Category	URL
_null	http://erddap.exploratorium.edu:8080/erddap/categorize/standard_name/_null/index.xhtml?page=1&itemsPerPage=1000
latitude	http://erddap.exploratorium.edu:8080/erddap/categorize/standard_name/latitude/index.xhtml?page=1&itemsPerPage=1000
longitude	http://erddap.exploratorium.edu:8080/erddap/categorize/standard_name/longitude/index.xhtml?page=1&itemsPerPage=1000
relative_humidity	http://erddap.exploratorium.edu:8080/erddap/categorize/standard_name/relative_humidity/index.xhtml?page=1&itemsPerPage=1000
time	http://erddap.exploratorium.edu:8080/erddap/categorize/standard_name/time/index.xhtml?page=1&itemsPerPage=1000