It is not so often to see diamond dust halos over the open sea, like here in the photograph of Pasi Snellman, taken on 5 November in Porvoo, Southern Finland. The display occurred only above the sea indicating that the open water was the moisture source for ice crystal growth. A couple of of kilometers upwind from the bridge is a small ski center, and according to Snellman snow making was under way there.
This may have provided the nuclei for the ice crystal formation. Snellman also tells that the air temperature was -7° C and sea +5° C.
On 5 November good diamond dust was seen also in Jämsä and Lahti, the latter of which is not reported here in Haloreports.
By Marko Riikonen