Re: Metrological data
If satellites could do the job as well as ground stations nobody with a satellite would be paying all that money to maintain all those ground stations.
I imagine there are lots of things which are probably difficult to measure accurately remotely, such as air pressure, humidity, wind speed, amount of precipitation, etc. You might get estimates, but getting good, consistent readings under all weather conditions can probably only be done from instruments on the spot. If it could be done remotely to the degree of accuracy required, then like I said they wouldn't spend so much money on local weather stations.
Also, a lot of satellite data can't be interpreted properly without on the spot references. I have read about satellite temperature readings having to be calibrated by comparing the satellite readings to on the spot temperatures. This then lets them interpolate the satellite readings for use in areas which don't have weather stations.
Good weather data has important military uses, as it is used to plan when operations are feasible. Also, knowing the weather in one location can help you predict the weather somewhere else days later. In WWII the Germans went so far as to establish secret remote unmanned automated weather stations in uninhabited parts of Greenland and Labrador which would make radio reports which were used to plan U boat operations. The weather stations were found after the war by following up on German records.