via curl command
if you want to download the data file from 2nd January 2009, type the command :
curl --insecure https://cds-espri.ipsl.fr/iasial2/iasi_o3/V1.2.1/2009/01/IASI_METOPA_L2_O3_COLUMN_20090102_ULB-LATMOS_CDR_V1.2.1.nc -O
if you want to download more than one file, type :
curl --insecure https://cds-espri.ipsl.fr/iasial2/iasi_o3/V1.2.1/2009/01/IASI_METOPA_L2_O3_COLUMN_200901[19-25]_ULB-LATMOS_CDR_V1.2.1.nc -O