The weather is a constant topic of conversation at Davis. Find out what the 9th Okta is.

The 9th Okta

Hi, my name is Jason Beachcroft and I am currently working my third winter for the AAD as a Field Training Officer. Over the 2nd and 3rd of June 2022 I was working on delivering some field travel training at Davis station for my fellow expeditioners. Thursday the 2nd of June was the last day of sunrise/sunset we had for approximately 6 weeks.

One of the things that I like about the work down here is that there is always somewhere new to explore and more importantly something new to learn. That night we were sitting inside Platcha Hut and I’m putting together our situation report (sitrep) for the evening. I questioned Jason Davey, who is Senior Bureau of Meteorology observer about my weather observations. We measure cloud cover in oktas. Consider that the sky is a pie and you slice it into 8 equal pieces. Each segment with cloud in it is an okta.

I was foolish enough to think okta meant 8 but was informed by Jason Davey said that we had 9 oktas of cloud. Now I wasn’t keen to believe that at first discussion. But alas I should have had more faith. Apparently, you can have 9 oktas when the sky is obscured from view or was that another way of saying that the sun won’t come up again for 6 weeks?

Ah, the mysteries of Antarctic weather observations.

Jason Beachcroft