Thunderstorms and Hurricanes: Formation, Stages, and Characteristics, Quizzes of Geography

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TERM 1 thunderstorms DEFINITION 1 a storm characterized by cumulonimbus (cn) clouds and accompanied by lighting and thunder lasts 2-4 hours strong wind gusts, heavy rain, some hail and tornados TERM 2 thunderstorm formation requirements DEFINITION 2 warm, moist air releases latent energy when lifted to providebuoyancyand maintain the lift high surface temperatures enhances the stability, air parcel warming and uplift TERM 3 stages of thunderstorm formation DEFINITION 3 cumulous stage build up of cumulous clouds fueled by updrafts of warm, moist air; droplet formation by both Bergeron and Collision Coalescence processes mature stage raindrops start to fall initiating downdrafts. process of entrainment the influx of cool, drysurroundingair helping to fuel the downdrafts; heavy rains, lightning and thunder and often hail during this stage dissipating stage downdrafts dominate, rain lessens, cooling occurs, storm breaks up TERM 4 locations of thunderstorm occurrence DEFINITION 4 can occur in most parts of the world: tropical areas along the ITCZ, rocky mountains,florida has the highest incidence (number of days per year)THE GREAT PLAINS isthe region with the greatest number per year TERM 5 derechos DEFINITION 5 stronger linear or "straight line" winds produced by a thunderstorm winds in excess of 58 mph and may reach speeds of over 100 mph result of downdrafts from the thunderstorm rushing out of the bottom and out ahead of the storm most derecho outbreaks occur between may and august in the upper midwest with a smaller peak in the southern us from september through april TERM 6 microbursts DEFINITION 6 small, severe downbursts are also a potential problem of thunderstorms. their wind shear is capable of causing damage to a plane, or causing it to crash TERM 7 lightning DEFINITION 7 flash of light generated by the flow of electrons between oppositely charged parts of a cloud or between the cloud and the ground TERM 8 causes for lightning DEFINITION 8 charges separated within the cloud as the thunderstorm develops positive charges near the top, negative charges at the base lightning is the clouds way of = out the charge difference after charge difference builds up millions or hundreds of millions, a lightning stroke occurs to discharge the negative base can do this by: within the cloud lightning, cloud to cloud lightning, cloud to ground lightning TERM 9 lightning stroke (cloud-to-ground lightning) DEFINITION 9 an invisible step leader ofelectronsis formed from the cloud base to the ground then the path is illuminated as the electrons move back cloud ward in the return stroke the first stroke is often followed by 3 or 4 more strokes within .2 seconds making the single flash that is seen TERM 10 ball lightning DEFINITION 10 a round, glowing mass of electrified air (size of a basketball) lasting around 15 seconds TERM 21 Hurricanes DEFINITION 21 an intense tropical cyclonic stormconsisting of a warm- core low pressure cell at its center, inward spiraling rainbands, and having sustained winds in excess of 119 kph (74 mph) TERM 22 Hurricanes have different names DEFINITION 22 Hurricane: Atlantic Ocean and Eastern Pacific OceanTyphoon: western pacific oceanCyclone: indian ocean TERM 23 Characteristics DEFINITION 23 cyclonic storm with warm-core low pressure at its center diameter of 160-960 km; avg = 600 km (360 mi) forms over warm ocean waters strong pressure gradient to generate strong winds; stronges near the center, in the eye wall, and decreases outward may have tornadoes within in; heavy rain/lightning have an average life span from 7-10 days, but may last over two weeks TERM 24 Requirements for Formation DEFINITION 24 1) Warm most air: yields greater instability and lift 2) Ocean water Temperatures > 27 degrees Celsius (81 degrees F): this is the systems fuel source 3) Uplift initiated by an easterly wave (trade winds at the ITCZ) 4)Must form between 5degrees- 20degrees latitude for sufficient Coriolis Force to initiate rotation TERM 25 Life of a Hurricane DEFINITION 25 1) Tropical disturbance: the initial mass of thunderstorms with weak, if any, cyclonic circulation* usually originate in conjunction with an easterly wave which is a large undulation or ripple in the normal trade wind pattern 2) Tropical depression: stronger cyclonic circulation, greater development *sustained winds near the center of the system between 25-37 mph (40-61 kph) *at this stage it is given a number 3) Tropical storm: 4) Hurricane: fully developed with strong cyclonic circulation, a distinct center or eye, eye wall and spiral rain bands TERM 26 Parts of a Hurricane DEFINITION 26 1) Eye: Eye, Eye Wall, Spiral Rain Bands 2) Eye Wall: center of low pressure, usually calm winds with weak downdrafts 2)Collar clouds: 3) Spiral bands:primarily stratus and nimbostratus clouds, with light to moderate rain Often find T-Storms imbedded with these bands Largest part of the storm in terms of areal coverage TERM 27 Destruction DEFINITION 27 1) From strong, fast winds; also tornadoes within the system; even tropical storm strength winds can do damage 2) Storm surge --- abnormal rise of sea level along the coast, & high waves as a result of the strong winds and low pressure associated with the hurricane*most severe on the right side of the storm as it makes landfall, because the winds here are blowing onshore and thus pushing even more water against the coastline 3) Flooding --- due to heavy rains and the storm surge TERM 28 2 primary ocean movements DEFINITION 28 currents upwelling TERM 29 ocean currents DEFINITION 29 the horizontal movement of ocean water, primarily at the surface --instrumental in the transfer of heat energy from the topics towards the Poles, and vice versa --they are driven by surface winds, which essentially drag the water along TERM 30 ocean currents 2 DEFINITION 30 * the speed is greatest at the surface & decreases with depth, with the influence of the wind essentially zero at about 100m * the direction is also governed by surface wind directions; comparing generalized global wind patterns to ocean current movements bears this out: TERM 31 ocean currents 3 DEFINITION 31 --- N & S Equatorial currents are moved by the Trade winds -- Gulf Stream & Kuroshio(Japan) currents by the Westerlies * but not directly; Currents flow at a 45 angle to the wind direction & like wind are deflected by Coriolis force to the right(or left);this curving increases with depth and at about 100 m depth the flow is almost 180 degrees to that surface TERM 32 Ekman Spiral DEFINITION 32 *will affect land temperature based on the temperature of the current -- warm current will keep the land area a little warmer in winter & a cold current will often keep the land area a little cooler in summer will affect precipitation amounts as well: warm currents usually result in higher amounts and cold currents usually result in lower amounts; but this can be complex -- warm current vs cold current; but this can be complex TERM 33 Upwelling DEFINITION 33 -the vertical movement of water within the ocean, between the surface and great depth -- the result of warmer surface water often being pushed seaward, (away from land), & replaced by colder water from depth; the surface water may be blown 'out to sea' by winds, or by the Ekman spiraleffect around areas of surface high pressure(atmo) --this often causes cooler temperatures on adjacent land surfaces -- but does increase nutrient supply at the surface, increasing the abundance of sea life (plankton, fish, etc) TERM 34 El Nio/Southern Oscillation (ENSO) Event DEFINITION 34 a combination of twoevents whichsometimes happen in the same years. TERM 35 El Nio DEFINITION 35 a southerly-flowing warm ocean current that generally develops off the coast of Ecuador and Peru around Christmastime and may last for several months * named "the boy child" or "little boy" after the Christ child because of its timing around Christmas * today it has a broader meaning which encompasses the change in weather this reversal in currents may induce TERM 46 La Nia DEFINITION 46 a condition when sea surface temperatures are cooler than normal in the eastern Pacific and this cool water extends farther westward than usual *sometimes referred to as the anti-el Nino or cold phase of an enso * they don't always follow an ENSO or El Nio event * they don't seem to have as distinct a cycle as El Nios TERM 47 La Nina impact on climate DEFINITION 47 *typically opposite of El Nino impacts *warmer drier winters in SE US *cooler winters in western US and Great Plains than normal * most recent events: 1984-85, 1988-89, 1998-2000 TERM 48 * Pacific Decadal Oscillation (PDO) DEFINITION 48 *Pacific Decadal Oscillation (PDO): shifting of SSTs between the northern & western Pacific and the eastern tropical Pacific Ocean * a much larger and longer-lived reversal pattern, ranging from 20-30 years TERM 49 PDO DEFINITION 49 * has awarm phase(high SSTs in the eastern tropical Pacific) and acold phase(low SSTs in the eastern tropical Pacific) * showed a fairly stable pattern from 1947 to 1976- 77 and then abruptly reversed until the late 1990s. *may also affect El Nio events,at times enhancing these impacts TERM 50 Arctic Oscillation (AO): DEFINITION 50 variation in pressure, wind and SSTs between northern polar regions and lower latitudes * in a warm phase event there is relatively low pressure over polar locations and higher-than-normal pressure at lower latitudes * as a result, cold winter air masses do not penetrate as far south in the eastern U.S., thus warmer winters * in a cold phase event the opposite conditions prevail TERM 51 North Atlantic Oscillation (NAO) DEFINITION 51 an oscillation similar to the PDO, but more closely linked to changes in the Arctic Ocean (the AO) cycle TERM 52 Weather Analysis DEFINITION 52 process of collecting, compiling, analyzing, and transmitting the observational data of atmospheric conditions. * this data & analysis is then used to forecast future weather conditions, both short-term and long-term TERM 53 The Forecast Process: DEFINITION 53 Forecasters analyze/interpret varied datasets to develop a 4- dimensional picture of the atmosphere. *Observations *Analysis *Diagnosis *Prognosis *Communication TERM 54 Types of data DEFINITION 54 *eachweather station, 10,000 around the world, collects the same dataat the same time, at least 4 times per day(0000, 0600, 1200, 1800 GMT) *mostUS stations also collect data continuously or at least every hour *anetwork of sea buoys, the Tropical Atmosphere Ocean/Triangle Trans-Ocean (TAO/TRITON) system, obtains data at sea *satelliteimages & data are also used extensively TERM 55 Data collected DEFINITION 55 :T,dpT, pressure, wind speed & direction, current& past weather (cloud cover,precip., etc) *Plottedon a station model, with each piece of data in a particularlocation on the symbol TERM 56 synoptic weather chart DEFINITION 56 chartsdrawn for various levels of the atmosphere at pressure levelsof 800mb, 700mb, 500mb, etc. *dailyweather maps are drawn for the surface & 500mb TERM 57 Weather Forecasting Methods DEFINITION 57 Synoptic Weather Forecasting,NumericalWeather Forecasting, Analog Approach/Statistical Methods,Short- Range Forecasting TERM 58 Synoptic Weather Forecasting: DEFINITION 58 *useof synoptic weather charts *forecasting what will happen in an area, based on what is happening now in an area upwind *usuallyaccurate for only a few hours or 1-2 days TERM 59 Numerical Weather Prediction(NWP DEFINITION 59 *used extensively in current forecasting for zone forecasts *useswhat is known of the physical principles of the gases of theatmosphere to predict future condition *reallyonly possible after the advent of high-speed computers & computermodels *localvariations must be added/considered TERM 60 Analog Approach or Statistical Method: DEFINITION 60 *past patterns and data are used to help forecast future weather *good for forecasting daily temperatures *usesidea that past weather & present weather may be the same undersimilar atmospheric conditions TERM 71 Climate change/variability DEFINITION 71 potential impacts on many human andnatural systems. TERM 72 Climate Change DEFINITION 72 Climate is always changing naturally. *ENSO, continental drift, orbital eccentricity, asteroid impacts, volcaniceruptions andmanymore. *Impacts of anthropogenicforcings. *Carbon emissions, land use changes, etc. TERM 73 Theory DEFINITION 73 TheEarths climate system is complex and dynamic. Must consider many spheres and scales. *Accuratemodeling of this systemmustaccommodate or approximateall coupling mechanisms involved. *Can be achieved by combining models. *Importance of anensemble approach. *MultipleGCMs and emissions scenarios. TERM 74 Dynamical Downscaling DEFINITION 74 Uses course output from a GCM or RCM to drive a model with higher resolution capabilities. TERM 75 Statistical (Empirical) DEFINITION 75 Deriving statistical relationships between large and local scale climate variables. TERM 76 what is a downscale DEFINITION 76 WhileGCM resolution is sufficient for analyzing large spatial patterns...natural and human processes are occurring at much smaller scales (e.g., convection, agriculture, river hydrology) *Complexlocal topography may exist TERM 77 Example DEFINITION 77 What are the impacts of an A2 emissions scenario on fires in Californias Santa Ana Valley? *Initializea RCM with observations, then downscale the output 5:1 using amesoscalemodel (e.g., WRF-NAM) TERM 78 Strengths DEFINITION 78 *can resolve climate variables on scales not resolvable by GCMs or RCMs *customizable for users and stakeholders TERM 79 Weaknesses DEFINITION 79 * Dynamically downscaled GCMs (RCM), can still be too course for desired output. *This often takes multiple nests and more computing power. *Takes on errors or assumptions of GCM used. TERM 80 Statistical Downscaling DEFINITION 80 Example What are the impacts of an A2 emissions scenario on fires in Californias Santa Ana Valley? *Establishempirical relationships for GCM/RCM output (predictor) and a local climate variable (predictand). TERM 81 Strengths DEFINITION 81 users are interested in output for a single point *Variable desired is not handled well by RCMs. *Can be a great tool if the predictor explains large amounts o variabilityof thepredictand. *long assessment periods TERM 82 Weaknesses DEFINITION 82 must have a good record of observations *Assumption that relationships of said variables will stay constant in future climates.