Merge branch 'master' into plotting_2dhist

Author: erikvansebille

parcels/field.py

@@ -201,8 +201,10 @@ def __init__(self, name, data, lon=None, lat=None, depth=None, time=None, grid=N
             raise ValueError("Unsupported mesh type. Choose either: 'spherical' or 'flat'")
         self.interp_method = interp_method
         self.fieldset = None
-        if allow_time_extrapolation is None:
-            self.allow_time_extrapolation = True if time is None else False
+        if self.name in ['cosU', 'sinU', 'cosV', 'sinV']:
+            self.allow_time_extrapolation = True
+        elif allow_time_extrapolation is None:
+            self.allow_time_extrapolation = True if len(self.grid.time) == 1 else False
         else:
             self.allow_time_extrapolation = allow_time_extrapolation