Pigboat
wrt pressure
pascal is a derived SI unit and is defined as 1 newton per square meter. As this is a very small pressure then atmospheric pressure = app 100 000 Pa. This was defined in the past as 1 bar. Unfortunately neither bar nor pascal is a realistic scale for human perception, so it was decided to use 1/1000 bar (= millibar). Under SI international measurement regulations, every unit should be derived from the 3 defined units of kilogram, metre and second. This means that bar is the official unit of pressure, but 100 Pa being a more usable unit, pressure is stated in hecto (=100) pascals. From the above equivalence of 100 000 Pa = 1 bar then 1 hPa =1 mb, so they are exactly the same, just that hPa is an SI unit; mb isn't. UTC is time at 0º; which of course is the same as GMT but more 'politically correct' as it does not refer to a specific geographical location