Quality assurance checks

@jescriba has spotted that in the monthly mean plots there are some high values over the southern ocean that should not be there. It is because the data is recorded around the cloudy regions, which should also be specified as a cloud.

We need to:

• filter this data out by applying the QA flags in the VIIRS raw data.
• Run a monthly mean again and show it at one of the meetings to see if people can spot any further issues

FYI: @cgile @eemili