared radiation enters the greenhouse and is absorbed. Long wave heat is re-radiated and unable to escape out through the glass. It gets trapped inside so it gets really really hot! K. Corbisiero 2010

Too much UV is BAD for you! Ozone A layer of ozone in the stratosphere that blocks the Suns ultraviolet radiation (which causes skin cancer) from reaching the surface of Earth. A hole in the layer is allowing too much UV reach Earth. Has NOTHING to do with global warming or cooling! Too much UV is BAD for you! Always wear sunscreen when outdoors! Even on a cloudy day! K. Corbisiero 2010

The End