I asked:
I’ve been trying to consider the
Volumetric or Cubical Expansion Coefficients of Liquids
and how it relates to water and climate change
It’s hard to wrap my head around… especially when you add melting sea ice to the equation
What do you think?
Will warmer water increase sea level rise even greater… the warmer the water the higher the rise? If the ocean temperature rises from from 62 to 68 will the increase temperature cause the sea level to rise due to expansion?
And, does it matter if ice starts as sea ice or ice on land?
How about the salinity? I’m guessing salinity will decrease as we add fresh water?
I found a tool box app. but I don’t think it takes any of these factors into account:
https://www.engineeringtoolbox.com/volumetric-temperature-expansion-d_315.html
Sidd replied:
ya, warming causes about a third to a half of current sea level rise but the other 2/3 is melting land based ice
the warming of the surface ocean (0-couple hundred meters) is not that important, it is the deep ocean that holds most of the water and it is warming much slower than the surface, but the expansion of the deep ocean causes most of the sea level rise
deep warming is very small compared to surface, a few thousandths to a hundredth of a degree, but there is a lot of deep ocean
90-95% of the warming due to CO2 goes into the oceans. There is better data now on where that heat is going in the ocean from the Argo floats.
theres a buncha papers on it, Cazenave is a good author to look for.
According to a new study published in the journal Nature, the disaster scenario of rising sea levels could play out much sooner than expected. Thwaites Glacier in Antarctica may become unstable in the next 30 to 50 years.
“We are not saying this is definitely going to happen,” said David Pollard, a researcher at Pennsylvania State University and a co-author of the new paper. “But I think we are pointing out that there’s a danger, and it should receive a lot more attention.”
If this does happen, sea levels could rise 6 feet in this century inundating coastal cities.
“You could think of all sorts of ways that we might duck this one,” said Richard B. Alley, a leading expert on glacial ice at Pennsylvania State University. “I’m hopeful that will happen. But given what we know, I don’t think we can tell people that we’re confident of that.”
In another study published in the journal Nature, scientists forecast “Millions projected to be at risk from sea-level rise in the continental United States”.
“Sea-level rise (SLR) is one of the most apparent climate change stressors facing human society. Although it is known that many people at present inhabit areas vulnerable to SLR few studies have accounted for ongoing population growth when assessing the potential magnitude of future impacts4. Here we address this issue by coupling a small-area population projection with a SLR vulnerability assessment across all United States coastal counties. We find that a 2100 SLR of 0.9 m places a land area projected to house 4.2 million people at risk of inundation, whereas 1.8 m affects 13.1 million people—approximately three times larger than indicated by current populations. These results suggest that the absence of protective measures could lead to US population movements of a magnitude similar to the twentieth century Great Migration of southern African-Americans. Furthermore, our population projection approach can be readily adapted to assess other hazards or to model future per capita economic impacts.”
NASA — Greenland’s snowy surface has been getting darker over the past two decades, absorbing more heat from the sun and increasing snow melt, a new study of satellite data shows. That trend is likely to continue, with the surface’s reflectivity, or albedo, decreasing by as much as 10 percent by the end of the century, the study says.
Greenland’s Darkening Ice
The Columbia study says:
Greenland’s snowy surface has been getting darker over the past two decades, absorbing more heat from the sun and increasing snow melt, a new study of satellite data shows. That trend is likely to continue, with the surface’s reflectivity, or albedo, decreasing by as much as 10 percent by the end of the century, the study says.
While soot blowing in from wildfires contributes to the problem, it hasn’t been driving the change, the study finds. The real culprits are two feedback loops created by the melting itself. One of those processes isn’t visible to the human eye, but it is having a profound effect.
The results, published in the European Geosciences Union journal The Cryosphere, have global implications. Fresh meltwater pouring into the ocean from Greenland raises sea level and could affect ocean ecology and circulation.
“You don’t necessarily have to have a ‘dirtier’ snowpack to make it dark,” said lead author Marco Tedesco, a research professor at Columbia University’s Lamont-Doherty Earth Observatory and adjunct scientist at NASA Goddard Institute of Space Studies. “A snowpack that might look ‘clean’ to our eyes can be more effective in absorbing solar radiation than a dirty one. Overall, what matters, it is the total amount of solar energy that the surface absorbs. This is the real driver of melting.”
The feedback loops work like this: During a warm summer with clear skies and lots of solar radiation pouring in, the surface starts to melt. As the top layers of fresh snow disappear, old impurities, like dust from erosion or soot that blew in years before, begin to appear, darkening the surface. A warm summer can remove enough snow to allow several years of impurities to concentrate at the surface as surrounding snow layers disappear. At the same time, as the snow melts and refreezes, the grains of snow get larger. This is because the meltwater acts like glue, sticking grains together when the surface refreezes. The larger grains create a less reflective surface that allows more solar radiation to be absorbed. The impact of grain size on albedo – the ratio between reflected and incoming solar radiation – is strong in the infrared range, where humans can’t see, but satellite instruments can detect the change.
“It’s a complex system of interaction between the atmosphere and the ice sheet surface. Rising temperatures are promoting more melting, and that melting is reducing albedo, which in turn is increasing melting,” Tedesco said. “How this accumulates over decades is going to be important, because it can accelerate the amount of water Greenland loses. Even if we don’t have a lot of melting because of atmospheric conditions one year, the surface is more sensitive to any kind of input the sun can give it, because of the previous cycle.”
National Oceanic and Atmospheric Administration (NOAA)
> November 2015 was the warmest November on record for the globe.
> January-November 2015 (YTD) was the warmest such period on record for the globe.
> September-November (N. Hemisphere fall) was the warmest such period on record for the globe.
> The November 2015 average global sea surface temperature was also the highest on record.
The Weather Underground reports Antarctica hit a record high temperature. Antarctica may have experienced its warmest day ever recorded on Tuesday, with the temperature reading of 63.5°F, reports The Weather Underground.
Tuesday’s record high temperature follows another high reading of 63.3°F set just the day before. Until this week’s heat wave, the highest-known recorded temperature on the continent was 62.6°F back in 1976.
The Antarctic Peninsula where the readings were made “is one of the fastest warming spots on Earth,” reports The Weather Undergound. The website cites studies from 2012 that show the world is warming at a quickening pace.
Five nations and territories have tied or hit all-time high temperature records so far this year.
