gnome.weatherers.cleanup

oil removal from various cleanup options add these as weatherers

Classes

RemoveMass	create a mixin for mass removal. These methods are used by CleanUpBase and
CleanUpBase	Just need to add a few internal methods for Skimmer + Burn common code
Skimmer	Just need to add a few internal methods for Skimmer + Burn common code
Burn	Just need to add a few internal methods for Skimmer + Burn common code
ChemicalDispersion	Just need to add a few internal methods for Skimmer + Burn common code

Module Contents

class gnome.weatherers.cleanup.RemoveMass

Bases: object

create a mixin for mass removal. These methods are used by CleanUpBase and also by manual_beaching.

valid_vol_units

valid_mass_units

prepare_for_model_step(sc, time_step, model_time)

Do sub timestep resolution here so numbers add up correctly Mark LEs to be skimmed - do them in order right now. Assume all LEs that are released together will be skimmed together since they would be closer to each other in position.

Assumes: there is more mass in water than amount of mass to be skimmed. The LEs marked for Skimming are marked only once - code checks to see if any LEs are marked for skimming and if none are found, it marks them.

class gnome.weatherers.cleanup.CleanUpBase(efficiency=1.0, **kwargs)

Bases: RemoveMass, gnome.weatherers.Weatherer

Just need to add a few internal methods for Skimmer + Burn common code Currently defined as a base class.

add ‘frac_water’ to array_types and pass **kwargs to base class __init__ using super

property efficiency

• Efficiency can be None since it indicates that we use wind to compute efficiency.

• If efficiency is not None, it must be a number greater than or equal to 0.0 and less than or equal to 1.0.

class gnome.weatherers.cleanup.Skimmer(amount=0, units=None, water=None, **kwargs)

Bases: CleanUpBase

Just need to add a few internal methods for Skimmer + Burn common code Currently defined as a base class.

initialize Skimmer object - calls base class __init__ using super() active_range is required cleanup operations must have a valid datetime - cannot use -inf and inf active_range is used to get the mass removal rate

water = None

amount = 0

property units

return units for amount skimmed

prepare_for_model_run(sc)

no need to call base class since no new array_types were added

prepare_for_model_step(sc, time_step, model_time)

Do sub timestep resolution here so numbers add up correctly Mark LEs to be skimmed - do them in order right now. Assume all LEs that are released together will be skimmed together since they would be closer to each other in position.

Assumes: there is more mass in water than amount of mass to be skimmed. The LEs marked for Skimming are marked only once - code checks to see if any LEs are marked for skimming and if none are found, it marks them.

weather_elements(sc, time_step, model_time)

Assumes there is only ever 1 substance being modeled! remove mass equally from LEs marked to be skimmed

class gnome.weatherers.cleanup.Burn(area=None, thickness=None, active_range=(InfDateTime('-inf'), InfDateTime('inf')), area_units='m^2', thickness_units='m', efficiency=1.0, wind=None, water=None, **kwargs)

Bases: CleanUpBase

Just need to add a few internal methods for Skimmer + Burn common code Currently defined as a base class.

Set the area of boomed oil to be burned. Cleanup operations must have a valid datetime for active start, cannot use -inf. Cannot set active stop - burn automatically stops when oil/water thickness reaches 2mm.

Parameters:

• area (float) – area of boomed oil/water mixture to burn

• thickness (float) – thickness of boomed oil/water mixture

• active_range (datetime) – time when the burn starts is the only thing we track. However we give a range to be consistent with all other weatherers.

• area_units (str) – default is ‘m^2’

• thickness_units (str) – default is ‘m’

• efficiency (float) – burn efficiency, must be greater than 0 and less than or equal to 1.0

• wind – gnome.environment.Wind object. Only used to set efficiency if efficiency is None. Efficiency is defined as: 1 - 0.07 * wind.get_value(model_time) where wind.get_value(model_time) is value of wind at model_time

Kwargs passed onto base class:

Parameters:

• name (str) – name of object

• on (bool) – whether object is on or not for the run

valid_area_units

valid_length_units

area = None

property area_units

property thickness_units

wind = None

water = None

property active_range

property thickness

prepare_for_model_run(sc)

resets internal _oilwater_thickness variable to initial thickness specified by user and active stop to ‘inf’ again. initializes sc.mass_balance[‘burned’] = 0.0

prepare_for_model_step(sc, time_step, model_time)

1. set ‘active’ flag based on active start, and model_time

2. Mark LEs to be burned - do them in order right now. Assume all LEs that are released together will be burned together since they would be closer to each other in position. Assumes: there is more mass in water than amount of mass to be burned. The LEs marked for Burning are marked only once - during the very first step that the object becomes active

weather_elements(sc, time_step, model_time)

1. figure out the mass to remove for current timestep based on rate and efficiency. Find fraction of total mass and remove equally from all ‘mass_components’ of LEs marked for burning.

2. update ‘mass’ array and the amount burned in mass_balance dict

3. append to _burn_duration for each timestep

class gnome.weatherers.cleanup.ChemicalDispersion(fraction_sprayed, active_range=(InfDateTime('-inf'), InfDateTime('inf')), waves=None, efficiency=1.0, **kwargs)

Bases: CleanUpBase

Just need to add a few internal methods for Skimmer + Burn common code Currently defined as a base class.

another mass removal mechanism. The volume specified gets dispersed with efficiency based on wave conditions.

Parameters:

• volume (float) – volume of oil (not oil/water?) applied with surfactant

• units (str) – volume units

• active_range (2-tuple of datetimes) – Range of datetimes for when the mover should be active

• waves (an object with same interface as gnome.environment.Waves) – waves object - query to get height. It must contain get_value() method. Default is None to support object creation by WebClient before a waves object is defined

Optional Argument: Either efficiency or waves must be set before running the model. If efficiency is not set, then use wave height to estimate an efficiency

Parameters:

efficiency (float between 0 and 1) – efficiency of operation.

remaining kwargs include ‘on’ and ‘name’ and these are passed to base class via super

fraction_sprayed

waves = None

make_default_refs = False

prepare_for_model_run(sc)

reset _rate to None. It gets set when LEs are marked to be dispersed.

prepare_for_model_step(sc, time_step, model_time)

1. invoke base class method (using super) to set active flag

2. mark LEs for removal

3. set internal _rate attribute for mass removal [kg/sec]

weather_elements(sc, time_step, model_time)

for now just take away 0.1% at every step