New ExternalEnergySource process to add simple constant source/sink t…

…erms. Version number incremented to 0.2.9

climlab/__init__.py

@@ -1,4 +1,4 @@
-__version__ = '0.2.8'
+__version__ = '0.2.9'
 
 #  This list defines all the modules that will be loaded if a user invokes
 #   from climLab import *

climlab/model/ebm.py

@@ -22,6 +22,7 @@
 class EBM(EnergyBudget):
     def __init__(self,
                  num_lat=90,
+                 S0=const.S0,
                  A=210.,
                  B=2.,
                  D=0.555,  # in W / m^2 / degC, same as B
@@ -39,6 +40,7 @@ def __init__(self,
             lat = sfc.axes['lat'].points
             initial = 12. - 40. * legendre.P2(np.sin(np.deg2rad(lat)))
             self.set_state('Ts', Field(initial, domain=sfc))
+        self.param['S0'] = S0
         self.param['A'] = A
         self.param['B'] = B
         self.param['D'] = D

climlab/process/energy_budget.py

@@ -31,3 +31,16 @@ def _temperature_tendencies(self):
     def compute(self):
         '''Update all diagnostic quantities using current model state.'''
         self._temperature_tendencies()
+
+
+class ExternalEnergySource(EnergyBudget):
+    '''A fixed energy source or sink to be specified by the user.
+    The user should modify the fields in the heating_rate dictionary,
+    which contain heating rates in W / m**2 for all state variables.'''
+    def __init__(self, **kwargs):
+        super(ExternalEnergySource, self).__init__(**kwargs)
+        for varname in self.state.keys():
+            self.heating_rate[varname] = np.zeros_like(self.state[varname])
+
+    def _compute_heating_rates(self):
+        pass