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Geopotential height of the SH polar vortex has Positive correlation with the AAO

An incredible correlation between vertical geopotential height and the phase of the AAO.

Amazing l have never noted that before. A light bulb moment.

When geopotential height between surface to 100 hPa is positive . The AAO index is negative.
When geopotential height between surface and 100 hPa is negative. The AAO index is positive.

Some convincing proof that the condition of the polar vortex affects our weather.
I will put this geopotential height anomaly in the polar vortex on my weekly observation  round.

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/hgt.aao.shtml

timeseries june to sept pv geoht

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Murray-Darling catchment

The Murray–Darling Basin is the largest and most complex river system in Australia. It runs from Queensland, through New South Wales and the Australian Capital Territory, Victoria and South Australia, spanning 77,000 kilometres of rivers, many of which are connected.

Towns and rural communities across the Basin rely on a healthy river system—our economy, food security and well being depend on it, now and into the future.

https://www.mdba.gov.au/discover-basin


Please scroll down to comments below for further information, comments or latest news on climate and the basin.

Click on the heading to load if necessary

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Cross equatorial winds

Winds don’t always stay in the same hemisphere . They do cross over in places across the equator 0 deg latitude.In both directions

I am starting this topic thread to investigate the flow of major wind streams from the Southern Hemisphere: SH and into the Northern hemisphere: NH   and vice versa ….in all seasons if l have the time.

I will capture the wind streams using ACCESS G model by BOM Australia

Greater Asia View because l am interested in the flow over Australia and across the equator

http://www.bom.gov.au/australia/charts/viewer/index.shtml?type=windbarb&level=gradient&tz=AEDT&area=DRSMC&model=G&chartSubmit=Refresh+View

Here is my first snap below. 8th September 2019. The first week of the Australian spring.

Notice how the winds from the southern cooler latitudes are conveyed up to the warmer northern mid , sub tropical and tropical latitudes.

You can see the importance of the high pressure cells , in particular the eastern flank, in transporting the cooler surface air to cool down the north latitudes.

The flow doesn’t stop here but continues into the NH in possible favorite more common spots along the equatorial line.

7th sept 2019 wind pattern asiaoz

Please go down to the comments section below for all further entries. Click on the heading to load if necessary.

 

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Smoke / Dust / Poor Visibility

A collection of pictures . All further posts will be in comments section below. Click on the heading to load them if necessary


BRISBANE..Smoke from fires. Raised dust yesterday as well .

7th September 2019

High pressure subsidence not helping

Possibly Canungra fire. Fire at Tenterfield as well and may be others in the hinterland

7th sepgm2019 smoke brisbane

Thanks to Ken Kato for these satellite images

https://www.weatherforum.com.au/Forum/posts/t3-SE-QLD-and-NE-NSW—Day-to-Day-Weather/page10

7th sept 2019 xust and fires NE NSW7th sept 2019 dust ztorms and fires

brisbane 9th sept2019 dust

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Indian Monsoon

Indian monsoon, the most prominent of the world’s monsoon systems, which primarily affects India and its surrounding water bodies. It blows from the northeast during cooler months and reverses direction to blow from the southwest during the warmest months of the year. This process brings large amounts of rainfall to the region during June and July.

Read on here

https://www.britannica.com/science/Indian-monsoon

5th sept_19 Indian monsoon

Indian meteorological society

Technical

http://www.imd.gov.in/pages/monsoon_main.php

Public

https://mausam.imd.gov.in/


All further information is in the comments section below.

Click on the title to load if necessary

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New understanding of the drivers behind hot and dry conditions over Australia’s north-east

Posted by BCG on 14th March 2019

http://www.climatekelpie.com.au/index.php/2019/03/14/new-understanding-of-the-drivers-behind-hot-and-dry-conditions-over-australias-north-east/

Predicting temperature extremes and dry conditions over spring and summer is vital for agriculture, water supplies, bushfire risk and human health. But to make accurate predictions the Bureau of Meteorology needs to better understand the climate drivers behind such extremes.

Bureau researchers have recently identified how wind patterns in the stratosphere around Antarctica can drive hot and dry conditions over southern Queensland and northern New South Wales.

This research was undertaken by the Forewarned is Forearmed (FWFA) project, which is part of the Federal Government Rural R&D for Profit program. FWFA is supported by the Bureau, a range of Rural R&D Corporations, Universities and state government agencies.

While most weather systems like storms, rain and high pressure systems are found in the troposphere, the relatively turbulent first layer of the atmosphere, the stratosphere above it is known for its stable air flows. Commercial airplanes target this layer to find jet streams for a smooth and efficient flight.

A key feature of the stratospheric circulation is the development of the wintertime polar vortex, whereby Antarctic circumpolar westerly winds (extending up to 40-50 km altitude) seasonally strengthen from autumn to winter as the polar cap region seasonally cools. The vortex weakens and breaks down during late spring as the polar cap warms up. In some years the vortex warms up and breaks down early, which can lead to hot and dry conditions on Australia’s surface during late spring-summer.

The early weakening of the polar vortex results in a strong downward air flow and a lack of clouds over eastern Australia (Figure 1) via another large-scale circulation that Australian farmers already know – a negative Southern Annular Mode (SAM) according to Bureau researcher Dr Eun-Pa Lim.

“A negative SAM is responsible for bringing hot and dry conditions to eastern Australia in our warm seasons” says Dr Lim. “Anything we can do to improve our ability to predict SAM will help people on the land to prepare for and manage these conditions. The long time–scale of the polar vortex weakening, which spans several months, means if we can capture it in our model, we can potentially predict low SAM conditions during late spring as early as late winter.”

Figure 1. A strong weakening of the polar vortex and the associated negative Southern Annular Mode leads to an abnormally strong downward air flow and a lack of clouds (orange indicates less than average cloud cover) over eastern Australia, which results in higher than average temperatures and dry conditions. This plot shows the cloud cover variation in late spring-early summer following the early break down of the polar stratospheric vortex.

But just what is a polar vortex and how does it influence Australia’s climate?

The abnormal weakening of the polar vortex and its downward coupling in spring to summer can be visualised in Figure 2. During winter the westerly winds associated with the SH polar vortex are stronger than usual in the upper stratosphere (as shown in orange), which can allow more atmospheric waves to propagate from the lower atmosphere into the stratosphere. Because these vertically propagating waves act to weaken the upper stratospheric westerlies, the polar vortex starts to weaken from early spring. As the vortex weakens over time, the weakening signal descends (shown in blue). The impact is felt at ground level from October to January.

Figure 2. When the abnormal polar vortex weakening happens, generally the vortex is abnormally strong during winter (shown in orange) and then weakens rapidly in spring. The process of weakening of the westerly winds descends after September (blue). Exact timings of the strengthening of the winter polar vortex and its subsequent weakening in spring to early summer can vary year-to-year.  Wind (m/s) is measured as being stronger or weaker than the average.

Impact on Australia’s climate

Developing an index to measure polar vortex weakening and strengthening has been a vital part of the Bureau’s recent research and has made it possible for them to study the impact of these events on Australia’s seasonal conditions.

“The Bureau has developed the stratosphere-troposphere (S­‑T) coupled mode index to identify these events and quantify their strength,” says Dr Lim. The index is based on monthly average wind data (1979-2017) over the Antarctic sub-polar region (55° to 65° South) at all available vertical levels from the surface to 50km altitude.

The index allows the Bureau to measure whether the polar vortex weakening is progressing at its usual pace. A high index means unusual weakening which leads to faster vortex breakdown. The strongest weakening event occurred in 2002 (Figure 3), which was related to the strongly negative SAM in spring 2002 that is believed to have played a more important role in driving hot and dry conditions than the relatively weak El Niño observed in the same year.

Figure 3. The Bureau have developed the S-T coupled mode index to identify polar vortex weakening (in red) and strengthening (in blue) events. The strongest vortex weakening event on record occurred in 2002 (based on monthly average wind data from April 2002 to March 2003 compared to wind data of all years).

Hot conditions

The Bureau’s S-T coupled mode index also highlights other less dramatic, but still significant, polar vortex weakening/strengthening events. By comparing historic temperatures and rainfall for the October to January period with the index the Bureau have found a very strong correlation between the polar vortex weakening and hot and dry seasonal conditions in southern Queensland and northern NSW.

For instance, maximum temperatures (Tmax) in the nine polar vortex weakening years (Index ≥ 0.8) were 1.2°C to 1.8°C warmer over southern Queensland and northern NSW than in the other 29 years studied between 1979 and 2017 (Figure 4). At the same time rainfall was 0.4 to 1.2 mm per day lower; that’s around 12 to 36mm a month.

Figure 4. The October to January mean maximum daily temperature is between 1.2°C and 1.8°C warmer and rainfall is 0.4 to 1.2 mm/day lower over southern Queensland and northern NSW during the nine identified polar vortex weakening years than in all the other 29 years.

“When you consider the seven hottest years (the top 20 per cent) – they are over four times more likely to occur when it is a polar vortex weakening year than a non-weakening year,” says Dr Lim.

“The research demonstrates that the Antarctic polar vortex is an important driver of heat and rainfall extremes in subtropical eastern Australia during late spring to summer.”

“The Bureau’s new ACCESS-S seasonal forecast system has a high level of skill in predicting S-T coupling from the beginning of September, which will improve our ability to predict temperature and rainfall extremes for the spring and early summer in polar vortex weakening years,” she said.

This result of the Bureau’s research implies that if land managers can be warned in September that they are likely to face hot and dry conditions through to January due to the polar vortex weakening, it will put them in a better position to make timely decisions such as how to manage livestock numbers, pastures and their supply of supplementary feed.

Lastly, since the beginning of spring 2018 the stratospheric polar vortex has been stronger than usual, which is likely to have somewhat mitigated the hot and dry conditions promoted by the development of El Niño over Queensland and northern NSW. This was something we could be thankful for during the tough dry spring of 2018”

Eun-Pa Lim, 03 9669 4000, eun-pa.lim@bom.gov.au

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Oceanography

https://www.foo.org.au/operationaloceanography/

 

 

Operational Oceanography is like weather monitoring and forecasting for the ocean. It can provide estimates of essential ocean variables (e.g. sea level, temperature and currents) for the present and the future, as well as for the past.

Ocean observations are required in real-time and near-real-time (within a few days or minutes of collection) and sourced from various national and international programs.

Some of these services are run in an operational setting, for example the World Meteorological Organisation or the Intergovernmental Oceanographic Commission.

Others are maintained through research funding, for example Australia’s Integrated Marine Observing System.

Australia’s operational ocean forecast system, operated at the Bureau of Meteorology has been developed under a partnership called BLUElink.

BLUElink is a partnership between the Bureau of Meteorology, CSIRO, and the Royal Australian Navy.

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Aurora Australis

This is the most amazing set of photos of the Aurora  l have ever had the privilege of seeing.. Amazing

Just go in and have a look

https://mobile.abc.net.au/news/2019-09-01/tasmania-aurora-australis-southern-light-display-photographs/11468692

 

Aurora Australis visible from Tasmania leaves southern lights chasers in awe

By Jessica Moran

 

Photo Craig Stevens said the aurora was one of the best he had seen in 20 years.

Supplied: Craig Stephens

 

 

 

 

Tipping Points

Fabulous archive of climate emergency media publications in the past 10years. Good work. Very interesting

Thongchai Thailand

tippingpoint

  1. 2004, GLOBAL WARMING TO MELT GREENLAND ICE SHEET
    A meltdown of the massive ice sheet, which is more than 3km-thick would raise sea levels by an average seven meters, threatening countries such as Bangladesh, certain islands in the Pacific and some parts of Florida. Greenland’s huge ice sheet could melt within the next thousand years if emissions of carbon dioxide (CO
    2) and global warming are not reduced.
  2. 2004, RAPID ARCTIC WARMING BRINGS SEA LEVEL RISE
    The Arctic Climate Impact Assessment (ACIA) report says: increasing greenhouse gases from human activities is causing the Arctic to warm twice as fast as the rest of the planet; in Alaska, western Canada, and eastern Russia winter temperatures have risen by 2C to 4C in the last 50 years; the Arctic will warm by 4C to 7C by 2100. A portion of Greenland’s ice sheet will melt; global sea levels will…

View original post 10,629 more words

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Volcanoes and global cooling

Found this amazing essay published on National geographic

Colossal volcano behind ‘mystery’ global cooling finally found

The eruption devastated local Maya settlements and caused crop failures around the world

https://www.nationalgeographic.com/science/2019/08/colossal-volcano-behind-mystery-global-cooling-found/?cmpid=org=ngp::mc=social::src=twitter::cmp=editorial::add=tw20190823science-colossalvolcanomystery::rid=&sf218005129=1


Some extracts

The ices of Greenland and Antarctica bear the fingerprints of a monster: a gigantic volcanic eruption in 539 or 540 A.D. that killed tens of thousands and helped trigger one of the worst periods of global cooling in the last 2,000 years. Now, after years of searching, a team of scientists has finally tracked down the source of the eruption.

The team’s work, published in Quaternary Science Reviews, lays out new evidence that ties the natural disaster to Ilopango, a now-dormant volcano in El Salvador. Researchers estimate that in its sixth-century eruption, Ilopango expelled the equivalent of 10.5 cubic miles of dense rock, making it one of the biggest volcanic events on Earth in the last 7,000 years. The blast was more than a hundred times bigger than the 1980 Mount St. Helens eruption and several times larger than the 1991 eruption of Mount Pinatubo. It dealt the local Maya settlements a blow that forever altered their trajector……

el salvador

 

Ice cores from Greenland and Antarctica show spikes of sulfate, a byproduct of large volcanic eruptions, at 536 and either 539 or 540. The two volcanoes were so large and so violent, they launched sulfur gases and particles miles into the sky. Since this material reflected sunlight away from Earth’s surface, it triggered severe global cooling: One 2016 study found that the volcanoes decreased average global temperatures by as much as 3.6 degrees Fahrenheit……

……

geologists published new evidence that the historical “dust veil” of 536 was caused by a volcano. In the other, researchers announced that the Tierra Blanca Joven extended into marine sediments off the coast of El Salvador. The Tierra Blanca Joven eruption was even bigger than Dull and others thought.…….

………..

Dull’s team also revised their estimate of Ilopango’s size, taking into account the thickness and spread of Tierra Blanca Joven deposits. They say that Ilopango may have even dwarfed the 1815 Tambora eruption, a huge volcanic event that ushered in “a year without a summer” because of the global cooling it caused. Ilopango likely launched up to a million tons of sulfur miles into the sky, high enough for stratospheric winds to spread the aerosols worldwide and trigger global cooling.…..


The actual Research paper

https://www.sciencedirect.com/science/article/abs/pii/S0277379119301465

Radiocarbon and geologic evidence reveal Ilopango volcano as source of the colossal ‘mystery’ eruption of 539/40 CE

https://doi.org/10.1016/j.quascirev.2019.07.037