Sunday, 1 June 2008

Körülírt halo és alsó oldalív - Circumscribed halo and infralateral arc

Magas napállásnál (ebben az esetben 64°) az alsó oldalív nagyon hasonlít a horizontális ívhez. Azonban míg az előbbit oszlopos kristályok, az utóbbit lapos kristályok okozzák. Mivel ebben az esetben az erős körülírt halo oszlopos kristályokra utal, ez nagy valószínűséggel alsó oldalív volt. Vecsésen 12:50 és 13:10 között lehetett megfigyelni, fél órával azután, hogy Alex Mogyoródon látta.

At high Sun altitude (here 64°), the infralateral arc looks pretty much like a circumhorizon arc. While, however, the former one is caused by column crystals, oriented plates are responsible for the latter one. As the strong circumscribed halo was indicative of a column display, it must have been an infralateral arc in this case. In Vecsés, it was observable between 12:50 and 13:10, half an hour after Alex saw it in Mogyoród, some 20-25 km away.

Teljes méretű képek / Full-size images ( 1 - 2 )





2 comments:

Marko Krusel said...

By the infralateral arc your probably meant circumhorizon arc !
Btw nice 22 circumscribed halo.

We have got a halo week over here. Parry arcs, cza arcs, upper and lower Lowitz arcs...bright 22 degrees. Haven't got time to process these yet.

Ágnes Kiricsi said...

No, I did mean infralateral arc :) It seemed to be a column display, and at high Sun elevations the infra looks pretty much like a circumhorizon arc. Have a look at this page:
http://www.ursa.fi/halot/atlas/pylvas/pylv_p1.html
I've edited the posting, so now there's more explanation.

Congratulations on the Lowitz arcs. I've never seen one. Or at least I'm not sure :) But today I might have caught the fragment of an upper suncave Parry.