Steve Sadlov seems to be the ice expert around here. Needless to say, I think you’re correct about needing heat from ocean currents to melt a lot of ice in a hurry, but this probably isn’t the right thread to discuss the details of your question. Try asking on the current Unthreaded #18 (at the moment). I need to construct some sort of chart to see if I can show some evidence of a change in trend without having to wait another five years.

Thanks for the post. I’ve been pursuing “The Great Melt Down” as a pet project the last several weeks. Since you seem up on the basics, maybe you could answer a few questions, or point to some sources.

I agree w/ Dr. Gray because my own (very)tentative suspicion is that there is simply not enough energy in either the atmosphere, or from insolation (or some combi thereof) to account for the loss of ice extent we’ve been seeing. Odd as it may seem, I have not been able to find a thing for basic heat transfer between atmosphere-ice (real world vs lab or course: temps, RH, wind factors, etc). Same for increased/decreased insolation & cloud cover. NSIDC has some general comments on summer cloud cover, which leads me to suspect that soot, etc, on the ice (increased absorption) also has not much to do w/it, but I can’t find tabularized monthly cloud cover summaries for the region, so at the moment, that’s just a guess as well.

So:

Surely, someone has run the basic heat transfer calcs – how many joules req’d to melt how many cubic meters of ice, after accounting for wind, waves, etc, and then compare to atmospheric heat capacity and insolation? That would narrow the search. Also, I’d guess that the peculiar composition of sea ice would have to be factored, althought I don’t recall seeing that over at NSIDC either; must check again. The data must be out there somewhere; I must be missing it.

In fact, how many cubic metres are we talking? Does anyone know, or is this all about area? Can those fancy satellites “see” ice depth?

Cloud cover stats – per-cent monthly daytime coverage, type and radiant transparency (& at what wavelengths?), ie: how much insolation is actually reaching the ice? In solar heating systems design, the cloudiness factor – “K” – cannot be ignored. Or maybe someone has stuck some sensors in the ice on a semi-regular grid and actually measured? Tough to do on sea-ice, I would guess.

Lastly, with all those fancy “we can measure the elevation of the Greenland ice cap to w/in 2cm” satellites, surely we can measure incoming vs outgoing radiance for very small regions. That at least would establish how out-of-balance the Arctic is, if not why. Has this been done?

If our suspicions are correct, and the melt-down is related to more energetic ocean currents – perhaps the NAO? – the next few years should tell the tale.

The UK Met Office station data can be found here. I’ve only looked a a few stations but there is an interesting increase of around 0.8 degrees in the years since 1987. From looking at other parts of the website this is probably due to the processing technique they use to weight stations and create a temperature grid across the UK. I don’t know how much contribution the UK adds to the global temperature estimate but it looks like something similar to the US data is going on in the UK. I suspect the data provided is not the raw data measurements. I can maybe see how some people would jump to the conclusion that there is unprecedented heating in the last 20 years but it looks more like something is up with the processing technique. I always try to apply the Principle of least astonishment and there’s something not quite right with the way the curves I have looked at have common artefacts.

And does anyone know why the arctic is warming but the antarctic is not?

Taking my cue from William Gray, IMHO it’s to a large if not primary extent a function of ocean currents (or thermo-haline circulation) which transfer heat from south to north. The AMO ramped up in 1995, not coincidentally the year the Arctic started it’s rapid warming trend. The Pacific equivalent has also been strong, but both should now be ramping down and I predict that Arctic temperatures have peaked and will soon be declining. See my post here. The same currents deliver chilled water to the Antarctic which helps to keep it cool.

Looking at the initial trend of rural to urban US and Brazil stations, it is becoming more urgent that a proper analysis of ground station data over the whole world is made because at this moment, to me anyway, the suspicious data looks like the GISS data and the implication is that the sun really is a principal driving effect in GW.

If the GISS is correct then the most probable conclusion is that recently there is another driver and honestly, a possibility is CO2.

But for now that is just speculation. I am neither a denier or an alarmist. Clear methods and data analysis first.

In any case, here’s a map of all currently active (conventional) meteorological stations in Brazil: http://www.inmet.gov.br/html/rede_obs.php
Left pane, link titled “Superfície Convencional INMET”. Very nice flash, but not too friendly for the purpose at hand. It does however provide the WMO number and lat/long data for each station, thus allowing a comparison with GHCN.

A list of all currently active Argentinian stations is here: http://www.smn.gov.ar/?mod=biblioteca&id=98

I believe it should be possible to get the data and perhaps some metadata for these stations from this NOAA ftp site, but I haven’t downloaded the files to check: ftp://ftp.ncdc.noaa.gov/pub/data/ghcn/v2/