Halliday & Matthiessen (2014: 312-4):
What, then, is the set of functions that is construed as circumstantial in the grammar of the clause as representation? We can start from time, place, cause and manner; but we need to realign them somewhat, to add to them, and to interpret them in relation to the process types as a whole. The list of circumstantial elements will then be as in Table 5-28.
