Sunday, 21 January 2018

Ranging around the matter of temperatures

In my weather reports I usually comment on maximum and minimum temperatures and less frequently mean temperatures.  I can't recall saying much about the range of temperatures.  As a result of some comments on a weather discussion group I decided to look into this aspect of our climate a little more.  The first lot of commentary refers to the period from 2014 using my Davis Weather Station, so the collection mechanism is constant.

I classified the daily ranges to arbitrary groups.
That looks pretty close to a normal distribution to me.

The total range of temperatures I have recorded is from -6.8oC to 40.7oC or 47.5oC.   So that basically sets a limit on daily ranges!

The greatest daily range I have recorded since starting up my weather station here in 2014 has been 29.2oC.  That occurred on 17 January 2014 and was a range from a minimum of  9.7oC to a maximum of 38.9oC.

The lowest range was 1.5oC, on 1 September 2016 from 4.2oC to 5.7oC.

When looking at these extreme ranges it seemed that low ranges mainly occurred at lower temperatures.  By way of example of the 106 lowest ranges (those equal to or less than 6.2oC) only 3 were associated with a maximum temperature of greater than 20oC.  In contrast looking at all maximums almost exactly half were greater than 20oC.

At the other end of the scale, of the 100 days with a range greater than or equal to 22.2oC, only 1 had a minimum below 0oC. This contrasts with 18% of all days having a minimum below zero.  I think this is fairly logical: if the weather conditions lead to a frost it implies weather coming from the South but to get a large range in temperature requires at least a warm maximum, more likely to be associated with weather coming from the north.

It is also logical (IMHO) that a high proportion (~63%) of the days with top 100 ranges have a minimum below 10oC.  This comes about through arithmetic.  Relatively few days have a maximum above 30oC (and in most of those the range is less than 22oC) so to achieve a range >22oC effectively demands a minimum below 10oC.

I also looked at the monthly average ranges.  Note that the vertical scale has been truncated to clarify - perhaps overstate - the pattern.
This pattern shouldn't be surprising in view of the relationship between size of range and temperatures (big range with higher temperatures, small range with lower temperatures).

I decided to have a look at the level of variation in the data for each month using the Standard Deviation (SD) function within ACCESS.  The surprising (to me at least) outcome of this  was how similar the level of variation was.  This becomes apparent when expressing the SD as a % of the mean.  8 of the 12 months had an SD within the range 29.85% - 33.77% of the mean average range.  The only outstanding value was June where the SD was 39.75% of the mean.  As I have trouble establishing whether June is the last month of Autumn or the first month of Winter on both meteorological or biological grounds this is probably to be expected (I have concluded it's the last month of Autumn). 

Longer range analysis

As well as my personal data I also have access to maximum and minimum temperatures collected since 1993 from two other sites in Carwoola.  Although I have some doubts about the maximum temperatures from the early -mid noughties I thought it might be interesting to look at the ranges from the earlier years (1993-2013) in comparison to my data.
The similarity of pattern is immediately obvious, as is the greater range shown in the earlier records.  I strongly suspect that this is mainly a function of the different collection methods (site/equipment) rather than indicating a change in the weather.

Thursday, 18 January 2018

Looking at heatwaves in January

This January is being disgusting for heat.  However, is it being more disgusting than usual?  Theer are many ways of looking at this and I have tried to set out some of them blow.

I'll begin with a chart plotting days with a maximum over 30oC for the last 4 years.  I have chosen that period as it comes from my Weather Station so change of site isn't an issue.
Last year was very hot (or bad, if you prefer). The spell of 12 days then was not as bad as the 17 consecutive days over 30oC recorded by Lynton in January - February 2011!

I have compiled a profile of maxima for January 2018 using my data to the 17th and the rest of the month from various forecast.  The next chart compares the result of that with the actual data for 2017.
I think that shows that last year was worse!

In terms of heat wave days (ie number of days in periods of 3 days or more of >30oC and minima >10oC), it looks as though this January will rack up 19 days (if the forecasts are correct).  Last year was 22. 

The average number of January Heat Wave Days since 2010 is 16.75 and since 1993 is 14.2 (which includes a period in the noughties where I think the recording device was biased upwards).  So this year is overachieving but not dramatically so. 

I charted the number of Heat wave days since the year ended 30 April 1994.  (I apologise for the unnecessary orange shadow, but it does look pretty!)

Although the value of r2 for the polynomial trend line is not great the pattern suggests that what we are experiencing now could be not a long way off what will become normal in the future.

Just for comparison in January the maximum temperature for Dubai in years since 2012 ranges between 27oC) and 30oC).  The average daily maximum over the month is between 20oC) and 24oC).  I wish I was there.

Wednesday, 17 January 2018

Glendale WW

I thought I'd start with a spiffy view from about the mid-point of the walk.

22 Members (I don't think there were any guests) arrived at Glendale Depot after car pooling at the Namadgi Visitors Centre.  It was fortunate that some of those present had recently visited Glendale and were aware that the gate is often closed: a change in policy.  It was open when we arrived but closed when we left (although it may not have been locked.
Our route was essentially a figure 8 starting by walking towards the Mighty Gudgenby River and then up towards the Depot itself.   This image of the route is from eBird, where Peter had the track function turned on.
An early Good Bird was the pair of resident Sacred Kingfishers.  They were soon followed by 3 Southern Whiteface which obligingly perched on various fences, wires and Verbascum stalks allowing most of us good looks.   One was very cooperative in perching next to a Dusky Woodswallow (of which there were many) so that we could be sure we weren't confusing the two species.

The first of several Pallid Cuckoos was seen in this stretch (thank Sandra who posted this image to the eBird checklist).
A family of Fuscous Honeyeaters (2 adults and 3 chicks) were observed in some eucalypts, which was quite exciting for some.

Proceeding towards the Depot ...
... a Lathams Snipe was flushed from a small watercourse.  This landed in, and was flushed again, ...
... accompanied by two others, from a damp, reedy area below the dam.  The dam contained two Australasian Grebes 
and a Pacific Duck.  The woodland around the dam contained 2 Diamond Firetails and at least 15 more Fuscous Honeyeaters and 5 Common Bronzewings.  As we left the area 19 Australian Wood Duck flew in.

We then travelled across country, logging up to 5 Rufous Songlarks and considering estimates of the number of Little Ravens in a dominant eucalypt.  The best estimate - a tree nearly full - was rejected and 50 was adopted.  More Fuscous Honeyeaters were seen and the final agreed tally was 40.  It was surprising that this didn't earn me a query from eBird- because I was using a NSW site as the basis of my off-line checklist and as soon as I switched to submit the final list for Glendale a query arrived.  I also got scolded for the 4 Pallid Cuckoos, the 30 Dusky Woodswallows - which I don't regard as an unusually high number for a walk approaching 4km - and the 5 indeterminate Martins (which is a very modest flock of Martins of either species)!

I didn't get a query for the input of 10 Australasian Pipits, which I thought on the higher end of abundance for this species.
Overall we recorded 48 51 species after adding in a few extras submitted by email and adjustments to the checklists (and a mixed record of Fairy/Tree Martins as the main observer couldn't be sure which they were).  A full list is at this eBird checklist.  

There was a lot of Verbascum major 
around the grassy area with no sign of any control measures.  Many of the birds seemed to like the stalks as elevated perches- 2 Pallid Cuckoos in particular were active on some of the dry stems (and these are often good spots for Hooded Robins) but they can be very invasive.  (It is disappointing that a Ranger reported to a member of the group that Hooded Robins bred at the site this year but this doesn't appear in either eBird or the ALA.  How can resources be managed or protected if key observers don't record their sightings?)

Another nice sighting was a clump of Bursaria spinosa in full bloom.
I wish that computers had a scent function as this lot were highly perfumed.  Unusually there were few insects around them.

Some members saw Cunningham's Skinks on the rocks but I had to settle for a Jacky Lizard.
A couple of other aspects of the Depot.  The pile of abandoned/reclaimed signs caused some amusement ...
 .. while the rubbish tip out the back was far less pleasant to see.
The final bit of amusement during the day was this huge "Right hand down a bit" by an aircraft.
I tried logging on to Flight Radar to find out where it was coming from and/or going to, but such informationwasn't available in the bowels of Namadgi!

Sunday, 14 January 2018

A walk round East Basin

Lake Burley Griffin is crossed by two bridges and is ended by Scrivener Dam.  This splits the water body into three sections known as West Basin (Scrivener to Commonwealth Avenue Bridge);  Central Basin (between Commonwealth and Kings Avenues) and East Basin (Kings Avenue to Dairy Flat)

Today we walked the 10km (approximately) around East Basin.  The route, done anticlockwise, is shown in this clip from Google Earth.
Although we wanted to do some birding at Jerrabomberra Wetlands it is no longer possible to park there without a risk to finding you car has been broken in to.  So we parked at the Canoe Club and schlepped our binoculars round the route.

The first birds were these vermin. 
I have no idea why the Parks people haven't converted them into pate or some other useful commodity.  Presumably they will only start to take notice when they have reached Myna levels of population. 

After crossing Kings Avenue Bridge we got to the site of a carpathon.  The gale that was blowing appeared to be limiting the amount of decarping being achieved,  This angler appeared to be handling the stress OK
So was this Black Swan, which seemed to be guzzling a junior anglers bait!
We left the Lake shore to take the most direct route we could find though the slums of Kingston.  As we past one group of apartment I noticed some interesting things about the letter boxes.

  • What happens with anything bigger than a standard envelope?  These people must spend as much time in line at the PO picking up their larger mail as they do at work or sleeping.
  • For some reason the boxes for #s 2 and 7 are out of order.  I saw this also on another block so it isn't a one off mistake.  But what could be the rationale for this?
  • Some years back I looked at the incidence of No Junk Mail stickers across a few suburbs of Canberra and attempted to find some correlations with Census data.  The one that worked was level of educational qualifications.  Areas with a lot of stickers (>60% of boxes) had a high proportion of people with tertiary quals.  A rate of 3 stickers for 21 boxes would equate to most people in the area finding 3rd grade the best 3 years of their lives.
We pressed on to the Wetlands and found a few species of birds.  I thought this Darter interesting as it appears to be mud-stained, which I have never noticed before.

After seeing a very noisy fledgling Eastern Koel being fed by its Red Wattlebird host (and having to leave a hide due to arrival of the most unpleasant bunch of mini-bogans I have ever seen there) we left the Wetlands and walked down Dairy Road.  That was enlivened by seeing 3 Sacred Kingfishers on or around some phone lines.
All up we recorded 34 species of birds.

Saturday, 13 January 2018

Some book reviews

Sometimes I find links to interesting books in other reading and sometimes I get lucky in picking ones up at random in a library,  Just recently Frances has followed the first approach and got some big winners, which I have subsequently read.  Here are a few comments.

I think it is merely coincidence that the two main entries involve Catholic priests.  I'm certainly not leading off with my left foot!

The Attachment: Ailsa Piper and Tony Doherty

This is in essence an annotated exchange of emails between the authors, and largely about matters of faith and\or beliefs.  Ailsa Piper's relevant back-story is walking one of the routes of the Camino de Compostela.  The friendship described though the book began when Tony Doherty, a priest in Rose Bay, emailed her to compliment her on the book she wrote about that.

The narrative of the book is interesting, although not necessarily happy all the time, and I found the discussion of their beliefs to be very thought provoking.  My only small cloud on the horizon is that Tony doesn't give the hierarchy of the Church a massive serve.  (He clearly is very concerned about the abusive priests but it isn't so clear about the senior folk in the system that covered them up.)

Frances wasn't sure I'd enjoy this but it was great.

Things you get for free: Michael McGirr

The two stories in this are basically a trip report by Michael McGirr covering a 6 week trip to Europe with his Mum interspersed with segments about his early life and becoming a Jesuit and his parents marriage.  There is also some coverage of his  father's family, especially his aunt Trixie - introduced as a friend of McGirr's Mum , but gradually revealed as a Baroness and influential British politician.

Basically he is a very good writer - by which I mean he strings words together in a way that gets you interested and amused, not that he writes the turgid crap that wins Literary Prizes under the caption of "A Novel".  

There are many very funny bits in the book and some rather sad bits.   Given the success of other members of his father's family it is a bit hard to understand why McGirr's father was somewhat of a loser.  At one point he says something to the effect that "I never knew my Father to have a job." and the father certainly got along doing the best he can (described by Damon Runyan as an occupation that is heavily oversubscribed).

The religion is very much part of the book but in an interesting way.  He says he leaves the Jesuits, after the events described in this book but doesn't explain why.  Hopefully that will be covered in another book, which we'll be able to track down.

Bypass: Michael McGirr

This is a sequel to "Things you get for free" and does include an explanation of why he left the priesthood.  Given the significance of this decision it is done in a very low key way, and I wonder if there are other factors involved.

Again there is more than one story covered side by each.  I was originally going to say there were two:
  • the author's relationship with his girlfriend (now wife, so that is a happy tale); and
  • the history of the Hume Highway.
However on thinking about it I would now split the second into 3 parts:
  • the exploration of the route by Hume and Hovell;
  • the impact of the road on the towns it passes through (and what happened when they were bypassed  - note the title of the book); and 
  • the story of Cliff Young, winner of the first Sydney to Melbourne running race.
Overall it is much lighter in tone than the previous book.  A very good read, especially as I'm quite familiar with many of the towns.  I LOLed quite a few times!

For I will consider my dog Percy:  Mary Oliver

This is a bit of a cheat as it is a single, quite short, poem by Ms Oliver.  However it is an excellent bit of work describing a dog who is no more.  I wondered about many things in the poem and did a bit of Googling to try to find out. This revealed that his friend Ricky is a small hairy terrier and delivered a photo of Mary Oliver and Percy.
I expect to read a lot more of her stuff.

Wednesday, 10 January 2018

Reclaiming the Stakes

Having had a medical interlude I decided that I now in condition where I should get back to the BBQ Stakes so took myself to the appointed spot.  It wasn't hard to find a trolley: just difficult to find one that wasn't attached to a few mates.
 On the subject of mates, at 11:58, all my friends were present.
 A few others began to turn up at 11:59 including a mysterious trolley pushing person.
 That turned out to be Roger, who had found a pair of trolleys that were at least pushable in their united position.
I left my $1 with Roger  and set off at noon, wondering if I could walk 6 km in 60 minutes.  A speed merchant went past me at about 2km (21 minutes).  Another person, who might have set off a bit closer to their handicap time, came past at the half way mark and is shown here gaining on Rad, who took the gentleman's route at the top of the hill.
On the Stakes Facebook page the guy in the blue cap admitted that he took a wrong turn at the substation and did an extra 1km!  The masses started to come past me in the last km and I finished in about 61 minutes which wasn't too shabby in the circumstances.

As the authorities have mentioned the incoming Ruby anniversary a few times recently I thought I'd finish with a snap of the plaque for the Emerald event.
I suspect that getting another plaque affixed to the wall will require several rounds of discussion with the ACT Government including stress testing the underpass.  Or someone brings a drill along and we just bolt one up.

For interest here
is a Google Earth snip of the route.  My total distance was actually 27m short of 6km, but the line did straighten a few things out which are not quite possible on the ground.

Rain in Carwoola

A friend recently enquired if the reason rain kept missing this area was because they went to the wrong Church.  I made some suggestions about how to adjust his congregational practices but as it hasn't yet got to Sunday the past pattern appeared to be continuing yesterday.

Here is the BoM radar image at 1548 on 9 January.  All moving East and we didn't get a drop out of this.
 The Bureau issued a specific Severe Thunderstorm warning at this time.  Here is the image showing the two storms bracketing us (at the blue cross).  As I said, not a drop!
Later in the day Weatherzone radar showed a massive storm covering a fair proportion of Central NSW.  I checked the local radar and it looked as though it was going to the North of us.
 However about 2230 I was awoken by the rain pounding down,  It only lasted for about 10 minutes, during which we received 6.8mm.  My weatherstation reported the rate as 101mm/hr, which is the 25th highest rate recorded.

The next day a few folks reported what they recorded: the variability indicates we were right on the edge.
After the storm last night we had got  9.6mm for the year and were 0.2mm in front of last year.  I have created a file that compares rainfall to date (by day) with historic records of that function.  Using that to extrapolate for the whole year (a dodgy idea, but its amusing) we can expect 291mm for the year (ie we are still way behind average).  Here is a graph which shows something I can't quite fathom yet.