The pathways and processes which control the water and carbon cycle and how the vary over time Flashcards
what is convectional rainfall
-as temperature falls overnight, evapotranspiration reduces the flow of water to the atmosphere. However, this will increase as daytime temperatures, begin to rise. remember temperature is going to drive evaporation and sunlight will drive photosynthesis (thus transpiration). This means typically, in the Amazon, we get convectional rainfall occurring at 4pm in the afternoon.
why is there a diurnal pattern of carbon dioxide in the Amazon
in the day, there is a greater amount of photosynthesis, due to there being light, leading to more carbon dioxide being in the atmosphere at night (respiration and deposition also occurs, at night)
why is the diurnal change in carbon dioxide levels, more apparent in areas with lots of vegetation.
due to the plants still respiring at night, thus meaning that they are releasing carbon dioxide into the atmosphere, but they cannot reabsorb it due to photosynthesis not occurring.
what controls the season in the amazon and when will these changes be more pronounced
they are control, by the intensity of solar radiation, meaning that in the winter there is a lower rate of evapotranspiration, and in the summer there is a greater rate.
what is the relationship, between discharge and sunshine hours
the months, that have a greater level of discharge, tend to have a higher level of sunshine hours.
explain how the water cycle, will be affected during a glacial period
- most of the water will be stored in ice sheets instead of oceans, thus leading to sea level to fall by around 100-130 meters.
- lower rates of evapotranspiration, will lead to less water being transferred between the atmosphere and the oceans
how could a cooler climate affect the carbon cycle in tropical regions?
- the rate of decomposition will decrease, thus meaning that less carbon dioxide will be returned to the atmosphere
- the formation of permafrost, could lead to a decrease in photosynthesis rates, thus increasing the amount of carbon in the atmosphere, as well as more carbon being trapped in the soil.
how might evapotranspiration rates, be affected by cooler climates
- a reduction in evapotranspiration rates, as higher temperatures are needed, in order to cause water to evaporate
state 2 impacts of glaciation on the water cycle
- sea levels fall. - during the last glacial maximum , sea levels where about 120m lower
- water cycle generally slows down, as there is a significant decrease in the amount of evapotranspiration
state 2 impacts of glaciation on the carbon cycle
- increase in ice coverage, means there is less vegetation and colder climates, have reduced NPP. this means there is a reduction in the amount of carbon stored in plants
- permafrost ice cover, means colder temperatures, thus meaning less decomposition. Therefore, there is a reduction in the flow of carbon between the soil and the atmosphere.