Heat waves of Gabo (and nearby)

Reader advisory

The linked documents are pretty lengthy (around 30 pages I think) and mainly consist of my rambling through piles of numbers. Several charts. You have been warned

Following from my previous post about Heatwaves (or as I call them “Hot Spells” and “Very Hot Spells”) for Mallacoota I wondered whether the longer period of observations for Gabo Island Lighthouse might give a more definitive answer.  Looking into this proposition took me a lot of time, exploring many dead-end burrows in a rabbit warren: at some points I turned so many times I nearly disappeared to “the place where the sun don’t shine” (see second and third examples in this). 

Examining the 110 year series for Gabo Island generates a series that looks at a glance to show an increasing number of Very Hot Spell Days in the warmer season.  However a very rough trend analysis does not show statistical significance.

I noted that there were quite a lot of missing values - particularly for minimum temperatures and particularly in later years.  I explored the idea of using data for Green Cape to impute values where they were missing from the Gabo series.  After considerable fiddling with the Green Cape data it seemed that there might be some value in imputing missing values for the final 20 years of the Gabo series.

Making these imputations increased, by about 9% the number of Very Hot Spell Days in those years but not enough to make a statistically significant difference..

My big ticket outcome is that I can’t say there is a significant increase in the number of Very Hot Spell days on Gabo Island.  Possibly a meteorologist may know of techniques that would demonstrate that, but possibly they would find flaws in my approach and dismiss it completely.

Beach(ish) sightings

 This will cover a few things seen on the beaches and rocky areas in a period of low tides.  The first few are from Quarry Beach on 24 December.

The next lot are from Bastion Point around 1700hrs on Christmas Day.

Cloudscapes of 23 December

 Around 1800 hours the sky, and the radar, looked as thought we were in for a good thunderstorm.  I took photos with my iPad (as I had that to hand) over the next 2 hours.  Spoiler alert: there was no (0, zilch, nada) rain.

This is timestamped 1803.

1816 for the next 2.

1834 - looks to be a lot of virga over (about) Gipsy Point.

Clearing quickly 1848.

A couple of closing views around 1955.

Walking Pebbly Beach nearly to Shipwreck ...

.. and back.  This walk is bought to you by the colour Yellow and the letter P.

Let us begin with a double header: a Yellow Flower that begins with 'p': Persoonia levis (Smooth Geebung).

Definitely yellow and I think Coronidium scorpioides (Button Everlasting).

Craspedia variabilis (Billy buttons)

Viminaria juncea (Golden Spray).  I have seen this in the past but not in such profusion as this year.  I suspect this is something to do with the amount of rain we have had.

This one is interesting: definitely Gompholobium sp but the flowers seemed much smaller than expected for G. hugelii.  Possibly G. glabratum - heath habitat matches but out of the range cited by VicFlora.  Let us see what iNaturalist has to say.

Possibly the commonest yellow flower Goodenia ovata.

A crap photo, but Ranunculus sp are not common here, although VicFlora has some 47 entries under the genus name!  Fortunately the Atlas of Living Australia only lists one species in this area: R. lappaceus

Getting in to the 'p's here is a Pimelea linifolia.

Pink Tetratheca sp.

A swathe of purple Comesperma erecinum poking out of the regenerating heath about 2 km from Pebbly Beach

Purple Thysanotus patersonii (Twining Fringe Lily).

A close up of Comesperma, with a few of the buds fully out.

Now to the supporting cast - not yellow or involving p.  Although I have just realised the first 3 are of Pebbly Beach!

This rock gets an award as Nargun Imitator.  It has been there for a while but recent storms have caused it to take a jump to the right: only appropriate for a spirit to do the Time Warp

Getting in to the bush it was obvious that the track hadn't been cleared recently.  That doesn't greatly fuss me: it is the bush, not Glebe Park.  I was more than somewhat pissed that I got caught up in the Kennedia vines and face-planted as a result,

Getting on to the beach about 3km in was a tad tricky as the track was a little overgrown but it isn't Glebe Park!

A view of the beach (rather like the usual English beach - covered with gravel)!

And a rocky gully at the end thereof.

Looking back towards Howe Peak and Gabo from the turn point.

The only butterfly of the day was this Variable Sword-grass Brown.

A couple of Xanthorrhoea spikes amongst all the expired ones from 2020.

The Callistemons would have been stunning when all in flower.  The foliage is still attractive,

There is one particularly damp gully.  Where there is damp there are frogs and where there are frogs ....