Night of the Big Wind

Oneiric 3

https://www.boards.ie/discussion/comment/117970569#Comment_117970569

I'm pretty sure, as simple and primitive as the people, as is implied by some the comments on here, were back in 1839, I'm sure they would have built homes that they knew would have withstood the brute force of Atlantic winters.. to the best of their ability at least. These people were far closer to nature than we could ever hope to be.

Orion402

https://www.boards.ie/discussion/comment/117970774#Comment_117970774

Thank you for sharing that and hopefully the true nature of the storm will be revisited without comparing it with recent storms.

Orion402

https://www.boards.ie/discussion/comment/117970569#Comment_117970569

The tendency to diminish the society who lived through the experience so the Met Eirean report could downplay its significance and bundle it with recent storms is hardly a good reflection on our era and how it deals with the forensics of Atlantic storms of this magnitude. The reports at the time extend on to wildlife and events nobody here ever witnessed and there is no reason to believe these people were exaggerating. Try telling people about the electrical storm in the summer of 1985 and the incessant noise and that was something people remember from that era, not as fear or awe but something so unusual as to remain in the memory.

"Loss in wildlife and livestock was huge, such a common species of bird like the crow became ‘nearly extinct’ for years after. In Monaghan, ‘the ground was reportedly ‘black’ with the mangled bodies of crows, showing how devastating this storm was. One Clare sheep farmer ‘losing 170 sheep’ and records showing ‘roosting hens being blown a distance of half a mile’ in County Leitrim, just showing the force of the Big Wind." Armagh Observatory

http://www.climate.armagh.ac.uk/publications/mpatterson_big_wind_2010dec03.pdf

I included that website as it has a different take on the ferocity of the winds.

Nabber

https://www.boards.ie/discussion/comment/117970820#Comment_117970820

My intention was not to down play their abilities or knowledge, but to show that implementing such is difficult during times of hardship

Nabber

https://www.boards.ie/discussion/comment/117970928#Comment_117970928

Again not my intention to diminish any society. It’s more so comparing historical events with a modern lens.

Building materials of today are far superior to those of the past, typically lighter, stronger, flexible, flame retardant, insulated ect. Builders of the past were unquestionably skilled with the materials they had.

200 years from now I’m sure building materials and standards will be far superior today, they will most likely fair better against hurricanes, storms flooding ect.

This can be said without without diminishing any contributions. Builders of the past paved (pardon the pun) the way for modern builders.

Like I said, record both human impact and actual recordings

Meteorite58

Without a doubt it was a fierce storm . I read reports that a lot of people lost their paltry life savings that would have been hidden in the thatch and subsequently blown away during the storm. There was reports of many houses catching fire as fires would have been let burn all night especially during January. One must remember the poverty , overcrowding and appalling state of many of the living quarters of the time. Thatched mud huts were common, 1841 census shows that 40% of the population living in one room cabins in South Cork. These cabins would have been built with what ever was found locally like rocks turf, rushes, branches or wood dug out of the bogs .

I remember my, then very elderly, mother telling me how she was shown the remains of famine era huts back in the 1930's near Rathmore , built into the side of the bogs.

Of course there was wealth and a middle class but there was huge poverty since the 1820's with the collapse of the textile industry and reports of 10's if not 100's of thousands of laborer's taking to the roads to try and find some form of work with families in desperation before the potato harvest. Complex times and little support from Britain.

Much of the damage was in Connacht and Ulster and a lot of the inland damage was caused by storm surge apparently. There are reports that even newly built buildings were damaged and I remember reading of steeples of churches crashing down through the roofs. Reading through reports it would seem much of the country was left unscathed especially on higher ground.

How terrified the people must have been especially that it occurred on the night of the Epiphany which led many to fear that the end of the world was happening, people being very religious at the time . What brutal times for many and to get worse in the following years......

Must try and get that book that Oneric mentioned.

Pics of what huts might have looked like.

Taken from Skibbereen Heritage Centre :

Some great recollections from Duchas

INFORMANT

Lawrence Walsh

Gender

male

Age

70

Address

Dunmore, Co. Kilkenny

From Duchas

John Halpin

Age

over 70

John Halpin tells me that his father often spoke to him about the night of the Big Wind. John himself is well over seventy now, and his father, he says, was ten or twelve years old the night of the Big Wind. That night the roof of Halpin's house was blown off, but despite all the people of the house remained in it until the wind abated. When the Halpins left the house in the moring not one of the outoffices was standing, the horses and cows were crowded into a sheltered corner of a field scared and nervous, walls were knocked, trees and bushes uprooted and the whole place was strewn with debris.

The neighbouring village of Quin was strewn with the thatch of the houses, and roofs were blown off many of them. A peculiar thing happened two houses opposite each other. The roofs of both were blown off, but the roof of one in its flight lodged on the bare walls of the other. An old hag with fierce long grinning teeth was noticed to pass from one house to another with the wind.

M.T. Cranium

I think the Met E account probably under-rates the 1839 storm relative to more recent ones for this reason -- they compared the overall wind gradient from the northern tip of the country to the southern tip, but in my conjecture, there was likely quite a deep secondary just off the Mayo coast which cannot be detected from the data available, therefore the gradient as the storm hit the west coast was almost the same over that two thirds of the total distance, as Met E estimated for the whole country (and probably accurately but by then the strongest gradients had begun to fill in). So in fact if the storm compared to a modern storm with a pressure differential over 2/3 of the distance, then it would have been 3/2 as strong or 50% stronger. That might be a bit high, let's say 30 to 40 per cent more likely. But a significant difference nonetheless.

There would be no hope of proving this secondary deep low idea, unless any actual pressure readings could be found, but as the wind speeds were clearly quite a bit stronger than the 1988 storm, I think it's a safe bet that Belmullet's pressure may have dropped well below what the study might lead one to believe (which would be 950 mbs perhaps) -- it may have been closer to 935 mbs there. This deepening must have been quite explosive to get the incredibly fast forward motion of the wind speed maximum which looks like it went from around 9 p.m. in Westport to a little before midnight in Belfast (about 11 p.m. in Dublin). We normally see 4-6 hour progressions of wind max with the tamer storms of modern times.

I'm sure a satellite image of that 1839 storm would be a very dramatic reverse-C with bands hitting the west coast around a stark centre in Donegal Bay.

Had a look at the CET temperatures in this sequence; evidently the low occluded very rapidly over Britain because the mean reported on the 7th was only 4.2, equal to the previous day. There was no sustained warm advection, and the temperatures then fell off to subzero briefly before a milder system pushed temperatures up to around 8 C on the 11th.

So in summary I would say the maps in the paper by Met E are probably fairly accurate but six hours earlier than the first map, a more complex structure with a secondary near the Mayo coast would perhaps have been the actual cause of the extreme winds.

Orion402

https://www.boards.ie/discussion/comment/117971656#Comment_117971656

I quite understand that, however, the conclusion of Met Eireann downplays the significance of the ferocity of the storm in an era when they now are pushing the ferocity of present storms that barely register among the population in damage to wildlife and forestry. The Met Eireann report attaches unnecessary commentaries on the experiences of people who back then realised this was something no living person had encountered before and perhaps since.

What happens when the next 'big wind' occurs for it surely will when conditions are right?. It is why a more practical forensic treatment of the 1839 storm is necessary before they send it in the direction of 'climate change modelling'.

Gaoth Laidir

One thing that stands out is that the people years ago would put us all to shame with the high standard of their handwriting. I can't remember the last time I wrote something like that by hand. A declining skill.

Nabber

https://www.boards.ie/discussion/comment/117972318#Comment_117972318

If it were to happen again it would be 'unprecedented' a once every 500year storm. There is a reason historical weather events are down played.

Oneiric 3

https://www.boards.ie/discussion/comment/117972150#Comment_117972150

I recall that many of the big events in the 90s more often than not were rapidly followed by potent secondaries that were poorly forecast, and which had the effect of prolonging the storms with barely a lull in-between.

Re-reading some of the accounts of the 1839 storm, lightning and aurora were seen during the height of the storm, which not only would have added to the ominous nature of the event, but also suggests that the strongest winds occurred in a post cold/newly formed occluded frontal air mass.

Orion402

https://www.boards.ie/discussion/comment/117972640#Comment_117972640

This is unfortunate as ultimately formatting the conditions for a historical storm makes for a far more interesting discussion than homogenising the 1839 monstrous event with recent and relatively placid events. I was on a 54 metre trawler 300 miles West of Ireland heading into a low pressure system of 952 mbs on our way from Iceland to the Canary Islands. There were moments of genuine fear for someone who thought I saw everything as the waves striking the bow were almost instantly striking the wheelhouse windows and most of the crew were Icelandic familiar with these things hardly seen that ugly green the sea takes on during those events just as the roaring onshore brings its own assault on the senses.

I suspect people are missing a trick here as I doubt Akrasia in the other thread will venture into this one and offer his thoughts on the conditions surrounding the development of the storm.

M.T. Cranium

Back in those days no doubt the 500 mb heights were a bit lower than we see nowadays in winter storm situations, that low might have been stacked under something like a 484 dm low at 500 mb and since subtropical heights were probably within 1 dm of today, the gradient wind would have been quite fierce. The winter of 1838-39 was not particularly cold for those decades, but the previous winter had some record cold weather in January (1838).

If this happened nowadays, I would imagine there would be serious damage to infrastructure on a scale not seen in modern times. As to how modern houses might fare, possibly a bit better, but there would be numerous roof removals even if not quite the scale of total collapse, and so many trees down causing havoc. It's clear that a storm surge came up the Shannon estuary from the Limerick reports, and the extent of the storm surge around Galway must have been far beyond what we've seen recently.

There was a very deep low also in Dec 1886 that is not that well publicized but probably ranks in the top three or four storms to hit Ireland in recent centuries. A pressure of 927 mbs was taken in east Ulster, and the main damage zone was north Leinster and across into Lancashire. That storm is more accurately depicted on historical weather maps, the 1839 storm in the NASA archives (wetterzentrale) is pathetically underdone for no obvious reason since there were reliable pressures in the 920s in northern Scotland.

M.T. Cranium

Probably the only reason this kind of storm would be unlikely in modern times is that component of the upper level flow attaining such deep polar vortex characteristics; in eastern Canada where those parameters have not changed very much, they still get peak wind gusts of the same intensity as back in the 19th century. This is somewhat at odds with orthodox climate change theory which implies an ongoing trend towards more intense storms, actually I believe the reverse is true. A lot of the most powerful windstorms I can find in most climate records are well back in the past. And that makes sense because winter season windstorms have an almost linear relationship to the depth of the 500 mb lows that are guiding them. If those heights relax with the warmer oceans and northward shift in the jet stream it stands to reason that the storms will be less intense (at the latitude of Ireland anyway). But you can't rule out some freak "perfect storm" scenario where the heights do fall to sub-480 dm over top of a bombing cyclone, then you'd have this all over again.

On the subject of the auroral display, the sunspot cycle that peaked in 1837-38 was a notably strong one and Caswell in his Providence weather journal has frequent reports of bright aurorae, one on the evening of Jan 10, 1839. The weather situation for Providence RI was indicative of storm development around the 4th-5th to the southeast, after some clear high pressure over the region 3rd-4th. There was no indication of a strong low but about three inches of snow fell in a northeast wind on the 5th, and it was cloudy for several days. Temperatures were generally about 5 deg below normal values.

beachhead

My truppence worth -- today's snowflakes need something to whinge about,including Met Eirinn.No reason to allow events of the 1830's to diminish their paranoia.We can only wonder how people survived weather events in the 1400-1800's or prior.Written accounts are scarce.Snowflakes avn't a clue

Orion402

https://www.boards.ie/discussion/comment/117972794#Comment_117972794

I remember the so-called Halloween storm ('perfect storm') well as I was living on the Eastern end of Long Island at the time and it happened a few months after hurricane Bob while doing more damage to the communities than the hurricane did. Like the storm that wiped out the Fastnet yacht race or the Sydney-Hobart a few decades ago, certain conditions came together to create anomalous weather events and may I include the freeze 10 years ago which encompassed this island only for the sake of expanding the issue beyond individual storms.

In this respect, the 1839 event was anomalous among all the other Atlantic storms that moved across or close to the island and that will always interest people as opposed to predicting future temperatures in order to project future trends in weather thereby robbing the interesting sequence of meteorological conditions that set up monster storms. It is not so much that the 'big wind' will happen again under the same conditions but rather the ferocity of winds will result from another set of parameters just as interesting as the ones that cause the Halloween storm and the massive 1839 event. The nuances may be lost to serve 'climate change modelling' and the imperatives dumped on society who have no control over the conditions for stormy, cold weather or heatwaves.

Thanks for your take on the reasons why the 1839 storm was weaponised using a secondary low pressure system creating something that devastated an island community that had little and were facing into the famine years. I am sure that forensic modelling of this nature is now far better than when the original Met Eireann report came out and certainly should be revisited. I have read the meteorological reports for the yacht races and they include secondary lows or merging storms like the 'perfect storm'-

https://journals.ametsoc.org/view/journals/wefo/15/5/1520-0434_2000_015_0543_tabdso_2_0_co_2.xml

Oneiric 3

Some accounts of the weather (UK specific) in the year leading up to 1839 and 1839 itself. An obviously cold period in weather history, which once again demonstrates that Ireland and the UK are subject more extreme events when the climate profile is in a cooler state:

1838 (February) THE 'BUDE BREAKWATER' GALE

1. On the evening of the 24th February, 1838, a southerly gale developed (" more violent than for years "), this veering west-southwesterly through the night and coincided with a high tide in the early hours of the 25th. The inside slope of the Bude Breakwater (built to protect the harbour/canal entrance between 1820 and 1822) gave way (?scouring / over-topping?), with three-quarters of the structure giving way. [ Apparently the mortar had been weakened by a severe frost in the winter; however, the structure was also deemed to have had too steep a slope, and the replacement breakwater was of much better construction, and has survived many a gale to this day/2003.] damage also occurred to sea structures all along the south coast of England, including the Plymouth breakwater. 12 1838 (late Summer / Autumn) Following a severe winter/early spring of 1838 over Scotland [ see above ], the crops were already delayed, and were then damaged in the ground by frost in August, with the cold, frosty weather continuing through September & October. A large proportion of the crop was lost, with much hardship for rural tenants. x 1838 Cold year: fog on 11 days in September (London/South). Snow showers on the 13th October (?London/South?). 

8 January 1839 "The Night of the 'Big Wind'": this is the most notorious of all storms to affect Ireland (also affected other parts of the British Isles - see later). An unusually deep depression (one of the deepest ever recorded so close to the British Isles) travelling in a north-east direction to the north of Ireland was responsible for gusts widely 75-90 knots, and in excess of 100 knots in a few places; Lamb says there is 'evidence of whirlwind / tornado activity'. At least 90 people were killed across Ireland & surrounding waters, though the death toll was surprisingly low, allowing for the lack of warning. There was considerable damage to buildings, shipping and crops right across the island. Around 20-25% of houses in Dublin experienced some form of damage, though some was minor (broken windows). Several tens of thousands of trees were uprooted. The aforementioned storm also affected other parts of the British Isles, particularly western & northern parts of Britain. The newly-built Menai Bridge was severely damaged. In Liverpool & in the adjacent waters of the Irish Sea, much damage ensued - building damage ashore, and loss of vessels & lives afloat. Deaths in the Liverpool area, both on land & at sea is stated to be around 115, with many-a-breach of local sea walls, and the death total across the entire British Isles may have been in excess of 400. (Remember that coastal shipping was of great importance in these days before the railway network reached all corners of the Kingdom - also Ireland was then an integral part of the United Kingdom). 6, 23 1839 May Showers of snow, sleet and hail on the 14th & 15th May. 

1839 (Summer, Autumn & early Winter) A wet summer (148% of LTA 1916-1950) across England & Wales. Specifically, July 1839 was in the 'top-10' of wettest such-named months in the EWP series.

Over the longer period from June to November 1839, using the EWP series, the RAINFALL %age was around 150% averaged over the England & Wales domain, and probably close to twice-average across southern England. 1, EWP 1839 (Annual) A wet year and a wet summer (in London).

A cold year for Scotland. Specifically for agricultural areas of NE Scotland (though not exclusively so - just that this is the area I have data), the following are noted:

> March: a severe snowstorm, with much drifting - loss of life.

> May: about the middle of that month, there was a heavy fall of snow with much drifting.

> September: Severe flooding after heavy rainfall. Damage / destruction of bridges in the area.

Over England & Wales, the period June 1839 to January 1840 was notably wet (including the wet summer - see above); the cumulative anomaly for this period was 140%.

In December, FOG 1st to 7th December (London/South).

Sourced from here: Weather in History 1800 to 1849 AD (weatherweb.net)

M.T. Cranium

You could add to that a very cold January in 1838 which saw the coldest daily mean temperature of any day in the series (daily means begin in 1772), a reading below -10 C. The monthly average was -1.6 C. The spring of 1837 was one of the coldest on record, especially April. But the period had high variability, May 1833 still outdoes any other May for warmth by over 1.0 deg (almost as isolated as Dec 2015) and June 1846 was also warmest on record. The winter of 1833-34 is one of the mildest, but March 1845 was second coldest and has the coldest daily mean for any March. This high variability climate seemed to give way to a more consistent rather cool regime later in the 19th century, without as many extremes in either direction. This is probably because in North America high variability peaked after 1870 and while the jet stream was probably further south than nowadays, all the cold air pouring out of North America at frequent intervals probably fired up a generally zonal flow across the Atlantic, albeit not quite the sort of mild conveyor belt situation of the early 21st century or the 1970s.

It's interesting that these three great storms -- 1703, 1839, and 1903 all happened just after or in the dying stages of long solar minima, the Maunder, the Dalton and whatever we call the late 19th century into the first decade of the 20th century which was considerably quieter than the mid-19th century. So ... we've been in a bit of a solar downturn recently. Maybe Darwin is all we're going to get, which was probably more than enough for most people affected by it.

beachhead

https://www.boards.ie/discussion/comment/117977268#Comment_117977268

I was under the impression that the current ice age began in the late 1400's and will progress for up to 15,000 years leaving an area north of Galway/Dublin line under ice.The northern hemisphere will see the ice cap covering a lot of Northern Europe.I don't plan on being around that long.

M.T. Cranium

Hard to say what the next glacial maximum will be like, the last two were apparently quite similar to each other, but this past one had probably two or three relative maxima separated by slightly less widespread ice cover, although far more than nowadays.

We used to speak of the glacial maxima as "ice ages" but the modern convention is to say glacial maximum because until the earth is fully deglaciated we are technically in an ice age. Opinions vary as to whether we are near the height of the inter-glacial now, or were during a slightly warmer climate that occurred before the Neolithic around six to eight thousand years ago. Our human modification of the climate may be distorting the actual signal, making it appear as though we are still emerging from the worst of the previous glacial instead of slowly descending into the next one.

The good news is that unlike the rather brief inter-glacial between the last two major glacial periods, this inter-glacial has a very long extinction period caused by slower variations in the three primary "milankovitch" factors, which include our axial tilt, the date of perihelion relative to northern winter, and eccentricity of earth's orbit. What's perfect for a northern hemisphere glacial max is larger tilt, perihelion in northern summer, and a more eccentric orbit. All of these factors tend to reach a sort of pause over ten to thirty thousand years, which supposedly means that (in the absence of human modification) the next glacial era would set in very gradually over that period of time.

It could be that our modification will have a longer delaying effect although by the year 3,000 (not very far into that longer interval) you would think we might have entirely weaned ourselves from fossil fuels and the greenhouse gas surplus would have settled out. Then there's the question of how a more advanced human civilization might be able (or willing) to control the weather. Perhaps there will not be another glacial maximum for those reasons.

The "Little Ice Age" (which really only ended in the early 20th century) shows that our climate can shift into a state that, while not cold enough to encourage continental glaciation, is severe enough to reverse smaller aspects of the ongoing glacial minimum that has been around ever since the more modern form of human history began. The fact is though, the modern homo sapiens and the Neanderthals were both around during the last portions of the recent glacial maximum, and possibly even as far back as the inter-glacial between the last two big glacial periods. There was speculation that when the Lake Toba volcano erupted and turned some portion of the recent glacial max into a super-chilled century without much sunlight, the human population dwindled to almost extinction rates and only a remnant survived that stress.

Rebelbrowser

It is disturbing how much knowledge some of you have!

Orion402

https://www.boards.ie/discussion/comment/117985262#Comment_117985262

Right now, the surface area with the North pole at its centre is slowing turning parallel to the orbital plane and into the dark hemisphere of the Earth, thereby creating an increasing circumference where the Sun remains continuously out of view. It will reach its maximum circumference (Arctic circle) on December 21st while its Southern counterpart reaches the maximum surface area where the Sun remains constantly in view.

The Milankovitch doctrine is a conceptual dog and obstructs the reasons why we have the seasons and the conditions for winter storms aside from anomalous events like the Big Wind event.

The crossover from planetary dynamics to Earth sciences like climate is in an awful state at the moment and requires people to work through the historical and technical nuances whereas the conditions which created the 1839 event can be extrapolated from atmospheric conditions at the time. Some people, like yourself, do much better with forensics of individual events but less so when it is necessary to work with larger scale systems which require accurate views of planetary dynamics-

" Since we cannot be universal and know all that is to be known of everything, we ought to know a little about everything. For it is far better to know something about everything than to know all about one thing. This universality is the best. If we can have both, still better; but if we must choose, we ought to choose the former. And the world feels this and does so; for the world is often a good judge" Pascal

Whereas it is possible to make a crossover to both disciplines without inheriting the flaws of those engaged in planetary dynamics, people become sore unnecessarily when such encouragement is brought up.

" When we wish to correct with advantage, and to show another that he errs, we must notice from what side he views the matter, for on that side it is usually true, and admit that truth to him, but reveal to him the side on which it is false. He is satisfied with that, for he sees that he was not mistaken, and that he only failed to see all sides. Now, no one is offended at not seeing everything; but one does not like to be mistaken, and that perhaps arises from the fact that man naturally cannot see everything, and that naturally he cannot err in the side he looks at, since the perceptions of our senses are always true. People are generally better persuaded by the reasons which they have themselves discovered than by those which have come into the mind of others. " Pascal

Oneiric 3

Another great Irish storm back in the 1920s: (October 1927)

oct07.qxd (met.ie)

which brought much tragedy along the west coast. Walter Maken alludes (fictionally) to this storm in his great book 'Rain on the Wind'. The eerie calm before the storm in which fishermen out in Galway Bay witnessed a ghost Currach rowed by 4 pale faced men sail silently pass them in the weak but sufficient moonlight before vanishing into thin air.

What followed was truly heart-breaking. A fictional tragedy that reflects the very real one that this October storm brought with it.

M.T. Cranium

I would challenge these two paragraphs ...

"The Milankovitch doctrine is a conceptual dog and obstructs the reasons why we have the seasons and the conditions for winter storms aside from anomalous events like the Big Wind event.

The crossover from planetary dynamics to Earth sciences like climate is in an awful state at the moment and requires people to work through the historical and technical nuances whereas the conditions which created the 1839 event can be extrapolated from atmospheric conditions at the time. Some people, like yourself, do much better with forensics of individual events but less so when it is necessary to work with larger scale systems which require accurate views of planetary dynamics."

-------------------------

There is no Milankovitch "doctrine" -- he took widely accepted facts in astronomy about cycles of the earth's orbital variables and attempted to fit those to other widely accepted facts in geomorphology concerning the timing of recent glacial periods (or ice ages as some would call them).

Within the atmospheric sciences, his theory has gained qualified acceptance. Many think there are other factors at play, or that he has not scaled the three variables important to his theory correctly.

I don't see where I come into this at all. The interactions between Milankovitch and orthodox scientists started out frosty and turned warmer at some point before I finished my education and I only gradually learned about these interactions over recent decades since Milankovitch passed away. Otherwise, I am not some stakeholder of any kind and wouldn't necessarily say that I am a proponent of his theory. It makes some sense to me that obliquity is an important driver of glaciation, one can imagine that if the earth tilted any more than the small range that it does so, we would have a much different climate altogether. The other two factors make more limited progress and are also more disputed by some critics.

If the commenter has any knowledge that Milankovitch cycles (not their causative effects, but the cycles themselves) do not exist, then that will come as news to orthodox science. The axial tilt of the earth is not always what we know it to be today. A partial proof of that is that some Neolithic monuments do not quite align as precisely as their builders intended with solstice or equinox solar phenomena, which became understood when it was realized that five thousand years ago, the axial tilt of the earth was slightly different than it is now, hence things like summer sunrises were not exactly where we see them on the horizon today. The bigger the axial tilt (and the earth can apparently add at least one degree to the modern tilt, as well as subtracting one degree at other times) the further off due east or west the solstice rising and setting points. A difference of one degree might not sound like much, but if we're talking about some monument with a long chamber designed to become illuminated at a precise time, then that one degree would be significant, just like if your car headlights were mis-aligned by one degree.

Anyway, even if Milankovitch is dead wrong, it has nothing to do with me. When I say "x has a theory ..." that's all I mean by it, there is no call to prayer or passing of the offertory plates. X could be dead wrong. In at least one case, X is dead wrong.

M.T. Cranium

Also this is widely known and has no origin within my own mind or work, Milankovitch took three variables of the earth's orbit which astronomers had already determined to exist, and calculated what would be the insolation at 65 deg N latitude in July. His reasoning was that small changes in insolation at that point in the weak arctic summer would have important effects on snowmelt. If snowmelt were reduced around that latitude, then a glacial cycle could begin. And he found that the three variables could sometimes combine to reduce that insolation by as much as 22 per cent compared to the relatively warm epoch we are now enjoying (or were until Greta started up).

I have no reason to doubt the 22 per cent estimate, and it makes sense from my own knowledge of Canadian arctic climates that very small changes in insolation could tip the scales. Some places I have studied are a bit further north than 65 deg N but maybe his work would show that they had even larger variability. Just in the quasi-random variability of the past seventy years or so, summer temperatures have varied by about five degrees from warmest to coldest cases, and snow cover has varied from nothing at all from early June to late August, to periods of light snow on the ground at random times all through the season. You can imagine that if this climate shifted colder by about 3 or 4 deg, the colder summers would probably have snow on the ground throughout, and that would begin to have a cumulative effect after a while, if several of those years happened consecutively.

This is probably what happened in those wild oscillations at the end of the last glacial, and by extension it is probably what happened to start the glacial periods altogether. But besides Milankovitch cycles, there could also be other reasons, such as volcanic dust, secular changes in the Sun's output (perhaps very long analogues to the Maunder minimum, for example), or just random interactions of extreme events. It used to be the generally accepted concept that climate was static but most recent research points more to a chaotic reality where decades or centuries can be much different. Over top of that we have the postulated effects of our human activity tilting the balance more towards warmth.

Nobody, least of all me, would argue any of this is simple, or easy to understand, and we see on a regular basis that prediction has not yet become reliable. A science that has no reliable prediction capability is not really a science at all, as I've said to annoy many an orthodox climate scientist over a lifetime, but it is a self-evident truth since science is basically the domain of acceptable predictions. We don't even claim to have those in long-range (very long-range let's say) weather forecasting. Climate change (the human activity, not the concept) has changed that by claiming an ability to make reliable forecasts (of warming) but we don't know what natural variability factors could get involved in those predictions even if they are by themselves valid (not universally accepted either).

Orion402

https://www.boards.ie/discussion/comment/117991317#Comment_117991317

This really isn't for you as I am not interested in Milankovitch and his theoretical cycles, I am looking at the observational restrictions faced by Copernicus himself when he sacrificed the motions of the North/South poles in a circle each orbit in his effort to satisfy the framework of Ptolemy-

"The third is the motion in declination. For, the axis of the daily rotation is not parallel to the Grand Orb's axis, but is inclined [to it at an angle that intercepts] a portion of a circumference, in our time about 23 1/2°. Therefore, while the earth's centre always remains in the plane of the ecliptic, that is, in the circumference of a circle of the Grand Orb, the earth's poles rotate, both of them describing small circles about centres [lying on a line that moves] parallel to the Grand Orb's axis. The period of this motion also is a year, but not quite, being nearly equal to the Grand Orb's [revolution]." Copernicus

http://copernicus.torun.pl/en/archives/astronomical/1/?view=transkrypcja&

If you don't know what he is describing then graphically it looks like this-

The motion of the North/South poles annually (where daily rotation is absent) represent beacons for the entire surface of the Earth entirely separate to daily rotation. This is explaining the combination of rotations responsible for the seasons for goodness sake!.

Challenge all you like, observational affirmation beats all contrary opinions, so anyone who looks with their own eyes at the dual surface rotations of Uranus where the dark hemisphere is absent will come to realise that a lot of work is necessary to replace deficient views due to the lack of observations from satellites with more productive ones-

https://hubblesite.org/contents/media/videos/1999/11/175-Video.html?news=true

The crossover here is between meteorology and planetary dynamics as Arctic sea ice development, hurricane season or any other large scale meteorological event is dependent on planetary dynamics. All this material was covered before and it is clear you wish to remain with notions based on a 'clockwork solar system'. You do best with individual weather events but lean on awful views of planetary dynamics when you stray into long term perspectives.

Orion402

 "A partial proof of that is that some Neolithic monuments do not quite align as precisely as their builders intended with solstice or equinox solar phenomena, which became understood when it was realized that five thousand years ago, the axial tilt of the earth was slightly different than it is now, hence things like summer sunrises were not exactly where we see them on the horizon today" MT

Thank you for borrowing my own perspectives and then botching it when it comes to the ancient alignments on this island.

If the 25,920 year axial precession cycle was a correct proposal, the North/South poles would have turned roughly 60 degrees since the builders first created the alignment 5,200 years ago, yet the alignment occurs on the same day on the December Solstice as it did all those many centuries ago.

To cut a long story short and for the benefit of those ancient builders rather than present day theorists, the minor 1 degree drift every 72 years or so known as the precession of the equinoxes is a result that the proportion of rotations to orbital circuits is not exactly 1461 rotations for 4 circuits (calendar framework) nor 365 1/4 rotations for 1 circuit.

You get to decide whether you wish to remain with deficient views or work towards a stable foundation for the relationship between planetary dynamics and the seasons first and then on to planetary dynamics and climate proper. It all requires a bit of consideration rather than a reaction.

Oneiric 3

This thread really isn't about historic Irish storms, is it?

Orion402

https://www.boards.ie/discussion/comment/117996299#Comment_117996299

It is unfortunate that the forensics of the 1839 event drifted into speculative conclusions without the physical considerations involved in such conclusions. I do care that a society who felt the full force of the storm lost their roofs, their livestock, their livelihoods and the lost of life so contemporaries who put the ferocity of the storm down to night time ignorance and no warning (whatever that is meant to convey) is failing society as they so frequently hype any Atlantic storm that comes our way in order to support 'climate change modelling'.

I genuinely came here to seek a more accurate explanation for the 1839 event using the ingredients which make such a storm/hurricane possible as it relies on short term atmospheric ingredients, however, if people feel it necessary to put on their predictive hats then they will run up against planetary dynamics which create a large part of those meteorological ingredients.

Let these threads take their own course, so long as it doesn't involve henchmen willing to shut down discussion. Nobody needs grandstanding, they do need the crossover between meteorology and planetary dynamics to explain all the large scale events annually and sometimes anomalous events like the Big Wind storm are outriggers of that discussion rather than central to it.

M.T. Cranium

I don't doubt that the comments made are true statements but I come away unsure whether Orion402 accepts or rejects the concept of changes of the earth's orbital tilt over time. There is a range between about 22.6 and 24.4 degrees, we just happen to be near the long-term average of this oscillating variable. What it means in practical terms when the obliquity reaches a maximum (above 24 deg) what he calls the circle of illumination covers a slightly larger portion of the northern hemisphere in summer. While you might find there to be continual sunlight at 67 deg N nowadays, you would have that at 66 deg N ... but there is a corresponding larger spread of polar night with a brief period of it near the winter solstice at a lower latitude than nowadays. Thus it is rather difficult to have a discussion when you aren't sure what the other person thinks about a specific concept and instead they just restate some other concept which you don't dispute. It doesn't bother me because it's up to Orion402 to present ideas in whatever framework he desires, but there is no implied expectation that everyone will conform to that, just as I don't expect everyone on this weather forum to accept my controversial theoretical framework, and would be quite surprised if they did so because it would indicate that they had duplicated my efforts to understand it. I doubt that everyone has the time to do all that.

But it has been an interesting discussion of the 1839 storm. One thing for certain is that the NOAA map reconstruction for that date as shown on the wetterzentrale archives is woefully inadequate, it merely shows a 975 mb low gradually deepening to about 960 mbs. I don't know what European obs they used for these maps but there were many more available than they utilized there. This makes one wonder what precision was achieved with any of the other maps shown. The maps for eastern North America that they produced seem to account for the Caswell (Providence RI) obs, but have no other obvious data points so what you tend to get there is a climatological average kind of map. These comments apply mainly to dates before 1850, after that I think the maps start to show some actual precision.

By the way, I didn't "botch" anything in that explanation. Apparently it was causing anthropologists some concern when they found some of the ancient monuments didn't exactly align with some solstice sunrise points as they had expected, but then when they consulted astronomers they found out something they hadn't realized, that sunrise did not take place at the exact same place on the horizon at summer solstice back in the Neolithic, but a point slightly further south due to that larger axial tilt. Some have also theorized that proper motion of the stars over long periods of time can account for some slight discrepancies in positions of Egyptian monuments and postulated astronomical signals that they were attempting to show as significant to them. The star Sirius has been changing in its relative position to other fixed stars and according to astronomers it will drop so far to the south eventually that we won't be able to see it at all in the northern mid-latitudes (nowadays it is quite prominent in the winter sky).

A lot of things that were considered to be unchanging or fixed a few centuries back have been found to be subject to small variations or even as in the case of Sirius, long-term large variations. Another thing that changed slightly was the length of the lunar orbit. This fact was verified when some ancient solar eclipse records from Assyria were discovered. These solar eclipses could not have happened if the synodic month of the moon's orbit had been exactly the same as what we have calculated it to be in the modern epoch. The moon used to be very slightly closer to the earth and thus its period was slightly shorter. The length of the earth's day has also gradually lengthened out, because with the Moon closer in geological historical times, the earth used to spin faster on its axis than it does now. There were probably over 400 days in a year back in the Cambrian era. These days if measured by our time systems now were only 21 hours long.