Ecology - Ch 2 Flashcards
Define climate.
Climate is the long-term average pattern of weather and may be local, regional, or global.
Define weather.
The combination of temperature, humidity, precipitation, wind, cloudiness, and other atmospheric conditions occurring at a specific place and time.
What differentiates climate from weather?
Climate is the aspect of the physical environment that most influences a particular ecosystem by placing the greatest constraint on organisms.
Why does the solar radiation that reaches earth varies with latitude?
At higher latitudes, solar radiation hits the surface at a steeper angle, spreading sunlight over a larger area. in addition, solar radiation that penetrates the atmosphere at a steep angle must travel through a deeper layer of air. in the process, it encounters more particles in the atmosphere, which reflect more of the shortwave radiation back into space. The result is a distinct gradient of decreasing mean annual temperature from the equator toward the poles.
Why does Earth experience seasons?
Earth’s axis of spin is tilted by an angle of 23.5 degrees. As a result, as the sun follows its elliptical orbit around the sun, the location on the surface where the sun is directly overhead at midday migrates between 23.5 degrees N and 23.5 degrees S latitude over the course of the year.
What is the coriolis effect? How does it affect both the atmosphere and the oceans?
The coriolis effect is the deflection in the pattern of global air flow; air masses in the northern hemisphere are deflected to the right (clockwise). Air masses in the southern hemisphere are deflected to the left (counterclockwise).
Describe the relationship between temperature and saturation vapour pressure.
Saturation vapour pressure varies with temperature, increasing as air temperature increases. Warm air has a greater capacity for water vapour than does cold air.
How does mean annual precipitation vary spatially, temporally, and with topography?
Precipitation is highest in the region of the equator, declining as one moves north and south. Two troughs occur in the mid latitudes interrupting the general patterns of decline in precipitation from the equator toward the poles. As the warm trade winds move across the tropical oceans, they gather moisture. The narrow region where the trade winds meet is the ITCZ, characterized by high amounts of precipitation. Where two air masses meet, air piles up, and the warm humid air rises and cools. When the dew point is reached, clouds form, and precipitation falls as rain. This causes the high precipitation in the tropical regions of eastern Asia, Africa, and South and Central America. The ascending air mass continues to cool as it splits and moves northward and southward. In the region of the subtropical high, where the cool air descends, two belts of dry climate encircle the globe. The descending air warms. In those belts, the world’s major deserts have formed. Moving north and south, they once again draw moisture from the surface, but to a lesser degree because of the cooler surface conditions. Moving poleward, they encounter cold air masses originating at the poles. Where the surface air masses converge and rise, the ascending air mass cools and the precipitation occurs. From this point on to the poles, the cold temperature and associated low-saturation vapour pressure function to restrict precipitation.
What factors affect microclimate?
- Proximity to the coastline. Areas farther from the coast, there is a greater seasonal variation in temperature. Closer to the coast, there is a smaller variation in temperature.
- Mountainous topography influences local and regional patterns of climate. Temperature decreases as altitude increases (the lapse rate).
- Variability in climate systems influences local and regional patterns of climate.
What is the correlation between atmospheric CO2 concentration and observed increases in global temperature?
As atmospheric CO2 concentrations increase, so does the global temperature.
What is adiabatic cooling?
The process of reducing heat through a change in air pressure caused by volume expansion.
What is atmospheric pressure?
Pressure within the atmosphere of earth.
What is the dew point?
For a given water content of a parcel of air (vapour pressure), the temperature at which saturation vapour pressure is achieved is called the dew point temperature.
What is condensation?
The process by which water vapour becomes liquid.
What is El Niño-Southern Oscillation (ENSO)?
A global event arising from large-scale interaction between the ocean and the atmosphere. The southern oscillation is an oscillation in the surface pressure between the southeastern tropical pacific and the australian-indonesian regions. When the waters of the eastern pacific are abnormally warm, sea level pressures drops in the eastern pacific and rises in the west. This is accompanied by a weakening of the low-latitude easterly trades.
