Weird El Nino

[Dry Spot]

Hi All,

I'm wondering is someone could explain this weird el nino in simple
terms?

Someone somewhere else said the other day that the warming in
America's was normal El Nino; but it was still normal current here?

Please explain....

Cheers

[Clyve Herbert]

Hi.
The present 'El Nino' which was predicted since last May is unusual, The
expected development did not occur instead a rather prolonged 'neutral
phase' developed through the winter and early spring (Aus). during mid
October a marked negative spike appeared . The unusual nature of this
present 'El Nino' is associated with an abnormal general warming of the
Pacific, 'normal' El Nino years are indicated by a warming of the eastern
pacific especially near the coast of South America (Peru) and a cooler than
normal western Pacific...this is not the case this year. For the Australian
region there are a number of factors that influence climate trends El Nino
is one of them, other influences are the Indian Ocean and Southern Ocean .
For the USA the El Nino has a marked influence of the winter bias however it
will be interesting to see what the present unusual conditions will
produce....regards Clyve Herbert....

> --
>
> You received this message because you are subscribed to the Google Groups
> "austpacwx" group.
> To post to this group, send email to aust...@googlegroups.com.
> To unsubscribe from this group, send email to
> austpacwx+...@googlegroups.com.
> For more options, visit this group at
> http://groups.google.com/group/austpacwx?hl=en.
>
>

[Marcus]

You wouldn't be dead for quids would ya?

Interestingly, I have noticed that media reports on climate change are
always local to the particular country, and In Australia, the land of
drought and flooding rains, I think the seriousness of the changes do not
have an effective impact on us because we are somewhat familiar with erratic
weather - Gen Y anyway. ( e.g. Drought in the Amazon)

My question is, are there any other oceanic currents that traditionally
behave in a similar way to ours, that are experiencing a similar occurrence?


That's all very "Day after tomorrow" isn't it. LOL

[Ken Kato]

Hi Marcus,
 
Generally speaking global warming will likely exacerbate the effects of weather/climate variability beyond what we already get now and cause a higher likelihood and frequency of extremes. If this happens, we're probably in a more vulnerable position than many other parts of the world because we're already "living on the edge" in terms of being on such a hot dry continent where we're already affected a lot from heatwaves, droughts, bushfires, etc. If they get worse, that will have a big impact on our agriculture/food and death and damage from more weather extremes. 
 
There's other oscillations in sea surface temps apart from ENSO which also affect the atmosphere/climate variability around surrounding nations like the Indian Ocean Dipole (eastern parts warm while the other cools and vice versa) but ENSO is probably the most major one in terms of how much of an effect it has on such a wide area.
 
Ken.

[Keith Barnett]

'Die?', he said, 'that's the last thing I'll do!'

 

Cheers..

.
>
>
>
>
> No virus found in this incoming message
> Checked by PC Tools AntiVirus (6.1.0.25 - 6.13650).
> http://www.pctools.com/free-antivirus/

[Blair Trewin]

El Nino/La Nina are defined in terms of the ocean temperatures in the central and eastern equatorial Pacific. From there, one can think in terms of related atmospheric/ocean changes, and related climate anomalies.

'Classical' El Nino signals include:

- low pressure in Tahiti and high pressure in Darwin (i.e. negative SOI)
- weakening of the easterly trade winds through the tropics
- relatively cool sea surface temperatures in the western tropical Pacific

...and, then moving on to 'climate' impacts:

- reduced winter/spring rainfall in much of eastern Australia (but not the NSW coast, where the relationship is weak or non-existent)
- reduced monsoon rainfall in the Indian subcontinent
- reduced summer rainfall in southern Africa
- fewer hurricanes in the Atlantic and more in the east Pacific
- fewer cyclones in the Australian region and more in the central Pacific
- increased winter/spring rainfall in the southwestern US

(among other things)

The most unusual aspect of this El Nino to date has been that warm waters have persisted in the western Pacific - something which may in turn be forcing the relatively weak SOI and trade winds signals. (That said, in the last few weeks the event seems to be becoming more 'classical' with western Pacific SSTs going closer to normal and the SOI dropping sharply).

Some of the other impacts have happened, some haven't. There was a strong impact in India (which had only modest impacts from the El Ninos of 2002 and 2006) with the lowest monsoon-season rainfall since 1972, and it's been a weak hurricane season in the North Atlantic. The impact on Australian rainfall has been less severe than in 2002 and 2006, but the vast majority of Victoria, NSW and Queensland is running below average for June-October (and the way November is going this signal will become stronger by the end of the winter-spring period). Elsewhere the main impacts don't typically emerge until our summer/the NH winter so it is too soon to tell the extent to which they have occurred.

Blair

-----Original Message-----
From: Dry Spot [mailto:mawi...@gmail.com]
Sent: Saturday, 7 November 2009 10:52 PM
To: austpacwx
Subject: [austpacwx] Weird El Nino

[Marcus]

Thanks Blair