Chemical Cycling Concepts

Question 1

Biogeochemical Cycles

Answer 1

Chemicals and reservoirs, transfer between flux.

Question 2

Reservoirs

Answer 2

oceans, lakes, ice, atmosphere 10^6 km3

Question 3

Fluxes

Answer 3

Evaporation, precipitation, discharge 10^6 km yr-1

Question 4

Steady State

Answer 4

Total input = total output, out of balance = level changes

Question 5

Residence time, t

Answer 5

Average time molecule stays in reservoir. T=reservoir content (size)/ total influx (in or out)

Question 6

Natural Mixing Times

Answer 6

Fluids which circulate the globe

Question 7

Atmospheric water

Answer 7

residence t less than mixing time => variable H2O conc. in space predicted

Question 8

More residence t than mixing time

Answer 8

More homogenous concentration

Question 9

Biogeochemical cycles can…

Answer 9

estimate size, fluxes, residence time, dispersion patterns by research and measurement

Question 10

Problems

Answer 10

Assesments - reservoir size, flux size, not easily measured physically, omit important fluxes, measurement disagreement