Category	URL
_null	https://er2webapps.emodnet-physics.eu/metadata//erddap/categorize/standard_name/_null/index.xhtml?page=1&itemsPerPage=1000
latitude	https://er2webapps.emodnet-physics.eu/metadata//erddap/categorize/standard_name/latitude/index.xhtml?page=1&itemsPerPage=1000
longitude	https://er2webapps.emodnet-physics.eu/metadata//erddap/categorize/standard_name/longitude/index.xhtml?page=1&itemsPerPage=1000
time	https://er2webapps.emodnet-physics.eu/metadata//erddap/categorize/standard_name/time/index.xhtml?page=1&itemsPerPage=1000