I./JG 51 on a frozen lake in Jan. '43

[CJE]

I'm trying to locate I./JG 51 in January 1943 and what I read seems somewhat confusing (at least to me).
All authors write that it was based on the frozen Iwansee (lake Ivan), but as far as I know, it's near Tula where the Don river rises.
Some are more specific in writing that it was fighting around Velikie-Luki, which looks more likely - but which frozen lake was it?
Any help would be welcome and thanks in advance.

Chris

[sveahk]

The Lake Ivan or Iwan-See is situated c. 30 Km south-west of Welikije Luki. According to Prien (Jagdfliegerverbände...) I./JG 51 had its base here between 6.1 and 28.1 1943.

Greetings
Hans

[CJE]

Thank you.