There are several ways hot to get to the Jurmala Airport with public transport:
If you arrive to RIGA Airport (RIX) by airline - get to the Riga Central Station - from there take a train to Tukums 1. From there - free bus shuttles will be available to the Jurmala Airport/Airshow Venue thanks to Tukums Municipality.
You can also go from Riga with a bus. Go to Riga Bus station and pick a bus to Tukums. There proceed with the same free bus shuttle to the Jurmala Airport. Tukums 1 Train station is at the same place as Tukums Bus station (just on the opposite side of the road)
The Schedule of the FREE TUKUMS-JURMALA AIRPORT BUS will be published closer to the event)