# xarray.core.rolling.DataArrayCoarsen.sum

`DataArrayCoarsen.``sum`(**kwargs)

  Reduce this DataArrayCoarsen’s data by applying sum along some dimension(s).

  Parameters:

  - skipna (bool, optional) – If True, skip missing values (as marked by NaN). By default, only skips missing values for float dtypes; other dtypes either do not have a sentinel missing value (int) or skipna=True has not been implemented (object, datetime64 or timedelta64).
  - min_count (int, default None) – The required number of valid values to perform the operation. If fewer than min_count non-NA values are present the result will be NA. New in version 0.10.8: Added with the default being None.
  - keep_attrs (bool, optional) – If True, the attributes (attrs) will be copied from the original object to the new one. If False (default), the new object will be returned without attributes.
  - **kwargs (dict) – Additional keyword arguments passed on to the appropriate array function for calculating sum on this object’s data.

  Returns: | reduced – New DataArrayCoarsen object with sum applied to its data and the indicated dimension(s) removed.
  Return type: | DataArrayCoarsen