Posts Tagged ‘Queensland’

Another ABC Fail

February 5, 2017

Viewers of ABC-TV news, and followers of ABC News Online, were treated to a story on Friday night about “Turtle hatchlings dying in extreme heat at Mon Repos”, as it was headlined at ABC News Online:

Piles of dead turtle hatchlings are lining Queensland’s famous Mon Repos beach amid a heatwave which has pushed the sand’s temperature to a record 75 degrees Celsius.

While the majority of hatchlings break free from their nests at night when the sand is cooler, those escaping in the day face overheating.

“They can’t sweat, they can’t pant, so they’ve got no mechanism for cooling,” Department of Environment and Heritage Protection chief scientist Dr Col Limpus said.

….

The extreme heat is also conducted down to the turtle’s nest, pushing the temperature to about 34C, which is approaching the lethal level for incubation.

That is the hottest temperature recorded in a nest in more than a decade.

A record 75 degrees sand temperature? Hottest nest temperature in more than a decade?

Time for a reality check.

I have no data on temperatures inside turtle nests, but I do have data on temperature at nearby Bundaberg Aero (Hinkler Airport), which is an ACORN site.

Using monthly Acorn data, here is a plot of all January maxima at Bundy.

bundy-jan-max

January’s mean maximum of 31.6 degrees C was equalled or exceeded in 1924, 1931, 1969, 1998, 2002, 2006, 2013, and 2014.  While monthly mean doesn’t tell us about individual days, it does give us a clue about daily temperatures in hot years.  For that I also use ACORN daily data- adjusted, homogenised, and world’s best practice apparently.

How do temperatures at this time of year compare with those of previous years?  The next figures show data for the first 45 days of every year, that is from January 1 to February 14.

bundy-jan-max-daily-45

The past three weeks at Bundaberg have been at the high end of the range, but no records have been broken, and no days have been even close to 35C.  What about previous years?  The next plot shows the number of consecutive days above 35 degrees: very likely to raise sand temperature above what it has been this year.

bundy-jan-max-daily-45-over-35

No days this year above 35C, but at least 27 occasions in previous years of single days reaching 35C, at least 6 of 2 days in a row, and one of 3 days in a row above 35C.

A 7 day running mean will show whether temperatures have been consistently high.

bundy-jan-max-7d-av-45

As you can see 2017 is high but not extreme.  2002 had a 7 day average just under 35C.

This graph plots temperatures of the first 45 days of years with similarly hot January temperatures.  2017 is the thick black line.

bundy-jan-max-daily-45-hot-yrs

On one day- January 20- 2017 was hotter than the other years.  Note how in several years the temperature drops to the mid 20s when heavy rain falls.  Note also the temperature reached the high 30s in February 2002.

The final graph shows the 7 day average of the same period of similarly hot years.

bundy-jan-max-7d-av-45-hot-yrs

Several previous periods were hotter than so far this year.

Once again we see misleading claims being made and reported by the ABC as gospel, without any attempt at fact checking.  A simple check shows that, while it may be true that the reported temperatures are the hottest recorded by these researchers, it is extremely unlikely that these were as high as they were in past years.  On every count- daily, monthly mean, 7 day mean, consecutive hot days- it can be shown that this year, while hot, is not as hot as many previously, and it follows that sand temperatures would similarly have been hotter in the past.

And that’s without considering the Holocene Optimum and the Eemian.

Another ABC fail.

Putting Daily Temperature in Context

December 14, 2016

In this post I demonstrate a simple way of comparing current temperatures for a particular location with those previously recorded.  In this way it is possible to show the climatic context.

Using data from Climate Data Online, I plot maximum temperature for each day of the year, and then for a particular short period: in this case the last week of November and the first week of December, which coincides with the recent very warm spell here in Queensland.  To account for leap and ordinary years this period is 15 days.  In ordinary years 24th November is Day 328 and 7th December is Day 341, while in leap years this same calendar period is Day 329 to 342.  I also calculate the running 7 day mean TMax for this period, and the number of consecutive days above 35C.

To put the recent heatwave in context, I have chosen six locations from Central and Southern Queensland which regularly feature on ABC-TV weather: Birdsville, Charleville, Roma, Longreach, Ipswich (Amberley RAAF), and Rockhampton.

Birdsville:

Fig. 1

whole-yr-birdsville

The Police Station data are from 1954 to 2005, and the Airport from 2000.  This shows the range of temperatures throughout the year.  The red arrow indicates the current period.   The next plot shows data only for the period in question.

Fig. 2:  24 November- 7 December: Airport data

14d-comp-birdsville-air

Note there were three days where the temperature this year was the highest for those days since 2000, but didn’t exceed the highest in this time period, which was in November.  The other days were well within the historic range.

For interest, let’s now see how this year compares with the Police Station record.  (The average difference in TMax during the overlap period was 0.0 to 0.3C.)

Fig. 3:  24 November- 7 December: Police Station data

14d-comp-birdsville-police

In a similar range.

Fig. 4

7d-avg-birdsville

This heatwave was the third hottest since 2000 and fifth overall.

Fig. 5

days-over-35-birdsville-air

Five previous periods had more consecutive days above 35C.  2006 had 22.

Charleville:

Fig. 6: Charleville Aero since 1942

whole-yr-charleville-aero

Temperatures in this period reached the extremes of the range on three days.

(Although the Post Office record begins in 1889, there are too many errors in the overlap period so the two records can’t be compared.)

Fig. 7:

14d-charleville-aero

A new record for early December was set, but note this was the same temperature as 29th November 2006.

Fig. 8:

7d-avg-charleville-aero

Definitely the hottest for this period since 1942.

Fig. 9:

days-over-35-charleville-aero

Note this was not the longest warm spell by a mile: there were many previous periods with up to 26 consecutive days above 35C.

Roma

Fig. 10:

whole-yr-roma

Although there is not one day of overlap so the two records can’t be compared, you can see that Airport (from 1992) and Post Office records are similar.

Fig. 11:

14d-comp-roma-air

A new record for this time of year was set: 44.4C, and six days in a row above 40C.  Pretty hot….

Fig. 12:

days-over-35-roma-air

…but there were longer hot periods in the past (since 1992).

Longreach

Fig. 13:  Longreach Aero since 1966.

whole-yr-longreach-aero

Fig. 14:

14d-longreach-aero

Hot, but no record.

Although there is good overlap with the Post Office, temperatures for this period differ too much: from -1 to +0.7C.

Fig. 15:

7d-avg-longreach-aero

Fifth hottest period since 1966.

Fig. 16:

days-over-35-longreach-aero

And in the past there have been up to 47 consecutive days above 35C at this time of year.

Ipswich (Amberley RAAF):

Fig. 17:

whole-yr-amberley

Fig. 18:

14d-amberley

Not unusually hot for this time of year.

Fig. 19:

7d-avg-amberley

Ninth hottest since 1941.

Fig. 20:

days-over-35-amberley

Hotter for longer in the past.

Rockhampton:

Fig. 21:

whole-yr-rocky

Fig. 22:

14d-rocky-air

Very hot, but no records.  (The heat lasted another two days, with 36.6 and 37.3 on 8th and 9th.)

Fig. 23:

7d-avg-rocky

Fourth hottest 7 day average on record (since 1939).

Fig. 24:

days-over-35-rocky-air

Again, a number of hot days, but there were as many and more in the past.

To conclude: the recent heatwave was very hot certainly, and was extreme in southern inland Queensland.  While Charleville had the highest seven day mean temperature on record, NO location had as many consecutive hot days (above 35C) as in the past.

This is a handy method for showing daily data in context.  It can used for any period of the year, can be tuned to suit (I chose TMax above 35C, but temperatures below a set figure could be found), and can be used for any daily data.

If you would like a comparison done for a location that interests you, let me know in comments including time period and parameters of interest (e.g. Sydney, first 2 weeks of December, TMax above 30C say, or Wangaratta, September, daily rainfall over 10mm say.)

Not the Worst Drought in 80 Years

January 7, 2015

Last night on the 7.00 p.m. ABC TV Queensland news there was a report on the Annual Climate Statement 2014 released by the Bureau of Meteorology yesterday (January 6).  I could not believe my ears, and as soon as it was on iview ( http://iview.abc.net.au/programs/abc-news-qld/NC1530Q005S00 ) I checked- several times.

The reader, Matt Wordsworth, clearly reports that the Bureau says Queensland has experienced “the worst drought in 80 years”.  The Bureau’s Jeff Sabburg was interviewed and claimed that 37.3% of the state was covered by the lowest rainfall on record.

Now I do know that much of Queensland has been very dry for a long time, with the northwest being especially bad, having missed two wet seasons (2012-13 and 2013-14).  Before you think I am callous, uncaring, and uninformed, I should let you know I was raised on a farm, my parents, grandparents, and great-grandparents were farmers, my brother and my brother-in-law are farmers, and I take a very keen interest in the land.

However, both the ABC news item and Jeff Sabburg’s claim, if quoted correctly, are complete nonsense.  Nothing like 37% of the State has had the lowest rainfall on record, and the drought is definitely not “the worst … in 80 years”.  The facts from the Bureau’s own websites (Climate Maps and Climate Change and Variability) show otherwise.

There follows a series of graphics clearly showing the state of Queensland’s rainfall and drought record.

Fig. 1:  12 month rainfall deficiency

qld 12m drought

Obviously recent rain has improved the situation, but what about over the last two years?

Fig. 2: 24 month rainfall deficiency

qld 24m drought

A-hah, that’s showing quite a lot of serious and severe rainfall deficiency, but not a lot of “lowest on record”.  However, compare that with the 24 month period to December 2003.

Fig.3:  24 months to December 2003

qld 24m drought 2003

I have been looking at Queensland rainfall closely in the past couple of weeks.  Here are some other ways of showing rainfall for Queensland.   I have shown 2013-2014 and 1929-1935 (the supposed 80 year ago worse drought), and more recent events, for ease of comparison.

Fig. 4: 12 month running mean of rain anomalies

qld rain 12m

Fig. 5:  24 month running mean of rain anomalies

qld rain 24m

Fig. 6:  27 month running mean of rain anomalies (covering the previous two wet seasons)

qld rain 27m

There was nothing unusual about Queensland’s rain in 2014.

The next graphics are plots of the 12 month counts of 12 month running means of rainfall with below average (bottom 30%), very much below average (bottom 10%), and severe deficiency (bottom 5%) rainfall.  In other words, counts of 12 month periods (January – December, February – January, March – February etc) with rainfall in each category.

Fig. 7: Count of 12 month periods of below average rain (lowest 30% of 12 month periods)

qld drought counts 12m belavg

Fig. 8: Count of 12 month periods of very much below average rain (lowest 10% of periods)

qld drought counts 12m verybelow

Fig. 9: Count of 12 month periods of severe rain deficiency (lowest 5% of periods)

qld drought counts 12m severe

There have been no episodes of statewide severe rain deficiency since January 2004.

Fig. 10: Count of 12 month periods of 24 month below average rain (lowest 30% of 24m periods)

qld drought counts 24m belavg

Fig. 11: Count of 12 month periods of 24 month very much below average rain (lowest 10% of periods)

qld drought counts 24m verybelow

Fig. 12: Count of 12 month periods of 24 month severe rain deficiency (lowest 5% of periods)

qld drought counts 24m severe

Fig. 13: Count of 12 month periods of 27 month below average rain (lowest 30% of 27m periods)

qld drought counts 27m belavg

Fig. 14: Count of 12 month periods of 27 month very much below average rain (lowest 10% of periods)

 qld drought counts 27m verybelow

Fig. 15: Count of 12 month periods of 27 month severe rain deficiency (lowest 5% of periods)

qld drought counts 27m severe

And just for information, this map shows the 36 month rainfall deficiencies to December 1902.

Fig. 16:  36 months to December 1902- the Federation Drought

qld 1902 36m drought

Now that’s a drought!

The current drought, bad as it is, barely rates when compared with previous droughts.

Perhaps the Bureau is using different data from what is shown on their websites.  Perhaps Jeff Sabburg was quoted out of context.  Whichever way, the public has been misled- not for the first time, and unfortunately not the last.

The Bureau of Meteorology should issue an immediate clarification, and the ABC should issue an immediate apology and correction.