US Heat and Drought Advisory June

Climatists are raising alarms about the rising temperatures and water shortages as evidence of impending doom (it’s summer and that time of year again).  So some contextual information is suitable.

First, a comparison of recent US June forecasts for temperatures.

NOAA US temp 2019 2021

And then for the same years, precipitation forecasts.

NOAA US rain 2019 2021

Finally, a reminder of how unrelated CO2 is to all of this.

us-wet-dry-co2rev-1

giss-gmt-to-2018-w-co2

What Solstice Teaches Us About Climate Change

From Previous Post When Is It Warming?

On June 21, 2015 E.M. Smith made an intriguing comment on the occasion of Summer Solstice (NH) and Winter Solstice (SH):

“This is the time when the sun stops the apparent drift in the sky toward one pole, reverses, and heads toward the other. For about 2 more months, temperatures lag this change of trend. That is the total heat storage capacity of the planet. Heat is not stored beyond that point and there can not be any persistent warming as long as winter brings a return to cold.

I’d actually assert that there are only two measurements needed to show the existence or absence of global warming. Highs in the hottest month must get hotter and lows in the coldest month must get warmer. BOTH must happen, and no other months matter as they are just transitional.

I’m also pretty sure that the comparison of dates of peaks between locations could also be interesting. If one hemisphere is having a drift to, say, longer springs while the other is having longer falls, that’s more orbital mechanics than CO2 driven and ought to be reflected in different temperature trends / rates of drift.” Source: Summer Solstice is here at chiefio

Monthly Temps NH and SH

Notice that the global temperature tracks with the seasons of the NH. The reason for this is simple. The NH has twice as much land as the Southern Hemisphere (SH). Oceans do not change temperatures as much as land does. So every year when there is almost a 4 °C swing in the temperature of the Earth, it follows the seasons of the NH. This is especially interesting because the Earth gets the most energy from the sun in January presently. That is because of the orbit of the Earth. The perihelion is when the Earth is closest to the sun and that currently takes place in January.

sun-distances

Observations and Analysis:

At the time my curiosity was piqued by Chiefio’s comment, so I went looking for data to analyze to test his proposition. As it happens, Berkeley Earth provides data tables for monthly Tmax and Tmin by hemisphere (NH and SH), from land station records. Setting aside any concerns about adjustments or infilling I did the analysis taking the BEST data tables at face value. Since land surface temperatures are more variable than sea surface temps, it seems like a reasonable dataset to analyze for the mentioned patterns. In the analysis below, all years refers to data for the years 1877 through 2013.

Tmax Records

NH and SH long-term trends are the same 0.07C/decade, and in both there was cooling before 1979 and above average warming since. However, since 1950 NH warmed more strongly, and mostly prior to 1998, while SH has warmed strongly since 1998. (Trends below are in C/yr.)

 Tmax Trends NH Tmax SH Tmax
All years 0.007 0.007
1998-2013 0.018 0.030
1979-1998 0.029 0.017
1950-1979 -0.003 -0.003
1950-2013 0.020 0.014

Summer Comparisons:

NH summer months are June, July, August, (6-8) and SH summer is December, January, February (12-2). The trends for each of those months were computed and the annual trends subtracted to show if summer months were warming more than the rest of the year (Trends below are in C/yr.).

Month less Annual NH
Tmax
NH Tmax NH Tmax SH Tmax SH Tmax SH Tmax
Summer Trends

6

7 8 12 1

2

All years -0.002 -0.004 -0.004 0.000 0.003 0.002
1998-2013 0.026 0.002 0.006 0.022 0.004 -0.029
1979-1998 0.003 -0.004 -0.003 -0.014 -0.029 0.001
1950-1979 -0.002 -0.002 -0.005 0.004 0.005 -0.005
1950-2013 -0.002 -0.003 -0.002 -0.002 -0.002 -0.002

NH summer months are cooler than average overall and since 1950. Warming does appear since 1998 with a large anomaly in June and also warming in August.  SH shows no strong pattern of Tmax warming in summer months. A hot December trend since 1998 is offset by a cold February. Overall SH summers are just above average, and since 1950 have been slightly cooler.

Tmin Records

Both NH and SH show Tmin rising 0.12C/decade, much more strongly warming than Tmax. SH show that average warming persisting throughout the record, slightly higher prior to 1979. NH Tmin is more variable, showing a large jump 1979-1998, a rate of 0.25 C/decade (Trends below are in C/yr.).

 Trends NH Tmin SH Tmin
All years 0.012 0.012
1998-2013 0.010 0.010
1979-1998 0.025 0.011
1950-1979 0.006 0.014
1950-2013 0.022 0.014

Winter Comparisons:

SH winter months are June, July, August, (6-8) and NH winter is December, January, February (12-2). The trends for each of those months were computed and the annual trends subtracted to show if winter months were warming more than the rest of the year (Trends below are in C/yr.).

Month less Annual NH Tmin NH Tmin NH Tmin SH Tmin SH Tmin SH Tmin
Winter Trends

12

1 2 6 7

8

All years 0.007 0.008 0.007 0.005 0.003 0.004
1998-2013 -0.045 -0.035 -0.076 -0.043 -0.024 -0.019
1979-1998 -0.018 -0.005 0.024 0.034 0.008 -0.008
1950-1979 0.008 0.005 0.007 0.008 0.012 0.013
1950-2013 0.001 0.007 0.008 -0.001 -0.002 0.002

NH winter Tmin warming is stronger than SH Tmin trends, but shows quite strong cooling since 1998. An anomalously warm February is the exception in the period 1979-1998.  Both NH and SH show higher Tmin warming in winter months, with some irregularities. Most of the SH Tmin warming was before 1979, with strong cooling since 1998. June was anomalously warming in the period 1979 to 1998.

Summary

Tmin did trend higher in winter months but not consistently. Mostly winter Tmin warmed 1950 to 1979, and was much cooler than other months since 1998.

Tmax has not warmed in summer more than in other months, with the exception of two anomalous months since 1998: NH June and SH December.

Conclusion:

I find no convincing pattern of summer Tmax warming carrying over into winter Tmin warming. In other words, summers are not adding warming more than other seasons. There is no support for concerns over summer heat waves increasing as a pattern.

It is interesting to note that the plateau in temperatures since the 1998 El Nino is matched by winter months cooler than average during that period, leading to my discovering the real reason for lack of warming recently.

The Real Reason for the Pause in Global Warming?

These data suggest warming trends are coming from less cold overnight temperatures as measured at land weather stations. Since stations exposed to urban heat sources typically show higher minimums overnight and in winter months, this pattern is likely an artifact of human settlement activity rather than CO2 from fossil fuels.

uhi_profile-rev-big

Thus the Pause (more correctly the Plateau) in global warming is caused by end of the century completion of urbanization around most surface stations. With no additional warming from additional urban heat sources, temperatures have remained flat for more than 15 years.

Data is here:
http://berkeleyearth.lbl.gov/regions/northern-hemisphere
http://berkeleyearth.lbl.gov/regions/southern-hemisphere

Happy Summer Solstice

White Nights

White Nights Festival, St. Petersburg

 

 

Whiplash from Climate News

Studio Shot Of Masn In pain Wearing Neck Brace

Warning:  Reading media reports about global warming/climate change can cause serious whiplash, far beyond the danger in watching a professional tennis match.  Take today, for example (all excerpts in italics with my bolds)

‘May already be too late to reverse global warming’ at hthk.hk.

The tipping point for irreversible global warming may have already been triggered, the scientist who led the biggest-ever expedition to the Arctic warned on Tuesday.

“The disappearance of summer sea ice in the Arctic is one of the first landmines in this minefield, one of the tipping points that we set off first when we push warming too far,” said Markus Rex.

“And one can essentially ask if we haven’t already stepped on this mine and already set off the beginning of the explosion.”

Rex led the world’s biggest mission to the North Pole, an expedition involving 300 scientists from 20 countries.

Summarising their first findings, Rex said scientists found that the Arctic sea ice had retreated “faster in the spring of 2020 than since the beginning of records” and that “the spread of the sea ice in the summer was only half as large as decades ago”. [Really?]

Arctic ice Sept Ave 2020

“Only evaluation in the coming years will allow us to determine if we can still save the year-round Arctic sea ice through forceful climate protection or whether we have already passed this important tipping point in the climate system,” Rex added, urging rapid action to halt warming.

Stefanie Arndt, who specialises in sea ice physics, said it was “painful to know that we are possibly the last generation who can experience an Arctic which still has a sea ice cover in the summer”.

“This sea ice cover is gradually shrinking and it is an important living space for polar bears,” said Arndt, while recounting observations of seals and other animals in the polar habitat. [What about this?]

when-al-gore-was-born-there-were-7000-polar-bears

Comment:  I agree it’s high time to stop trying to cut emissions, and commit to adapting to whatever nature brings: whether warming, or the greater threat, cooling.

Climate change to blame for ‘catastrophic’ French frost: analysis at Daily Sabah

122221-1

As temperatures fall below zero degrees celsius during the night, anti-frost candles burn through sunrise in the Chablis vineyards near Chablis, Burgundy, France, April 7, 2021. (AFP Photo)

Scientists said Tuesday that climate change had sharply increased the odds of devastating events such as the frost that wiped out a third of French wine production at a cost of around 2 billion euros ($2.42 billion) in the space of a few nights in April. The frost blanketed the country’s most well-known and prestigious wine-producing regions in what minister Julien Denormandie called “probably the greatest agricultural catastrophe of the beginning of the 21st century.”

Scientists warned that climate change would raise the risk of such events even further in the future.

28239_cartoon_main

Greta Thunberg calls out hypocrisy of world leaders for eating steak and lobster at climate summit.  at VegNews

vegnews.gretathunbergborisjohnson

This week, vegan climate activist Greta Thunberg expressed her disappointment with world leaders making empty promises about climate action during the G7 (Group of Seven) summit at the luxury Carbis Bay Hotel in Cornwall, England. Led by United Kingdom Prime Minister Boris Johnson and attended by United States President Joe Biden, the purpose of the three-day event was for the group to meet prior to this year’s United Nations conferences to discuss a variety of global issues, including their collaborative effort to tackle the climate crisis.

Throughout the weekend, event attendees were treated to a variety of meals, including a five-course dinner which included turbot fish, a selection of Cornish cheeses, and dairy-based desserts on Friday; and a lavish beach barbecue on Saturday which included seafood appetizers made with scallops, mackerel, and crab claws, and a traditional surf-and-turf entrée that featured sirloin steak and lobsters. The meals were marketed as sustainable and “carbon neutral” because animals such as lamb and crab were sourced locally.

Greta sees

Wildfire Ashes Dumped on Pelosi’s Porch as Youth Climate Activists Descend on US Lawmakers’ CA Homes at Sputnik News.

Last month, the Sunrise Movement, a youth-led political movement against climate change, kicked off a series of ‘Generation on Fire’ marches in California and the Gulf Coast. Since then, members of the group have marched hundreds of miles and held a demonstration in Paradise, California, the site of a 2018 fire that displaced nearly 50,000 people.

The San Francisco, California, homes of House Speaker Nancy Pelosi (D-CA) and longtime Sen. Dianne Feinstein (D-CA) became the sites of protest as over 100 young activists of the Sunrise Movement ended a 266-mile march on Monday.

The climate change activists could be overheard chanting, among many things, “Whose future? Our future!” as they marched across the Golden Gate Bridge to get to Pelosi’s Normandie Terrace home and Feinstein’s mansion.

reality-check-30-yrs.-of-climate-policy

Big Four beancounter PwC to hire 100,000 employees world-wide as it expands consultancy services at This Is Money.

44264489-9689735-image-a-1_1623781755632

Big Four accountant PwC plans to hire 100,000 employees world-wide as it expands lucrative consultancy services in areas such as climate change.

The hiring spree over the next five years will take its global headcount to nearly 384,000.

It is part of a £8.5billion investment to take advantage of huge demand from businesses for advice on environmental, social and governance (ESG) issues.

PwC is investing in recruitment, training and technology to foster expertise on subjects ranging from how firms can cut carbon emissions, to ‘hybrid’ working practices after the pandemic and how to hire executives from a mix of backgrounds.

Florida skies to turn orange as dust storm travels over from Sahara at The Independent.

photojoiner_photo2028929

Florida’s skies are set to be turned orange this week by a giant Saharan dust storm that has traveled across the Atlantic.

The dust is part of 60 million tons of sand and mineral particles that are annually swept up off the African desert floor and pushed westwards across the ocean by winds.

Weather experts predict that the cloud of dust is due to arrive in the Gulf of Mexico this week and will likely hit Florida on Wednesday.

Should we pay a carbon tax to our own government or to someone else’s? at WA Today.

Despite Prime Minister Scott Morrison’s popular determination to tackle climate change with “technology not taxes”, the decision might not long remain in Australian hands if the G7 leaders’ statement from the weekend meeting in Cornwall is anything to go by.

Soon we might have to decide if we want to pay a carbon tax to our own government, or one to someone else’s.

151214paris-climate

June Arctic Ice Returns to Mean

 

Arctic2021159

A previous post reported that Arctic Sea Ice has persisted this year despite a wavy Polar Vortex this spring, bringing cold down to mid-latitudes, and warming air into Arctic regions.  Now in June, after tracking in deficit the sea ice extent is matching the 14-year average on day 159.  Note that SII (Sea Ice Index) since mid-May has been showing 200 to 400k km2 more ice than MASIE, and currently the two datasets have converged on a value of ~11.25 M km2.

Note that on the 14-year average, during this period ~1.7M km2 of ice extent is lost, which 2021 is matching, as did 2007.  Both 2020 and 2019 were much lower than average at this date, by ~600k and ~700k respectively.  

Why is this important?  All the claims of global climate emergency depend on dangerously higher temperatures, lower sea ice, and rising sea levels.  The lack of additional warming is documented in a post Adios, Global Warming

The lack of acceleration in sea levels along coastlines has been discussed also.  See USCS Warnings of Coastal Floodings

Also, a longer term perspective is informative:

post-glacial_sea_level
The table below shows the distribution of Sea Ice across the Arctic Regions, on average, this year and 2007.

Region 2021159 Day 159 Average 2021-Ave. 2007159 2021-2007
 (0) Northern_Hemisphere 11240999 11259536  -18538  11316498 -75500 
 (1) Beaufort_Sea 1019264 964689  54575  1000434 18830 
 (2) Chukchi_Sea 849650 820007  29642  828275 21375 
 (3) East_Siberian_Sea 1018939 1060847  -41907  1065467 -46528 
 (4) Laptev_Sea 719152 797804  -78652  750975 -31824 
 (5) Kara_Sea 786077 768820  17257  805583 -19506 
 (6) Barents_Sea 253238 260182  -6944  312729 -59491 
 (7) Greenland_Sea 664297 581528  82769  579724 84573 
 (8) Baffin_Bay_Gulf_of_St._Lawrence 755645 803058  -47412  811860 -56215 
 (9) Canadian_Archipelago 802846 802905  -60  783908 18938 
 (10) Hudson_Bay 1022997 1058859  -35862  1027039 -4042 
 (11) Central_Arctic 3233401 3215315  18085  3235047 -1646 
 (12) Bering_Sea 59415 70145  -10729  62751 -3336 
 (13) Baltic_Sea 0 8 -8  0
 (14) Sea_of_Okhotsk 54471 53989  482  51031 3440 

The main deficits are in Laptev and East Siberian Seas, Baffin and Hudson Bays, offset by surpluses in Beaufort, Chukchi and Greenland Seas.

 

Ordinary Arctic Ice Extents in May

Arctic2021151

A previous post reported that Arctic Sea Ice has persisted this year despite a wavy Polar Vortex this spring, bringing cold down to mid-latitudes, and warming air into Arctic regions.  Now in May, the sea ice extent matched the 14-year average on day 144, tracking alongside until month end.  Surprisingly  SII (Sea Ice Index) is showing ~400k km2 more ice, which is also ~70k km2 higher than the 14-year average for SII on day 151 (not shown in chart).

Note that on the 14-year average, May loses ~2M km2 of ice extent, which 2021 matched, as did 2007.  Both 2020 and 2019 finished lower than average, by 300k and 400k respectively.  In contrast SII shows a May loss of only 1.3M km2.

Why is this important?  All the claims of global climate emergency depend on dangerously higher temperatures, lower sea ice, and rising sea levels.  The lack of additional warming is documented in a post Adios, Global Warming

The lack of acceleration in sea levels along coastlines has been discussed also.  See USCS Warnings of Coastal Floodings

Also, a longer term perspective is informative:

post-glacial_sea_level
The table below shows the distribution of Sea Ice across the Arctic Regions, on average, this year and 2007.

Region 2021151 Day 151 Average 2021-Ave. 2007151 2021-2007
 (0) Northern_Hemisphere 11605537 11733260  -127723  11846659 -241122 
 (1) Beaufort_Sea 1034779 992955  41825  1059461 -24682 
 (2) Chukchi_Sea 900868 861978  38891  894617 6251 
 (3) East_Siberian_Sea 1051959 1065828  -13869  1069198 -17239 
 (4) Laptev_Sea 738294 831217  -92923  754651 -16357 
 (5) Kara_Sea 824068 831440  -7373  895678 -71610 
 (6) Barents_Sea 325745 322981  2765  323801 1944 
 (7) Greenland_Sea 615174 567365  47810  591919 23255 
 (8) Baffin_Bay_Gulf_of_St._Lawrence 812548 908759  -96211  934257 -121709 
 (9) Canadian_Archipelago 811040 811378  -338  818055 -7015 
 (10) Hudson_Bay 1084892 1098368  -13476  1077744 7148 
 (11) Central_Arctic 3232324 3219180  13144  3230109 2215 
 (12) Bering_Sea 89124 122512  -33388  112353 -23228 
 (13) Baltic_Sea 0 161 -161  0
 (14) Sea_of_Okhotsk 83572 97612  -14040  83076 495 

The overall deficit to average happened yesterday, being an extent 1% lower, and two days earlier than average.  The largest deficits to average are in Baffin Bay and Laptev Sea, along with Bering and Okhotsk.  These are partly offset by surpluses elsewhere, mostly in Beaufort, Chukchi, and Greenland Seas.

 

 

May 24, 2021 Arctic Ice Matches Average

Arctic2021144

A previous post reported that Arctic Sea Ice has persisted this year despite a wavy Polar Vortex this spring, bringing cold down to mid-latitudes, and warming air into Arctic regions.  Now in May, the sea ice extent matches the 14-year average.  In the chart above, MASIE has caught up to its average, while SII (Sea Ice Index) is showing 300k km2 more ice.  This is also 200k km2 higher than the 14-year average for SII on day 144 (not shown in chart).

Why is this important?  All the claims of global climate emergency depend on dangerously higher temperatures, lower sea ice, and rising sea levels.  The lack of additional warming is documented in a post Adios, Global Warming

The lack of acceleration in sea levels along coastlines has been discussed also.  See USCS Warnings of Coastal Floodings

Also, a longer term perspective is informative:

post-glacial_sea_level
The table below shows the distribution of Sea Ice across the Arctic Regions, on average, this year and 2007.

Region 2021144 Day 144 Average 2021-Ave. 2007144 2021-2007
 (0) Northern_Hemisphere 12146819 12145771  1048  12035185 111634 
 (1) Beaufort_Sea 1014946 1014623  323  1063324 -48378 
 (2) Chukchi_Sea 926443 884593  41850  925212 1232 
 (3) East_Siberian_Sea 1074468 1068410  6057  1061115 13353 
 (4) Laptev_Sea 847289 862328  -15040  797581 49708 
 (5) Kara_Sea 850992 857488  -6495  898743 -47750 
 (6) Barents_Sea 414971 371726  43245  302721 112250 
 (7) Greenland_Sea 621173 588159  33015  573583 47591 
 (8) Baffin_Bay_Gulf_of_St._Lawrence 861138 985037  -123899  962331 -101193 
 (9) Canadian_Archipelago 836025 824730  11295  828387 7638 
 (10) Hudson_Bay 1109942 1135136  -25194  1091181 18761 
 (11) Central_Arctic 3241735 3223613  18121  3231990 9744 
 (12) Bering_Sea 212840 196725  16115  190680 22160 
 (13) Baltic_Sea 0 1039 -1039  619 -619 
 (14) Sea_of_Okhotsk 133703 130236  3467  105796 27907 

The largest deficit to average is in Baffin Bay, with Laptev and Hudson Bay also starting to melt.  These are offset by surpluses elsewhere, mostly in Chukchi, Barents, and Greenland Sea.

 

 

Mid May 2021 Persistent Arctic Ice

ArcDay135 2007 to 2021

 

Typically in climate observations, averages are referenced without paying attention to the high degree of component variability from year to year, and over longer time periods.  Mid May is when the Spring melt is well underway, but with the Arctic core still frozen solid.  Yet the animation above shows on day 135 over the last 15 years, there are considerable differences as to how much ice is in which regions. 

On the bottom left is Bering Sea which had ice extents on this day ranging from a high of 682k km2 (2012) to a low of 38k km2 (2018).  The day 135 average for Bering is 293k km2, but with a standard deviation of 192k (65%).  Okhotsk center left is the next most variable, from 290k (2012) to 99k (2019), averaging 188k with std. deviation of 63K (33%).  Barents Sea center top has a large variability from 568k km2 (2009) to 223k (2012), averaging 422k km2 +/- 111 k km2.  Other Arctic regions vary little on this day from year to year.  For example, Hudson Bay is close to 1.2M km2 every year on day 135.

The effect on NH total ice extents is presented in the graph below for the period mid April to mid May, comparing the 14-year average with 2021 MASIE and SII, and some other years of interest.

Arctic2021135

Note on average this period shows an ice loss of 1.5M km2.  MASIE 2021 is about 200k km2 below average, 1.6% down, or having the same total extent 3 days ahead of average.  Interestingly, SII shows about 200k higher, matching the MASIE average for day 135.

The table below shows the distribution of sea ice across the Arctic regions.

Region 2021135 Day 135 Average 2021-Ave. 2007135 2021-2007
 (0) Northern_Hemisphere 12490666 12692542  -201876  12431928 58738 
 (1) Beaufort_Sea 1058904 1044067  14837  1057649 1255 
 (2) Chukchi_Sea 926504 921289  5215  953491 -26987 
 (3) East_Siberian_Sea 1083562 1081242  2320  1075314 8248 
 (4) Laptev_Sea 852338 881285  -28948  828738 23600 
 (5) Kara_Sea 858111 882730  -24619  876053 -17942 
 (6) Barents_Sea 396873 421592  -24719  351553 45320 
 (7) Greenland_Sea 669899 618664  51235  564865 105035 
 (8) Baffin_Bay_Gulf_of_St._Lawrence 892167 1093916  -201749  1018780 -126614 
 (9) Canadian_Archipelago 852422 838509  13913  830604 21818 
 (10) Hudson_Bay 1160950 1194448  -33497  1167310 -6360 
 (11) Central_Arctic 3242075 3223985  18089  3234305 7769 
 (12) Bering_Sea 271137 293222  -22085  298268 -27130 
 (13) Baltic_Sea 3752 7215 -3463  6368 -2617 
 (14) Sea_of_Okhotsk 220784 188072  32712  164833 55951 

Overall NH extent March 31 was below average by 200k km2,  equivalent to the deficit in Baffin Bay.  Elsewhere smaller deficits were offset with surpluses. The onset of spring melt is as usual in most regions.

April 2021 Resilient Arctic Ice

 

ArcApr2021 107 to 120

Previous posts noted how Arctic ice extents waxed and waned in response to the wavy Polar Vortex this year.  The animation above showed how the ice fluctuated over the last two weeks.  Okhhotsk upper left steadily lost ~225k km2, while Bering Sea lower left lost ~130k km2 in the first week then waffled around the same extent.  Barents at the top lost ~170k km2 early, then in the last 10 days gained back most of it. Greenland Sea middle right waffled down and up with little change up to yesterday.  Baffin Bay lower right produced the largest deficit on the Atlantic side ~180k km2.

The effect on NH total ice extents is presented in the graph below.Arctic2021120The graph above shows ice extent through April comparing 2021 MASIE reports with the 14-year average, other recent years and with SII.  The average April drops about 1.1M km2 of ice extent.  This year MASIE showed two sharp drops and two recoveries, the last one coming close to average day 118.  SII showed a less than average April loss of ~870k km2.  In the end MASIE 2021 matched 2020, and higher then 2007.

The table below shows the distribution of sea ice across the Arctic regions.

Region 2021120 Day 120 Average 2021-Ave. 2007120 2021-2007
 (0) Northern_Hemisphere 13311402 13551290  -239888  13108068 203334 
 (1) Beaufort_Sea 1058557 1068405  -9848  1059189 -632 
 (2) Chukchi_Sea 962680 954463  8217  949246 13434 
 (3) East_Siberian_Sea 1087137 1085503  1635  1080176 6961 
 (4) Laptev_Sea 897827 888936  8891  875661 22166 
 (5) Kara_Sea 915674 911257  4417  864664 51010 
 (6) Barents_Sea 572380 558256  14124  396544 175837 
 (7) Greenland_Sea 605335 649955  -44620  644438 -39103 
 (8) Baffin_Bay_Gulf_of_St._Lawrence 1004774 1231673  -226899  1147115 -142341 
 (9) Canadian_Archipelago 854597 848502  6095  838032 16565 
 (10) Hudson_Bay 1236512 1242200  -5687  1222074 14439 
 (11) Central_Arctic 3239759 3238255  1504  3241034 -1275 
 (12) Bering_Sea 426670 473606  -46936  475489 -48819 
 (13) Baltic_Sea 12293 20617.28786 -8324  14684 -2390 
 (14) Sea_of_Okhotsk 435360 376555  58804  295743 139617 

Overall NH extent March 31 was below average by 240k km2, or 2%.  With Bering deficit offset by Okhotsk surplus, the entire difference from average matches the Baffin Bay deficit. The onset of spring melt is as usual in most regions.

Cool 2021 Spring Continues

imagehy1p

Dr. Judah Cohen provides a weather outlook based upon his study of the Arctic Oscillation at his blog Arctic Oscillation and Polar Vortex Analysis and Forecast April 19, 2021.  Excerpts in italics with my bolds.

The PV is in its waning days of the 2020/21 cold season and will likely be nearly or completely disappeared by the next blog update. This seems to me to be a clear dynamically assisted Final Warming as vertical Wave Activity Flux (WAFz and is proportional to poleward heat transport) has been active for at least a week now and is predicted to remain active for the next two weeks. A dynamic Final Warming can result in some cooler weather across the mid-latitudes; and in my opinion the snow and possibly record cold temperatures predicted for the Eastern US this week is related to the dynamic Final Warming. The PV is being stretched from Siberia to Canada that creates cross polar flow from Siberia to North America that drives cold air south across Canada and the US east of the Rockies. I do believe that this is a short-term impact only and will not have an influence on the summer weather across North America.

Europe has had an impressively cool April, relative to recent Aprils (probably the coolest April since 2013 and maybe even since 2003), which is directly attributable to Greenland blocking that has also extended into the North Atlantic for much of the month. There are no strong signs that the Greenland blocking will disappear any time soon, and as long as it persists, Europe can experience relatively cool temperatures. I see no obvious signs that the Greenland blocking is tied to PV variability and it is therefore more challenging for me to anticipate how long it will last. But it is likely that the streak of cool weather is dependent on the persistence of the Greenland blocking. If and when the Greenland blocking abates, European temperatures could start to climb.

As noted in previous posts, when cold Arctic air pushes south, it is replaced by warmer air contributing to ice melting.  To be clear, sea ice melts primarily because of sunshine directly, and indirectly by intruding sun-warmed water, mostly from the Atlantic by way of Barents Sea. The Arctic in summer daily receives more solar energy than does the equator.  Warmer air is a tertiary contributing factor.

ArcApril 099 to 110

The animation shows Okhotsk upper left lost ~250k km2 of ice extent over the last 10 days.  Bering Sea lower left waffled with little change until losing ~60k km2 the last two days.  On the Atlantic side, Barents Sea upper right gained ~100k km2 over a week, then lost most of it ending about the same.  Greenland Sea middle right lost ~100k km2m, while Baffin Bay lower right waffled and lost very little.

Arctic2021110

The overall impact on NH sea ice is shown in the graph above.  Firstly a drop starting April 10, then recovering April 14 and holding firm to draw near to average, before another drop the last two days.

Background Previous Post  Spring 2021: Warm is Cold, and Down is Up

The cold Spring this year is triggering responses turning natural factors upside down and backwards, confusing causes and effects.  For example, this article at Science Daily Snow chaos in Europe caused by melting sea-ice in the Arctic.  The simplistic appeal to “climate change” is typical: “It is the loss of the Arctic sea-ice due to climate warming that has, somewhat paradoxically, been implicated with severe cold and snowy mid-latitude winters.”  In fact, as we shall see below, it is the wavy Polar Vortex causing both cold mid-latitudes from descending Arctic air, and melting ice from intrusions of warmer southern air.  Importantly, global warming theory asserts that adding CO2 causes the troposphere to warm and the stratosphere to cool.  What we are experiencing this Spring is an unstable Polar vortex due to events of Sudden Stratospheric Warming  (SSWs), not cooling.

Seasoned meteorologist Judah Cohen of AER shows the mechanism this way:

My colleagues, at AER and at selected universities, and I have found a robust relationship between two October Eurasian snow indices and the large-scale winter hemispheric circulation pattern known as the North Atlantic or Arctic Oscillation pattern (N/AO).

The N/AO is more highly correlated with or explains the highest variance of winter temperatures in eastern North America, Europe and East Asia than any other single or combination of atmospheric or coupled ocean-atmosphere patterns that we know of. Therefore, if we can predict the winter N/AO (whether it will be negative or positive) that provides the best chance for a successful winter temperature forecast in North America but certainly does not guarantee it.

He goes on to say that precipitation is the key, not air temperatures, and ENSO is a driving force:

As long as I have been a seasonal forecaster, I have always considered El Nino/Southern Oscillation (ENSO) as a better predictor of precipitation than temperature across the Eastern US. I think this is supported by the observational or statistical analysis as well as the skill or accuracy of the climate models.

There have been recent modeling studies that demonstrate that El Nino modulates the strength and position of the Aleutian Low that then favors stratospheric warmings and subsequently a negative winter N/AO that are consistent with our own research on the relationship between snow cover and stratospheric warmings. So the influence of ENSO on winter temperatures in the Mid-Atlantic and the Northeast may be greater than I acknowledge or that is represented in our seasonal forecast model.

Summary

As Cohen’s diagram shows, there is an effect from warming, but in the stratosphere. Global warming theory claims CO2 causes warming in the troposphere and cooling in the stratosphere. So whatever is going on, it is not due to CO2.

Cohen’s interview with the Washington Post.

its-easier-to-fool-people-than-to-convince-them-that-they-have-been-fooled

 

The current situation is described in Cohen’s most recent post at his Arctic Oscillation blog:

The stratospheric PV always disappear in the spring due to the increasing solar radiation in the polar stratosphere. However, during some springs in addition to the radiative warming of the polar stratosphere, there is also dynamic warming of the polar stratosphere due to the absorption of upwelling Wave Activity Flux (WAFz) from the troposphere. This occurred last spring, which did result in a cool May and even some rare snowfall in the Northeastern US. The predicted return of Ural blocking coupled with Northeast Asia/northern North Pacific troughing is conducive to more active WAFz. The latest PV animation (see Figure ii) shows the stratospheric PV filling (weakening) and meandering over the northern Asia in response to the more active WAFz. This could be the beginning of a dynamically assisted Final Warming that could result in a period of cooler temperatures in parts of the mid-latitudes.

imagesj5oh

Figure ii. Observed and predicted daily geopotential heights (dam; contours) and anomalies (shading) through April 21, 2021. The forecast is from the 00Z 5 April 2021 GFS ensemble.

Background is at post No, CO2 Doesn’t Drive the Polar Vortex 

graphic20-20polarvortex_explained_updated2001291920-204034x2912-1

 

Spring 2021: Warm is Cold, and Down is Up

The cold Spring this year is triggering responses turning natural factors upside down and backwards, confusing causes and effects.  For example, this article at Science Daily Snow chaos in Europe caused by melting sea-ice in the Arctic.  The simplistic appeal to “climate change” is typical: “It is the loss of the Arctic sea-ice due to climate warming that has, somewhat paradoxically, been implicated with severe cold and snowy mid-latitude winters.”  In fact, as we shall see below, it is the wavy Polar Vortex causing both cold mid-latitudes from descending Arctic air, and melting ice from intrusions of warmer southern air.  Importantly, global warming theory asserts that adding CO2 causes the troposphere to warm and the stratosphere to cool.  What we are experiencing this Spring is an unstable Polar vortex due to events of Sudden Stratospheric Warming  (SSWs), not cooling.

Seasoned meteorologist Judah Cohen of AER shows the mechanism this way:

My colleagues, at AER and at selected universities, and I have found a robust relationship between two October Eurasian snow indices and the large-scale winter hemispheric circulation pattern known as the North Atlantic or Arctic Oscillation pattern (N/AO).

The N/AO is more highly correlated with or explains the highest variance of winter temperatures in eastern North America, Europe and East Asia than any other single or combination of atmospheric or coupled ocean-atmosphere patterns that we know of. Therefore, if we can predict the winter N/AO (whether it will be negative or positive) that provides the best chance for a successful winter temperature forecast in North America but certainly does not guarantee it.

He goes on to say that precipitation is the key, not air temperatures, and ENSO is a driving force:

As long as I have been a seasonal forecaster, I have always considered El Nino/Southern Oscillation (ENSO) as a better predictor of precipitation than temperature across the Eastern US. I think this is supported by the observational or statistical analysis as well as the skill or accuracy of the climate models.

There have been recent modeling studies that demonstrate that El Nino modulates the strength and position of the Aleutian Low that then favors stratospheric warmings and subsequently a negative winter N/AO that are consistent with our own research on the relationship between snow cover and stratospheric warmings. So the influence of ENSO on winter temperatures in the Mid-Atlantic and the Northeast may be greater than I acknowledge or that is represented in our seasonal forecast model.

Summary

As Cohen’s diagram shows, there is an effect from warming, but in the stratosphere. Global warming theory claims CO2 causes warming in the troposphere and cooling in the stratosphere. So whatever is going on, it is not due to CO2.

Cohen’s interview with the Washington Post.

its-easier-to-fool-people-than-to-convince-them-that-they-have-been-fooled

 

The current situation is described in Cohen’s most recent post at his Arctic Oscillation blog:

The stratospheric PV always disappear in the spring due to the increasing solar radiation in the polar stratosphere. However, during some springs in addition to the radiative warming of the polar stratosphere, there is also dynamic warming of the polar stratosphere due to the absorption of upwelling Wave Activity Flux (WAFz) from the troposphere. This occurred last spring, which did result in a cool May and even some rare snowfall in the Northeastern US. The predicted return of Ural blocking coupled with Northeast Asia/northern North Pacific troughing is conducive to more active WAFz. The latest PV animation (see Figure ii) shows the stratospheric PV filling (weakening) and meandering over the northern Asia in response to the more active WAFz. This could be the beginning of a dynamically assisted Final Warming that could result in a period of cooler temperatures in parts of the mid-latitudes.

imagesj5oh

Figure ii. Observed and predicted daily geopotential heights (dam; contours) and anomalies (shading) through April 21, 2021. The forecast is from the 00Z 5 April 2021 GFS ensemble.

Background is at post No, CO2 Doesn’t Drive the Polar Vortex 

graphic20-20polarvortex_explained_updated2001291920-204034x2912-1