harpmerge Error on RUS VM environment

Hi there,

I am trying to use the harpmerge tool to group about 60 sentinel 5-P .nc’s into one, clipping to a smaller region of interest (Portugal+Spain).

After checking the documentation and forum.step.esa.int/ treads, I tried several options, to no avail:

harpconvert -a ‘latitude>35;latitude<45;longitude>-10;longitude<15;bin_spatial(400,35,0.025,600,-10,0.025);derive(latitude{latitude});derive(longitude{longitude})’ ./ S5P_L3__NO2.nc
ERROR: could not open ./ (not a regular file)

harpconvert -a ‘latitude>35;latitude<45;longitude>-10;longitude<15;bin_spatial(400,35,0.025,600,-10,0.025);derive(latitude{latitude});derive(longitude{longitude})’ S5P_OFFL_L2__NO2*.nc S5P_L3__NO2___.nc
ERROR: input and/or output product file not specified

harpconvert -a ‘latitude>35;latitude<45;longitude>-10;longitude<15;bin_spatial(400,35,0.025,600,-10,0.025);derive(latitude{latitude});derive(longitude{longitude})’ ./ …/…/L3.nc
ERROR: could not open ./ (not a regular file)

harpconvert -a ‘latitude>35;latitude<45;longitude>-10;longitude<15;bin_spatial(400,35,0.025,600,-10,0.025);derive(latitude{latitude});derive(longitude{longitude})’ ~/Desktop/temp/*.nc …/…/L3.nc
ERROR: input and/or output product file not specified

Anyway to merge these 60 files together at once?
Thanks in advance.