Week 3 Flashcards
What does the box represent in a box model?
Small parcel of air or the entire globe
What do we assume within a box model?
That the box is well mixed
What is another way of thinking of the lifetime t of X in the box?
The average time that a molecule of X remains in the box
Equation to workout lifetime t of X in the box
t= m/Fout+L+D
What does P represent in atmospheric box?
Chemical production
What does L represent in box model?
Chemical loss
What does E represent in box model?
Emission
What does D represent in box model?
Deposition
What is lifetime?
The average/median time that a molecule of X remains in the box
Residence time
When the loss terms are physical loss e.g. Fout or D
Generalised chemical rate constant is chemical loss rate is:
Fout+ L +D=(kout+kL+kD)=km
Chemical rate constant equation:
kout=1/tout
What is the concept of mass balance?
Mass is conserved- what is produced in one place must be lost elsewhere
Sources in a box model
Inflow (Fin), Emission and Chemical production
Sinks within box model:
Chemical loss, deposition and Outflow (Fout)
Overall Source rate Equation:
S = Fin+E+P
