diff --git a/atmPy/data_archives/NOAA_ESRL_GMD_GRAD/aero/__init__.py b/atmPy/data_archives/NOAA_ESRL_GMD_GRAD/aero/__init__.py
index fac3e39..0090f82 100644
--- a/atmPy/data_archives/NOAA_ESRL_GMD_GRAD/aero/__init__.py
+++ b/atmPy/data_archives/NOAA_ESRL_GMD_GRAD/aero/__init__.py
@@ -1 +1,2 @@
-from .aero import network
\ No newline at end of file
+from .aero import network
+from .file_io import open_nfan
\ No newline at end of file
diff --git a/atmPy/data_archives/NOAA_ESRL_GMD_GRAD/aero/file_io.py b/atmPy/data_archives/NOAA_ESRL_GMD_GRAD/aero/file_io.py
new file mode 100644
index 0000000..e9294bb
--- /dev/null
+++ b/atmPy/data_archives/NOAA_ESRL_GMD_GRAD/aero/file_io.py
@@ -0,0 +1,53 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+Created on Wed Jan 15 14:52:06 2025
+
+@author: htelg
+"""
+
+import xarray as xr
+
+def open_nfan(fn = '/nfs/iftp/aftp/aerosol/bos/2020/ESRL-GMD-AEROSOL_v1.0_HOUR_BOS_s20200101T000000Z_e20210101T000000Z_c20210214T053935Z.nc'):
+    '''
+    Open a standard nfan file. You might have to install h5py for this to work?
+
+    Parameters
+    ----------
+    fn : TYPE, optional
+        path to file.
+
+    Returns
+    -------
+    dsall : TYPE
+        DESCRIPTION.
+
+    '''
+    
+    ## time, pressure and temp
+    
+    ds = xr.open_dataset(fn, group='data')
+    
+    ## light_scattering
+    
+    dss = xr.open_dataset(fn, group='data/light_scattering')
+    dss = dss.assign_coords({'time': ds.time})#xr.open_dataset(fn, group='data').time})
+    dss = dss.rename({'wavelength': 'wl_neph'})
+    
+    # particle_concentration
+    
+    dspc = xr.open_dataset(fn, group='data/particle_concentration')
+    dspc = dspc.assign_coords({'time': ds.time})
+    dspc = dspc.drop_vars(['sample_pressure','sample_temperature']) #They interfer with same variable in scattering, also they both were empty in my test file
+    
+    ## Absorbtion
+    
+    dsa = xr.open_dataset(fn, group='data/light_absorption')
+    dsa = dsa.assign_coords({'time': ds.time})
+    dsa = dsa.rename({'wavelength': 'wl_clap'})
+    
+    ## merge
+    
+    dsall = xr.merge([dss, dsa, dspc])
+    
+    return dsall
\ No newline at end of file