Astronomy & Meteorology Final Exam Review PDF

Astronomy & Meteorology Final Exam Review YOUR GROUP IS RESPONSIBLE FOR CREATING SLIDES ON ALL TOPICS LISTED FOR YOUR UNIT Unit 1: History of the Universe → 6 Unit 2: Stars & Stellar Evolution → 4 Unit 3: Orbital Motion and the Sun/Earth/Moon → 6 Unit 4: Earth’s Atmosphere → 5 Unit 5: Meteorology & Climate → 6 Unit 1: History of the Universe Salomé Berger de Nomazy. Samantha Griffin, Kathryn Drzewicki, Kenzie Bologna, Nina Price The Expanse of Time- lessons 3, 4, 8 Big Bang Theory- lessons 4, 5 Redshift / Doppler Effect- lessons 4, 6 Light-Years Expanse of time - The universe began 14 billion years ago. - The scientiﬁc Ewan Hubble make a key discovery about the expanding of the universe: the further away a galaxy is from us, the faster it to be moving away galaxy - The "expanse of time" means the huge, never-ending stretch of time. It includes everything that has happened in the past, everything happening now, and everything that will happen in the future. PRACTICE QUESTION: What is important about Hubble’s discovery that there is a red shift in the spectra of galaxies? A. It proves the Big Bang theory. B. It suggests the existence of black holes. C. It suggests that the universe is expanding. D. It suggests that the universe is contracting. Why?? The red shift in galaxy spectra shows that galaxies are moving away from us. This means the universe is expanding, as their increasing distance stretches the light toward the red end of the spectrum. Expanse of time Time of the Universe Death of the Dinosaurs: Formation of the solar system: 65 millions years 4.5 billions years ago ago The big bang (beginning of Birth of life on First humans: the universe): Earth: 14 billions years ago 200,000 years ago 3,8 billions years ago Big Bang Theory Time Begins - The universe began ~13.7 BIllion years ago - The universe began as a violent expansion ~ All matter and space Georges Lemaître were created from a single point of pure energy in an instant The Big Bang Theory was ﬁrst proposed in the late 1920s by Georges Lemaître ~ It states that there was an inﬁnitely small, inﬁnitely dense point that contained everything that is the universe Big Bang Theory TImeline Several hundred thousand of years after Big 3 minutes after the Big Bang Bang - The universe has grown from the size - Atoms form (speciﬁcally Hydrogen and of an atom to larger than the size of a its isotopes with a small amount of grapefruit Helium - Energy “froze” into matter according to - The early Universe was about 75% Albert Einstein's equation (E-mc^2) Hydrogen and 25% Helium. It is still ~ This basically says that like almost the same today snowﬂakes freezing, energy forms matter into clumps and today we call Hundreds of millions of years after the Big Bang protons, neutrons, and electrons - 1st stars and galaxies form as particles/gasses - These parts later form into atoms begin collecting due to the force of gravity 4.6 billion years after the Big Bang - Our Solar System forms Big Bang Theory Evidence - The expansion of the universe ~ Many involved including George Lemaitre, who proposed the universe was expanding and in the past there was primeval “super-atom” Georges Lemaître - Edwin Hubble’s 1929 observation that galaxies were generally receding from us provided the ﬁrst clue that the Big Bang theory might be right Edwin Hubble Big Bang Theory Misconceptions - The Big Bang Theory does not explain where or how the universe originated. It is a model of what happened 1.0 x 10^-42 seconds after the Big Bang - The theory explains the history of the universe from a fraction of a second after it came into being to the present time - There was no “explosion”; there was (and continues to be) an expansion ~ Rather than imagining a balloon popping and releasing its contents, imagine a balloon expanding: an inﬁnitesimally small balloon expanding to the size of our current universe (but doing so VERY quickly!) and you can never reach the edge of the balloon. Redshift/Doppler Effect The Doppler Effect : the apparent change in the frequency of a wave caused by relative motion between the source of the wave and the observer → When an object moves away from us, the light is shifted to the red end of the spectrum. ○ The waves behind the object spread out as it moves away, and these spread out waves reach our eyes at a lower frequency, causing the red color. → When an object moves toward us, the light is shifted to the blue end of the spectrum. Absorption lines : ○ The waves in front of the object bunch up as it wavelengths of visible light moves closer, causing the waves to reach our energy that are absorbed eyes at a higher frequency, causing the blue color. allowing electrons to move up energy levels ☆ Almost every star/galaxy we can see is moving away from us, and therefore looks red due to redshift. Higher frequency —→ Lower freq. → This is evidence for the Big Bang Theory (that the Absorption spectrum universe is expanding). Redshifted: lower energy → The farther away a star/galaxy is, the faster it is moving Blueshifted: higher energy away from us, and the more it will be redshifted. Light Years Deﬁnition: A light-year is the distance light travels in a single Earth year. Light moves at a constant speed, approximately 9.5 × 1012 km, or nearly 6 trillion miles. ◆ Light-years are used as a standard of measuring vast distances in space, such as stars and galaxies. Examples: The closest star to Earth, Proxima Centauri, is about 4.24 light-years away.The Andromeda Galaxy, the nearest large galaxy, is about 2.537 million light-years away. Relation to Time: A light-year also implies looking back in time. Since light takes time to travel, observing an object 1 light-year away means you see it as it appeared 1 year ago. ◆ This is known as look-back time and helps astronomers study the early universe by observing distant galaxies and cosmic phenomena. Calculating Light-Years: As greater distances are considered, such as those beyond our solar system, another standard of measurement is necessary because even the magnitude of AU numbers can become extremely large. ◆ Distance- Speed x Time ◆ Light-year- 299,792 km/s x 31,557,600 seconds (in a year). The distance of 150 million km is designated as 1 astronomical unit (AU). Unit 2: Stars & Stellar Evolution (Brennan, Noah, Joshua, Ben) Apparent and Absolute Magnitude Hertzsprung - Russell Diagram and Analysis Life Cycle of Stars A Star’s Temperature and Luminosity Mass- Solar Mass (M☉) is the standard unit of mass in Astronomy equal How to Characterize a Star? to 2 x 1030 kg. It is equal to the mass of the Sun. 1. The Mass (Size of the Star) Temperature- Stars show different colors based on their temperature 2. Surface Temperature (How hot is the Star) contrary to belief, if a star gets redder, that means it’s colder, and if it’s 3. Luminosity (How bright is the Star?) - bluer, it’s hotter. Luminosity = the amount of energy every square meter produces multiplied by its Blue is the hottest temperature, with red being the coldest surface area temperature. Star colors in order from hottest to coldest: Blue, Blue-White, White, Yellow-White, Yellow, Orange, Red Apparent Magnitude Apparent Magnitude- The brightness of a star as it appears from earth with the naked eye. The more to the left a star or negative it is placed, the brighter it appears. For example in the picture shown, the sun is the brightest star at apparent brightness to our eyes. Absolute Magnitude Absolute Magnitude is the measure of how bright a star would be if it was 32.6 light-years from earth or 10 parsecs. *Absolute magnitude is the measure of true star luminosity. * 1 parsec = ~3.26 light years ------------------------------------------------------------------------- DISTANCE MODULUS: - M=absolute magnitude - m=apparent magnitude - Distance modulus = M-m (absolute magnitude-apparent magnitude) Larger the negative magnitude a star has, the brighter it is Larger the positive magnitude, the fainter the star Hertzsprung - Russell Diagram and Analysis The H-R Diagram describes the relationship between luminosity and temperature of stars. The model categorizes different types of stars: ○ White Dwarfs ○ Main Sequence ○ Giants ○ Supergiants Our Sun is in the Main Sequence of stars. The cooler the temperature, the more red the star, and the hotter the star the more blue. Luminosity is based on the sun, and all other stars are in magnitudes greater or less than the Sun. Luminosity is measured absolutely in the Hertzsprung-Russell Diagram. Life Cycle of Stars The mass of a star determines the fate of a star (an average mass star becomes a white dwarf, a large mass star becomes a neutron star, and a very large mass star becomes a black hole) All stars start as stellar nebula or star clouds It takes more than 10 billion years to reach dwarf star stage, more than 50 million years to reach the neutron star stage, and 5 million years to reach the black hole stage As the mass of the star increases, the lifespan of a star decreases Bigger supergiants have a greater temperature in Kelvin than other supergiants A black hole’s temperature is 0 K Unit 3: Orbital Motion and the Sun/Earth/Moon Properties of the Sun Kepler’s Laws of Planetary Motion Moon Phases Eclipses Kam, Jonathan, joey,maximus, Colin Properties of the Sun It is a yellow star but often said as an ordinary star. There are six layers-- radiative zone, convective zone, photosphere, chromosphere, and lastly the outer corona. The layer that is visible is the photosphere. Sunspots are visible on its atmosphere. They are small areas of strong magnetic forces on the sun’s surface that appear as darker spots because they are cooler. They also release solar ﬂares. They are large eruptions of electromagnetic radiation that occur near sunspots, usually at the dividing line between areas of opposite magnetic ﬁelds. Flares can cause power outages on earth due to the high amount of radiation it produces. Kepler's Laws of planetary motion Kepler's 2nd Law: A line joining the planet and the sun sweeps equal areas in equal time. Kepler's 3rd Law: A planet’s orbital period squared is proportional to the distance to the Sun cubed = P2 = D3 Therefore, the farther a planet is from the Sun, the longer the period of revolution. Moon Phases There are 9 phases of the moon showing different parts of the moon at different times of the year. There's the new moon,waxing crescent, ﬁrst quarter, waxing gibbous, full moon, waning gibbous, third quarter, waning crescent and then back to new moon. Eclipses There are two different types of eclipse, Solar and Lunar. A solar eclipse occurs when the moon crosses in between the Sun and Earth, and it casts its shadow upon the Earth. A lunar Eclipse occurs when the Earth casts its shadow upon the Moon. In an area that is experiencing a total eclipse, the light from the sun will completely be blocked out. Unit 4: Earth’s Atmosphere - Why are there seasons? As the earth spins on its axis, producing night and day, it also moves about the sun in an elliptical orbit. The earth's spin axis is tilted with respect to its orbital plane. This is what causes the seasons. When the earth's axis points towards the sun, it is summer for that hemisphere. When the earth's axis points away, winter is expected. Since the tilt of the axis is 23 1/2 degrees, the North Pole never points directly at the Sun, but on the summer solstice it points as close as it can, and on the winter solstice as far as it can. Midway between these two times, in spring and autumn, the spin axis of the earth points 90 degrees away from the sun. This means that on this date, day and night have about the same length: 12 hours each, more or less. So essentially, seasons depend on the orbit and tilt of the Earth around the sun. Atmosphere Composition / Layer Thermosphere:Altitude: Extends Troposphere:Altitude: Extends from Stratosphere:Altitude: Extends from Mesosphere:Altitude:Extends from from the top of the mesosphere to Exosphere:Altitude: Extends from the the Earth's surface to about 10-12 the top of thetroposphere to about 50 the top of the stratosphere to about about 600 kilometers (372 miles). top of the thermosphere to about 10,000 kilometers (6-7 miles). kilometers (31 miles). 85 kilometers (53 miles). Temperature: Increases kilometers (6,200 miles). Temperature: Decreases with Temperature: Increases with altitude Temperature:Decreases with altitude, dramatically with altitude due to the Temperature: Very high, but the gas is altitude. due to the absorption of ultraviolet radiation by ozone. Characteristics: reaching the coldest temperatures in absorption of high-energy solar so thin that it doesn't feel hot. Characteristics: Contains most of the Earth's weather, including Contains the ozone layer, which the atmosphere. radiation. Characteristics: The Characteristics: The outermost layer clouds, rain, and storms. It's where protects us from harmful UV Characteristics: Meteors burn up in International Space Station orbits in where atoms and molecules can escape we live and breathe. radiation. It's also where commercial this layer, creating shooting stars. this layer. It's also where the aurora into space. airplanes ﬂy. borealis (northern lights) occurs. Unit 4: Earth’s Atmosphere Air Pressure and Wind ○ What types of weather are associated with each pressure system? High pressure: dry conditions, clear skies. Low pressure: cloudy/rainy. Air sinks and moves outward on the surface while vertically the air is also descending, leading to a subsidence pattern with clear skies and low cloud formation. ○ What causes winds? Pressure gradients cause air to move. The main reason we have winds is because of the constant changes in pressure. ○ The pressure always points from high to low pressure. Air moves from areas of high pressure to areas of low pressure. ○ Isobars: H: When isobars increase toward a central area with closed isobars surrounding the area of highest pressure. Air is more dense, therefore it sinks and spreads out. L: When isobars decrease toward a central area with closed isobars surrounding the area of lowest pressure. Air is less dense, therefore it rises and more air is pulled inward to replace. Unit 4: Earth’s Atmosphere Global Wind Patterns In the United States (north of the 30° N latitude line), the prevailing winds blow from west to east Winds always blow from high pressure toward low pressure, and they curve due to the Coriolis effect Along the equator, the air mostly rises because it is a low-pressure zone Air rises in certain areas because gravity pulls low-pressure air towards the surface of the earth and pushes high-pressure air away (rising) Winds to be deﬂected to the right or the left as they ﬂow from high pressure to low pressure due to the rotation of the earth Most of the United States is within the westerlies wind belt. It inﬂuences our typical weather patterns in Michigan because most of our wind ﬂows from west to east Unit 4: Earth’s Atmosphere Global Wind Patterns The Earth’s surface is constantly being heated by energy from the sun. Because tropical regions are warmed more effectively than polar regions, differences in atmospheric pressure develop between these latitude extremes. Such pressure differences result in planet-wide winds. Air heated at the surface in the lower latitudes is lifted and replaced by cooler, denser air ﬂowing from the higher latitudes. If the Earth did not rotate, if it was not inclined on its axis, and if the surface was uniform throughout, planetary atmospheric circulation would probably be relatively simple. Alas, such is not the case! In fact, global wind systems are extremely complex, and details of worldwide wind patterns are still not clearly understood by earth scientists. However, basic circulation patterns recognized by scientists do exist, and they are used to help understand certain worldwide climate and weather patterns. The purpose of this activity is to examine the location and extent of some of the general planetary wind and pressure systems that are currently recognized by earth scientists. In order to complete this activity, you will need to keep three facts in mind 1. Air tends to ﬂow out of regions characterized by relatively high pressure and into regions characterized by relative low pressure. 2. Because of the Earth’s rotation, winds tend to be deﬂected or directed toward the right in the Northern Hemisphere and toward the left in the Southern Hemisphere. 3. Winds are named for the direction from which they originate. For example, a north wind is one that ﬂows from the north. Unit 4: Earth’s Atmosphere Coriolis Effect Coriolis Effect In the Northern Hemisphere, objects are deﬂected to the right of their direction of motion. In the Southern Hemisphere, objects are deﬂected to the left. It inﬂuences wind patterns and contributes to the rotation of large-scale weather systems, like cyclones and hurricanes (counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere) How does it inﬂuence pressure centers and winds in general in the Northern hemisphere? In the Northern Hemisphere, the Coriolis effect causes winds to be deﬂected to the right, resulting in counterclockwise circulation around low-pressure centers and clockwise circulation around high-pressure centers Unit 5: Meteorology and Climate Humidity / Psychrometer Weather Station Models Frontal Boundaries & Air Masses Analyzing Weather Maps Hurricane Development / Motion Brody jennings Cooper sieving Elizabeth Litogot James kavanaugh Humidity Humidity Psychrometer Specific humidity is the amount of water vapor that is A psychrometer is a measuring tool that uses two thermometers. actually in the air while relative humidity is the amount One thermometer measures the current air temperature. The of moisture in the air compared to the maximum the air other thermometer measure the temperature as the water can hold. Specific humidity is how many grams of evaporates. Using these two temperatures you can find the water vapor per kg of air. To calculate relative humidity difference between the two and that is the wet bulb depression, you take the amount of water vapor in the air divided by using a chart you can find the relative humidity. the maximum the air can hold and times it by 100. Ex. if the dry bulb temperature is 20 degrees celsius and the welb bulb temperature is 16 degree celsius what is the relative Ex. If the amount of water humidity? vapor in the air is 5g/kg and the maximum is 10 g/kg what 20 - 16 = 4 is the relative humidity? Go to where it says “difference between 5/10 x 100= 50% wet and dry bulb Temperature” Go to where it say 4 Dew point : the temperature when air reaches 100% degrees celsius and go down until you reach the 20 degrees humidity. The closer this temperature is to the actual celsius row there is your relative humidity. temperature the higher the humidity Weather Station Models Weather station models are used to easily convey weather data on maps and not take up as much space. Calculating: Air pressure if the three digits on the station model are less than 500 you place a 10 in front of them if it is More than 500 than you place Temperature Cloud Air Pressure a nine before the number. cover 997 -> 99.7 -> 999.7 352 -> 35.2 -> 105.2 Change in Visibility and pressure weather Dewpoint Precipitation (in) Wind Speed And Direction Unit 5: Frontal boundaries & air masses Air masses can stay in the same space for days or weeks Air masses are large area of the troposphere that is the same in temperature and humidity Continental Tropical is an air mass that forms in the south west us in the summer Maritime Tropical is an air mass that forms from the gulf of mexico, paciﬁc ocean, and atlantic ocean. Warm fronts is where warm air is pushing cold air bring warm air and humidity Hurricane Development / Motion Normally, an ocean temperature of 26.5 °C (79.7 °F) spanning through at least a 50-metre depth is Coriolis force considered the minimum to maintain a tropical A minimum distance of 500 km (310 mi) from the cyclone.This value is well above 16.1 °C (60.9 °F), the equator) is normally needed for tropical cyclogenesis. global average surface temperature of the oceans The Coriolis force is how the winds rotate towards Tropical cyclones are known to form even when The low pressure centre normal conditions are not met. For example, cooler air It happens do to earths rotation Schema temperatures at a higher altitude (e.g., at the 500 hPa around level, or 5.9 km) can lead to tropical cyclogenesis at this cas winds lower water temperatures, as a certain lapse rate is the Nort required to force the atmosphere to be unstable pressure enough for convection. In a moist atmosphere, this represe hat Coriolis lapse rate is 6.5 °C/km, while in an atmosphere with the perpend less than 100% relative humidity, the required lapse red arro reate rate is 9.8 °C/km. Heres a Demostration ay lead Hurricane Development / Motion Low level disturbance Part 2 Whether it be a depression in the Intertropical Convergence Zone (ITCZ), a tropical wave, a broad surface front, or an outflow boundary, a low-level feature with sufficient vorticity and convergence is required to begin tropical cyclogenesis. Weak vertical wind shear Vertical wind shear of less than 10 m/s (20 kt, 22 mph) between the surface and the tropopause is favored for tropical cyclone development. Weaker vertical shear makes the storm grow faster vertically into the air, which helps the storm develop and become stronger. If the vertical shear is too strong, the storm cannot rise to its full potential and its energy becomes spread out over too large of an area for the storm to strengthen. Strong wind shear can "blow" the tropical cyclone apart Unit 5: Analyzing Weather Maps Weather Maps give us information about the current weather conditions of certain areas using terms like “Cold fronts”, “Warm fronts, Maritime and polar tropicals. Weather maps also show High and low pressure areas. To read a Weather map, you need to understand the symbols used in said weather map. When a line uses spikes, it signiﬁes a cold front is moving in. When a line has half circles, that signiﬁes a warm front moving in. If a line has both half circles and spikes, it means its stationary Weather maps are very useful to weathermen because it can help accurately predict not only what weather you should expect, but show low and high pressure areas

Astronomy & Meteorology Final Exam Review PDF

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