| Term: | Net mass balance |
| Definition: |
According to Anonymous (1969), the sum of accumulation and ablation over the mass-balance year in the stratigraphic system. In common usage, 'net balance' has a number of meanings inconsistent with that of Anonymous (1969; Appendix A). It is used for the balance over approximately one year, regardless of the time system (see fixed-date system, floating-date system), and for balances over other periods than the mass-balance year. In these usages 'net' has its plain-language meaning, referring to the change of mass after all deductions (here ablation) have been made. To resolve this ambiguity, it is recommended that the original definition of 'net mass balance' be retired, and that i) Annual mass balance be used instead for the mass balance over a mass-balance year in any time system; and ii) explicit information about the time system be given as metadata whenever it is relevant (as it is for all measurements by the glaciological method). The adjective 'net' thus becomes a plain-language word, and in many cases becomes redundant because the meaning of 'balance' includes the meaning of 'net'. IHPGlacierMassBalance
GCW |