Upwelling

Posted by: NFIP

Upwelling - 25/11/2010 21:12

G'day all,

A newbie here tho' been reading on and off for a while, thinking my first post.

OK. Why does only a Northerly wind cause the upwelling and dropping of the inshore coastal water temps?
Why does not a Southerly cause a similiar effect causing the water replacement ??

I would think (logically ??) a Southerly brings in the colder water.....

I also notice it has been a few degs. warmer only a couple of hundred metres out off the beach of late.
Posted by: Mark Hardy

Re: Upwelling - 25/11/2010 21:40

I assume you are talking about the NSW coast.

The wind's drag produces a surface current in the direction of the wind. But over time (several hours) the effects of the earth's rotation causes the current to deflect to the left of the wind direction. Additionally layers below the surface are deflected increasingly so. Look up Ekman Spiral for a detailed explanation of this.

The net result is after lengthy northerly or NE winds, the direction of movement of water near the surface is away from the coast - towards the SE. This causes upwelling near the coast of colder deeper water. So along the NSW coast it is common to see a dramatic drop in beach water temperatures after several days of N/NE winds.

In southerly winds the opposite occurs, the surface currents turn in towards the coast. Water well offshore the NSW is typically warmer than near shore because of the east Australian current. So several days of southerly winds will often produce a warming of beach temperatures as a result of warmer water being pushed towards the coast.
Posted by: lightning chaser

Re: Upwelling - 26/11/2010 18:56

An interesting point you make about the earth's roation affecting current Mark. I had always assumed that temperature was the main factor in controlling currents.

i've consistently noticed over many years of fishing spearfishing and bodyboarding that a few days of southerlies will bring in the bluer warmer water around jervis bay and currarong, as well as blowing the bluebottles back out to sea smile . from looking at the satellite images of sea surface temperature it also appears that the east australian current often circulates off jervis bay back in towards the coast.

persistent westerly winds also frequently produce upwellings in this area. keep in mind that after heavy rain there will often be a thin layer of fresh/brackish water that will float above the ocean water - this will generally be much cooler also.
Posted by: NFIP

Re: Upwelling - 28/11/2010 18:11

Thanks people.
It is an interesting one.
Your info. has been very helpful to a few of us folk down here at Mollymook SLSC.
Posted by: kizz

Re: Upwelling - 09/12/2010 10:16

Getting a bit tired of the NE wind and that damned Ekman! Water temperature took a 4 degrees drop in the past 36 hours.
Sydney SST .
Posted by: HumphreyBear

Re: Upwelling - 10/12/2010 15:33

I wonder if these eddies have any effect on La Nina? It's a bit of a self fulfilling prophecy, La Nina tends to produce lots of 'black nor'easters' which will lead to the eddies and locally cooler SSTs.
Posted by: kizz

Re: Upwelling - 11/12/2010 09:52

Well the eddies and Ekman seem to be working in harmony now. SST off Sydney is 17 and falling!
Looks like it is over 25 a bit further east. Cruel!
Posted by: CoastalStorm22

Re: Upwelling - 11/12/2010 10:32

Right in time for a warm sunny weekend too!
Posted by: Canberra's Weather

Re: Upwelling - 13/12/2010 11:51

What's wrong with low SSTs?
Posted by: lightning chaser

Re: Upwelling - 13/12/2010 12:49

Originally Posted By: Canberra's Weather
What's wrong with low SSTs?


1) not everyone enjoys surfing wearing a 5mm wetsuit
2) pelagic fish such as marlin, mahi mahi, wahoo follow the warm currents
3)underwater visibility is generally lower, not ideal for diving
4) less energy avialable to fuel nighttime thunderstorms

on the plus side:
1) less crowded surf
2) less bluebottles
Posted by: SAsurfa

Re: Upwelling - 13/12/2010 14:19

Mark gave a pretty good explanation but for further reading check this article out NFIP..

http://www.swellnet.com.au/news/125-why-does-the-water-get-colder-in-sydney-after-a-nor-easter
Posted by: kizz

Re: Upwelling - 14/12/2010 11:22

Originally Posted By: Canberra's Weather
What's wrong with low SSTs?


Everything!
Putting a steamer on and taking it off is more tiring than paddling around for a couple of hours.
If it is over 30 out of the water that steamer gets very uncomfortable very quickly.
In extreme events people need medical treatment for shock and hypothermia from the water; using up valuable life saving resources.
Plus
Stronger seabreeze due to temp gradient blows everything in your face - sand, salt spray, water spray etc.
The wind chill can get a bit much coming off 16 degrees water.
Sea fog rolling in makes the beach a dull and cool place on an otherwise warm and sunny day.
I'll stop there.
Posted by: HumphreyBear

Re: Upwelling - 14/12/2010 15:12

Low SSTs would actually produce a hot, dry summer around these parts CW... be careful what you wish for! Climate would be similar to Southern California, pleasant if you're 100 yards or less from the beach but roasting further inland.
Posted by: ozthunder

Re: Upwelling - 18/12/2010 09:02

Yesterday I went for a surf in the wetsuit and for the first time in many days it started to feel just a little too warm. Last weekend I took the kids to the beach and it was cold. The water colour is always a dead giveaway, a dull green/gray instead of blue.

There was a massive decaying Jellyfish that left many people with an itchy present.
Posted by: kizz

Re: Upwelling - 11/01/2011 09:56

With the sustained E-NE winds onto the NSW coast the BoM's BLUElink models are going for another upwelling event off the Hunter and Illawarra this week.
Very disappointing as the SSTs have only just started to climb into the 23-24 range.
Posted by: kizz

Re: Upwelling - 15/01/2011 21:12

The upwelling is having a disastrous impact on the NSW beaches south of about Port Macquarie at the moment. The SST off Batemans Bay has fallen to 15.9C from the low twenties a week ago.

A nasty shock for holiday makers awaits in the brine!
Posted by: CoastalStorm22

Re: Upwelling - 16/01/2011 12:48

Have you checked out Sydney's SST this morning? has shot up to almost 25c!!! Batemans Bay has also shot up from the low of 15c yesterday to be sitting on 18c. smile
Posted by: kizz

Re: Upwelling - 17/01/2011 09:15

Well Sydney SST still staying mostly in the 24-26 degree range. I hope it stays like that; I never enjoy that initial cold shock when I enter the water.
That stubborn eddy off the central coast and the upwelling are still menacing the coast. Poor old Batemans Bay is still freezing.
Posted by: kizz

Re: Upwelling - 09/01/2012 12:29

Seems that the fickle eddies and upwellings are a perennial curse for the NSW coast. The current water temperature off Crowdy Head is a numbing 15 degrees - http://www.mhl.nsw.gov.au/www/wave_temp_crowdy.htmlx (will update). A nasty shock for locals and tourists.

This is despite the look of an express train current transporting water down from the bath waters of the Coral Sea - http://imos.aodn.org.au/oceancurrent/SE/latest.html (will update).
Posted by: Tom1234

Re: Upwelling - 10/01/2012 17:18

Glad i just bought a springsuit lol. As a pool swimmer anything lower then 24 feels cold to me, 16 is just stupid.
Posted by: Steve777

Re: Upwelling - 11/01/2012 09:43

The water off Crowdy Head has been amazingly cold - it seems to have been stuck around 16 deg since I first looked at the Manly Hydraulics Lab site about 2 months ago, apart from a couple a brief excursions towards 19-20. If I visit the area I don't think I'll be swimming in the ocean.

It would be interesting to see what the weather has been like at places like Harrington. Possibly often cool and foggy like Syndey beaches in early November? The nearest NSW 'coastal' stations shown on the BOM site - Taree Airport & Port Macquarie Airport - are some distance inland.

Sydney waters seem to have settled at their seasonal average of about 22 deg. I expect this means that sunny days with no strong general wind circulation will max out at a seasonal 24 - 26 deg near the coast.
Posted by: kizz

Re: Upwelling - 27/01/2012 11:54

Crowdy Head water temperature just getting worse and worse! It was below 14 degrees for a time yesterday. Has warmed up to 14.6 at the latest report.
Posted by: kizz

Re: Upwelling - 31/01/2012 09:39

Wow! I have never seen the water temperature this low, ever, off NSW.
11C in January!!

Posted by: HumphreyBear

Re: Upwelling - 31/01/2012 12:10

WTF? Hopefully the trend continues towards winter when the Tasman will freeze over and NSW is blanketed in a metre of snow.
Posted by: kizz

Re: Upwelling - 01/02/2012 12:16

Crowdy Head SST still gone crackers at 12 degrees this morning.

I wonder if there are any reports of hypothermia or cold shock heart attacks around Seal Rocks or Forster way.
Posted by: Tom1234

Re: Upwelling - 01/02/2012 15:12

im going to guess that the Crowdy head boy has been missreading for a while now. I could understand a day or two of 16c water mid summer, but this is just silly. Port Mac is not overly far from crowdy head and the water temp is 21c.
Posted by: Steve777

Re: Upwelling - 14/03/2012 14:33

MHL shows that sea temperature off Sydney has dropped to 21 since the start of the month after being around 23 since mid January. I think it's too early and too big to be seasonal cooling, so I suppose this must be upwelling.

Crowdy head has consistently been in the mid teens for months, so as Enrique says, it must be misreading (unless its measuring deeper water).
Posted by: Steve777

Re: Upwelling - 02/04/2012 08:44

Some big fluctuations in SST off Sydney over the last couple of days - 17 deg to 24.


SST 120402 by Stevevii77, on Flickr
Posted by: Tom1234

Re: Upwelling - 02/04/2012 15:12

hmm thats pretty odd, must be a little bit of localised upwelling offshore or an error ( Swell readings are missing from the same time as those dips). Im in the newcastle region and near shore temps were buitiful on fri/sat mornings.
Posted by: kizz

Re: Upwelling - 21/04/2012 17:14

The Sydney bouy must be catching the western edge of that large anticlockwise eddy.
Water temperature now 24-25C in the brine off Sydney.

The new mhl site is loading veeeeeery slowly for me. They may have to tweak this page - http://new.mhl.nsw.gov.au/data/realtime/sst/Sydney as the image is cut off at the right where the temperature is shown. You have to right click > View image to be able to see the temperature.
Posted by: GDL

Re: Upwelling - 22/04/2012 08:56

Enrique,those water temps sound good,iam having three weeks at Corlette in May GDL
Posted by: Steve777

Re: Upwelling - 21/05/2012 17:58

Looks like MHL has fixed the SST measuring device off Crowdy Head (near Port Macquarie, NSW). Looks quite warm for this time of year, but now seems reasonably consistent with Coffs Harbour and Sydney:


crowdy_temp by Stevevii77, on Flickr
Posted by: kizz

Re: Upwelling - 14/11/2012 11:23

Manly Hydraulics have added 3 temperature bouys to the NSW coast.
http://new.mhl.nsw.gov.au/data/realtime/sst/

That makes 7 locations once the troublesome Crowdy Head gets back online.
Posted by: Tom1234

Re: Upwelling - 04/12/2012 10:59

Crowdy head is still offline frown

Looks like SST's have climbed in the last few weeks, now around 21c in the Newcastle region, just need some good surf to go along with it.
Posted by: david frank

Re: Upwelling - 17/01/2013 15:45

The mainly association in the ocean of upwellings is with the divergence of currents the purpose of which is to bring deeper and colder and some kind of rich waters to its surface.
Posted by: kizz

Re: Upwelling - 29/01/2013 09:25

Check out some of the temperature drops off NSW - http://new.mhl.nsw.gov.au/data/realtime/sst/.

In less than a week -
Crowdy Head: 26 > 17
Coffs Harbour: 26 > 17
Byron Bay: 27 > 20

A disaster!
Posted by: Tom1234

Re: Upwelling - 30/01/2013 18:29

hopefully it should rebound pretty quick now that the storm system has moved on.
Posted by: Brett Guy

Re: Upwelling - 30/01/2013 18:38

I suppose it depends on how far off shore the influx iof freshwater pushes. Rivers like the clarence will pump enough fresh out of them too push the warmer currents quite a few miles out.
Posted by: kizz

Re: Upwelling - 13/03/2013 10:57

I see that Sydney Morning Herald's weather section (provided by weatherzone) states that the water temp in Sydney is 26.1. Impressive.
A bit of snooping on the MHL site shows this occurred at midday yesterday. So I guess that is when weatherzone source their stats for Sydney sea temps.

Most of the NSW coast is enjoying SST around 25 now. Only the south coast is shivering in miserable sub 20 brine.
Posted by: CoastalStorm22

Re: Upwelling - 13/03/2013 16:47

Sounds great Kizz, lets hope the inshore temps are just as warm! My understanding is the buoy is about 13km offshore of the northern beaches, if Im not mistaken.
Posted by: GrizzlyBear

Re: Upwelling - 14/03/2013 13:55

That is a strange thin tounge of cold water on the coastal fringe of the south coast, must be upwelling. Doubt it can last long, should get pushed out by warmer water soon, hopefully. Quite flucky for Sydney to get such a warm patch reaching the coast. Much cooler at Port Macquarie.
Posted by: GrizzlyBear

Re: Upwelling - 18/03/2013 20:04

The temps have risen again on the South Coast, nearly 21 yesterday while Sydney has dropped back to 23. One thing that I do not get is why the ABC weather seems to show different sea temps to these Manly Hydraulic readings. Eg this evening they showed Sydney as 22 and Batemans Bay as 23. I have noticed a big discrepancy for a couple of month now.
Posted by: crikey

Re: Upwelling - 04/04/2013 18:12

From the herald sun today .4th april 2013
Tens of thousands of small fish washed up along the Adelaide coastline died because of an algal bloom sparked by unseasonable weather, scientists say.
Biosecurity SA said tests suggests the deaths, which began before Easter and continued this week, were the result of AN UPWELLING of COLD WATER from deep in the ocean.
Dolphins and penguins have also died concerning the authorities
---------------


I thought algal bloom was a warm water phenomena?
Makes you wonder about toxic dumping?

---------------
Posted by: GrizzlyBear

Re: Upwelling - 05/04/2013 20:58

I could not find any info on cold water being the cause?. Just some mention of the hot weather a possible sewer contamination being possible causes.

"SA Health told The Advertiser algal blooms, found across the state's coastline most likely due to March's prolonged hot weather"

"Pathology results on a dolphin autopsy conducted last week found E coli near the dolphin's blowhole, which Dr Kemper said was an unusual spot to find the bacteria."

http://www.theaustralian.com.au/news/gul...6-1226608492179
Posted by: crikey

Re: Upwelling - 06/04/2013 17:35

Also of coincidence is that there has been food poisoning in conjunction with contaminated Oysters from Tasmania in the same time period.
I believe hundreds of people were admitted to hospital
The Oyster industry believes ships may be off loading their sewerage close to the coast..YUK and deadly for both marine life and humans eating fish.
Of course E COLI bacteria is consistent with human excrement
Posted by: Tom1234

Re: Upwelling - 13/04/2013 09:14

Originally Posted By: crikey



I thought algal bloom was a warm water phenomena?
Makes you wonder about toxic dumping?

---------------



Cold waters are nutrient rich which may have triggered a bloom.
Posted by: Steve777

Re: Upwelling - 23/04/2013 09:32

Sea surface temperatures off Sydney have dropped significantly off Sydney in the past week or so, from 23-24 for the first 20 days of April down to around 21 in the last few days.

http://new.mhl.nsw.gov.au/data/realtime/sst/Sydney
Posted by: Tom1234

Re: Upwelling - 23/04/2013 18:23

probably from the low off the coast whipping up large surf. I recall it happened after the last big blow/swell we had come through.

The water at the beach is still nice but it rarely gets as warm as the off buoys unfortunately.
Posted by: LQQKN

Re: Upwelling - 06/08/2013 11:49

water is about to get a lot colder this time of year when the northerly's come threw bringing the bottem of the ocean to the surface,
Posted by: kizz

Re: Upwelling - 09/08/2013 09:22

Originally Posted By: LQQKN
The water is about to get a lot colder this time of year when the northerlies come through bringing the bottom of the ocean to the surface.


Some grammar and spelling fixed!
Posted by: Steve777

Re: Upwelling - 19/11/2017 09:13

Thought I might revive this thread after 4 years.

Sea temps off Sydney are now quite cold, cooler than I noticed at any time the last Winter (never below 17). It is now just 16.55 about 10km off Manly. The situation is similar at all MHL bouys South from Crowdy Head (between Forster and Port Macquarie) following over a week of persistent North Easterlies.



The NE winds look likely to continue for 7-10 days as a stagnant high squats in the Southern Tasman Sea. This will likely result in continued chilly waters (good for fishing I understand), cooler, stronger sea breezes, cooler temps on the coastal fringe and possibly also sea fogs.
Posted by: Kino

Re: Upwelling - 19/11/2017 11:44

Thats an insane drop! Upwelling is indeed great for fishing, not so good for those who like the beach.

Climate impacts? Obv cooler stronger sea breezes as the thermal variation would be greater. Assume it would also kill any local storm chances as maritime air is less buoyant and more stable?
Posted by: Wave Rider

Re: Upwelling - 19/11/2017 17:29

Originally Posted By: Kino

Climate impacts? Obv cooler stronger sea breezes as the thermal variation would be greater. Assume it would also kill any local storm chances as maritime air is less buoyant and more stable?


And it causes bigger inversions which are bad for storms, and it can create sea fog too because it's easier for the dew point to exceed the temp of the ocean when the water is cold, thus creating fog.
Posted by: Petros

Re: Upwelling - 19/11/2017 18:05

Havent looked in the climate thread yet, hope its noted there.
Posted by: Steve777

Re: Upwelling - 20/11/2017 23:38

Here is the infrared satellite view of central part of the NSW coast earlier this evening. There is a bit of low cloud about, but skies are fairly clear near Sydney. You can clearly see the boundary of the colder water (lighter colour) upwelling off the coast, maybe 12-20 km out to sea.

Posted by: Steve777

Re: Upwelling - 07/01/2019 18:01

I think we can see a bit of a pattern in the sea surface temperatures measured off Sydney's Northern Beaches by the Manly Hydraulics Laboratories:



Sea temperatures are showing a daily swatooth pattern overlaying a downward trend. SST's have dropped nearly 3 degrees in a week down to levels common in late Autumn. The 10 days to January 4 featured almost constant NE'ers, with winds turning briefly NW on the 5th, then light S-SE on the 6th and 7th. Constant NE'ers tend to cause upwelling off the NSW coast, while Southerlies normally 'fix' it.
Posted by: kizz

Re: Upwelling - 09/01/2019 08:26

Evil Eddy is also sitting off the Illawarra coast like a big, stinking turd. So I don't think we can entirely blame Ekman.

You can see the EAC being shaped by the eddies on the IMOS site. The mid north coast is getting particularly hammered. Averaged SST on the coast there have been as low as 16 while only a few tens of kms out to sea it is 10 degrees warmer.
http://ocean-grids.csiro.au/avg-sst/
Posted by: Kino

Re: Upwelling - 09/01/2019 10:50

Originally Posted By: kizz
Evil Eddy is also sitting off the Illawarra coast like a big, stinking turd. So I don't think we can entirely blame Ekman.

You can see the EAC being shaped by the eddies on the IMOS site. The mid north coast is getting particularly hammered. Averaged SST on the coast there have been as low as 16 while only a few tens of kms out to sea it is 10 degrees warmer.
http://ocean-grids.csiro.au/avg-sst/


Fascinating, thanks. All that hot lovely water way off the coast frown
Posted by: kizz

Re: Upwelling - 12/01/2019 10:43

That stinking turd eddy off the Illawarra seems to be weakening. Let's hope it makes like a tree and allows some soupy bath water to kiss our beaches.

The Byron and Coffs bouys are just starting to show what we should be getting temp wise.
Posted by: kizz

Re: Upwelling - 13/01/2019 16:23

So Byron Bay bouy goes shooting over 28 and then goes offline. Seriously? What is it with these things going offline when things get interesting?

So now we are to guess whether the bouy started to malfunction or a cruel coincidence.

As if to confirm the latter, Coffs bouy then warms up to 28.6. By some miracle it has stayed online. Two independent bouys indicating that there is 28+ degree SST off the NSW coast.

Sometimes the data from the bouys back updates so will have to wait and see.
Posted by: ozthunder

Re: Upwelling - 22/01/2019 14:44

My real water tests ( surfing ) here in Illawarra have been all over the shop last 4-5 weeks. The water just starts to recover to 21C and its back into high teens. Too many NE days. Overall however it is still yet to hit a temperature I am comfortable with >22C. Last weekend was the warmest it has been, but if anything still under 22C
Posted by: kizz

Re: Upwelling - 11/02/2019 11:51

If only the Coffs Harbour buoy reading was genuine.
http://new.mhl.nsw.gov.au/data/realtime/sst/

And the entire coast was enjoying this.
Posted by: Steve777

Re: Upwelling - 12/02/2019 07:49

Here's the UV image of NSW a little while ago:



It's a clear morning apart from a cloud bank a few hundred kilometers out to sea. Temperatures on land will be a little above their minimum. The cooler water along the coast South of Port Macquarie shows up very clearly.
Posted by: batty

Re: Upwelling - 14/03/2019 16:04

Originally Posted By: kizz
So Byron Bay bouy goes shooting over 28 and then goes offline. Seriously? What is it with these things going offline when things get interesting?

So now we are to guess whether the bouy started to malfunction or a cruel coincidence.

As if to confirm the latter, Coffs bouy then warms up to 28.6. By some miracle it has stayed online. Two independent bouys indicating that there is 28+ degree SST off the NSW coast.

Sometimes the data from the bouys back updates so will have to wait and see.


Taken offline for a reason in hopes to not advertise what we are not meant to see. Ocean currents are changing and effects every part of the globe and will remain as a long term anomaly unless it falls within seasonal averages.