EE.18 Flashcards
(30 cards)
what is the primary driver of biological processes?
solar radiation
what do global air circulation and oceanic currents have major impacts on?
ecological processes which can result in droughts, flooding, and swings in marine productivity
what are the key features of the worlds climates?
Latitude
Maritime or continental influence
altitude
aspect
How does a change in latitude affect the environment?
the intensity of solar radiation is inversely proportional to the cosine of the latitude, therefore at higher latitudes the solar radiation intensity decreases. As solar radiation is the primary driver of biological processes, this has a major impact on the enviroment, in general reducing productivity.
why is latitude important?
latitude affects both radiation and the seasonality, it initiates fundamental circulation. Causing the temperature to be much hotter at the equator than at the poles, and therefore impacting on where air rises, and where air falls
what is the difference between horse latitudes and frontal systems?
at horse latitudes, which are found closer to the equator, the colder air is falling and moves in opposite direction to each other, whereas in frontal systems, closer to the poles, you get two air “fronts” moving towards one another
where do you find the hadley cells?
there are two 0 - 30 degrees above and below the equator. the hot air rises at the equator and falls down back tog ground surface at around 30 degrees north and south, creating a cyclic air flow.
how do you describe direction of wind?
from where the wind is coming from, not the direction it is going
Coriolis forces
the speed of the atmosphere at different latitudes changes, it is much faster at the equator (1000mph) than in britain (700mph). therfore air flowing away from the equator will be moving over slower ground. air flowing north defelcts east, and air flowing south deflects west
give an outline of the global wind patterns
starting at the equator, you have the NE trade winds 0-30 degrees N, and the SE trade winds 0-30 degrees S. at 30 -60 degrees N and S you find westerly winds. and polar easterlies at each of the poles
what causes the seasons?
the elliptical orbit of the earth around the sun
what are the three main long term cycles affecting the climate of the earth?
Orbital cycles
Cycles of earths axis tilt
Sun spot cycles
how can orbital cycles affect the earths climate?
also known as Milankovitch cycles, they can be about 95,000 yr long, and generate long term cycles such as glacial and pluvial interglacial periods
How long is a sun spot cycle?
11 years
Dry adiabatic lapse rate
as air rises it expands, and thos expantion results in a loss of energy and so heat, the tmperature falls 10 degrees C every Km vertical rise
what is the difference between the dry adiabatic lapse rate and the moist abiabatic lapse rate?
the temperature drops 10 degrees with every Km rise in the dry lapse, where as for the moist lapse rate as the air cools it gains some heat as condensation and therefore the temperature only falls 6 degrees with every km rise.
what drives oceanic currents?
oceanic currents are driven primarily by prevailing winds . wind patterns are driven by solar radiation and the earth spinning around.
what are the impacts of oceanic currents?
the currents impact majorly on sea temperatures, and therefore terrestrial weather patterns
why is the sea level higher on the Caribbean side than the panama side of america?
because of the direction of the prevailing winds, which push masses of sea water up against continents
what is the El Nino effect?
el nino reverses the current, causing flooding in peru and nutrient poor warm water upwellings, in south east Asia the climate is much drier resulting in droughts and fires
why does the ocean act as a heat sink?
water has a high latent heat and can therefore act as both a sink and a radiator, as it can absorb and release relatively large amount of heat into the atmosphere without itself changing temperature
how do continents affect winter temperatures?
snow cover increases the albedo affect
cold artic temperatures in winter spread over into asia and north america
high pressures over continetal interiors cause cold air to flow towards the oceans
how does the affect of aspect change with latitude?
at higher latitudes aspect is amplified
where is rainfall lowest in the world?
at the poles, and then after that at the horse shoe latitudes
