Argon is an inert gas that is present in seawater at concentrations that are in equilibrium with the atmosphere at the temperature and salinity of the sample. The vertical profile shows concentrations at the surface which are slightly lower than those in deep water because gas solubility decreases as temperature increases
Argon is a colourless and odourless gas present to a very small extent in the atmosphere. Argon is very inert (indeed it is referred to as one of the noble gases) and is not known to form true chemical compounds. It makes a good atmosphere for working with air-sensitive materials since it is heavier than air and less reactive than N2. Today, the chemical symbol for argon is Ar but until 1957 its sybol was simply A.