Modern jet stream patterns in Europe can be described as natural variation, based on this research. A new study says ‘Northern and southern summer EU JSL [Jet Stream Latitude] excursions thus induce a dipole between BRIT [British Isles] and NEMED [N. East Mediterranean] summer weather that is reflected not only in a variety of climate variables (Fig. 1) but also in vegetation productivity’. The article calls it a seesaw pattern.
– – – ScienceDaily Summary: Tree-ring data reveal that periodic shifts in strong winds high above the Earth’s surface have driven opposite climates in different parts of Europe for the past 700 years and likely much longer, resulting in contrasting patterns in weather, agricultural and societal extremes.
. . .
During her summer travels to her native Belgium, University of Arizona professor Valerie Trouet noticed something that turned casual curiosity into a major scientific discovery: When the sun hid behind an overcast sky and people around her put on sweaters instead of summer clothes, the weather tended to be warm and dry in Italy, Greece and the Balkans, popular summer escapes for tourists from the cooler climates of central and northern Europe.
At U of A’s Laboratory of Tree-Ring Research, Trouet studies tree-rings to gather clues about what past climates were like, reading wavy, wooden lines like a linguist might decipher an ancient text.
What if, she mused, the key to understanding the capricious summers in Europe could be hidden in trees, silent witnesses to centuries of warm and cold, sunshine, rain and snow?
. . .
Jet streams are concentrated bands of wind in the upper atmosphere that travel around the globe in the northern and southern hemispheres. Their exact locations are not fixed; in response to changes in the position and intensity of high- and low-pressure weather systems, they may shift north or south or change their course, resembling a swiftly running stream at some times, and a slow, meandering river at others.
The jet stream, it turns out, largely determines summer climate in Europe, and it does so in a seesaw-type pattern that climate researchers call a “dipole.”
“When the jet stream is in an extreme northern position, we get cooler and wetter conditions over the British Isles and warmer and drier conditions over the Mediterranean and the Balkans,” explained study co-author Ellie Broadman. “This is related to the climate conditions we are witnessing right now, such as catastrophic flooding in central Europe.”
Hotter conditions over the Balkans cause more moisture than normal to evaporate from the Mediterranean Sea and rain down further north.
Conversely, when the jet stream migrates further south, it drags warmer and drier air over the British Isles and pushes cooler temperatures and more moisture toward southeastern Europe.
Measurements of the jet stream have only been around since the late 1940s, Trouet said. By using tree-ring samples from across Europe as proxies for temperature, the research team was able to reconstruct jet stream variation over the past 700 years.
Each year, trees add a ring consisting of less dense wood in the spring and denser wood in the summer. By analyzing tree rings under the microscope, dendrochronologists can compile an archive of past climates.
“We link tiny, subcellular cell wall features in the wood to atmospheric winds that weave through the atmosphere many miles above the Earth, which is fascinating,” Trouet said.
Remarkably, the team found past patterns of the jet stream reflected on a societal level, recorded in historic documents.
“Europe has a long history of writing things down,” Trouet said. “For example, there were monks in Ireland who started recording storms that happened in the 600s, the early Middle Ages, and you have centuries-long records of grape harvests, grain prices and epidemics.”
By comparing historical records to the jet stream reconstruction, Trouet’s team discovered that the climate dipole created by the jet stream has influenced European society for the past 700 years and likely much longer.
“Epidemics happened more frequently in the British Isles when the jet stream was further north,” Trouet said. “Because summers were wet and cold, people stayed indoors, and the conditions were more conducive to spreading diseases.”
From 1348 to 1350, the plague, known as the Black Death, raged in Ireland. At that time, the jet stream was in an extreme, far-north position over Europe.
The findings provide critical data to improve climate models that researchers rely on to predict future climate, Broadman said. Much research has focused on how the jet stream is affected as a result of global warming.
“It’s hard to do that if you only have 60 years’ worth of data, which is why a reconstruction going back 700 years is very useful,” she said. “It allows you to actually compare the past to what’s been happening since we started putting greenhouse gasses into the atmosphere.”
Full article here.
– – – Image: Forecaster highlights the jet stream over the UK [credit: BBC]
Evapotranspiration, ET, is a common term in agriculture used in connection with plant growth. ET: water going to the atmosphere from the earth’s surface. ET’s connection with climate change is described by the CRGW theory (def to follow) which starts out with a decrease in land ET (over time) that naturally (through the CRGW theory) leads to a global increase in ET. The localized land decrease in ET can occur in special parcels (urban heat islands,UHIs, deforestation, mining, etc) where the virgin land has been changed. The ET value of this change from virgin land is (in most cases) lost to time. Without an estimate of the change in ET over time the CRGW theory is not useful. This paper summarizes papers from Mazrooei et al. (2021) (1) and Lu Hao et al. (2021) (3) that present a creative method with NASA satellite data on local (urban Heat Islands, UHI’s) ET differences around the world. Their data (in climate change terms) show a wide range of ET that is correlated to the environment the UHI is in. Ariad UHI’s environments can have positive ET’s and wet environments have negative UHI ET’s. Mazrooei et al. (2021) uses a creative “bull’s eye” approach with satellite ET data. The UHI is in the center of the bull’s eye and the rural area in the outer ring. The ET from these two areas is used to calculate a precent difference in ET, showing a range of +10% to -50% and an average of -12% which may be a good estimate of the global UHI – virgin land difference.
The CRGW theory of ET related climate changes is: A localized ET decease (in a special parcel: UHI’s, deforestation, mining, etc.) = higher VPD (vapor pressure deficit) = air rising in a plume = less clouds or less reflective clouds = more sun = higher temperature and more evaporation of water = higher global ET: Cloud Reduction Global Warming, CRGW. In the CRGW theory the %ET/unit area difference between virgin land and special parcel remains about the same with time. What changes over time is the size of the special parcel (some albedo change may also occur). The result of this natural process can be seen in the current atmospheric “fingerprint” over time (1970 to 2020): Increasing temperature, increasing specific humidity, decreasing relative humidity, decreasing cloud fraction, and increasing VPD (vapor pressure deficit). The atmospheric “fingerprint” shows the end results of this theory but does not show the beginning ET decrease in a local area. We can see the current ET of a UHI but we will never know what the ET was before the UHI was there. The “fingerprint” is evidence that the sum total of all earths local (Special Parcel) ETs has decreased over the 1970 to 2020 period of time. The work of Mazrooei et al. (2021) (1) may be the closest we can estimate how much the ET of the earth has changed.
Introduction
Evapotranspiration, ET, is defined as the total amount water flux evaporated into the atmosphere from surface and plant (dew) Evaporation and plant Transpiration. ET is a term used in agriculture water management to aid in crop growth and is usually measured by monitoring soil moisture change over time and plant types. The units of measure are height of liquid water evaporated/unit time/area, mm/yr/m^2, etc. Atmospheric measurement of ET is best done by a “eddy covariance tower” (5) which uses relative humidity and temperature at several point to calculate local ET. Land/satellite-based ET calculation is quite complicated, see (4) and (12)for examples. The exploration of ET as a correlation to climate change is just beginning (7), (9), (11). The CRGW theory is only applicable to the period 1970 to present and uses the total global ET from land and oceans. Global ET vs time data currently has very short history, but significant progress is being made, (10). The limited data suggest global ET increasing over time. The following assumptions show that ET is related to specific Humidity, SH:
ET (global) = global upward water flux = (global %water in surface air) X (global air flow rate up).
(Note the horizontal air flow rate is (important in other ET equations) not in this equation because the %water is global and yearly, thereby averaging out all the horizontal ET effect.)
On a daily basis the air flow rate up can vary a lot; but, on a monthly or annual basis the average air flow rate up is rather constant.
Likewise:
Change in ET = change in atmospheric water + change in precipitation.
There is currently no detectable change in global precipitation.
Therefore, ET is proportional to SH
Global change in ET mm/yr ≈ Global change is Specific Humidity, SH g/kg(da)
SH change is a good estimate of ET change as long as the precipitation remains constant. This is the change (% or fraction) in SH or ET not the actual value.
Figure 1 shows the year-to-year increase in specific humidity, SH, suggesting that global ET is also increasing over time.
Figure 1 Specific Humidity, SH vs time from Climate Explorer (6).
The CRGW theory assumes that the difference between current and virgin land ET/unit area remains constant as the size of the special parcel increases. It is recognized that the albedo of the special parcel may also change (usually decrease) with time. From Dubal et al (2021) (15) data in Blaisdell (16) (estimate the global correction for albedo to be about 15% of the total albedo change. An albedo correction could be added to the CRGW but not discussed in this paper.
The CRGW theory is reversable. A local decrease in in ET results in a global increase in ET and temperature. But, an increase in local ET will result in a global decrease in ET and temperature.
Estimation of local %ET decrease.
The CRGW theory for climate change begins with a local-land decrease (or increase) in %ET (=% change in SH, Specific Humidity). The initial ET (and SH) of the current UHI’s area cannot be measured (the virgin land’s ET has been changed by cities, forest to crop, or mining) but the present day UHI’s ET and SH can be measured and the ET (and SH) of rural area around the UHI can also be measured. The difference between the UHI’s and Rural ET would be a good estimate of what change in ET (and SH) has occurred over time. New science from NASA satellites and Mazrooei’s et al.’s (2021) (1) clever procedure can estimate the initial change in %ET. Mazrooei et al.’s (2021) procedure (1) with small pixel data from NASA satellites that covers an existing urban land scape and a surrounding buffer area using a multivariable algorithm calculates the difference in ET of the city and the ET of the rural area around the city, see concept in Figure 2. The marked up Figure 2 is from SMAP Hydroblocks (8) surface ground moisture data, SGM, satellite annual data. On a daily basis SGM is nonlinear to ET (at high or very low levels of SGM ET does not change) yearly data is more linear.
Figure 2. Copyed from (8) app. SMAP Hydroblocks. The surface ground moisture, brown indicating low surface moisture light green is higher surface moisture.
Figure 2 has concept circles. Mazrooei et al.’s (1) paper captures NASA satellite data on about 12 variables for each area for calculation of ET. The Mazrooei uses a boundary area around (not circles) each city’s irregular area – see Mazrooei et al. (1)Figure 1 for examples. Mazrooei et al.’s (2021) (5) defines the following calculation from the ET data :
ET(delta) = ET(urban) – ET(non-urban) Eq 1
ET(lamda) = ET(urban)/ET(non-urban) Eq 2
For the CRGW theory %ET (=%SH) change is need:
%ET = ET(delta)/ET(non-urban) Eq 3
Data from Mazrooei et al. paper looked at over 2300 cites. Mazrooei et al. (2021) objective was water management and UHIs not climate change. Thanks to Mazrooei et al.’s attachment of supporting data, the calculation of %ET change between city and rural could be done on over 1500 UHIs.
Mazrooei et al. (2021) paper’s Figure 2 summarized their data. Mazrooei’s Figure 2 (Figure 3 below) sorting their findings by Koppen Climate Classification, KCC, a system that tries to take into account the many variables of water getting into the atmosphere: latitude, altitude, vegetation, dryness, wetness, snow, etc. A wide range of urban and rural ET values in units of mm(of water)/mo(or)yr, low of about 1 to a high of 140 mm/mo(or)yr over many classes of land scape is shown in Mazrooei et al.’s Figure 2 (now Figure 3) highlighting the effect of the KCC land type on urban and rural ET.
Figure 3. ET diversity globally and by landscape type from Mazrooei et al’s. (1)Figure 2.
While very informative this data was not intended for climate change modeling. Mazrooei et al. (2021) attached (to their paper) data that was used to estimate the initial %ET change needed for the CRGW model. Table 1 shows the results in %ET change between Urban and non Urban using Eq 3. Table 1 mirrors the Mazrooei et al.’s (1) Figure 3 results for KCC classification. For CRGW modeling the summation of all the data is needed, that number came out to be -12% ET change for all the UHIs in the study. At the present time this -12% change is the best estimate of global %ET change (change of present day UHI’s – virgin land) we have for the invisible initial ET change. The large number of cities and variety of climates suggest that Mazrooei et al.’s study may be representative of all the UHI’s on earth for an estimate of the global %ET change of all UHIs. Note that this %ET change is on a 24 hr/day annual basis – previous CRGW model (in Blaisdell (2)) will be changed from a 12 hr/day annual basis. Also note this ET data is on a constant area of land for all cities and rural areas not weighted for the specific urban area. To get the %ET change contribution to global climate change each %ET in Mazrooei et al.’s paper needs to be multiplied by the area of it’s city (that data was not available). The CRGW model will use the -12% ET and total area of Special parcels.
Table 1. %ET change of UHIs calculated from Mazrooei et al data.
Reading Mazrooei et al.’s paper is highly recommended. Some interesting data from the paper are:
Not all UHI are the same, some have very high negative %ET change and some even have positive %ET. Mazrooei points out this is related to Arid nature of where the city is located:
Most big cities have Higher (negative) %ET than the global average: Miami Florida = -41%, New York New York = -36%, and Paris France = -26.
UHIs in Arid areas can put more water into the air than their surrounding rural area, Tucson Arizona = +11%.
Mazrooei et al.’s technique could also be used on other land changes (deforestation, crop change, mining, etc)
Mazrooei et al.’s (1) highlighted two cities that had opposite ET(delta) Tucson Az (positive ET(delta) and Greensboro NC (negative ET(delta). The results are shown in Mazrooei et al.’s (1)Figure 7 with conclusions drawn around water management. The climate change variable %ET change for this data is shown in Figure 4.
Figure 4. %ET change for two very different cities Tucson in a desert climate and Greensboro in a humid highly vegetative climate. Data from Mazrooei et al.’s (1) Figure 7.
Ten years of data in Figure 4 show little change in %ET. That is expected for an urban or non urban setting as long as nothing is done to change the water run off rate per unit of area or the vegetation (albedo in general). What does change is the total ET (water) that goes into the atmosphere as the urban area size increased over time. Figure 4 does highlight the excellent quality of Marzooei et al.’s data.
Significance in the CRGW model
The average of Mazrooei et al.’s (1) data of -12% in the CRGW theory along with the cloud cover/VPD ratio of -7.5 (from Blaisdell (13)) and average plume size of 2x (from Blaisdell (14)) suggest CRGW theory can account for a significant part of the 1970 to 2020 observed temperature increase and the atmospheric finger print (Blaisdell (2)) (details not shown).
Discussion
The work by Mazrooei et al is a significant contribution to the exploration of ET in climate change. The invisible decrease in ET of special parcels (UHIs) is now estimated. Mazrooei et al.’s work proves that the (invisible) starting step of the CRGW theory is real, significant, and negative. The Mazrooei – NASA procedure is recommended for measuring the deforestation and mining ET. The CRGW model comes close to matching the atmospheric fingerprint: a strong suggestion that CRGW is a significant contributor to climate change.
6. Climate Explorer web siteClimate Explorer: Select a monthly field (knmi.nl) go to “Cloud Cover” or any other data set, for CC click “EUMETSAT CM-SAF 0.25° cloud fraction” click “select field” at top of page on next page enter latitude (-90 to 90) and longitude (-180 to 180) for whole earth. Raw data link is above the graph.
The Times UK writes, two Just Stop Oil activists have been jailed for throwing tomato soup at Van Gogh’s Sunflowers and damaging its antique frame. Phoebe Plummer and Anna Holland, both 22, threw two tins of Kraft Heinz tomato soup at the painting at the National Gallery and then glued themselves to the wall in October 2022 in the group’s high-profile stunt.
Plummer was jailed for two years and Holland for 20 months. The maximum sentence for the offence is ten years’ imprisonment. The bail conditions stipulate that they must not carry glue, paint or any adhesive substance in a public place and must not visit any galleries or museums.
While the painting, which was completed in 1888 and is worth up to £72.5MM, was protected by a glass cover, prosecutors believe the soup, which is said to have acted as a “paint stripper”, may have caused £10,000 worth of damage to its 17th-century Italian frame.
The court was told that the pair had visited the museum a day before the incident to carry out reconnaissance and had bought the soup from supermarket.
In a statement read to the jury, Isabella Kocum, a frame conservator, said she was “shocked and dismayed by the extent of corrosion this tomato soup” caused to the “exquisite antique frame”.
She told the court, “The frame was specifically chosen for Van Gogh’s painting because of the matching colouration. I remain amazed at how corrosive the soup was to the frame. Even once the majority of the soup had been removed, I was alarmed to see that the remainder was acting like a paint stripper in front of my eyes.”
Prior to the sentencing, more than a hundred artists, curators and historians called for the activists to be spared jail because they had upheld a “centuries-old tradition of calling on our social conscience through art.”
Plummer, who studied at the University of Manchester and represented herself at the trial, told the court that she decided to use tomato soup “because it would stand out” and that it “symbolised the link between the climate crisis and the cost of living crisis”
Plummer and Holland said they were taking instructions from someone in Just Stop Oil but refused to identify the person. Plummer told the jury she loved the painting. In her closing speech, she claimed that she was ‘sounding an alarm bell” on climate change and invoked the example of the suffragettes and the civil rights movement in the US.
She said, “I don’t think that action like this fits the black and white letter of the law. Sometimes morality is different from the law, different from justice, different from legal directions. We caused some damage to the frame. The painting was returned to the gallery the same day.
Our Take: Note the self-comparison to the struggle for universal sufferage. That’s what they’ve been told—civilization’s means of lifting 3 billion people out of poverty in a matter of decades is an injustice to all of mankind. That they’ve no idea is telling.
The final word belongs to Vogi Schulz, who commented:
These crazy protesters blatantly ignore that “civilization’s means of lifting 3 billion people out of poverty in a matter of decades is an injustice to all of mankind.”
If you want to accelerate the energy transition, reduce your consumption of fossil fuels. You’ll quickly learn how hard that is. If you manage most of it, you’ll notice how your quality of life has deteriorated.
At the Nobel Prize ceremony on December 10, 2007, Al Gore predicted an ice-free Arctic by 2014. Since then there has been no trend in the minimum, mean or maximum extent. https://ift.tt/odzphLa
Iowa Climate Science Education 