diff --git a/ERA5_Data_Request.py b/ERA5_Data_Request.py
index e861e37..92511a2 100644
--- a/ERA5_Data_Request.py
+++ b/ERA5_Data_Request.py
@@ -47,7 +47,7 @@ Operations you want to be performed:
 ascent_only = False  # True   # get only ERA5 data for ascent (e. g. for new location or time within same region)
 download    = False  # True   # download raw ERA5 files
 stitch      = True   # False  # create stitched files
-delete      = False  # False  # delete original files
+delete      = True  # False  # delete original files
 
 
 """
@@ -328,32 +328,28 @@ if stitch == True:
     if ascent_only == True:
         pass
     else:
-        df1 = xr.open_mfdataset(floatfiles, chunks={'time': 100}, combine="nested", engine='netcdf4', concat_dim="time",
-                                parallel=True)
-        df1 = df1.assign_coords(time=np.linspace(tstart, tend, (tend - tstart) + 1))
-        df1.to_netcdf(os.path.join(folder,
-                                   "FLOAT_" + str(ident2) + "_" + str(start.year) + str(start.month) + "_to_" + str(
-                                       end.year) + str(end.month) + ".nc"), mode='w', format="NETCDF4",
-                      engine="netcdf4",
-                      encoding={"z": {"dtype": "float32"}, "t": {"dtype": "float32"}, "u": {"dtype": "float32"},
-                                "v": {"dtype": "float32"}, "w": {"dtype": "float32"}})
-
-        df2 = xr.open_mfdataset(singlefiles, chunks={'time': 500}, combine="nested", engine='netcdf4',
-                                concat_dim="time",
-                                parallel=True)
-        df2 = df2.assign_coords(time=np.linspace(tstart, tend, (tend - tstart) + 1))
-        df2.to_netcdf(os.path.join(folder,
-                                   "RAD_" + str(ident2) + "_" + str(start.year) + str(start.month) + "_to_" + str(
-                                       end.year) + str(end.month) + ".nc"), mode='w', format="NETCDF4",
-                      engine="netcdf4",
-                      encoding={"cbh": {"dtype": "float32"}, "hcc": {"dtype": "float32"}, "lcc": {"dtype": "float32"},
-                                "mcc": {"dtype": "float32"}, "skt": {"dtype": "float32"}, "ssr": {"dtype": "float32"},
-                                "str": {"dtype": "float32"}, "sp": {"dtype": "float32"}, "ssrd": {"dtype": "float32"},
-                                "strdc": {"dtype": "float32"}, "strd": {"dtype": "float32"},
-                                "tisr": {"dtype": "float32"},
-                                "tsr": {"dtype": "float32"}, "ttr": {"dtype": "float32"}, "tcc": {"dtype": "float32"},
-                                "fdir": {"dtype": "float32"}})
+        with xr.open_mfdataset(floatfiles, chunks={'time': 100}, combine="nested", engine='netcdf4', concat_dim="time", parallel=True) as df1:
+            df1 = df1.assign_coords(time=np.linspace(tstart, tend, (tend - tstart) + 1))
+            df1.to_netcdf(os.path.join(folder, "FLOAT_" + str(ident2) + "_" + str(start.year) + str(start.month) + "_to_" + str(end.year) + str(end.month) + ".nc"),
+                          mode='w', format="NETCDF4", engine="netcdf4",
+                          encoding={"z": {"dtype": "float32"}, "t": {"dtype": "float32"}, "u": {"dtype": "float32"}, "v": {"dtype": "float32"}, "w": {"dtype": "float32"}})
 
+        with xr.open_mfdataset(singlefiles, chunks={'time': 500}, combine="nested", engine='netcdf4', concat_dim="time", parallel=True) as df2:
+            df2 = df2.assign_coords(time=np.linspace(tstart, tend, (tend - tstart) + 1))
+            df2.to_netcdf(os.path.join(folder, "RAD_" + str(ident2) + "_" + str(start.year) + str(start.month) + "_to_" + str(end.year) + str(end.month) + ".nc"),
+                          mode='w', format="NETCDF4",
+                          engine="netcdf4",
+                          encoding={"cbh": {"dtype": "float32"}, "hcc": {"dtype": "float32"},
+                                    "lcc": {"dtype": "float32"},
+                                    "mcc": {"dtype": "float32"}, "skt": {"dtype": "float32"},
+                                    "ssr": {"dtype": "float32"},
+                                    "str": {"dtype": "float32"}, "sp": {"dtype": "float32"},
+                                    "ssrd": {"dtype": "float32"},
+                                    "strdc": {"dtype": "float32"}, "strd": {"dtype": "float32"},
+                                    "tisr": {"dtype": "float32"},
+                                    "tsr": {"dtype": "float32"}, "ttr": {"dtype": "float32"},
+                                    "tcc": {"dtype": "float32"},
+                                    "fdir": {"dtype": "float32"}})
 
     startfile = Dataset(ascentfiles[0], "r", format="NETCDF4")
     endfile = Dataset(ascentfiles[-1], "r", format="NETCDF4")
@@ -364,15 +360,13 @@ if stitch == True:
     startfile.close()
     endfile.close()
 
-    df3 = xr.open_mfdataset(ascentfiles, chunks={'time': 800}, combine="nested", engine='netcdf4', concat_dim="time",
-                            parallel=True)
-    df3 = df3.assign_coords(time=np.linspace(tstart, tend, (tend - tstart) + 1))
-    df3.to_netcdf(os.path.join(folder, "ASCENT_" + str(ident1) + "_" + str(start.year) + str(start.month) + ".nc"),
-                  mode='w', format="NETCDF4", engine="netcdf4",
-                  encoding={"z": {"dtype": "float32"}, "t": {"dtype": "float32"}, "u": {"dtype": "float32"},
-                            "v": {"dtype": "float32"}, "w": {"dtype": "float32"}})
-
-    print("Stitching finished!")
+    with xr.open_mfdataset(ascentfiles, chunks={'time': 800}, combine="nested", engine='netcdf4', concat_dim="time", parallel=True) as df3:
+        df3 = df3.assign_coords(time=np.linspace(tstart, tend, (tend - tstart) + 1))
+        df3.to_netcdf(os.path.join(folder, "ASCENT_" + str(ident1) + "_" + str(start.year) + str(start.month) + ".nc"),
+                      mode='w', format="NETCDF4", engine="netcdf4",
+                      encoding={"z": {"dtype": "float32"}, "t": {"dtype": "float32"}, "u": {"dtype": "float32"},
+                                "v": {"dtype": "float32"}, "w": {"dtype": "float32"}})
+        print("Stitching finished!")
 else:
     pass