258 David Prandle
Appendix A Supplement to Table 13.2
A briefnote on the parlance of Marine Forecasting is required in re1ation to Table
13.2.
'Operational Modelling' indicates real-time simulation with future extrapolation in time to produce forecasts - analogous to daily weather forecasts.
'Pre-operational modelling' infers model simulations similar to that above (i.e.
with synoptic specifications of initial, boundary and forcing conditions) but run for
past events. Since some synoptic data, e.g. remote sensing images or chemical
concentrations, can only be obtained subsequent1y, some simulations are restricted
to this mode. The complex interactions between physical, chemical and biological
parameters increasingly requires this mode of simulation even when the interest is
to understand isolated specific aspects of a marine system.
'Climate Mean', many simulations are restricted by the availability ofthe associated data (referred to above), by simulating 'climatic mean' conditions, data gathered over many years can be interpolated to provide representative descriptions.
Moreover, in annua! cycle simulations, climatic mean conditions can be used for
repeated yearly cycles to achieve 'cyclic convergence' - often independent of initial
conditions. Unfortunately these mean conditions may differ in character from
actual conditions found in any one year, for example sharp density fronts that
migrate annually in location might disappear.
'Experimental' is used here to indicate specific simulations applicable to a limited set of observations as collected in intensive experimental campaigns.
In contrast to the above definition for Operational Modelling, 'Operational
Oceanography' extends beyond such 'forecasting' to include 'nowcasting' and
'hindcasting'. 'Nowcasting' might typically involve Pre-operational Modelling
whereby models are run subsequent1y (when non real-time data processing has
been completed) to provide an up-to-date description of, for instance, the net thermaIor nutrient budget of asea region. 'Hindcasting' reflects the capability and
enhanced value of using the most advanced models to simulate historical
sequences (with perhaps climate-mean prescribed data where gaps exist) to both
re-interpret specific events or construct relevant statistical data sets.
Appendix A Supplement to Table 13.2
A briefnote on the parlance of Marine Forecasting is required in re1ation to Table
13.2.
'Operational Modelling' indicates real-time simulation with future extrapolation in time to produce forecasts - analogous to daily weather forecasts.
'Pre-operational modelling' infers model simulations similar to that above (i.e.
with synoptic specifications of initial, boundary and forcing conditions) but run for
past events. Since some synoptic data, e.g. remote sensing images or chemical
concentrations, can only be obtained subsequent1y, some simulations are restricted
to this mode. The complex interactions between physical, chemical and biological
parameters increasingly requires this mode of simulation even when the interest is
to understand isolated specific aspects of a marine system.
'Climate Mean', many simulations are restricted by the availability ofthe associated data (referred to above), by simulating 'climatic mean' conditions, data gathered over many years can be interpolated to provide representative descriptions.
Moreover, in annua! cycle simulations, climatic mean conditions can be used for
repeated yearly cycles to achieve 'cyclic convergence' - often independent of initial
conditions. Unfortunately these mean conditions may differ in character from
actual conditions found in any one year, for example sharp density fronts that
migrate annually in location might disappear.
'Experimental' is used here to indicate specific simulations applicable to a limited set of observations as collected in intensive experimental campaigns.
In contrast to the above definition for Operational Modelling, 'Operational
Oceanography' extends beyond such 'forecasting' to include 'nowcasting' and
'hindcasting'. 'Nowcasting' might typically involve Pre-operational Modelling
whereby models are run subsequent1y (when non real-time data processing has
been completed) to provide an up-to-date description of, for instance, the net thermaIor nutrient budget of asea region. 'Hindcasting' reflects the capability and
enhanced value of using the most advanced models to simulate historical
sequences (with perhaps climate-mean prescribed data where gaps exist) to both
re-interpret specific events or construct relevant statistical data sets.