diff --git a/python/ucf/tools/ucf_mpiio_tar b/python/ucf/tools/ucf_mpiio_tar
new file mode 100755
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+++ b/python/ucf/tools/ucf_mpiio_tar
@@ -0,0 +1,128 @@
+#!/usr/bin/env python3
+import sys
+import io
+import os
+import tarfile
+import argparse
+import numpy as np
+import ucf
+import configparser
+
+parser = argparse.ArgumentParser(description='Reads an ucf.tar archive, downsamples it and saves it to a new ucf.tar archive. Can be used as a pipe.')
+parser.add_argument('indir', metavar='dirin', help='input directory')
+parser.add_argument('iseq',  metavar='iseq', help='sequence number')
+parser.add_argument('base',  metavar='base', help='filebase to be archived: "uvwp" or "scal"')
+parser.add_argument("-o", "--outfile", metavar='file',nargs='?', default=None, help="name of the output file [default: snapshot_XXXX.ucf.tar]", action="store")
+parser.add_argument("-v", "--verbose", help="activate verbose output", action="store_true")
+args = parser.parse_args()
+
+dir_in  = args.indir
+iseq    = int(args.iseq)
+base    = args.base
+verbose = args.verbose
+
+if not base in ('uvwp','scal'):
+  raise ValueError('Invalid base key: {}',base)
+
+if args.outfile is None:
+  if base=='uvwp':
+    file_out = 'snapshot_{:04d}.ucf.tar'.format(iseq)
+  elif base=='scal':
+    file_out = 'snapshot_scalar_{:04d}.ucf.tar'.format(iseq)
+else:
+  file_out = args.outfile
+
+# Check if all required files are available
+files_req = ('parameters_{:04d}.asc','proc_{:04d}.bin','grid_{:04d}.bin','particles_{:04d}.bin',base+'_{:04d}.bin')
+for files in files_req:
+  path_check = '{}/{}'.format(dir_in,files.format(iseq))
+  if not os.path.isfile(path_check):
+    raise IOError('File does not exist: {}'.format(path_check))
+if verbose:
+  print("[x] parameters")
+  print("[x] grid")
+  print("[x] processor grid")
+  print("[x] particles")
+  if base=='uvwp':
+    print("[x] fluid field")
+  elif base=='scal':
+    print("[x] scalar field")
+
+# Open tar file for output
+ftar = tarfile.open(name=file_out,mode='w',pax_headers=tarfile.USTAR_FORMAT)
+
+def transform_filename(filename,iseq):
+  return os.path.basename(file_in).replace('_{:04d}'.format(iseq),'')
+
+# Parse parameters to construct file headers, then add it to tar
+file_in = '{}/parameters_{:04d}.asc'.format(dir_in,iseq)
+config = configparser.ConfigParser()
+config.read(file_in)
+nxprocs = int(config['parallel']['nxprocs'])
+nyprocs = int(config['parallel']['nyprocs'])
+nzprocs = int(config['parallel']['nzprocs'])
+nprocs = nxprocs*nyprocs*nzprocs
+
+print(transform_filename(file_in,iseq))
+fid = open(file_in,'rb')
+info = tarfile.TarInfo(name=transform_filename(file_in,iseq))
+info.size = os.path.getsize(file_in)
+ftar.addfile(info,fileobj=fid)
+fid.close()
+
+# Add proc.bin
+file_in = '{}/proc_{:04d}.bin'.format(dir_in,iseq)
+print(transform_filename(file_in,iseq))
+fid = open(file_in,'rb')
+info = tarfile.TarInfo(name=transform_filename(file_in,iseq))
+info.size = os.path.getsize(file_in)
+ftar.addfile(info,fileobj=fid)
+fid.close()
+
+# Add grid.bin
+file_in = '{}/grid_{:04d}.bin'.format(dir_in,iseq)
+print(transform_filename(file_in,iseq))
+fid = open(file_in,'rb')
+info = tarfile.TarInfo(name=transform_filename(file_in,iseq))
+info.size = os.path.getsize(file_in)
+ftar.addfile(info,fileobj=fid)
+fid.close()
+
+# Add particles.bin
+file_in = '{}/particles_{:04d}.bin'.format(dir_in,iseq)
+print(transform_filename(file_in,iseq))
+fid = open(file_in,'rb')
+info = tarfile.TarInfo(name=transform_filename(file_in,iseq))
+info.size = os.path.getsize(file_in)
+ftar.addfile(info,fileobj=fid)
+fid.close()
+
+# Split uvwp/scal files and add them
+def positionFromRank(rank,nxp,nyp,nzp):
+  ip = rank//(nyp*nzp)
+  jp = (rank//nzp)%nyp
+  kp = rank%nzp
+  return (ip,jp,kp)
+
+file_in = '{}/{}_{:04d}.bin'.format(dir_in,base,iseq)
+ucf_data = ucf.UCF(file=file_in)
+if nprocs!=ucf_data.NumTimestep:
+  raise ValueError('Number of steps does not equal number of procs: {}, {}',ucf_data.NumTimestep,nprocs)
+
+for iproc in range(0,nprocs):
+  print(base+'.{:05d}'.format(iproc))
+  # Construct a new UCF file
+  ucf_data.addFileHeaderToBuffer(
+              rank=iproc,
+              rankijk=positionFromRank(iproc,nxprocs,nyprocs,nzprocs),
+              ftype=ucf_data._UCF__typeID
+            )
+  ucf_data.copyStepToBuffer(iproc+1,recursive=True)
+  ucf_bytes = ucf_data.flushBuffer()
+  # Write it to tar
+  info = tarfile.TarInfo(name=base+'.{:05d}'.format(iproc))
+  info.size = len(ucf_bytes)
+  ftar.addfile(info,fileobj=io.BytesIO(ucf_bytes))
+
+# Close tar file
+ftar.close()