Comment style . . . a few hints.

Rocky Rex

Everyone has their own style, but there are some hints to make your comments more readable.

Remember that the average reading age in the UK is 9 years …. the “Sun” has a reading age of 8 years.

If you want people to read comments …..

Spread the content out.

Short sentences are best….. break up longer ones as you prepare your comment for posting.

Use a new paragraph for each sentence. . . blank space reduces the reading age of text.

If you can replace a long word with a shorter one, that helps.

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Antarctic sea ice area in winter is slowly increasing – why?

Rocky Rex

This is complex, but the following explanation deals with some factors in an easy-to-read form….

The Antarctic sea ice melts almost to the coast each summer.

The winter sea ice has increased by around 1 % over the last few decades.

This is not difficult to explain.

All linked to melting of the land ice on Antarctica…..

Seawater will not freeze until it is around minus 2 degrees C, due to the salt content.

This effect of salt, of course, is used to help defrost roads.

The meltwater off Antarctica’s ice sheets is freshwater.

Freshwater has a low density, so it forms a layer on the sea.

Freshwater freezes (of course) at zero degrees C, so a layer of ice can form more easily on top of the sea.

Also windchill helps to freeze that top layer.

A useful comparison of Antarctic and Arctic sea ice ……

Arctic vs Antarctic 

http://nsidc.org/cryosphere/seaice/characteristics/difference.html

See especially the comparison chart at the end.

New Climate Myth – Geothermal heat is melting ice-sheets in Antarctica, not climate change

Rocky Rex

There have been claims that volcanic activity and/or geothermal heat are the reason for melting ice-sheets on Antarctica.

This new myth was not easy to track down, but its origin lies in a total misinterpretation of this paper, describing research on the Thwaites Glacier….

http://www.pnas.org/content/111/25/9070.full

which has been massively misreported.

All this research implies is that the Thwaites Glacier is behaving more like a warm-based glacier (as found in temperate regions) rather than a cold-based glacier (as normal for polar glaciers)

http://www.geographylwc.org.uk/A/AS/asice/warmcoldbased.html

http://www.coolgeography.co.uk/A-level/AQA/Year%2012/Cold%20environs/Ice%20movement/Glacier%20movement.jpg

This article …..

Strong Sensitivity of Pine Island Ice-Shelf Melting to Climatic Variability

https://www.sciencemag.org/content/343/6167/174.short?cited-by=yes&legid=sci;343/6167/174

is useful ……hat-tip to ‘chrisbrown’ who sent the link.

Climate myth – temperatures havn’t been rising for ??? years.

Rocky Rex

A popular quote ….

Best to reply with graphs and charts.

Annual ……from NASA Institute for Space Studies (GISS)

http://www.giss.nasa.gov/research/news/20140121/gistemp_nino_100.jpg

Note ….. every La Nina ‘year’ since 1998 was warmer than every El Nino ‘year’ before 1995.    (Hat-tip to greenveggie for this observation)

Decadal….. from the World Meteorological Organisation

http://www.wmo.int/pages/mediacentre/press_releases/images/clip_image002_006.gif

Of course, ‘climate’ is conventionally an average over 3 full decades…..

For example the UK Met Office climate averages for 1981-2010

http://www.metoffice.gov.uk/climate/uk/averages/key-features-1981-2010

If the Earth gains heat steadily, why doesn’t temperature rise steadily?

Rocky Rex

Heat can enter a system without causing a temperature rise.

Extra heat can be used in ‘changing state’ instead of raising temperature.

A change of state could be …solid melting to liquid. Or liquid evaporating to gas.

So heat is needed to change ice at zero C to water at zero C.

And to change water into water vapour….. without raising the temperature.

This is latent heat

http://www.bbc.co.uk/bitesize/standard/physics/energy_matters/heat_in_the_home/revision/3/

The climate systems include atmosphere, water and ice.

So if ice is warming up, that will use heat from the air, and so that bit of heat is not warming the air.

If the oceans warm, that bit of heat is not heating the air.

So these bits of heat don’t show up in rising air temperatures.

The amount of heat that might be doing one or other of these things will change constantly, so the air temperature will not rise smoothly.

Carbon excursions

Rocky Rex

There are several examples in the geological record of things called

Carbon excursions’..….

http://essayweb.net/geology/quicknotes/carbonexcursion.shtml

All five of the major Phanerozoic mass extinction events are matched by significant carbon isotopic excursions.

Negative CEs involve lots of gaseous carbon compounds adding to the air, causing warming.

Positive CEs involve the reverse…. processes absorb the gases and cooling follows.

Examples of +ve CEs include…..

‘Snowball Earth’ events.….

http://www.space.com/22501-snowball-earth-ice-ages-history.html

An example of a -ve CE is the PETM.

The Palaeocene-Eocene Thermal Maximum

http://www.whoi.edu/cms/files/higgins06epsl_138364.pdf

See Section 9 ..Conclusions… last sentence.

Ecosystems recovered from the PETM ….. it ‘only’ took 100,000 years.

The earth systems simply react to the chemistry ….. how the gases get into the air is unimportant.

And currently CO2 is rising at 20 ppm per decade.

The ice core record (800,000 years) shows that the fastest rise in CO2 over that time was 20 ppm…..in 1000 years.

http://www.antarctica.ac.uk/bas_research/science_briefings/icecorebriefing.php

Nothing like this has happened in the time of Homo sapiens.