Green Cape trip

 Needing to get fuel for the Pajero in the near future I noticed that the price of diesel at the cheapest place in Eden was 199.9c/l: 32 cents less than Mallacoota. Is the Mallacoota servo (or their wholesaler) working on a business plan that says they have a captive market so gouge it before the tourists leave? No surely not. 😂

There were also a few groceries we needed that would be better priced in in Eden, so off we went, deciding that we would call in to Green Cape on the way home.

The drive in to Green Cape was enlivened by crossing with a few Muppets who seemed to either think it was a one way road or not have worked out that it was a dirt. (Note from the future: on the way back I estimate we crossed with at least 15 cars, all displaying this quality of conductivity.)

Our first stop was Pulpit Rock which on our previous visit had been our first sight of the Shearwater migration. This time there were only about 50 here rather than the 10,000 I estimated last visit. Here is an optimistic shrub growing above the rock platform.

This is the view to the North.

A clip showing the colour of the water off the rocks and the pattern of the backwash.  The larger waves were breaking into the pool visible above the run off.

Definitely a Hakea: I suspect H. decurrens.

The most common shrub was Banksia serrata known as Old Man Banksia or Sawleaf Banksia.  Most plants had some nice flowers.  It being a National Park they are all still there.

A view over the heath.

Spot the birdie!  A New Holland Honeyeater: the closely related Tawny-crowned Honeyeater was Bird a Day.

We finished by driving down to the Lighthouse, which we found a lot more exposed to wind than Pulpit Rock or the heath.  There were more (~300) Shearwaters here as well as a Gannet and a Kestrel.

A visit to the near West

 On 23 January I visited two of the cultural sites of Mallacoota: the Waste Water Treatment Works (WWTP, also known as the sewage works or the poo pits) and the Waste Facility (also known as the Tip).

The most exciting thing was a the entire time I was at the WWTP - close to an hour - was a flock of about 60 White-throated Needetails was swooping at great speed above the ponds.

Displaying great foresight I didn't have my camera with me so offer a 3 image offering courtesy of my iphone. The first is a still image in normal view with about 20 swifts circled in red.

The second is a similar shot but the camera zoomed so the birds are actually visible.

The third is a video clip with a single bird showing the full meaning of 'zoom'.

I think the country must be drying out to the West. There were about twice as many of the common duck species as in the recent past and there were Coots and both usual species of Grebe back after being very hard to find recently. Still a few ducks missing (Hardhead; Shoveler; and PInk-eared) but some positive signs for birders at least.

Getting back to the tip I was very pleased and amused by the use made of donations to form installations. The site manager commented that people sometimes go there just to take photos. Here is the welcome sign.

Note the smiley on the rock!

If your calls haven't been getting through ...

I thought the array of toys needed a close up.

Personally, I'd use a four iron, rather than a wood, for this hole.

Various sightings

 This is a miscellany of sightings from 7 January.  It begins with a few snaps from our garden, as much about the flowers as the birds.

Little Wattlebird on Red-hot Poker.

New Holland Honeyeater (NHH) on Red Hot Poker.  This causes me to remember that at our last house, in Carwoola NSW the only time we used to see NHH was when the Pokers came in to flower, and then they would hang around until the flowering stopped.  The nearest place at which NHH were regular was about 3km away (straight line) and over a couple of small ridges, so how they new about this flowering beats me!

Little Wattlebird looking at Canna.

This sign, presumably erected by EGSC, has appeared at the start of the Casuarina Walk.  An excellent guide to many birding points,

The walk is a good spot to find Hyacinth Orchids.  This is Dipodium roseum.

An interesting collection of fungus. 

Underside of the fungus.

In the afternoon I went to add some biomass (bait) to the waters of the Inlet.  I removed a little biomass (weed) from the Lake but added nothing to our diet.  It was amusing to watch a flock of Little Black Cormorants feeding around a Pelican.  Frances has raised the question of whether Cormorants glide: I can't recall seeing this Pelicans are absolute glidemeisters, both in level flight inches above the water and spiralling upwards in a thermal or an orographic updraft.

THis mainly to show the wing action of a Silver Gull.

I tried to get images - OK, an image - of the Little Terns fishing in the vicinity but failed.  I suspect they were doing better than me.

Annual Weather Report 2022

 This will be a brief summary of the weather during the year.  Most of the data will come from my Weather Station (WS) because (a) the BoM site at the Airport was out of action for a time; and (b) as the BoM Climate Data Online is experiencing "technical problems" it is more or less impossible to assess/access what data they do have.

One sentence summary!

It was a very wet year with mild maximum temperatures and relatively high minima.

Rainfall

A very wet year, with the 4th highest rainfall - 1351 mm -recorded.  The two heaviest days were 2nd and 3rd April with 144.8 and 120.8 mm respectively, contributing to the monthly total of 300.2 mm (7th highest monthly total ever recorded).

In this chart the final 4 years are WS data, the rest is BoM.

I compared the past four years with BoM totals and for 2020 and 2021 the totals were very close.  

• For 2019 (the lowest rainfall recorded by BoM at the site) the record at my WS was even lower: I suspect this was due to squalls along the coast not making it to my site.  
• For 2023 the situation is a little more complicated:
• Comparing daily records after the event (when that can be extracted for the BoM)  is made complicated by the BoM reset at 0900 each day while my WS (and I suspect) every private WS working on calendar days.
• My WS recorded 62 mm more than the BoM in December2022: without being able to check (see point b in the preamble) I assume this is due to the BoM station being offline during the major rainfall event of the month (I hope that this will be lead to the BoM eventually nullifying the December - and thus annual - records.)
• I also recorded a lot more than the Airport site during an event in April 2022 and in February and March of the year.  
• There are no months in 2022 in which BoM significantly exceeded my recorded fall
• A Nylex gauge is next to my WS and has - within 1 or 2 mm each event - confirmed the WS readings.

My conclusion is that it is more informative to use the longer BoM as an historical backdrop, accepting that it will have some inconsistencies, than to just present a 4 year series from my WS.

Days of Rainfall

As well as the amount of rain which fell the number of days with rainfall is important, especially for gardeners.  My station has a minimum recording quantity of 0.2mm, which is frequently delivered by a heavy dew: while effectively meaning there has been little evaporation such trivial "falls" do not provide soil water.  So I disregard falls of 2mm.  A meteorologist acquaintance suggested 5mm was needed to be of assistance for gardening so I have 2 metrics for rain days reflecting those limits (the numbers above the bars show the number of days covered by each bar).  

I have a series of daily rainfalls going back to 1975, but in the early parts of this period there are frequently observations accumulated over several days which makes the data useless for evaluating this metric.

Rate of rainfall

My WS records the maximum rate of rainfall in each one hour interval.  To get an easy to handle indicator out of that I use maximum rate recorded in a day.  The highest rate recorded in a day in 2022 was 240mm/hr with 2 other days recording peak falls of 118.8 mm/hr.  This next chart shows 3 groups of rates equivalent to low, medium and high rates.

Not only did 2022 have the greatest number of raindays but it had, by a fair margin, the highest number of days with a high maximum rate.

Another way of looking at rate of rain is the amount that actually fell in a one-hour recording period.  The two heaviest periods in 2022 were 1800 hrs and 1900 hrs on 3 April with 29.8 and 29.2 mm respectively.  The third highest fall was 28.6 mm on 23 March

Temperatures

My overall metric for temperature is the temperature anomaly: the mean temperature for a period minus the long term average mean temperature.  (Note[1]: I have become a little uncertain about exactly how I have calculated some of these data wrt to the maximum values applied.  I don't think the resultant picture changes much as a result, but some detailed analysis will happen, once the CDOL becomes reliably available again. [2} I have now 'regularised' the data and don't think it has altered the overall picture by veymuch.  Details available on request. )

The overall anomaly for the year was -0.04C (effectively 0!) The first chart shows the anomaly for each month of 2022.  The value for December (-0.91C is the lowest value obtained in the 4 years for which I have calculated the value for (at least most) months.  For the months with positive values (ie a warmer than usual month) none of the results are extreme: the greatest positive anomaly recorded is 2.41C in December 2019.

I have also calculated a form of annual anomaly using the difference between annual average minima and maxima compared with the 30 year average of those values.   The result is shown below.

I am reluctant to make any large statements about these data (see caveat above) but it certainly does not show a declining series.

The following chart shows the average minimum, mean and maximum daily temperatures from my WS for the 4 year in which it has been operating.

The last two years appear to have been a little cooler than the preceding 2.

Maximum temperature

The next chart shows a time series of maximum temperatures with adjustments applied to the years prior to 2019 to adjust for the sea breeze effect at the airport.

Clearly 2022 was quite a cool year in terms of average maximum temperature (19.6C vs long term average 20.5C).  This quite probably reflects the relatively frequent cloud cover due to rain events.  This blocks the heating effect of solar exposure.

Minimum temperatures

The sea breeze effect doesn't affect the minimum temperature to any extent that I have been able to determine so the back series in this chart is as recorded by BoM.  The average minimum temperature in 2022 was 11.76C against a long term average of 11.0C.

In the case of minimum temperatures the presence of cloud holds in the warmth of the day so it should be expected that a wet year has high minima.  (A scatterplot shows a positive, but not significant relationship between rainfall and minimum temperature.)  There seems to be a fairly significant increase shown by the trend line (based on a rule of thumb that r2 >0.5 is significant).

Humidity

Even when fully operational CDOL contains very limited information about Humidity (which is explainable by there having to be some limit to the data provided at no cost).  I also have doubts about the usefulness of data from the BoM site, exposed to sea breezes, to compare with my site which is both more inland and much less exposed to wind.   So I have used data from my WS to show the annual average values of rH for the two standard recording times.

Not surprisingly, in view of the rainfall, 2022 is the highest of the 4 years available on both measures.

Wind

Again very limited data available from BoM for good reasons.  I have from time to time compared wind gusts at my site with those recorded at the Bom site and concluded that overall the gusts are ~30% stronger at the BoM site, with significant variation according to the direction of the wind.  So the chart below shows only data from my site.

The average run has dropped since 2019 with the last two years very similar in run.

I have in the past looked at other measures of 'windiness' using maximum gust or average gust and found the correlation extremely high.  I favour average daily run as it includes an entire day rather than a point in time as do the gust based data.  The maximum gust recorded in 2022 was 61.2 kph similar to the previous 2 years, but well below the 72.9 kph recorded in 2019.

A short walk from Genoa Rd

 This afternoon we did a brief stroll on the Captains Creek Fire Trail to start improving our gumtree identification skills.  I'm not sure how far we got on the track of gumtrees - the reference book doesn't have a section on what bark looks like after it has been burnt but saw a few interesting things.

Dipodium variegatum (I think).

Dianella sp. berries

A bull ant (Myrmecia sp. - that is as far as ALA records go for this area!)

Weather report December 2022

 A somewhat schizophrenic month with a wet cold patch developing into a hot dry finish.

A particularly interesting set of records come from 26 December when around 1330 hours my WS was reading 31.6C and the airport site showing 24.2C.  That situation continued until late afternoon when the wind at the Airport swung from NE to N and dropped a few kph, around 1600hrs, and the temperature quickly rose, reaching 29.7 at 1832.

Rainfall 

We ended the month with 110.6 mm well above the median fall of 65.8 mm  and the (very low) 43.6 mm recorded in December 2021.

The concentration of the rain in the early-mid part of the month is indicated by the blue line (LH axis) while the squally nature of the events in indicated by the pale orange line (RH axis).

Temperatures

The anomaly, mainly using BoM data from the airport, ended up at -0.91C which is a reasonably large divergence from zero.  I have added "mainly" as the BoM site was AWOL for 6 days early in the month due to maintenance issues.  (I shall examine the scope for using my weather station (WS) data for the anomaly going forward and report in a separate post.)

Here are the extremes from my WS.

On the topic of temperature generally I have done some research into time series for the BoM stations at Mallacoota and Gabo Island (the latter comes with a side-serve of Green Cape) The conclusion is that I am not confident to say that they show the expected climate change towards  warmer temperatures (but I would be confident to say they do not support change towards cooler temperatures).  I will comment on Hot spells and cool spells in the next two subsections.

Minimum temperatures

The average minimum temperature for the month was 12.75C, 1.01C below the mean and somewhat below last year.

The time series looks like a profile of the Alps (with Mt Blanc a feature in 2016).  A linear trend does slope upwards, but not a significant trend.

The equivalent to a Heat Wave is probably a Cold Snap and an equivalent definition would be " 3 consecutive days with both minimum and maximum significantly below long term averages".  I haven't researched the history of Cold Snaps in the same was as I have for Heat Waves (see links above) but for December the following analysis applies:

• 7 days with maximum more than 1 SD below average;
• 8 days with minimum more than 1 SD below average;
• 3 days with both extremes more than 1 SD below average; 
• No periods of 3 consecutive days with both extremes more than 1 SD below average.

Maximum temperatures

As I have explained before consideration of long term maximum temperatures is a little complicated as the BoM site is very exposed to cooling sea breezes, while my WS is somewhat sheltered from them.  I have adjusted the BoM data in my long term series of monthly maxima to allow for this.  Looking at this adjusted series,  the mean temperature of 22.3C was 0.8C below the long term average (and about 1 degree below 2021.

Again there is a lot of variability in the time series of average temperatures and the trend, while upward-sloping is not significant.

In terms of Heat Waves:

• 3 days with maximum more than 1 SD above average;
• 5 days with minimum more than 1 SD above average;
• 2 days with both extremes more than 1 SD above average; 
• No periods of 3 consecutive days with both extremes more than 1 SD above average.

Humidity

Here is a chart of daily readings at the standard times.  The number of times the 1500hrs reading is the higher is unusual, as is the number of times the 0900 reading was below 90%.  

For both standard times the average mean rH was above the longer term average but below last year's equivalent value.

Wind

The windiest day was the 8th, with a run of 214km (the 108th longest recorded by my WS).  The daily readings show the continual passage of squally events.

Overall, windier than last year but slightly under average.