'Massive melting event' sinks billions of tons of Greenland ice amid heat wave

[Job Bautista]

https://www.accuweather.com/en/weather-news/massive-melting-event-sinks-billions-of-tons-of-ice-amid-heat-wave/993907

> Scientists are raising alarms that ice has vanished from the
> Greenland ice sheet in a dramatic melting event in recent weeks. So
> much so that the liquid released could cover the entire state of
> Florida with 2 inches of water.
>
> Home to the world's second-largest ice sheet, only behind Antarctica,
> Greenland's 656,000 square-miles of ice play a crucial role in
> containing the majority of the world's freshwater supply. Over 99% of
> the world's freshwater ice supply is stored in the ice sheets between
> Greenland and the Antarctic.
>
> But in the final few days of July, an extreme heat wave sent
> temperatures skyrocketing in the northern portion of Greenland,
> hitting a high of 74 degrees Fahrenheit on July 29 at the Nerleit
> Inaat Airport. According to the Polar Portal, a site run by Danish
> research institutions that monitor the Greenland ice sheet, that heat
> wave triggered what was dubbed a "massive melting event."
>
> As the heat wave pushed temperatures nearly 70 degrees Fahrenheit
> above seasonal norms, over 8 billion tons of ice sank into the ocean
> on four consecutive days of last week. From July 28 to Aug. 4, nearly
> 60 billion tons of ice have been lost, according to data from Polar
> Portal.
>
> "It's quite an interesting melt event though," Dr. Ruth Mottram told
> AccuWeather in an email. "I think it is worth pointing out that prior
> to this recent heat wave, the mass budget of the ice sheet had been
> above average due to the large amount of snow that fell in early
> summer."
>
> Mottram, a climate scientist at Danish Meteorological Institute,
> added that a particularly rainy summer has also shifted the melting
> dynamics even before the record-breaking heat arrived. In some areas,
> that rain has proven helpful when it freezes and adds to the ice
> layer.
>
> In warmer locations, however, the opposite can occur.
>
> "The rain that falls on the ice sheet can refreeze if there is a deep
> surface snow pack so it actually helps the ice sheet gain ice," she
> said. "But in other regions, where the snow is thin, rain can
> accelerate melt and can have an effect on ice sheet dynamics."
>
> Once that ice melts, some of it flows directly into the ocean and
> adds to the ongoing problem of sea-level rise, and ice that refreezes
> sets the stage for more melting in the future.
>
> This is the second summer of severe melting in recent years, as 2019
> also brought unfathomable losses to the ice sheet. In a single day
> that summer, 11 billion tons of ice were lost.
>
> According to Mottram, the quantity of this year's ice loss may be
> eye-popping, but the real unique twist with this year's melting is
> the vast area in which the melting is occurring.
>
> "The melt event was unusual not just in total amounts but because it
> was very widespread with large amounts of surface melt at quite high
> altitudes over the ice sheet," she said. "Ice cores show that these
> widespread melt events were really rare prior to the 21st century,
> but since then, we have had several melt seasons."
>
> She pointed specifically to the years of 2002, 2010, 2012, 2019 and
> now 2021 for those notable seasons, before adding that "we are really
> seeing a new normal" in regards to the ice melt at higher
> elevations.
>
> While Montross did add that this high-elevation melt is not
> contributing to sea-level rise in most cases, due to the fact that it
> refreezes in underlying snow, experts such as Brad Lipovsky told The
> Guardian that the sea-level rise is hard to stop once it gets
> started.
>
> Image from one of the Copernicus Sentinel-2 satellites captures the
> severe water discharge from melting glaciers into the Arctic Ocean as
> a result of unusually high temperatures in Greenland.
>
> “The alarming thing to me is the political response, or lack of it,"
> said Lipovsky, a glaciologist at the University of Washington.
> "Sea-level rise is like a slow-moving train, but once it gets rolling
> you can’t stop it. It’s not great news.”
>
> Such extreme melting could trigger future melting concerns, glacier
> expert Marco Tedesco told the Guardian, creating a feedback loop of
> sorts. As the white snow melts, the ice sheet loses its protective
> layer against the sun, thus exposing darker ground underneath which
> absorbs more heat and triggers further melting.
>
> It may be many decades or even centuries before the entire Greenland
> ice sheet could entirely melt, but its impact on the rising sea level
> has already had a startling effect, scientists say.
>
> “It’s a very high level of melting and it will probably change the
> face of Greenland, because it will be a very strong driver for an
> acceleration of future melting, and therefore sea level rise,”
> Tedesco told the Guardian, before adding that these extreme melting
> events have happened in the past but not at this frequency. “It’s
> amazing to see how vulnerable these huge, giant areas of ice are. I’m
> astonished at how powerful the forces acting on them are.”

--
Job Bautista

An XUL fanatic, and an add-ons developer. I also do some simple
userscripts and bash scripting.

I like Cyndaquil. He's obviously the best Pokemon starter. Every Johto
Pokemon is cool too.

http://rw.rs/~job/