PART 10/ Opdaterede Sol/Is/temp/hav data

Paleoclimatologists have long suspected that the "middle Holocene," a period roughly from 7,000 to 5,000 years ago, was warmer than the present day. Terms like the Altithermal or Hypsithermal or Climatic Optimum have all been used to refer to this warm period that marked the middle of the current interglacial period. Today, however, we know that these terms are obsolete and that the truth of the Holocene is more complicated than originally believed.

What is most remarkable about the mid-Holocene is that we now have a good understanding of both the global patterns of temperature change during that period and what caused them. It appears clear that changes in Earth's orbit have operated slowly over thousands and millions of years to change the amount of solar radiation reaching each latitudinal band of Earth during each month. These orbital changes can be easily calculated and predict that the Northern Hemisphere should have been warmer than today during the mid-Holocene in the summer and colder in the winter. The combination of warmer summers and colder winters is apparent for some regions in the proxy records and model simulations. There are some important exceptions to this pattern, however, including colder summers in the monsoon regions of Africa and Asia due to stronger monsoons with associated increased cloud cover during the mid-Holocene, and warmer winters at high latitudes due to reduction of winter sea ice cover caused by more summer melting.

In summary, the mid-Holocene, roughly 6,000 years ago, was generally warmer than today during summer in the Northern Hemisphere. In some locations, this could be true for winter as well. Moreover, we clearly know the cause of this natural warming, and we know without doubt that this proven "astronomical" climate forcing mechanism cannot be responsible for the warming over the last 100 years.

PS: Tjek Vest for Baffin Island 2018. Over 5 meter tyk is, ca 1 August. Man tænker om det mon er dette område hvor istider starter?

Niels K Sørensen skrev:
Forskningen ved ikke hvorfor de sidste 10000 år - som vi har opbygget vores civilisation under - har været så stabil en periode, ligesom forskningen heller ikke ved, hvor meget der skal til, før ustabilitet i klimaet indtræder igen.

Frank Lansner skrev: isen omkring Norpolen, det centrale Arktis er særdeles kompakt

"Vi kämpar med isen som är ca 90 - 100% koncentrerad, är tjock och kompakt. Detta i mitt högst ovetenskapliga perspektiv som navigatör, men jag har ju varit här uppe förr och inte sett dessa förhållanden sedan 2005.
...
Som jag nämnde i texten ovan har det varit väldigt kompakt is, jag har inte sett liknande förhållanden sedan 2005.
2016, som var förra gången när Oden var så här långt norrut gick det på ca 5 dagar från iskanten till denna latitud med snitt fart på dryga 6 knop. Det har tagit betydligt längre tid enna gång och med en snittfart på ungefär 3 knop.
Vi är i skrivande stund ca 45Nm (83km) från Nordpolen. När isen bjuder på detta motstånd blir man som is-navigatör glad, då det konstant varit dystra nyheter om "extremt liten is utbredning i Arktis" "Isfritt i Norra Polarhavet" "isbjörnarna drunknar" "rederier som planerar rutter över Nordpolen".
Ja, det är då inga isbjörnar som drunknar här. Det kanske till och med är så att det kan vara svårt att få ner tassarna i vattnet.
"

Arctic sea ice extent for July 2018 averaged 8.22 million square kilometers (3.20 million square miles). This was 1.25 million square kilometers (483,000 square miles) below the 1981 to 2010 long-term average sea ice extent, and 550,000 square kilometers (212,000 square miles) above the record low for the month set in July 2012. July 2018 was the ninth lowest July extent in the satellite record.

Frank Lansner skrev:
Hej Sören, dejligt at du stadig titter ind en gang imellem :-)

Din reference direkte fra the centre of the action er jo super.

De viser herunder et billede af is-flække som er væltet om på siden så man kan se hvor tyk den er. De viser hvor lang 3 meter er, og isen er altså tykkere end 3 meter, måske 3,5 meter eller 4 ?

Even if the heat delivered to Antarctica by the Amundsen Sea has pulsated over decades, the regions glaciers are slow to react and so, overall, their contribution to global sea level has risen steadily.

"Today's ocean melting is driving the ice sheet to retreat 10 times faster than at any time in the geological record, and so it's important to learn whether the warm ocean currents will continue to pulse and drive accelerating sea-level rise in future decades."

Nasa : June 2018 continued the warming trend of the past 40 years. According to the monthly analysis of global temperatures by scientists at NASA's Goddard Institute for Space Studies (GISS) in New York, the past month surpassed the 1951-1980 June mean by +0.77°C. It tied with June 1998 as the third warmest June in 138 years of modern record-keeping, with only June 2015 and 2016 (+0.80°C and +0.79°C) being warmer.

The mean temperature anomalies of +0.77°C for both June 1998 and June 2018 cannot be distinguished from each other given the uncertainty of the measurement. However, June 1998 was exceptionally warm at the time due to the then prevailing strong El Niño conditions — about 0.33°C above the trend line of the late 1990s. In contrast, the current El Niño phase is considered neutral. The temperature anomaly for June 2018 is similar to other recent monthly mean temperature anomalies, and lies within the expected range of +0.75±0.05°C.

Jeg så TV2 her til aften