Thread: Send her down, hughie!

Originally Posted by V8Ian

It's being reported that levels are at heights not seen since '74.

Just to illustrate how wacky our weather is getting ..... the Southern Oscillation Index indicates how strong the La Nina is. In November 1973 it was +31.6, which is why we then had the biblical rain. This year it was +18.3 in September but +21.2 in April. The last really high SOI was in 2010 when it hit +27.1, which is when the millennium drought broke. But the rainfall appears to be heavier this year than it was in 2010, which was affected by the drought notwithstanding the strong La Nina. This year is wetter because of the tropical moisture being pushed down, due to some other larger and apparently changing pattern.

Originally Posted by Arapiles

Just to illustrate how wacky our weather is getting ..... the Southern Oscillation Index indicates how strong the La Nina is. In November 1973 it was +31.6, which is why we then had the biblical rain. This year it was +18.3 in September but +21.2 in April. The last really high SOI was in 2010 when it hit +27.1, which is when the millennium drought broke. But the rainfall appears to be heavier this year than it was in 2010, which was affected by the drought notwithstanding the strong La Nina. This year is wetter because of the tropical moisture being pushed down, due to some other larger and apparently changing pattern.

I can't decode that. In plain speak, does that indicate it's getting worse, better or 'just an anomaly'?

Just the current state of play of Indian and Atlantic ocean surface temperatures, trade winds strength and direction causing lots of rising moist air over the tropics above Australia.

Originally Posted by JDNSW

I think that '74 must be the year I saw VWs floating down Elizabeth St in Melbourne, and I walked home from the city to Kew because trams were not moving - and beat my neighbor home who was driving.

From memory Elizabeth St runs where a creek used to, pre- colonial settlement.

I can remember it being partially closed for months after that episode while the drainage was enlarged under the pavement.

DL

Originally Posted by BradC

I can't decode that. In plain speak, does that indicate it's getting worse, better or 'just an anomaly'?

It means that things aren't behaving the way that they should be from past records, most likely due to anthropogenic heating of the atmosphere.

Originally Posted by Arapiles

It means that things aren't behaving the way that they should be from past records, most likely due to anthropogenic heating of the atmosphere.

Also has a lot to do with modified ocean currents because of acidification of the oceans, which changes thermal currents and which then changes wind currents as well. Predictions are we are going to swing from massive wet to massive dry into the future in Australia as the norm. So drought to flood regularly without much stable weather in between.

Originally Posted by 350RRC

From memory Elizabeth St runs where a creek used to, pre- colonial settlement.

I can remember it being partially closed for months after that episode while the drainage was enlarged under the pavement.

DL

This:

From the Archives, 1972: Chaos as floods batter Melbourne





It still happens too, because the hills to East and West of Elizabeth Street funnel water into it. It was supposedly once a creek that ran into the Yarra.


Flood Elizabeth St Melbourne Part 2 - YouTube

Originally Posted by gusthedog

Also has a lot to do with modified ocean currents because of acidification of the oceans, which changes thermal currents and which then changes wind currents as well. Predictions are we are going to swing from massive wet to massive dry into the future in Australia as the norm. So drought to flood regularly without much stable weather in between.

The acidification is also due to anthropogenic climate change:

"Because of human-driven increased levels of carbon dioxide in the atmosphere, there is more CO2 dissolving into the ocean. The ocean’s average pH is now around 8.1offsite link, which is basic (or alkaline), but as the ocean continues to absorb more CO2, the pH decreases and the ocean becomes more acidic."

https://www.noaa.gov/education/resource-collections/ocean-coasts/ocean-acidification#:~:text=Because%20of%20human%2Ddrive n%20increased,the%20ocean%20becomes%20more%20acidi c.


Basically we're turning the oceans into salty soft-drink.