via curl command
if you want to download the data file from 1st January 2019, type the command :
curl --insecure https://cds-espri.ipsl.fr/iasibl2/iasi_dust/V2.2.0/2019/01/IASI_METOPB_L2_DUST_20190101_LMD_V2.2.0.nc -O
if you want to download more than one file, type :
curl --insecure https://cds-espri.ipsl.fr/iasibl2/iasi_dust/V2.2.0/2019/01/IASI_METOPB_L2_DUST_201901[19-25]_LMD_V2.2.0.nc -O