Atmospheric composition
Atmospheric Composition
Composition of the atmosphere Gas %o by volume 78.08 02 20.95 Ar 0.93 Dry air C02 0.03 All other gases(Ne, He, 0.01 Kr, h, etc) Water Variable
Composition of the atmosphere Gas % by volume N2 78.08 O2 20.95 Ar 0.93 CO2 0.03 All other gases (Ne, He, Kr, H, etc) 0.01 Water Variable Dry air
Water vapor in the air The %volume of Water vapor is variable depending on temperature, precipitation rate of evaporation and other factors at a particular location The percentage of water vapor ranges from 0.1 5%. Generally it is 1-3%(the 3rd most abundant constituents in the air)
Water vapor in the air • The % volume of Water vapor is variable, depending on temperature, precipitation, rate of evaporation and other factors at a particular location. • The percentage of water vapor ranges from 0.1- 5%. Generally it is 1-3% (the 3rd most abundant constituents in the air)
Expressing the amount of substances in the atmosphere Concentration the amount(mass, moles, molecules, etc) of a substance in a given volume divided by that volume. The example concentration units are mg/m3 mol/m3 molecules /cc, and etc Mixing ratio the ratio of the amount of the substance in a given volume to the total amount of all constituents in that volume
Expressing the amount of substances in the atmosphere • Concentration – the amount (mass, moles, molecules, etc) of a substance in a given volume divided by that volume. – The example concentration units are mg/m3 , mol/m3 , molecules/cc, and etc. • Mixing ratio – the ratio of the amount of the substance in a given volume to the total amount of all constituents in that volume
Mixing ratio total n; is the molar concentration of /and nota is the total molar concentration of air. parts per million(ppm) 10-6 umol mol-1 parts per billion(ppb) 10-9 nmol mol-1 parts per trillion(ppt 10-1 pmol mol-1 (Ppm)=10°x total
Mixing Ratio ni is the molar concentration of i and ntotal is the total molar concentration of air. parts per million (ppm) 10-6 mmol mol-1 parts per billion (ppb) 10-9 nmol mol-1 parts per trillion (ppt) 10-12 pmol mol-1 total i i n n = total i i n n ppm x 6 ( ) =10