January 3, 2009

Halo statistics in 2008

Note: click on the image for detailed view !

Some halo statistics for 2008. Only 0 halo observations in January! No wonder when browsing the weather observations on EMHI (The Estonian Meteorology and Hydrology Institute) which shows the following information for January '08: 18 days of low level clouds and precipitation, 9 days of fog or minimal visibility and 4 days of sunny weather. Halos started to appear from second half of spring until the end of August. In those days I got approximately 14 days of halos and 36 halo phenomenas per month.

Observations were done mainly in Keila and its surroundings (about 40 km radius).
Innerland and south Estonia regions would provide much more better results. Especially at winter when temperature and wind speed are much more lower and humidity is higher there. In south Estonia snowguns are switched on at winter and due to previously mentioned conditions, ice cristals form and halodisplays are more frequent.
Halostatistikat kah. Jaanuarikuu kohta 0 päeva halosid! Imestamiseks ei ole põhjust, kui uurida EMHI ilmavaatluste ajalugu, mille järgi oli meil 18 pilves/kohati pilves ilmaga päeva, 9 päeva udu/minimaalset nähtavust ja 4 päikeselist päeva. Halod hakkasid ilmuma alles kevade teisest poolest kuni augustikuu lõpuni välja. Nendel päevadel sai kirja pandud keskeltläbi 14 vaatluse päeva ja 36 halonähtust kuus.
Vaatlused on tehtud põhiliselt Keilas ja selle lähiümbruses raadiusega u. 40km. Mandri ning Lõuna Eesti regioon annaks kindlasti paremaid tulemusi - eriti talvel, kus õhutemperatuur ja tuulte kiirus on märgatavalt madalam ning on kõrgem õhuniiskus. Lõuna Eestis alustavad talvel tööd lumekahurid, mis eelnimetatud ilmastikutingimuste mõjul paiskavad õhku jääkristalle, milles võivad tekkida halonähtused.


Ágnes Kiricsi said...

16 days for August! That's a lot. I find it very interesting that you had the highest number of halo observations in the summer. Is it usually like that in every year? In Hungary it's always spring and autumn that bring the most halos.

Marko Krusel said...

Yes..in winter and autumn we either have low clouds or no clouds at all. For an example, January '08 was cloudy - 18 days of clouds, 9 days of fog and only 4days of sunlight - no wonder it gave 0 halo observations.

Things start to change in middle of springtime and best part of the year is April to August. This brings all the radius and other rare halos among the more common ones.

Ágnes Kiricsi said...

Thanks! That's an interesting difference. I wonder how it is in Finland. I'll ask the guys.

Marko Krusel said...

From where I live it's only 100km to Helsinki so I guess the statistics should be similar but in north the diamond dust turns the tables.

Ágnes Kiricsi said...

Yeah, sure. You are right. I won't even ask then.

Ágnes Kiricsi said...

You've given me a good idea of how to make the detailed table. I followed your system. :)

You had loads of odd radius halos. I'm very unlucky with those...

Anonymous said...

Congrats Marko! Nice observations.
How many of them were diamond dust displays? It is also really interesting you catch so many odd radius halos.


Marko Krusel said...

Diamond dust displays none. Actually I have seen it only once in my life and even then I left the camera's battery charging :)
Yes, I was lucky to observe several complex radius display in summer.