We’ve been observing sea level with satellites for 24 years now.
All sea level is local!
All sea level is local!
Different points on different coastlines will experience different levels of sea level rise due to a variety of factors. Maryland is getting a quadruple whammy:
Thanks for an illuminating link. It’s a great illustration of the kinds of discussions more juridictions should be having. The contribution of the Gulf Stream was a neat bit, too.
I find it fascinating the way SLR is way more complicated than a naive understanding would suggest (‘surely water just evens out’). With variable heating bulges and gravitational bulges and stream movements creating slopes. Turns out sea level is just as hard to measure on a global scale as temperature.
Wow, that’s a great summary, full of useful perspective and broad-based knowledge.
It’s interesting to watch the Western and Eastern Pacific alternate the ENSO and PDO surface bubble. One of the things I am most curious about is where OHC will be at the end of 2016. SLR updated 12/11/2016:
Yes. It certainly looked like sea level rise had something to do with El Nino and La Nina, but the relationship seemed oddly out of synch. SLR seems highest during El Nino spans when you’d think it would be lowest. Very confusing.
Jeffrey, the page that sea level chart comes from also has a link to a paper by some of the people who produce the graph, discussing ENSO and sea level.
Scroll down a little here.
Jeffrey – I think the sloshing of Pacific water back and forth from East to West and back is approximately zero sum.
Barry – the big events on the MEI graph appear to be the rebound from the volcano just before the satellite series begins; the 1997 through 2001 ENSO events; the 2010-2011; and the 2015-2016-whenever ENSO events.
The sea height response appears to be almost instantaneous. The 2015 El Niño actually starts at the end of 2014, and the spike in GMSL started soon after. So what is doing that? The 2010-2011 La Niña dumped a huge amount of evaporated ocean water on the continents of Australia and South America. Possibly elsewhere as well. This caused a pronounced drop in sea level. So is the reverse what is happening with the big El Niño events… like the current EL Niño? Does a large amount of evaporated ocean water suddenly drop on the oceans instead of the continents, causing a large, but transitory, increase in GMSL? If so, when ENSO slides from El Niño to neutral, the rain must almost immediately revert to falling on land.
I think this is the most recently updated graph, and it show the same downturn the MEI graph shows:
Barry – is this the study you mentioned?
Previous studies suggest that both the global ocean and climate system lose heat during El Niño events (e.g., Roem-
mich and Gilson, 2011; Loeb et al., 2012; Trenberth et al., 2014). This would appear to conflict with our finding that the ocean is warmer during El Niños. …
This is one of the things I have doubted… that the oceans warm the atmosphere during an El Nino by losing OHC. I think OHC goes up during an El Niño.
Ah – there used to be a reference to Boening et al 2012 – The 2011 La Niña: So strong, the oceans fell – near the graph.
As far as I’m aware a general correlation between ENSO events and sea level fluctuation is not yet determined.
Tamino wrote a bit about it here.
HTML fail, apparently.
Barry – I missed Tamino’s post. Thanks for linking to that. Reading the paper again to which I linked, I was reminded of the simplified graphical explanation for changes in OHC between the deeper layers of the Pacific:
Winds slow down/speed up; the ocean responds quickly.
Well, this is interesting on ENSO and OLR:
Outgoing Longwave Radiation (OLR) data at the top of the atmosphere are observed from the Advanced Very High Resolution Radiometer (AVHRR) instrument aboard the NOAA polar orbiting spacecraft. Data are centered across equatorial areas from 160°E to 160°W longitude. The raw data are converted into a standardized anomaly index. Negative OLR are indicative of enhanced convection and hence more cloud coverage typical of El Niño episodes. More convective activity in the central and eastern equatorial Pacific implies higher, colder cloud tops, which emit much less infrared radiation into space. More information can be found at the Climate Prediction Center OLR page.
What I’d be curious to see is OLR data *globally*, not just for the Pacific. If GMST goes up, so should global OLR.
Here’s a 2008 paper which is a bit more cautious on the connection between ENSO events and sea level fluctuations. To balance the opinions a bit.
The paper you referenced, JCH, opines something I’ve read here and there, that “It has long been known that nonseasonal variations in global-mean sea level (GMSL) are correlated with El Niño–Southern Oscillation (ENSO).” I had taken this to be the case until having another dig around during this conversation.
If there is a physical connection, that is not well understood. The papers that zoomed in on the 2010/11 Nina point to ENSO-influenced changes in rain patterns being responsible. Your ref suggests that steric and eustatic (mass) contribution may be proportional during these events.
Barry – in the new paper to which I linked, I was disappointed that this study was not referenced: Study: Rising Seas Slowed by Increasing Water on Land, and I wonder how it would change the result?
They reversed a contribution to balancing the sea level budget?
At this month’s AGU, the talk after mine discussed detecting ENSO from sea -level fluctuations. I thought it was well known that this was possible if by nothing other than the inverse barometric effect.
It is easy enough to detect this from tidal gauges such as located in Sydney harbor. Follow this method I outline here:
I suppose it’s the drought especially in Amazon region: Less water on land, more in oceans.
The data indicate that sea levels can fluctuate 10cm (or more) in a year. Is there enough water in the atmosphere to account for this rapid fluctuation? Can Greenland/Antarctica contribute/remove 10cm in a year? Can ocean expansion contribute 10cm in a year? How does science account for these rapid changes? How does the model account for both rising and falling sea levels.
[Response: It doesn’t fluctuate that much in a year — not globally. More like 10 mm, not 10 cm.]
Global Mean Sea Level Time Series (seasonal signals retained)
realclimate, unforced variations Dec ’16, response #177 by Brian Dodge addresses my bigger question (show me the acceleration?!) and also partly addresses my question here.