Rutgers-led study suggests extreme weather will become more common
Persistent weather conditions, including dry and wet spells, generally have increased in the United States, perhaps due to rapid Arctic warming, according to a Rutgers-led study.
Persistent weather conditions can lead to weather extremes such as drought, heat waves, prolonged cold and storms that can cost millions of dollars in damage and disrupt societies and ecosystems, the study says.
Scientists at Rutgers University-New Brunswick and the University of Wisconsin-Madison examined daily precipitation data at 17 stations across the U.S., along with large upper-level circulation patterns over the eastern Pacific Ocean and North America.
Overall, dry and wet spells lasting four or more days occurred more frequently in recent decades, according to the study published online today in Geophysical Research Letters. The frequency of persistent large-scale circulation patterns over North America also increased when the Arctic was abnormally warm.
In recent decades, the Arctic has been warming at least twice as fast as the global average temperature, the study notes. The persistence of warm Arctic patterns has also increased, suggesting that long-duration weather conditions will occur more often as rapid Arctic warming continues, said lead author Jennifer Francis, a research professor in Rutgers’ Department of Marine and Coastal Sciences.
“While we cannot say for sure that Arctic warming is the cause, we found that large-scale patterns with Arctic warming are becoming more frequent, and the frequency of long-duration weather conditions increases most for those patterns,” said Francis, who works in the School of Environmental and Biological Sciences.
The results suggest that as the Arctic continues to warm and melt, it’s likely that long-duration events will continue to occur more often, meaning that weather patterns – heat waves, droughts, cold spells and stormy conditions – will likely become more persistent, she said.
“When these conditions last a long time, they can become extreme events, as we’ve seen so often in recent years,” she said. “Knowing which types of events will occur more often in which regions and under what background conditions – such as certain ocean temperature patterns – will help decision-makers plan for the future in terms of infrastructure improvements, agricultural practices, emergency preparedness and managed retreat from hazardous areas.”
Future research will expand the analysis to other regions of the Northern Hemisphere, develop new metrics to find causal connections, and analyze projections to assess future risks from extreme weather events linked to persistent patterns, she said.
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The paper: https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL080252
North American weather regimes are becoming more persistent: Is Arctic amplification a factor?
Jennifer A. Francis, Natasa Skific, Stephen J. Vavrus
Abstract
Rapid Arctic warming is hypothesized to favor an increased persistence of regional weather patterns in the northern hemisphere [Francis and Vavrus 2012]. Persistent conditions can lead to drought, heatwaves, prolonged cold spells, and storminess that can cost millions of dollars in damage and disrupt societal and ecosystem norms. This study defines a new metric called long‐duration events (LDEs) ‐‐ conditions that endure at least 4 consecutive days ‐‐ and takes two independent approaches to assessing seasonal changes in weather‐pattern persistence over North America. One applies precipitation measurements at weather stations across the United States; the other is based on a cluster analysis of large‐scale, upper‐level atmospheric patterns. Both methods indicate an overall increase in LDEs. We also find that large‐scale patterns consistent with a warm Arctic exhibit an increased frequency of LDEs, suggesting that further Arctic warming may favor persistent weather patterns that can lead to weather extremes.
Plain Language Summary
Rapid Arctic warming and sea‐ice loss are expected to affect weather patterns around the northern hemisphere. An increased persistent of weather regimes is one hypothesized impact. Long‐lasting weather conditions can lead to destructive extreme events, such as droughts, prolonged cold spells, heatwaves, and flooding. This study uses daily precipitation measurements across the United States, as well as daily large‐scale atmospheric patterns over the eastern Pacific and North America, to assess changes in weather‐regime persistence, and whether any changes are associated with a rapidly warming Arctic. We find an increased frequency in long‐lived patterns in recent decades, especially those with abnormally warm high latitudes, suggesting that further Arctic warming may favor an increase in extreme events caused by prolonged weather conditions.
The paper is paywalled, but the SI is here: grl58052-sup-0001-2018gl080252_s01 (PDF)
I’m not very impressed by this paper for several reasons.
- There’s a question mark in the title abstract, suggesting the paper is mostly speculation.
- They don’t seem very cognizant of long-term natural patterns as being the driver, instead assuming climate change/AGW is the driver from the get-go.
- They apparently only use data back to 1950, even though older data is available. This completely eliminates the dust bowl years of the 1930’s for no apparent good reason except it might not produce the results they want.
- 17 stations across the U.S. isn’t a very representative sample. How did they choose those stations? Sounds like a recipe for cherry picking to me.
- Lead author is Jennifer Francis, who in my opinion is just as openly biased as Dr. Michael Mann, which makes me doubt the veracity of her work.
The claims that a warming world is responsible for all bad weather now is nonsense, since bad weather has always been with us. Probably much worse weather in a colder world than we have now in a warmer world. Our (human) problem is that it is subjective, because it flooded my beach front house or my community was flooded in a river flood plain. Well, maybe we shouldn’t build in a flood plain if we can’t handle the water periodically. It is only perceived as bad because it messes up our lives, usually because we didn’t take heed and build in a suitable location, or with proper materials, or didn’t follow a proper building code. Haiti comes to mind regarding building code, or Calgary on a flood plain from a river upstream aptly named High River. The first clue should have been the name of the river. And it rained on a high elevation snow pack in mid June after a long cold spring had a heavy rain and big melt water all come at once. Or Tropical Storm Sandy hit New York conveniently at a King Tide. Or New Orleans when hit by Katrina as a Cat 3, and breached key levees, including the 17th Street and London Avenue canals in the heart of the city, failed with water well below levels they were designed to withstand. There are dozens of other examples I could give, but these are man made disasters, not proof of some nefarious dangerous happenings of climate change. If we lived a nomadic life, we would just pull up our tent and barely even get our feet wet.
The planet Venus is very warm, in fact hot, but it doesn’t have any significant winds at the surface. That is because there is no major temperature gradient differential to cause mass movement of air masses at ground level. Different story higher up in the Venusian atmosphere where the heat is escaping to space. In the ice age, I think it safe to assume that the hurricanes were much more intense and moving much, much faster because of the greater temperature gradient towards the poles. Probably less rain but with the hurricane tracking very fast and added to the wind speed within the hurricane itself, then a very destructive combination.
But if the Arctic really does significantly warm up, then that logically says that the storm intensity movement should become slower. Perhaps in a warmer world the atmosphere will hold more water vapor, causing more rain in some areas where the storm tracks are and in a slower moving storm, means it may rain longer in one spot such as when Hurricane Harvey in Houston stalled out and caused major flooding. But then Houston is pretty much paved over in a flood plain, and the flooding damage that was caused to humans which was what made it so terrible. And Harvey just ran into another higher pressure weather event that slowed it down so nothing really unusual about that. If Houston had hills, and most everyone lived on the hillsides, the flooding damage would have been that much less and nowhere near the tens of billions in damages. Same for the Cat 2 Hurricane Florence that just hit South Carolina. Lots of rain for a fairly long time, but the flooding damage was because of the large population density in the river valleys over a very large area. The same storm 100 years ago, would have had 10% of the damage to humans. So, we have to differentiate between the damage caused because of so many people living in the way, instead of blaming all this on CAGW. Therein be the crux of the problems, in my opinion. But like the peoples of ancient times, we will need to blame it on something, and for now, it appears to be at the Alter of ‘Carbon’ and CACC and CAGW. Bonus, they can tax it too. But now, they are starting to sacrifice people to this religion, and this must be stopped, or we just repeat history all over again.
Earthling2- I don’t think the gradient has an effect on hurricanes.
Will people move from the dangerous areas because of AGW?
So patterns of normal weather are more persistent then as well. Oh noes!
I would say the weather patterns are less persistent, at least over the central United States. Back in the very warm 1930’s, high pressure systems pesisted for months at a time over the central plains, and the entire decade of the 1930’s was like this.
There is no comparison between the 1930’s and today. Today, the only thing persistent is good, mild weather.
Surely you are referring to the unadjusted 1930’s.
But the ice doing something not seen before-
https://www.msn.com/en-au/news/world/new-research-shows-the-world’s-ice-is-doing-something-not-seen-before/ar-AAAGJnL
“Obviously, this is an evolving area of study and all of the questions have not yet been answered.”
Obviously and so much for the science being settled so call me in a few centuries with the more evolved area of study.
Why four days? It seems rather subjective. Do they get the same results with three days or five days, and/or did they just mine the data to find any pattern they could? I would have thought that there out to be some more rigorous statistical technique available to measure the “clumping” of any particular metric.
And if they lived in the Arctic I bet they would turn it around and blame recent warming on persistent North American weather patterns.
Hmmm, so arctic warming causes longer lasting weather spells.
Doesn’t that then say that a warmer arctic causes more stable weather?
Go for it i would think, these changes in weather always cause me the most grief.
Especially with the wardrob selection and i’m not at my best in the morning anyway 😉
Makes planning a lot easier as well,
Have a good one,
Willem
Maybe the presently warm oceans cause both Arctic warming and persistent weather conditions.
That makes the most sense to me.
Willem – The planetary waves grow larger and have more inertia with Arctic warming. Embedded waves in these waves give us weather changes at the surface.
Because the earth absorbs most infrared energy nearest the equator with much larger areas and much of that energy is moved through to the poles with smaller areas through atmospheric and oceanic currents, it is actually natural for the polar regions, especially the Arctic for geographic reasons, to warm faster as part of the process of removing heat through the atmosphere. This happens with normal warming and is born out by long term records of Arctic warming. When the temperature differential between the poles and the equator is less, it allows the jet stream to meander with more north and south movement rather that a tighter more latitude consistent path. This is called meridional circulation. When troughs go further south and ridges go further north, then we have increased likely hood of unusually high or low temperatures. And these patterns of ridges and troughs can lock in place for extended periods of time. Since this happens with natural, not anthropogenic forcing, it’s occurence is only evidence of warming. It does not provide attribution to the cause of warming. Referring to “Arctic Amplification” misses the idea this happens naturally. We are currently at a point where warming from the late 1970’s to about 1998, largely stalled post 2000. We are also seeing reduced solar activity which can mean that the incoming radiation at the equators is reduced and the warming there is likely slowing. A slowing of warming near the equators at the same time previous warming in the Arctic, delayed from equatorial input, is still persistent can produce less temperature differential that when the entire planet is warming. This is a better situation for meridional circulation. So these results are not surprising and can happen with naturally driven warming.
I said in my previous post that “Since this {meridional circulation] happens with natural, not anthropogenic forcing, it’s occurrence is only evidence of warming.” I should clarify that anthropogenic forcing can produce a similar, though not identical result. However, differentiation between the two causes, natural and anthropogenic is frequently not addressed and not easily addressed. Using models to claim what portion of warming is natural are highly dependent on assumptions and data and continue to see a large range of sensitivities to anthropogenic forcing.
https://eos.org/research-spotlights/polar-warming-makes-jet-stream-stable-not-wavy-blocked
Polar Warming Makes the Jet Stream Stable, Not Wavy or Blocked
An idealized climate model suggests polar warming stabilizes the jet stream and reduces atmospheric blocking at midlatitudes.
mike – which effect has more influence over the wave pattern? Maybe it’s cyclical short term.
Alaska just had the best Indian Summer evah. Although fishing wasn’t so hot, darn that PDO.
Weak jet stream will lower the tropopause over the Great Lakes.
http://www.cpc.ncep.noaa.gov/products/stratosphere/strat_int/gif_files/gfs_hgt_trop_NA_f24.png
Galactic radiation levels rise.
This pattern is typical of winter weather in North America.
The temperature in northern Canada is falling fast.
http://masie_web.apps.nsidc.org/pub/DATASETS/NOAA/G02186/plots/4km/r09_Canadian_Archipelago_ts_4km.png
‘Arctic warming linked to more persistent weather patterns in US, and elsewhere.’
Fixed. It’s called poleward heat transport, Arctic humidity events, and warm AMO anomalies.
Why do they think that we have any control over extreme weather events at all? They can’t even tell one kind of warming or not anyway – and….. “…We are still going to see extreme weather events whether or not humans are influencing the climate.” – Judith Curry
It’s what weather and climate do. We just experience a summer with Kilauea creating its own weather system and the East coast is still recovering from a hurricane we could do nothing to stop – and they still maintain that lowering our contribution to CO2 would stop these things? That is delusional thinking.
https://www.facebook.com/fourtimesayear/photos/a.427072877441780/547074252108308/?type=3&theater
“They can’t even tell one kind of warming or not anyway” should be “They can’t even tell one kind of warming from another” – the perils of editing one’s comments by moving texts around, lol
In Finland the climate has not warmed at all for about 80 years. It is easy to check at our FMI, Finnish Meteorological Institute pages. The corruption of the institute has not yet reached all the way through, so pages in Finnish are still truthful, but pages in English are completely different. Try googling Ilmatieteen Laitos (FMI), there “ilmasto” (climate), “vuositilastot” (annual statistics), and the graph of Sodankylä and Helsinki Kaisaniemi (Lapland at Arctic Circle, and southernmost Finland inside biggest city with UHI). If choosing the same page in English, there is just the normal liturgia of global warming.
This is excellent news – for Governor Cuomo. He had earlier stated that people were leaving New York for Florida – not because of high taxes – but because they seek warmer weather. I thought he had forgotten the Global Warming meme, but this article gives him cover: New York is getting colder because the Arctic is getting warmer.