For large parts of southern and eastern Australia, dry conditions have now persisted since October
1996, a total of eleven years. For some areas, the accumulated total rainfall deficit over this period
now exceeds a full year’s normal rain.
For the agriculturally important Murray-Darling Basin, however, October 2007 marks the sixth
anniversary of lower than average rainfall totals, with the November 2001 to October 2007 period
being its equal driest such six-year period on record.
This extreme dry period for the Murray-Darling Basin has also been accompanied by high
temperatures, exacerbating the low rainfall. Both daytime maximum and daily mean temperatures
for the six years from November 2001 to October 2007 have surpassed the previous records by a
Read the 6 page pdf:
Six years of widespread drought in southern and eastern Australia
November 2001–October 2007
Issued 1st November 2007
National Climate Centre
Interesting report and supports what I have observed. October 2007 in NSW was also the equal hottest on record. Certainly El Nino is a factor in the rainfall decline, but it can’t explain the temperature rise. Something to do with the south pole vortex?
The Bureau of Meteorology just can’t do it, can they? They simply won’t admit that the Southern Oscillation influences rainfall in the Murray Darling Basin.
At http://mclean.ch/climate/Murray_Darling_rainfall.htm a graph demonstrates that with few exceptions, winter-spring rainfall correlates reasonably well with the Southern Oscillation Index over that time.
The BoM doesn’t tell us about variations in cloud cover either. The diurnal temperature range is a pretty good guide and guess what? Yes, over at http://www.bom.gov.au/cgi-bin/silo/reg/cli_chg/timeseries.cgi you can display the diurnal temperature range and it’s been pretty high over the last 5 years. In fact it’s reverted to pre-1950 levels.
With rainfall and diurnal temperature both now close to the levels from 1910 to 1949 maybe we should start thinking that 1950-2000 was the abnormal period, not the recent years.
I think somehow BoM may know about the SOI – Neville Nicholls (ahem).
So a dry 11 years overall – I wonder why the neutral years also brought little relief. 🙂
I was referring particularly to the statement in the report which said “For the agriculturally important Murray-Darling Basin, however, October 2007 marks the sixth anniversary of lower than average rainfall totals, with the November 2001 to October 2007 period being its equal driest such six-year period on record.”
Take a look at http://www.bom.gov.au/cgi-bin/silo/reg/cli_chg/timeseries.cgi and you’ll find that rainfall in the MDB wasn’t too bad in the late 1990s.
In a rare moment I agree with you about the Bureau of Met knowing about the SOI. Several staffers have written papers about the correlation – which makes it all the more reason to wonder why the BoM failed to mention the SOI in this report.
I’m not so sure about Neville Nicholls still being at BoM. According to that recent “Healthy Planet healthy people” report (see http://www.thankyouday.org/content/documents/e_EnviroReportRA.pdf) he’s now in the School of Geography and Environmental Science at Monash University.
Sid Reynolds says
John is correct in pointing out that the high diurnal temps. of last five years are in line with pre 1950 levels.
How does this equate with the BoM’s statement that the daily max. and mean temps. for past six yrs.,Nov./Oct. have surpassed prev. records by a considerable margin?…..Easy; the BoM simply doesn’t recognise pre 1950 temp. data. Why? Because such data is an Inconvenient Truth which would muck up the BoM’s promotion of the ideology of AGW.
Neville has moved to Monash after a long career at BoM. It was he who suggested the evaporative flux of recent droughts is worse from AGW warming. Nicholls is also a very conservative scientist who hasn’t come to global warming easily.
I agree with the time series. However the MDB is a VERY big place – from headwaters in Qld south of Emerald for the Darling River to the Snowy Mtns for the Murray RIver.
To make a really incisive analysis of drought you really have to convert to the unit of interest e.g. megalitres of dam water or kg of wheat or pasture.
Simulations can reasonably estimate the integral of rainfall seasonality, amount, distribution, antecedent conditions (so soil water balance), and evaporative demands like wind, radiation (cloud), vapour pressure deficit and temperature. So runoff, river inflows or plant growth can be calculated and made into percentiles or time series like rainfall.
Your comment on cloud is perceptive – evaporation a function of radiation, humidity (more correctly vapour pressure deficit), wind run and temperature. Wind run has also changed in parts.
Anyway most of the integrated approach ends up in amplifying the effect – i.e. makes it worse on average.
Full landscape modellers would also add in vegetation clearing, changes in albedo, surface roughness (wind effects) and stomatal resistance of the vegetation. Whether these amplify local climate effects is another good debate.
So if we look at the six years – the basin has been warm, the neutral years also have not delivered – rainfall missing the continent – southern annular mode changes perhaps ?? and why.
El Nino/La Nina is debatable.
Wind run? Vapour pressure deficit ? Radiation ?
Sid – really and uninformed comment by yourself – do you know that for a fact? Have you confirmed that with David Jones – a quick email would inform you. Or do you prefer to conduct a one-sided propaganda war where you can throw any muck you’re dreamed up with no right of reply. Very poor behaviour Sid if you consider yourself a gentleman farmer.
The 4AR has noticed the change in diurnal temperature pattern too.
A lot of Bureau data before the 1950s is not available on computer – but a selection of high quality data sets have been prepared and you can are available on their own web site.
Even more surprising a less combative attitude can also have questions answered and other analyses made.
But it’s easier for you to spray accusations – looks good to the cheer squad here as it adds to that “big conspiracy feeling”. If you haven’t made the phone call or email – you have not closed the loop and are full of shit if you want to make public comment. Journalists call it “checking source”.
Taking a high moral tone Luke, you thinking of entering the priesthood?
What do you mean “thinking”. My son let us pray for your redemption.
Your son a priest too? – think I will do my praying standing up thanks.
“A lot of Bureau data before the 1950s is not available on computer – but a selection….” !! . “..do you prefer to conduct a one-sided propaganda war where you can throw any muck you’re dreamed up with no right of reply.” “But it’s easier for you to spray accusations..”
Seems to prove the point Sid was making.
Well so you’re saying their reference network is inadequate or what? Sid’s just an old BoM basher. Wouldn’t matter what they said he’d try one on. Still waiting for his drought analysis which never seems to come though.
Sid Reynolds says
The BoM has a very large pool of recorded data on rainfall and temperature and othe weather and climate records going right back into the 19th centuary. It has some of the world’s best recording instrumentation placed throughout the country. The Bureau has a large, skilled and dedicated workforce…. These are the positives.
The negatives are…
The BoM, as a public Authority, should be meticulously objective in the study and presentation of recorded data on matters climate.. Here, the BoM fails the test.
In fact, the BoM has become an active player in
the promotion of the politics of AGW.
So much so that the head of the Bureau, Dr. David Jones, (a) Attended a screening of An Inconvenient Truth,and publicly endorsed Gore’s porkies contained therein…… And..
(b) Issued a statement condemning the screening of Durkin’s TGGWS in Australia.
So committed to the ideology of AGW, is the Bureau,and in particular, its climate division, that all its forecasts, media releases and public pronouncements are heavily biased towards AGW.
An example of this has been the BoM’s seasonal climate forecasts over the past three quarters. In each case it was said that Australia could expect a hotter summer/warmer autumn/milder winter because of climate change. (This month we await more of the same re the coming summer).
However the BoM’s Seasonal Climate Summaries for the three aforementioned periods tell a different story, showing, on the whole, much cooler climatic recordings then those forecast. These were played down, waffled over and made the best of, with a bit of cherry-picking into the bargain. (eg. ‘hottest May on record’). What record, where?
If the BoM could be a bit more objective, it could provide a much more valuable and reliable service to the Australian people.
Sid – please point to these statements “In each case it was said that Australia could expect a hotter summer/warmer autumn/milder winter because of climate change”.
Good one Sid, now could you kindly present some evidence for your claims :).
Sid Reynolds says
Simply go to the BoM’s seasonal climate forecasts, or outlooks for last summer, autumn, winter and the current spring. Then have a look at their seasonal climate summaries for the same seasons. Of course the spring summary will not be available till next month.
Suggest you pin up their soon to be released climate outlook for the forthcoming summer, and the media trumpetings of the same. More than likely it will be more of the same… ‘Hotter, drier, more violent storms, worse bushfires etc etc.’
Then when the climate summary for the same period is quietly released by the Bureau, along with subdued media reports, sometime next March,… do a comparison. Meanwhile fellas compare the outlooks and summaries for the past seasonal periods…..Along with the media reporting of same….Or in the case of the Summaries….Lack of media reporting.
Well just having a bit of difficulty Sid – can you show me specifically “In each case it was said that Australia could expect a hotter summer/warmer autumn/milder winter because of climate change”.
I looked through their temperature for “climate change” and “global warming” but had some difficulties finding the phrase.
Can you also show me “Hotter, drier, more violent storms, worse bushfires etc etc.” or is this just your OPINION.
And can you tell us how the Bureau release material quietly. What’s the difference in their style – do they use loud drums when they want you to listen or do you personally think it’s “quietly” if you don’t like the press attention? Now we have seemed to have moved from the Bureau’s advice to “media trumpeting”.
Seems like Siddles isn’t going to put up.
Sid Reynolds says
Nothing to ‘put up’ Luke, its all available in the BoM reports available on their website. Maybe your search difficulties have something to do with ‘There’s none so blind as those who wont see!’.
As I’ve mentioned above, watch for the BoM’s summer season climate outlook due to be released this month. If true to form, it will have more of the same…. But after so many duds, they may give up on releasing them!
However, if the do, pin it to the wall, along with the associated press bally-hoo. Then next March, when the Bureau releases their Australian Seasonal Climate Summary: Summer, 2007/8 (December-February), do a comparison….. You never know, after so many losses, they may even have a win! Then for the first time, their summary will make the media.. bigtime.
If you can’t wait ’till Feb., early next month, the BoM should release their Seasonal Climate Summary for the spring Qr. Grab it and compare it to the titilating Spring Qr. Outlook they issued in August.
So Siddles all you had to do was list a URL with your quoted “climate change” words enclosed. I’ll take your duck as that as “you can’t”.
Don’t bother changing the subject.
You need to put up. You’ve been called !
One more obfuscation and we may have to say you’re lying your skanky butt off. And we wouldn’t want that would we?
Oh Sid – that web link?
ooooo Sid ….