add another gc collect

mlair/helpers/filter.py

@@ -423,8 +423,10 @@ class ClimateFIRFilter:
             # combine historical data / observation [t0-length,t0] and climatological statistics [t0+1,t0+length]
             logging.info(f"{data.coords['Stations'].values[0]} ({var}): history")
             history = self._shift_data(d, range(int(-(length - 1) / 2), 1), time_dim, var_dim, new_dim)
+            gc.collect()
             logging.info(f"{data.coords['Stations'].values[0]} ({var}): future")
             future = self._shift_data(a, range(1, int((length - 1) / 2) + 1), time_dim, var_dim, new_dim)
+            gc.collect()
             logging.info(f"{data.coords['Stations'].values[0]} ({var}): concat to filter input")
             filter_input_data = xr.concat([history.dropna(time_dim), future], dim=new_dim, join="left")
             # filter_input_data = history.combine_first(future)