Growth Of Antarctic sea ice due to fewer winter clouds, Chinese scientists find 

Posted: April 29, 2019 by oldbrew in Clouds, research, sea ice
Tags:

Antarctica


Growth of polar sea ice is of course mainly a winter phenomenon, each polar region being continuously dark for several months during that period. The researchers here looked at the role of clouds during the dark Antarctic winter and as one said, “Fewer clouds mean more heat is lost from the ocean.” This then led to higher summer sea ice in some areas.
Which begs the question: why were there fewer winter clouds?

– – –
H/T The Global Warming Policy Forum (GWPF)

BEIJING, April 26 (Xinhua) — Researchers have discovered that lower cloud coverage in the Antarctic can promote sea ice growth.

Unlike the rapid decline of Arctic sea ice in the warming climate, Antarctic sea ice witnessed a modest extension over the past four decades, according to the paper published in the Journal of Geophysical Research-Atmospheres. […]

The researchers from China and the United States found that Antarctic sea ice had a strong rebound from 2011 to 2012.

“We quantified the effects on sea ice growth via a thermodynamic model based on reanalysis and satellite data and concluded that lower cloud coverage cooled the sea surface and accelerated the sea ice storage,” said Wang Yunhe, a researcher from the Institute of Oceanology, Chinese Academy of Sciences.

“Clouds are like a down jacket for the Antarctic to preserve heat during winter,” said Bi Haibo, a researcher from the institute. “Fewer clouds mean more heat is lost from the ocean.”

Rapid temperature decline and thicker sea ice in the Antarctic during the winter in 2011 was mainly due to fewer clouds, he said.

Source here.

Comments
  1. oldbrew says:

    In the abstract they say negative cloud‐fraction anomalies in winter can play a vital role in the following summer sea‐ice distribution.

    https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2018JD029435

  2. Curious George says:

    Nonsense. Science has been settled a long time ago. 🙂

  3. P.A.Semi says:

    I’ve been recently analysing NOAA NCEP-reanalysis datasets, daily data (maps) since 1948…
    ftp://ftp.cdc.noaa.gov/Datasets/ncep.reanalysis.dailyavgs/

    Among other things (more on it sometimes later), it’s interesting to compare their temperature averages with reality or other models…

    For example comparing this NOAA dataset with ECMWF (European center for medium-range weather forecast) daily data, which I download only since 2015 (the “WMO-essential” datasets), shows cca 0.4 °C difference in global temperature average, which is not little, if they have their goals of 2 °C per century… (ECMWF has warmer july and colder december by these cca 0.4 °C)

    Then it is interesting to compare it with these reports like “Rapid temperature decline … during winter 2011” arround Antarctic

    Here is monthly surface temperature anomaly of Antarctic and an ocean arround it in NOAA dataset. Difference of monthly average temperature from long-term average for that month, and the series for Feb,May,Aug,Nov are marked with different symbols to ease reading… Horizontal lines show 0, +1°C, -1°C … Here it’s region southern from 58° south latitude…


    Their winter 2011 (August) temperature arround Antarctic is unusually warm, not cold… It is suspicious… (I’ll need to make it more specific to exclude Antarctic land and compare only ocean…? Sometimes later…)

    Because looking at their global temperature anomaly (here it is 850hPa temperature some kilometer aloft… straight purple lines and arrows added manually in graphics editor, dark-red bold line is 2-year gaussian of original red serie, which is anomaly (difference) of global average daily temperature from long-term global average for that day-of-year. Using average of pixels on rectangular map gives bigger weight to polar regions, I’ve got other charts for different regions separately eliminating this effect… )

    it shows:
    – No significant trend in 1950-1976, some oscilation arround a constant average
    – 0.5°C fast step upward during 1976-1981
    – No significant trend in 1981-1997, with an exception of Mt. Pinatubo effect in 1991-1993 (or 1995), which is visible on most temperature charts of that time from other sources too
    – Steady (constant-slope) rise since 1995 or 1997 until today by some 1°C already (in some 20 years)
    – Their year 2018 is still quite warmer than previous years, which does not seem to match reality of recent cold winter(s)?
    – What has changed in 1995-1997 ? If it was anything related to CO2, it has been rising since at least 1850 already, and there is no such rise in their past temperature data…

    – Most of the warming (while comparing regional series) can be sumarized, as there are less severe winters in Siberia and northern polar region (by some 10°C, from -26°C to -14°C), there is 2°C warming arround Antarctic south of 60°S, while most mid-latitude oceans and lands do not significantly warm… IF the global warming is limited on Siberia and north polar region while they are still very safe below 0°C, it is not that bad after all ?!

    The trend is very suspicious and not very probable, it looks like they intentionally lowered past temperatures before 1976 by a constant to create impression of modern warming, and the recent trend looks too artificially with a constant-slope too…

    Notice also, when IPCC was established – there was no warming yet, they invented it only later… Were they prophets of the warming, or architects of that fake?

    Is there another such dataset for download to compare them? I’ve heard of ERA15, but it is probably commercial ??

  4. phil salmon says:

    What is unique about Antarctica is that it’s snowy surface is so pristine that it has a higher albedo than the tops of clouds. Every other land surface is cooled by cloud cover in summer. But Antarctica is relatively warmed, since cloud albedo is less than the snow surface albedo. Over that frigid continent clouds do not trap heat (there’s little enough to trap) – instead they warm the land by reflecting less sunlight than the unique whiteness of the land surface.

  5. oldbrew says:

    Unlike the rapid decline of Arctic sea ice in the warming climate

    …which has not been at all rapid for a decade or more – contrary to IPCC climate models and the loud predictions of alarmists.

  6. oldbrew says:

    @ PA Semi – Dr. Roy Spencer has various reports of temp data on his website, e.g.:

    UAH Update for January 2011: Global Temperatures in Freefall
    February 2nd, 2011 by Roy W. Spencer, Ph. D.

    …although this, too, shall pass, when La Nina goes away.

    http://www.drroyspencer.com/2011/02/uah-update-for-january-2011-global-temperatures-in-freefall/
    – – –
    UAH v5.6 Global Temperature Update for Nov. 2013: +0.19 deg. C
    http://www.drroyspencer.com/2013/12/uah-v5-6-global-temperature-update-for-nov-2013-0-19-deg-c/

    Also this blog post:

    Century-old photos discovered in Antarctica hut
    December 31st, 2013 by Roy W. Spencer, Ph. D.

    I stumbled upon a recent article about a pile of old photo negatives found in a hut in Antarctica. They were from Captain Scott’s 1911 expedition base, Cape Evans, Antarctica, discovered by Antarctic Heritage Trust (New Zealand) researchers.

    What is kind of surprising is the number of photos with lots of open water. I’m not very familiar with the various coastal regions of Antarctica, but the weather in some of the photos looks almost balmy…here’s one example:

    http://www.drroyspencer.com/2013/12/century-old-photos-discovered-in-antarctica-hut/

    ROSS SEA PARTY PHOTOS
    Our conservation specialists, working in expedition photographer Herbert Ponting’s darkroom at Scott’s Cape Evans base, discovered a small box of cellulose nitrate negatives clumped together.

    The photographs are from Ernest Shackleton’s Ross Sea Party (1914-1917), which spent time living in Scott’s hut after being stranded on Ross Island when their ship blew out to sea.

    https://www.nzaht.org/pages/ross-sea-party-photos

  7. oldbrew says:

    43-year-old mystery of Polynya in Antarctica unraveled
    Date: April 24, 2019
    Source: New York University

    Summary:
    A new study has unraveled the four decade long mystery surrounding the occurrence of a mid-sea Polynya — a body of unfrozen ocean that appeared within a thick body of ice during Antarctica’s winter almost two years ago.
    – – –
    “Once opened, the Polynya works like a window through the sea-ice, transferring huge amounts of energy during winter between the ocean and the atmosphere.” said Francis. “Because of their large size, mid-sea Polynyas are capable of impacting the climate regionally and globally as they modify the oceanic circulation. It is important for us to identify the triggers for their occurrence to improve their representation in the models and their effects on climate.

    https://www.sciencedaily.com/releases/2019/04/190424102234.htm