Surfer does not offer globe-wide located analysis, as there it is currently impossible to run such search within Google. Google will always use a location to run a query.
You can pick a country or city from the list available when making a query. Surfer will then mimic a query run from that location so you get results relevant to the location. If you want a general search, you can select the USA as the location, which would be similar to selecting Google.com.
SERPs can vary depending on the location the search is generated, which means that there will always be a specific location included when you run a search on Google.