The annual competition between ice and water in the Arctic ocean has reached the maximum for water, which typically occurs mid September.  After that, diminishing energy from the slowly setting sun allows oceanic cooling causing ice to regenerate. Those interested in the dynamics of Arctic sea ice can read numerous posts here.  This post provides a look at mid September from 2007 to yesterday as a context for understanding this year’s annual minimum.

The image above shows Arctic ice extents on day 260 (lowest annual daily extent on average) from 2007 to 2024 yesterday.  Obviously, the regions vary as locations for ice, discussed in more detail later on. The animation shows the ice deficits in years 2007, 2012, 2016, 2020 and 2023, as well as surplus years like 2010, 2014, 2022 and 2024.

Note that for climate purposes the annual minimum is measured by the September monthly average ice extent, since the daily extents vary and will go briefly lowest on or about day 260. In a typical year the overall ice extent will end September slightly higher than at the beginning.  2024 September ice extent averaged 4.6M over the first 16 days, and is likely to end the month with at least that amount for the entire month. For comparison, the 17 year average for Sept. 1-16 is 4.7M.

The melting season to mid September shows 2024 tracked lower than average but ended the period slightly above.

The graph above shows September daily ice extents for 2024 compared to 18 year averages, and some years of note. Day 260 has been the lowest daily ice extent on average for the last 18 years.

The black line shows on average Arctic ice extents during September decline 358k km2 down to 4.5M Km2 by day 260. The average increase from now on is 490k km2 up to 5.0M km2 end of September.  2024  tracked a little lower than the 18-year average in the second week reaching a low of 4.49M km2 on day 255, before going above average on day 260.

SII was reporting deficits as high as 0.5M km2 (half a Wadham) compared to  MASIE early in September.  For some reason, apparently data access issues, that dataset has not been updated for the last five days.  2023 bottomed out at 4.1M while 2007 daily minimum hit 4.0M, ended ~ 0.5M km2 in deficit to average and 535k km2 less than MASIE on day 260.  2020 ice on day 260 was ~740k km2 in deficit to average.

The main deficit to average is in CAA with a smaller loss in Chukchi, overcome by surpluses almost everywhere, especially in Central Arctic along with Laptev and Greenland seas. And as discussed below, the marginal basins have little ice left to lose.

The Bigger Picture 

We are close to the annual Arctic ice extent minimum, which typically occurs on or about day 260 (mid September). Some take any year’s slightly lower minimum as proof that Arctic ice is dying, but the image above shows the Arctic heart is beating clear and strong.

Over this decade, the Arctic ice minimum has not declined, but since 2007 looks like fluctuations around a plateau. By mid-September, all the peripheral seas have turned to water, and the residual ice shows up in a few places. The table below indicates where we can expect to find ice this September. Numbers are area units of Mkm2 (millions of square kilometers).

The table includes some early years of note along with the last 4 years compared to the 17 year average for five contiguous arctic regions. BCE (Beaufort, Chukchi and East Siberian) on the Asian side are quite variable as the largest source of ice other than the Central Arctic itself.   Greenland Sea and CAA (Canadian Arctic Archipelago) together hold almost 0.5M km2 of ice at annual minimum, fairly consistently.  LKB are the European seas of Laptev, Kara and Barents, a smaller source of ice, but a difference maker some years, as Laptev was in 2016 and 2023.  Baffin and Hudson Bays are inconsequential as of day 260.

2024 extent of 4.58 is 1.3% over average, mainly due to surpluses in Chukchi and East Siberian seas.

For context, note that the average maximum has been 15M, so on average the extent shrinks to 30% of the March high (31% in 2022) before growing back the following winter.  In this context, it is foolhardy to project any summer minimum forward to proclaim the end of Arctic ice.

Resources:  Climate Compilation II Arctic Sea Ice

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September 17, 2024 at 03:39PM

53.38144 -1.49138 Met Office assessment CIMO Class 5 Installed 1/1/1882

A significant landmark in Sheffield, the Weston Park Observatory was constructed in 1880 and has a continuous site record from 1882. There is nothing outwardly particularly contentious about this site. The Met Office accepts it is CIMO Class 5 and unquestionably subject to significant Urban Heat warming effects. Despite this the Met Office describe the site as “Satisfactory”.

From the multiple historic A57 street view images on google maps nearly half show an ice cream van parked close by the Weather station no doubt with its engine frequently running. No longer an ideal site so why should it be of any great concern? Well there are implications…….

Think of all those weather forecasters comments “these overnight temperatures shown are for towns and cities – it will be a few degrees colder in rural areas” or “and maybe a touch of ground frost in the countryside”. Obviously nobody has set up artificial cooling devices for rural areas so it is the urban areas that are artificially several degrees warmer – the Urban Heat Island Effect. Basic stuff.

From Wikipedia, the Urban Heat Island effect elevates temperatures by

“heat trapping due to land use, the configuration and design of the built environment, including street layout and building size, the heat-absorbing properties of urban building materials, reduced ventilation, reduced greenery and water features, and domestic and industrial heat emissions generated directly from human activities”.

The temperature elevation effect is, however, known to be generally greater at night times than day times with overnight lows holding up significantly higher than elsewhere and raising daily average temperatures. So, in many respects, for city dwellers this can be a good thing – saves on the heating bills. Conversely those in rural sites will experience colder averages and consequently more expensive heating bills.

UHI and the increasing loss of rural located quality weather stations over recent years will be the topic of a separate detailed post demonstrating the effect this has had on the historic temperature record. For now this post concentrates on more social issues.

Not to be confused with “Winter Fuel Payments“, for those in the UK on most means tested benefits there are additional “Cold Weather Payments” (CWPs) which automatically pay extra money to those deemed financially and/or physically vulnerable during colder conditions. Extra considerations are given for those families with young children under 5 years old. The trigger for these payments is the average temperature measured at specific weather stations allocated to specific post code areas across the UK.

“You’ll get a payment if the average temperature in your area is recorded as, or forecast to be, zero degrees celsius or below over 7 consecutive days. {editors note: what “average” method?}

You’ll get £25 for each 7 day period of very cold weather between 1 November 2024 and 31 March 2025.”

This charity advice site below lists all the weather stations applicable to postcodes for which CWPs were made in winter 2022/3.

https://lottie.org/fees-funding/dwp-cold-weather-payment/

So what if you live in a higher altitude rural post code area surrounding Sheffield well away from the UHI experienced in Weston Park and significantly colder? The total postcodes allocated to Sheffield are:

If Weston Park doesn’t average below the trigger point it is tough luck on you however cold it may actually be if you live in any of its allocated post codes.

The Met Office must know of this issue, they surely cannot be that naive or just maybe they never gave it a thought – just drew some lines on a map. Whatever, the responsibility must lie with them as they are supposed to be the experts in this field and the DWP simply refers to them for advice.

Alarmingly, from the full allocation listing, a high proportion of triggering sites are found to be in known UHI affected areas such as Sheffield and are equally at CIMO Class 4 or 5 levels of inaccuracy.

I am raising this point with our new (allegedly) more socially responsive government for their views. It will be interesting to see who the responsible Ministers side with. I will report back any responses.

Meanwhile it is worth remembering there are more immediate implications to poor weather station siting than just corrupting the historic temperature record. I will cover these other equally surprising implications in future posts.

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September 17, 2024 at 03:12PM

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September 17, 2024 at 12:07PM

By Paul Homewood

h/t Philip Bratby

On the day that Labour’s poll rating dips below 30% in record time after an election win, we are reminded of two good reasons why.

Ed Miliband told the EnergyUK conference this morning that he wants to take on the ‘blockers, delayers and obstructionists’ who stand in the way of Britain’s energy security. Oh good, does that mean that finally he appreciates that the North Sea needs some encouragement? And that a UK fracking industry will finally be allowed to commence, after years of being blocked in the courts by environmentalists spinning false stories about how it will cause your water taps to burst into flames and cause devastating earthquakes (including those actually felt at the Earth’s surface)?

Er, sadly not. Miliband, of course, rather likes blockers and delayers when they are on his side. Indeed, the entire government does, which is why it is not challenging the High Court’s decision last week to quash planning permission for a Cumbrian coal mine. This mine would have provided coking coal for the UK’s steel industry (or at least would have done before the previous government pulled the plug on Britain’s primary steel industry, forcing us to import steel instead).

Is Lammy’s mind really on his job?

Stand in the way of oil and gas – which even the Labour party manifesto accepted is going to form part of our energy mix for decades to come – and the government will won’t lift a finger to stop you. But as for people who are a little reluctant to accept vast acres of the countryside disappearing beneath wind and solar farms, they are a threat to Britain’s energy security – and indeed ‘national security’ – and must be denounced.

Miliband isn’t alone in taking up this theme of national security to try to defend Labour’s green policy. Foreign secretary David Lammy is at it too this morning, telling us that climate change presents a ‘more fundamental’ threat to national security than terrorism does.

Is Lammy’s mind really on his job? Sure, there are all sorts of reasons why it might be desirable to shift towards cleaner energy if it is affordable. But does he seriously think that climate change deserves more of his attention as foreign secretary than the threat from terrorism? London might be a bit warmer than it was half a century ago, and a little wetter, too, while sea levels might be rising by 3 mm a year (the capital is also a little less stormy, less foggy and its population a lot less prone to hypothermia than in the past, though we rarely hear about that side of the climate change ledger). But David, what I would really love to know is what you are doing to guard against the very real possibility that a bunch of terrorists could get hold of nuclear material and explode a ‘dirty bomb’ in Trafalgar Square? Or a 9/11 style attack on Canary Wharf?

That is before we even get into the matter of what a rogue state could do to us, with the full backing of armed forces. I know there are a lot of young people who have grown up on climate paranoia and have been really quite traumatised by what they see as the threat of being ‘fried’ by slightly higher summer temperatures. But those of us who were brought up in the Cold War have a slightly different perspective: by far the greatest threat to humanity continues to be nuclear war – which really would lead to large numbers of people genuinely being fried, and to somewhat rapid and dramatic climate change.

I hope, deep down, that our foreign secretary appreciates this, and that his comments this morning are just a bit of politicking to try and defend a green energy policy which is beginning to crumble in the face of reality. The trouble is that, with Lammy, I feel we can never be quite sure.  

https://www.spectator.co.uk/article/the-problem-with-labours-energy-policy/

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September 17, 2024 at 12:05PM