BIO 373 1st Edition Lecture 3 Outline of Last Lecture I Physical Environment a Case study b Climate i Temperature ii Precipitation iii Winds iv Other factors c Surface Winds i Currents ii Salinity levels iii upwelling Outline of Current Lecture I Regional Climates a Elevation and precipitation b Deforestation II Climate variation a Intertropical convergence zone b El Nino Souther Oscillation c La nina d Pacific Decadal Oscillation e Long term climate variation III The chemical environment a Salinity b Oxygen availability Current Lecture Regional Climates Regional climates reflects the influence of distribution of oceans continents mountains and vegetation Elevation and precipitation o Rain shadow effect These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Mountains influence patterns of wind and temperature gradients and precipitation Side of mountain with prevailing winds get little rain Windward side gets more rain because wind carries the moisture from oceanic currents Deforestation o Influence of vegetation on climate Increase loss of solar radiation due to reflection Higher sensible heat loss due to convection Decrease loss of energy due to decreased evapotranspiration due to lack of plants Decrease water available for precipitation Climate Variation Seasonal and long term associated with changes in Earth s position relative to the sun o Due to solar radiation differences from summer to winter Variation is greater in continental land masses o Less continental land mass greater effect of water bodies water s high specific heat more resistant to temperature change Intertropical convergence zone ITCZ o Wet and dry season in this zone o ITCZ shifts north in June and south in December o ITCZ warmer temperature increase radiation due to angle of Earth and angle of sun more precipitation El Nino Southern Oscillation ENSO events o Occurs every 3 8 years and lasts about 18 months o Shifts on pressure cells between western and eastern Pacific Positions of high and low pressure systems switch Trade winds weaken less upwelling Less fish because of this fisherman usually notice the effects of El Nino first o La nina typically after El nino Pacific Decadal Oscillation o 20 30 year periods o Shift in water surface temperature in Northern Hemisphere Long term climate variation millions of years o Associated with variation in Earth s orbital pattern Circular versus elliptical pattern Changes over 100 000 year period Shift in tilt of axis 23 24 5 degrees Celestial stars can also change orbit The Chemical Environment Influences salinity acidity and oxygen availability o Biological function Salinity more organic acids in areas of high salinity Oxygen availability pH differences can effect metabolic pathways o Relatively consistent in atmosphere o Elevation increase elevation decrease oxygen o Oxygen not very available in water lower concentration or soil
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