Diurnal (daily) Changes –
Water = Low temps reduce evapotranspiration at night. Convection rainfall significant in
Tropical convectional storms occurs during the day.
Carbon = Daytime photosynthesis by terrestrial vegetation and phytoplankton. Flux reversed
at night.
Seasonal Changes –
Water = Controlled by variations in intensity of solar radiation. Impacts evapotranspiration
and precipitation. In summer, low land areas may lose 80% of precipitation to
evapotranspiration.
Carbon = Changes in NPP driven by mid and high latitudes, photoperiod and temperature.
Norther Hemisphere summer trees in full foliage so rapid photosynthesis creates new flow
of CO2 to atmosphere. Boreal temperate forests extract CO2 in growing season. Winter
natural decomposition releases CO2. Increased photoperiod stimulates photosynthetic
activity in marine life and creates algal blooms.
