noctilucent clouds over the daugava river in kipsala island, riga, latvia on july night.

blue daugava river kipsala latvia nlc riga astronomy atmosphere atmospheric background beautiful bright calm water city dark dawn dusk evening glow high industial landscape light luminescence mesosphere mesospheric midnight nature night nightscape people noctilucent clouds nordic outdoors phenomena polar port rare reflection scenic shining silver sky space stars summer tranquil twilight weather yachts