By Simon Torok
Here’s a simple backyard science experiment for you to try, which has global implications.
Grab a garden hose, turn it on, and then put your thumb over the end of it. The flow of water thins, while its power intensifies.
Okay, now multiply that by a few million and you have some idea of the impact of recent La Niña conditions on a major ocean current north of Australia.
The Indonesian Throughflow is a series of ocean currents linking the Pacific and Indian Oceans. It carries water from the Pacific to the Indian Ocean through the passages and straits of the Indonesian Archipelago.
Researchers – led by Janet Sprintall at Scripps Institution of Oceanography in the United States, and including Susan Wijffels from CSIRO in Hobart – have found that the flow of water in the Indonesian Throughflow has become more shallow and intense since the late 2000s due to La Niña conditions, just as the water flow thinned and intensified while you played with that garden hose.
The paper, The Indonesian seas and their role in the coupled ocean-climate system appears in today’s online publication of the journal Nature Geoscience.
The Indonesian Throughflow is the only place in the world where warm equatorial waters flow from one ocean to another; consequently, the throughflow is an important chokepoint in the flow of heat in the climate system.
The paper suggests that human-caused climate change could make this shallowing and intensification a more dominant feature of the Indonesian Throughflow, even under El Niño conditions.
Changes in how much warm water is carried by the Indonesian Throughflow will affect the sea surface temperature, and in turn the patterns of rainfall in our region.
So you may need to think a bit more about how you use that garden hose.
When clouds block the sun, solar panels and the electricity networks they are hooked up to need time to adjust to the fluctuations. Saad is working out how to maximise solar efficiency as part of the Energy Networks Team in the CSIRO Energy Flagship. He is looking at various solutions including smart grids, solar energy management and solar “forecasting”.
Beau Leese – General Manager – Strategy, Performance and Flagships
Beau is responsible for the development and implementation of the CSIRO’s overall enterprise strategy, new strategic initiatives, science portfolio investment, planning and performance management, Impact 2020 and cross Flagship collaboration (phew). Beau led CSIRO’s operating model review and the startup phase of the integrated reform program. He is a member of CSIRO’s Executive Management Council, SICOM and Major Transactions Committee.
Lisa is CSIRO’s Project Scientist for the Australian Square Kilometre Array Pathfinder in WA.
The daughter of a Primary School teacher and a house-dad, Lisa left school at the age of 11 and taught herself at home, where her passion for astronomy developed. Her scientific publications span a number of fields from star formation, cosmic magnetic fields and gravitational lensing to supernova remnants. When not designing telescopes and studying galaxies billions of light-years away, she enjoys ultra-long-distance running, including 12 and 24-hour races. In 2012 she was appointed chair of the steering committee of the Women in Astronomy Chapter of the Astronomical Society of Australia.
Rather than chipping on to the 9th green on the professional golf circuit, Nick Roden is now looking at how different biological and physical processes combine to influence the carbon cycle in the waters around East Antarctica. A few years ago Nick, who is based in Hobart, decided that studying the biology of the waters around East Antarctica as part of a PhD had a brighter future than being a professional golfer, so Nick chucked in the clubs and joined CSIRO. We’re glad he did.
Vanessa (Ginny) Hill – Social Media Advisor – Communications
Vanessa is one of the team leading CSIRO into the digital age as far as social media is concerned –video content produced by Vanessa has had more than 13 million views on YouTube. Other platforms such as Twitter and news@CSIRO blog take CSIRO’s and Vanessa’s work to millions more each year.
Even when Vanessa is at home or on holidays – she keeps on tweeting and communicating science.
This coming Sunday when the clocks are wound back one hour, the curtains will stop fading faster, birds and cows will no longer be confused by the ‘extra’ sunshine and life will return to its natural rhythm.
For those living in South Australia, NSW, Tasmania, Victoria and the ACT, Daylight Saving comes to an end this week.
Daylight Saving has caused much debate since it was first conceived by Benjamin Franklin in 1784.
Not that “adjusting” time to suit our needs was new then. Ancient civilizations adjusted daily schedules to the sun – often dividing daylight into 12 hours regardless of day length, so that each daylight hour was longer during summer.
Roman water clocks had different scales for different months of the year. In Rome the third hour after sunrise started just after 9am and lasted 44 minutes at the winter solstice, but at the summer solstice it started just before 7am and lasted 75 minutes.
Modern Daylight Saving never really got off the ground until 1895 when an entomologist from New Zealand, George Vernon Hudson, wrote a paper that proposed a two-hour shift forward in October and a two-hour shift back in March. He followed up his proposal with an article in 1898, and although there was interest in the idea, it was never followed through.
Some places in Argentina, Iceland, Russia, Uzbekistan and Belarus have introduced permanent Daylight Saving and the United Kingdom stayed on it from 1968 to 1971.
There are also apparently some health issues related to Daylight Saving.
People who are already vulnerable to heart disease may be at greater risk right after sudden time changes.
Recently a study was released in the US which showed that people who were already vulnerable to heart disease may be at greater risk right after sudden time changes.
According to the study, turning clocks forward an hour for Daylight Saving time was followed by a spike in heart attacks on the Monday following. Monday is traditionally the day when most heart attacks occur – it is suggested that the stress of returning to work may be a cause. There was a 25 per cent jump in the number of heart attacks occurring the Monday after the spring time change – or a total of eight additional heart attacks. But when clocks fall back and people gain an hour of sleep, there was a drop (21 per cent) in heart attacks on the Tuesday.
So, it seems the odds are increased that I will live a bit longer – at least until Daylight Saving comes back.
While it seems that every article about Daylight Saving has to have the curtain fading gag, is there ‘extra’ sunshine?
In the 1950s scientists in our Division of Physics were using a flare-patrol telescope to observe disturbances in the Sun’s chromosphere. It showed the appearance and growth of several flares and surges. Some of these disturbances are observed against the disk of the Sun. Those too faint for this are studied at the limb, or edge, of the Sun.
Coronal mass ejections on the Sun release huge amounts of matter and electromagnetic radiation which can cause particularly strong aurorae (Northern and Southern Lights), disrupt radio transmissions and cause damage to satellites and electrical transmission line facilities.
Coronal mass ejections reach velocities between 20km/s to 3200km/s with an average speed of 489km/s. They take between one and five days to reach Earth.
So is that extra sunshine?
Every two years CSIRO and the Bureau of Meteorology get together, crunch the numbers and release a definitive report on long term trends in Australia’s climate – The State of the Climate.
The SoC 2014 released today is focused on the changes that have been observed in Australia’s long-term climate trends and it shows that temperatures across Australia were, on average, almost 1°C warmer than they were a century ago, with most of the warming having occurred since 1950.
“Australia’s mean temperature has warmed by 0.9°C since 1910,” BoM chief Dr Vertessy said. “Seven of the ten warmest years on record in Australia have occurred since 1998. When we compare the past 15 years to the period 1951 to 1980, we find that the frequency of very warm months has increased five-fold and the frequency of very cool months has decreased by around a third.
“The duration, frequency and intensity of heatwaves have increased across large parts of Australia since 1950. Extreme fire weather risk has increased, and the fire season has lengthened across large parts of Australia since the 1970s.
“We have also seen a general trend of declining autumn and winter rainfall, particularly in southwestern and southeastern Australia, while heavy rainfall events are projected to increase. Australian average annual rainfall has increased slightly, largely due to increases in spring and summer rainfall, most markedly in northwestern Australia.”
CSIRO boss Megan Clark said Australia has warmed in every State and Territory and in every season.
“Australia has one of the most variable climates in the world. Against this backdrop, across the decades, we’re continuing to see increasing temperatures, warmer oceans, changes to when and where rain falls and higher sea levels,” Dr Clark said. “The sea-surface temperatures have warmed by 0.9°C since 1900 and greenhouse gas concentrations continue to rise.”
CSIRO and the Bureau of Meteorology play a key role in monitoring, measuring and reporting on weather and climate, contributing to improved understanding of our changing global climate system. State of the Climate 2014 is the third report in a series and follows earlier reports in 2010 and 2012.
Below are some of the main facts from the report.
- Australia’s mean surface air temperature has warmed by 0.9°C since 1910.
- Seven of the ten warmest years on record have occurred since 1998.
- Over the past 15 years, the frequency of very warm months has increased five-fold and the frequency of very cool months has declined by around a third, compared to 1951–1980.
- Sea-surface temperatures in the Australian region have warmed by 0.9°C since 1900.
- Rainfall averaged across Australia has slightly increased since 1900, with a large increase in northwest Australia since 1970.
- A declining trend in winter rainfall persists in southwest Australia.
- Autumn and early winter rainfall has mostly been below average in the southeast since 1990.
Heatwaves and fire weather
- The duration, frequency and intensity of heatwaves have increased across large parts of Australia since 1950.
- There has been an increase in extreme fire weather, and a longer fire season, across large parts of Australia since the 1970s.
Global atmosphere and cryosphere
- A wide range of observations show that the global climate system continues to warm.
- It is extremely likely that the dominant cause of recent warming is human-induced greenhouse gas emissions and not natural climate variability.
- Ice-mass loss from the Antarctic and Greenland ice sheets has accelerated over the past two decades.
- Arctic summer minimum sea ice extent has declined by between 9.4 and 13.6 per cent per decade since 1979, a rate that is likely unprecedented in at least the past 1,450 years.
- Antarctic sea-ice extent has slightly increased by between 1.2 per cent and 1.8 per cent per decade since 1979.
- The Earth is gaining heat, most of which is going into the oceans.
- Global mean sea level increased throughout the 20th century and in 2012 was 225 mm higher than in 1880.
- Rates of sea-level rise vary around the Australian region, with higher sea-level rise observed in the north and rates similar to the global average observed in the south and east.
- Ocean acidity levels have increased since the 1800s due to increased CO2 absorption from the atmosphere.
- Atmospheric greenhouse gas concentrations continue to increase due to emissions from human activities, with global mean CO2 levels reaching 395 ppm in 2013.
- Global CO2 emissions from the use of fossil fuel increased in 2013 by 2.1 per cent compared to 3.1 per cent per year since 2000.
- The increase in atmospheric CO2 concentrations from 2011 to 2013 is the largest two-year increase ever observed.
Future climate scenarios for Australia
- Australian temperatures are projected to continue to increase, with more hot days and fewer cool days.
- A further increase in the number of extreme fire-weather days is expected in southern and eastern Australia, with a longer fire season in these regions.
- Average rainfall in southern Australia is projected to decrease, with a likely increase in drought frequency and severity.
- The frequency and intensity of extreme daily rainfall is projected to increase.
- Tropical cyclones are projected to decrease in number but increase in intensity.
- Projected sea-level rise will increase the frequency of extreme sea-level events.
Media: Huw Morgan M: +61 417 834 547
Blue Marlin: This week a blue marlin washed up on a suburban Adelaide beach. It is thought this is the first time a marlin has been found in the cool waters of Gulf St Vincent where Adelaide sits.
Scientists from the South Australian Research and Development Institute think the fish took a wrong turn at Kangaroo Island and ended up in the Gulf.
They also think that the 3.2m long, 250kg marlin swan along the WA and SA coasts in the warm Leeuwin Current which at this time of year flows down the WA coast and around into the Great Australian Bight.
Below is a picture of the current (red turning to yellow and green as it cools) whipping around the bottom of WA. The second image shows the SA coast with the relatively warm water flowing around Kangaroo Island.
More images of the ocean currents around Australia can be found at the Bureau of Meteorology site which gets the information through the Bluelink program run by CSIRO’s Wealth from Oceans Flagship in collaboration with the Bureau of Meteorology and the Royal Australian Navy.
Anyway, back to the blue marlin. There is a debate going on about the classification of the Atlantic blue marlin and the
Indo-Pacific blue marlin (Makaira mazara) as separate species. Genetic data seems to show that although the two groups are isolated from each other they are both the same.
The blue marlin spends most of its life in the open sea far from land and preys on a wide variety of marine life and often uses its long bill to stun or injure its prey.
Females can grow up to four times the weight of males and the maximum published weight is 818kg and 5m long.
Blue marlin, like other billfish can rapidly change color, an effect created by pigment-containing iridophores and light-reflecting skin cells. Mostly they have a blue-black body on top with a silvery white underside.
Females can spawn up to four times in one season and release over seven million eggs at once. Males may live for 18 years, and females up to 27.
Dark Smiling Whiptail: I was trying to be smart and find a fish with some sort of connection to the Winter Solstice (today) to try and make the shortest day of the year bearable. So I started to search the ScienceImage database using words like solstice, daylight, night etc etc and came across the Dark Smiling Whiptail.
I have got to tell you there is very little of interest about this fish. It lives down to about 850m of water which is something, but apart from that, not much.
Then I started to have a look at the scientists who described the fish and named it in 1999 – T. Iwamoto & A. Williams. As it turned out Dr Tomio Iwamoto has been the Curator of Ichthyology for 37 years at the California Academy of Sciences.
Then I found a connection to CSIRO. Dr Iwamoto is named as one a number of scientists who have made a major contribution to the fishmap interactive database which is a part of the Atlas of Living Australia. Dr Iwamoto has done a lot of work in Australian waters and contributed an enormous amount of information and experience to marine science.
There is always something interesting about everything.
So, hopefully this has helped get you through the day. For those in the Southern Hemisphere, from now on things are looking brighter!