« Melting momentum: May 2017 | Main

Comments

Feed You can follow this conversation by subscribing to the comment feed for this post.

Wade Smith

I am looking at the Global Sea Ice Area Graphic, which is probably the most reliable data set for monitoring Global Warming, and it looks like we are going to verify last year's ridiculous curve.

If this happens, it is a strong indicator that a bifurcation has happened in the Southern Hemisphere; The rate of forcing will begin to melt Antarctic Sea ice in earnest.

A few years ago, I was wondering how long it would take before forcing in the Southern Hemisphere caught up with the Northern Hemisphere, since the CO2 concentration and Methane Concentration of the Southern Hemisphere lags behind the northern by several years worth of Keeling Curve development.

Well, it looks like I have my answer, and the limit has apparently happened about 5 years earlier than I thought it might.

This is the first time in 8 years that I've actually under-estimated some aspect of Global Warming.

It's insane that we saw a 2.5 million km change in the second maximum area in a single year, to the point that the inflection points of the curve's 30 year mean don't even represent the behavior data any more.

Wade Smith

So NASA's GRACE experiment finds that the East Antarctic landmass is actually gaining ice, offsetting sea level rise by about 0.5mm per year, for now. This is apparently being caused by increased convection coming from the Southern Ocean near Australia. NASA Scientists predicted that this would continue for a few decades, but will eventually reverse, which will be bad news indeed over the longer, generational time scales. Besides all this, considering how rapidly Sea Ice area was depleted last year, this will eventually begin to play into Positive Albedo feedbacks to melt continental ice even faster; That prediction was made before this event happened, so it has not be refined by said data.

This means there is a half-millimeter per year worth of sea level rise unaccounted for, which is not coming from Glaciers or ice caps. Since the deep ocean is definitely not warming fast enough for this to be caused by thermal expansion, I can only hypothesis that this is coming from the mechanical displacement of water due to a geologic force, most likely sub-oceanic volcanism in the Pacific. Anyway, without invoking cosmic events, I'm out of ideas, because I don't know of anything else besides Geology which could explain that big of a change. We'd probably need another 10 years worth of data to confirm this or rule it out.

D_C_S

NASA's GRACE mission shows net declining of Antarctic land ice.

Wade Smith

When?

I read an article a while back on physdotorg, which was published by NASA, which said the West Antarctic was experiencing net loss, but because of gains in the East it was actually net positive.

It would seem that Antarctica should be warming at about the same rate as Greenland, but because concentration of CO2 and Methane takes 5 to 10 years to mix all the way down to Antarctica from the Northern Hemisphere, the warming actually lags behind by 5 to 10 years.

In any case, my own attempt to calculate the rate of melt acceleration of Greenland suggests Greenland will contribute around 10.5 Inches to global mean sea level rise by the end of the century. I expect Antarctica to do about the same, since over the long term greenhouse effects should impact both poles about the same, though albedo effects and Urban Heat Island effects are obviously not the same.

This puts my projection for global mean seal level rise between 25 and 30 inches for 2100, because you still have to account for mountain glacier retreat in places like Patagonia, Alaska, the Himalayas, and so forth.

Since this is slightly above the latest IPCC report, I take it the IPCC is getting closer to the truth these days.

AH Crap.

While searching for that other article, I found a more recent one on the same news site, which contradicts it...maybe they made some sort of mistake?

Wade Smith

"The melting rate from West Antarctica, however, grew by 18 billion tons per year every year, Harig and Simons found. Accelerations in ice loss are measured in tons per year, per year, or tons per year squared."

Read more at: https://phys.org/news/2015-04-gravity-antarctic-ice-sheet-increasingly.html#jCp

Ah, yes, this is about the same as the net average acceleration of Greenland. However, they didn't say exactly how much of this is offset by the east.

So, this is easily predictable and is in line with my prediction of roughly 10.5in per century per pole contribution to sea level rise....for the next century. In the century after that it actually rises even faster.

Wade Smith

This year, there is a slight cold pocket in the North Atlantic which had not been as large in recent years.

In recent years, there has been a heat build-up off the coast of New England and Newfoundland, which gets mixed back in with the Gulf Stream and carried up to Greenland and Iceland. This warm pocket is weaker than it was in recent years too.

Any ideas what is causing this discrepancy?

D_C_S

https://twitter.com/lenaertsjan/status/798128755248164864

D

Hello Neven,

OT. But can you please refresh my memory of the subject of my sea ice bet with William Connelly from some years back?

Neven

You should be able to find it on the Stoat's blog, D.

Wade Smith

Northern Hemisphere Ice Extent continues to duplicate previous record low curve. This could be an indicator that the "mean" is now over-taking that previous record low year.

Global Sea Ice Area continues to run well below the previous record low, with almost every day being easily below the previous record. While I don't expect last years "slow recovery" to become the normal right away, I do expect this year's curve to end up bisecting the curves between the two previous record lows. It's unlikely that the "mean" experienced that much acceleration in a single year.

I believe the next 5 years will be "transitional", where we'll see more net melting of Antarctic Sea Ice Area, and then the years after that will establish a down trend.

Since this has turned into a Neutral ENSO year, I am interested to see how many Tropical Cyclones we end up with in the Atlantic, and how many of them influence Greenland and the rest of the Arctic this year. An average Neutral year produces 18 named storms, but we are already on pace to have more like 22 named storms this season.

Verify your Comment

Previewing your Comment

This is only a preview. Your comment has not yet been posted.

Working...
Your comment could not be posted. Error type:
Your comment has been posted. Post another comment

The letters and numbers you entered did not match the image. Please try again.

As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.

Having trouble reading this image? View an alternate.

Working...

Post a comment

Your Information

(Name is required. Email address will not be displayed with the comment.)