Quiz 2 Short answers Use your answers of the Ekman spiral to explain your answers to a and b The surface layer of the water is being moved by the wind but it also has the coriolis force acting on it This causes the water to actually move at an angle 45 degrees not straight with the wind The layer below that one is then influenced by the layer above it as well as the coriolis force at 90 degrees This continues with each layer getting weaker and weaker as it travels down causing a net movement of 90 degrees clockwise in the northern hemisphere or 90 degrees to the right of the wind How does this explain the cold water along the shore when warmer water is just off the coast SHORE UPWELLING Since the Ekman spiral causes the water to be moving away from the shore there needs to be some way to replace the water that is moving The bottom water comes in through upwelling but it is much colder water initially since it is lower less solar rays reach it to warm it causing colder water along the shore I also drew a picture for this one What causes downdrafts in the storms Precipitation pushes the cooler air back down How does wind shear promote the growth of multicell storms Wind shear promotes the growth of multicell storms because it offsets the updraft from the downdraft so they will not interfere with each other Urban Heat Island Effect what causes it and what are some effects it has to its surroundings An increase in temperature in an urban area compared to the city s local surroundings inadvertent modification of climate by humans changing energy balance reduce nighttime cooling of the air long wave energy gains also pollution less vegetation means warm more rapidly heat island max in summer also affects precipitation 1 Feedbacks Climate feedback mechanism that is a climate response to an initial change Positive feedback amplifies initial change i e the ice albedo feedback more ice leads to a higher albedo which helps create more ice etc I think it s the opposite melting It goes both ways right Ice melting leads to more exposure of the ocean which absorbs more sunlight which warms surface temperatures which melts more ice and so on Negative feedback diminishes the initial change Water vapor feedback Humans release CO2 Temperature surface rises Water evaporates Increase of water vapor Surface temperature rises more repeat Cloud feedback increase in temperature more water vapor more clouds higher clouds will trap more heat in the earth heat more vapor more clouds positive feedback lower clouds will reflect more sunlight lower the temperature negative feedback Aerosol feedback emitted from fossil fuel s combustion erosion etc aerosols scatter reflect absorb solar and terrestrial radiation direct effect Act as cloud condensation nuclei Can change cloud properties indirect effect Trend forecasting recognizes that weather causing patterns move but assumes the following remains unchanged speed intensity size direction Now Casting forecasts a few hours in advance Persistence forecasting the weather tomorrow will be like the weather today This depends a lot on where you are in Hawaii this could work but where there are strong jet streams this will not work we know this is wrong because eventually the weather will change Climatology the weather tomorrow will be like the long term average of weather for tomorrow we know this is wrong because eventually the weather will deviate from the average Analog weather does change but it will be the same under the same kind of conditions For example you could use historical data to see how a cyclone will behave All of these methods are hit or miss and are not up to modern needs Gravity Waves air traveling over uneven terrain ie over a mountain bottom layer moves up and pushes the layers of air above it up as well Creates lines of clouds in the sky where the air travels up upward movement of air causes condensation and cloud formation Lee waves because they form on the leeward side of the mountain Can form rolls or lenticular clouds 2 Derechos severe wind storm that forms near squall lines that form along a cold front Updraft brings warm humid air downdraft spreads the cool air along the surface textbook definition Hours long windstorms associated with a line of severe thunderstorms Derechos are the result of straight line winds not the rotary winds of a tornado They are often associated with bow shaped echoes on weather radar Chinook Winds Air rushing down the downwind side of the mountain warms and dries as it sinks leading to warm surface winds textbook A dry warm wind in western North America on the lee side of the Rocky Mountains The chinook speeds the melting and evaporation of snow Small scale winds difficult to predict and track strongly affected by geography and NOT coriolis Buildings can affect wind i e wind tunnels downdraft so they will not interfere with each other Downdraft is caused by precipitation pushing the cooler air back down Thunderstorms air needs to rise for them to occur require moist air that rises crucial factors for development are temp moisture wind speed and direction from ground another factor affecting thunderstorm type is windshear change of wind speed and direction 2 basic categories ordinary and supercells multi cell storms can be a mix of both Ordinary Cell Cumulus stage is initial stage cools at dry adiabatic 10 deg C per 1km Mature stage is second stage thunderstorm begins and precipitation starts this stage produces most precipitation and lightning dissipating stage is when updraft weakens and collapses air mass thunderstorm is a single cell thunderstorm Multicell thunderstorms is single cells all at different stages difference is that this has a presence of moderate amounts of wind shear the prevents the precip from falling into the updraft and quenching it squall line individual intense thunderstorm cells usually in front of cold front Supercell thunderstorm large single cell storm requires very unstable atmosphere and strong vertical wind shear mesocyclone vertical column of rotating air inside a severe t storm tornadoes often form below 3 mesocyclones Microburst dangerous thunderstorm when rain falling evaporates underneath the cloud cooling the air below air swirls upward as a result of PGF dangerous Tornadoes high winds spiral around very narrow regions of low pressure beneath thunderstorm Tornado Formation develop underneath supercells rotating thunderstorms deda cloud base under updraft may lower forming