Pacific sea level predicts global temperature changes

Pacific sea level predicts global temperature changes
The Jason series of US/European satellites can measure the height of the ocean surface. Credit: NASA/JPL-Caltech

The amount of sea level rise in the Pacific Ocean can be used to estimate future global surface temperatures, according to a new report led by University of Arizona geoscientists.

Based on the Pacific Ocean's in 2015, the team estimates by the end of 2016 the world's average surface temperature will increase up to 0.5 F (0.28 C) more than in 2014.

In 2015 alone, the average global surface temperature increased by 0.32 F (0.18 C).

"Our prediction is through the end of 2016," said first author Cheryl Peyser. "The prediction is looking on target so far."

Scientists knew that both the rate at which global surface temperature is rising and sea level in the western Pacific varied, but had not connected the two phenomena, said Peyser, a UA doctoral candidate in geosciences.

"We're using sea level in a different way, by using the pattern of sea level changes in the Pacific to look at - and this hasn't been done before," she said.

Peyser and her colleagues used measurements of sea level changes taken by NASA/NOAA/European satellites starting in 1993.

Using sea surface height rather than sea surface temperatures provides a more accurate reflection of the heat stored in the entire water column, said co-author Jianjun Yin, a UA associate professor of geosciences.

"We are the first to use sea level observations to quantify the global surface temperature variability," Yin said.

The team found when sea level in the western Pacific rises more than average—as it did from 1998 to 2012—the rise in global surface temperatures slows.

In contrast, when sea level drops in the western Pacific but increases in the eastern Pacific as it did in 2015, global bump up because the heat stored in the ocean is released, Yin said.

The paper by Peyser, Yin, Felix Landerer of NASA's Jet Propulsion Laboratory, Pasadena, California, and Julia Cole, a UA professor of geosciences, titled, "Pacific Sea Level Rise Patterns and Global Surface Temperature Variability," is being published online in Geophysical Research Letters.

People already knew the tropical Pacific Ocean was relatively higher in the west—the trade winds blow from east to west, piling up water on the western side of the Pacific.

However, the degree of the tilt from west to east changes over time, much like a seesaw. Sometimes the western Pacific near Asia is much higher than the ocean's eastern coast with the Americas. At other times, Pacific sea level in the west is not much greater than sea level in the east.

Others had documented that two different climate cycles, the Pacific Decadal Oscillation and the El Niño/La Niña cycle, affected how much the surface of the Pacific Ocean tilted from west to east.

From 1998 to 2012, the rate at which the global surface temperature increased slowed down—a phenomenon dubbed "the global warming hiatus." During the same time period, sea level in the western tropical Pacific Ocean increased four times faster than the average global .

Yin wondered if the two phenomena - sea level and global surface temperature—were related and asked Peyser, his graduate student, to investigate.

To figure out whether there was a connection, Peyser used state-of-the-art climate models that show what the climate system would do in the absence of global warming.

The models showed that changes in sea level in the western Pacific were correlated with changes in global surface temperature.

Verifying the correlation allowed the researchers to calculate the numerical relationship between amount of tilt and global surface temperature.

Once the researchers had the correlation, they used actual Pacific sea level data from satellites to calculate the Pacific Ocean's contribution to global surface temperature.

"What I found was that during years when the tilt was steep in the western Pacific, global average temperature was cooler," she said. "And when the seesaw is tilted more toward the eastern Pacific, it's warmer."

"We could say that for a certain amount of change in the tilt, you could expect a certain change in the temperature," she said. "Natural variability is a really important part of the climate cycle."

Understanding the variability is crucial for understanding the mechanisms underlying the warming hiatus, Yin said.

During the global warming hiatus, more heat was being stored in the deeper layers of the western Pacific Ocean, muting warming at the surface, the researchers said. Because warmer water expands, that stored heat contributed to the extreme sea level rise in the western Pacific during that time.

Starting in 2014 the ocean's tilt started to flatten out as the climate cycle changed to an El Niño pattern. The heat previously stored in the ocean was being released, warming the Earth's surface and reducing sea level in the western Pacific.

Yin was surprised to find the Pacific Ocean plays such an important role in the global surface temperature. He said, "Our research shows that the internal variability of the global climate system can conceal anthropogenic global warming, and at other times the internal variability of the system can enhance anthropogenic warming."

The next step, he said, is figuring out the mechanisms that allow the Pacific to change the global surface temperature so quickly.


Explore further

Researchers create means to monitor anthropogenic global warming in real time

More information: Cheryl E. Peyser et al, Pacific sea level rise patterns and global surface temperature variability, Geophysical Research Letters (2016). DOI: 10.1002/2016GL069401
Journal information: Geophysical Research Letters

Citation: Pacific sea level predicts global temperature changes (2016, August 18) retrieved 22 September 2019 from https://phys.org/news/2016-08-pacific-sea-global-temperature.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
538 shares

Feedback to editors

User comments

Aug 18, 2016
Fascinating study and a unique way to measure ocean temperatures, but there are a couple statements not backed up by data.

During the global warming hiatus, more heat was being stored in the deeper layers of the western Pacific Ocean, muting warming at the surface

This has often been repeated but there is no data to support it. Here is a graph of ocean temperatures on the Argo floats website derived from prior studies and the more recent Argo data (since 2000).

http://www-argo.u...gure.jpg

Here's global air temperature during the 1998-2015 "hiatus" from satellite measurements:

http://www.nsstc....raph.png

The 700-2000 meter deep ocean temperature trend shows a very slight steady increase in deep ocean heat, both before and after the "warming hiatus"; no evidence it was absorbing any more heat after 1998 than before. It's an unsupported theory minimizing the fact that warming isn't always due to CO2 emissions.

Aug 18, 2016
Nice job Aksdad, except you got a couple of things wrong.
more heat was being stored in the deeper layers of the western Pacific Ocean
The 700-2000 meter deep ocean temperature trend shows a very slight steady increase in deep ocean heat
First, Argo's only measure the temperature of the top 2000 feet of the ocean. The bathypolagic and the abyss, which is what they are actually talking about here, is from about 3500 to about 19,000 feet (http://www.seasky...am.jpg). It has been pointed out to you previously (more than once I think) that the satellite measurements did not actually show a pause, once the drift of the satellites was accounted for (http://www.hngn.c...sts.htm) although there is some argument that is may have slowed - only to catch back up in the last few years.

There is no "minimizing" the fact Aksdad. It is recognized and accounted for.

Aug 19, 2016
and solar activity

This may be the first time I've ever seen you acknowledge this, care to share what "solar activity" you are referring to?

Aug 19, 2016
and solar activity

This may be the first time I've ever seen you acknowledge this, care to share what "solar activity" you are referring to?

Well, not to speak for GO, as he is very capable of speaking for himself, but for me solar activity means the activity we see from the sun. One of the things that climate scientists have to account for (maybe one of those minimizing facts Aksdad was on about) are changes in solar activity. Such can be evidenced by the numbers of sunspots, which they use for proxy determination, but more recently satellites have provided very specific information.

For what it's worth, satellite measurements have shown that our star has been quite stable, maybe showing a slight decrease in insolation over the last few decades.

Aug 19, 2016
I was just trying to understand what factors you are talking about, since I've brought the idea up previously only to be shot down since TSI 'only' varies by .1% during a solar cycle.

The article you linked does a good job of explaining this, but still:
"Many climate scientists agree that sunspots and solar wind could be playing a role in climate change, but the vast majority view it as very minimal and attribute Earth's warming primarily to emissions from industrial activity"

Emissions, btw, can't be totally attributed to industrial activity. The average wildfire releases about the same amount of CO2 in two weeks as do car emissions in a year. We've had a few large ones recently...
http://www.livesc...ars.html

Another thing to consider is the solar wind's influence on the ionosphere, whose interaction with the troposphere isn't really understood.

Also, the relationship between sunspots/GCRs has been known to influence cloud formations.

Aug 19, 2016
The 700-2000 meter deep ocean temperature trend shows a very slight steady increase in deep ocean heat, both before and after the "warming hiatus"; no evidence it was absorbing any more heat after 1998 than before. It's an unsupported theory minimizing the fact that warming isn't always due to CO2 emissions.


Ehhh... yes, the ocean heat temperature data was too uncertain back before 1998 for us to tease out a change in warming trend before and after.

On the other hand, we also know that during "the slowdown", the incidence of La Ninas increased quite a bit relative to the two decades years before. And we know that La Ninas cause more upwelling of cold water in the eastern Pacific and push warmer water down in the western Pacific. There's a direction connection there.

So there is some moderately-strong evidence supporting the article's claim, yes.

Aug 19, 2016
Emissions, btw, can't be totally attributed to industrial activity. The average wildfire releases about the same amount of CO2 in two weeks as do car emissions in a year. We've had a few large ones recently...
http://www.livesc...ars.html
But, because of emissions wildfire season is expanding, both in time and in ferocity. That's a feedback.
Another thing to consider is the solar wind's influence on the ionosphere, whose interaction with the troposphere isn't really understood.
Consider it how?
Also, the relationship between sunspots/GCRs has been known to influence cloud formations.
Sure, but the affect appears to be small on a net basis, and there is argument over whether it reflects more energy than it retains.

Aug 19, 2016
Consider it how?

I mean we know they interact, sprites have been observed for years. The question is how much influence is there?

there is argument over whether it reflects more energy than it retains.

Exactly. The science isn't really settled on what the affects are, which is why I brought it up.

Solar irradiance variations can only be a minor contribution

But a minor contribution over an extended period could have significant effects, such as the Maunder min.

Aug 19, 2016
If solar radiation was either constantly increasing, or decreasing - then sure - over time the effect would have an impact

It is constantly changing though, except during solar minimums. You've heard of the little ice age right? That was sandwiched around the MM, which I'm assuming someone as versed as you has heard of. Look at estimated TSI at that point:
http://lasp.color...ical_TSI
I'm just using Maggnus' logic and saying that such an extended period of low TSI also plays into different feedback loops. The oceans absorb a lot of energy, plant growth is effected by it, clouds are changed, the ionosphere "weakens", lot's of options really.

Unlike the effect of CO2 increase, the direct effect of a solar irradiation change is reversible

Da, what? I think you got that backwards: We can reverse the amount of CO2 in the atmosphere, but we can't do a damn thing about the sun doing it's thing

Aug 19, 2016
Also to consider is the uncertainty of the proxy data, with regards to temperature and TSI. I mean, just look at it:
http://www.global...y-data-0

We could very easily be underestimating how low TSI can go. A couple w/m^2 is a lot of energy, and open ocean water absorbs 94% of that energy.
https://nsidc.org...edo.html

And we can likewise be skeptical of how certain our historical temperatures are.

Aug 20, 2016
Our species has a hundred years to live before ambient temps in the tropics go over 160 degrees actual temperature. Inasmuch as sea temps will track as well, we will cook all the fish in the sea and all will starve while choking on rotting lifeforms. Looks like the Arabs will be the first to go, which is why they want to invade Russia and Europe

Aug 20, 2016
Also to consider is the uncertainty of the proxy data, with regards to temperature and TSI. I mean, just look at it:
http://www.global...y-data-0

And we can likewise be skeptical of how certain our historical temperatures are.
I can't help but wonder if you really grasp the importance of that graph. We can be relatively certain of the historical temperatures, within the error bars. That's the whole point.

Aug 21, 2016
I can't help but wonder if you really grasp the importance of that graph. We can be relatively certain of the historical temperatures, within the error bars. That's the whole point.


Yes. If you understood how to read that graph you'd see we can be relatively certain of two things:

1) It's completely possible the temperature didn't change at all during the entire period.

2) The data were very obviously taken using different methods.

One more point that probably shouldn't go without mention; the graph is based on data collected by a serial liar.


Aug 21, 2016
Phys1 writes: "If you have an idea how to capture the CO2 and put it back underground go ahead."

OK smartass, how did it get there to start? Trees. Trees died. They bound carbon. We still have trees and they still bind carbon. No magic or advanced technology involved.

For the bonus round, would you care to explain why trees don't make coal anymore?

Aug 21, 2016
Genius. And all we need to do to solve the immediate warming problem is to plant 950 billion trees and wait 40 years. I suspect Phys1 was referring to *feasible* solutions to the current problem. Since there's not enough growing land on the planet. And I somehow doubt the entirety of human civilisation could stop for 40 years while we waited.

Aug 22, 2016
BackBurner (BB) belligerently utters drawing attention to himself
OK smartass, how did it get there to start? Trees.Trees died.
Sure & plankton & other life millions or so years ago as it metamorphosed into coal, oil & gas gradually...

BBs facile line
They bound carbon. We still have trees and they still bind carbon
Sure, at best rate despite lesser trees & as higher CO2 can bind a bit more over ~100yrs or so for CO2 decline IF we did reduce fossil fuel emissions. ie If fires not fed by low density lignin recent growth in high CO2

BBs oddball sarcasm
No magic or advanced technology involved
So ? combusting million year+ fossil fuels En Masse for one species needs isn't part of natural cycle ie Equivalent of >230,000 Liters petrol per second (big oil confirmed ~2013), ie Where extra CO2 accumulates since ~150yrs ago

BB claims/asks
... why trees don't make coal anymore?
No continues slowly but, Needs Much More material !

Aug 22, 2016
There's currently methods for CO2 capture:
https://www.techn...ly-work/
https://www.techn...al-leaf/
There are currently no methods for limiting solar output.

Aug 22, 2016
There's currently methods for CO2 capture:
https://www.techn...ly-work/
There are currently no methods for limiting solar output.

I'm not sure what your point is. Given that solar output has been pretty constant (something like a 0.01% variance over the last 500 years or so) I don't know how you think this is germane to the article above.

Aug 23, 2016
But it is going to cost, that is irreversibility in financial terms.
There are currently no methods for limiting solar output.
Easy, put an enormous shield in a geostationary orbit.
Expensive but so is digging out 300 million years worth of fossil fuel only to rebury it.

Wow, where to begin. Pretty concerning that you would put a price on the health of the planet. Also a little crazy you think that a plan Mr. Burns used in the Simpsons is a good idea, and even crazier there is at least four people here that agree...

I'm not sure what your point is

Phwyz said we could limit solar output, but do nothing about CO2, hence the articles about using the CO2 to create fuel.

Aug 23, 2016
Wow, where to begin. Pretty concerning that you would put a price on the health of the planet. Also a little crazy you think that a plan Mr. Burns used in the Simpsons is a good idea, and even crazier there is at least four people here that agree...
Not as crazy as you make it out to be: http://www.bbc.co...-warming
Phwyz said we could limit solar output, but do nothing about CO2, hence the articles about using the CO2 to create fuel.
I don't think that is what Phys1 said at all. I think his intention was to suggest that limiting solar insolence would be impractical, and therefor we should strive to limit our emissions of Co2.

As to your articles, these are all very preliminary and currently, beyond our capabilities beyond a very limited scope. That is not to say they will always be. Again, our best answer right now is to limit our Co2 emissions.

Aug 23, 2016
Again, our best answer right now is to limit our Co2 emissions

Agreed.

Aug 24, 2016
So then it would not be very smart of us to cut down our forrests - right?

-- da OnionTard
Uh huh. How "bright" was it to boast about how you drove 1200 miles in 2 days? Talk about supporting Big Oil. It's a "good" thing onionTard is so afraid of CO2

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more