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Sunday, June 26, 2022

Systematic warming pool discovered in the Pacific due to human activities

UNIVERSITY OF HAMBURG

Systematic warming in the Pacific due to human activities — IMAGE: THE IMAGE SHOWS THE INCREASE OF WATER TEMPERATURE OVER THE NORTHEAST PACFIC OCEAN FROM 1996 TO 2021 (PACFIC WARMING POOL). THE MEASURMENTS ARE SHOWN IN °C PER DECADE INCREASE. THE WHITE COUNTER REPRESENTS THE 2019-2021 MARINE HEATWAVE CO-LOCATED WITH THE “WARMING POOL”. view more
CREDIT: UHH/CLICCS/A. BARKHORDARIAN

In a study just released in the journal Nature Communications Earth and Environment, Dr. Armineh Barkhordarian confirms that this systematic warming pool is not the result of natural climatic variations – but of human influences instead. “This warming pool will continue to increase the water temperature in the future, increasing both the frequency and intensity of local marine heatwaves. "The sharp increase in average water temperature is pushing ecosystems to their limits,” explains Barkhordarian, an expert on atmospheric science and member of Universität Hamburg’s Cluster of Excellence “Climate, Climatic Change, and Society” (CLICCS).

Barkhordarian and her team show how the long-term warming pool has promoted local marine heatwaves in the past. One of these phenomena gained notoriety as the deadly “Pacific Ocean Blob,” which had devastating consequences between 2014 and 2015: marine productivity faltered, toxic algal blooms formed, and seabirds and marine mammals died in droves. In addition, the event led to severe droughts on the west coast of the USA.

The most recent marine heatwave continued for three years, from 2019 to 2021, producing water temperatures up to six degrees Celsius above average. Barkhordarian’s team have now proven that increased anthropogenic greenhouse-gas emissions were directly responsible for the extreme event. The probability of such a heatwave arising without human influences is less than one percent; there is a 99-percent probability that increased greenhouse-gas emissions were also required.

In addition, the study shows that the water temperature over the warming pool in the northeast Pacific increased by an average of 0.05 degrees Celsius per year over the past 25 years. Overall, the region cooled less in winter and the summer was 37 days longer on average. As a result, over the past 20 years there have been 31 marine heatwaves in this region alone, compared to just nine between 1982 and 1999.

“More frequent and extreme marine heatwaves are a serious burden for affected ecosystems. This not only poses a tremendous threat to biodiversity; it can also push these marine ecosystems past a tipping point, after which they can no longer recover,” says Barkhordarian. “The discovery of the long-term warming pool will now provide us with crucial information on the likelihood of such extreme events in the future.”

To what extent are human beings responsible? In what is referred to as attribution research, experts compare how the world developed with human influences, and how it would have done so without them. In the present study, the percentage of marine heatwaves resulting from additional anthropogenic greenhouse gases since 1982 was calculated. This allows statistically based conclusions on the future to be drawn.

Publication:

Barkhordarian A, Nielsen DM, Baehr J (2022): Recent marine heatwaves in the North Pacific warming pool can be attributed to rising atmospheric levels of greenhouse gases; Nature Communications Earth and Environment, DOI: 10.1038/s43247-022-00461-2

JOURNAL

Nature Communications

DOI

10.1038/s43247-022-00461-2

METHOD OF RESEARCH

Computational simulation/modeling

ARTICLE TITLE

Recent marine heatwaves in the North Pacific warming pool can be attributed to rising atmospheric levels of greenhouse gases

ARTICLE PUBLICATION DATE

21-Jun-2022

Damaged plants and fake perfumes can be identified rapidly and reliably in real time

Researchers develop a highly sensitive novel technique capable of detecting chiral molecules within complex gas mixtures

Peer-Reviewed Publication

JOHANNES GUTENBERG UNIVERSITAET MAINZ

optical chiral polarimeter — IMAGE: AT THE CORE OF THE NEW DEVICE IS AN OPTICAL CHIRAL POLARIMETER WITH WHICH IT IS POSSIBLE TO DETERMINE THE CHIRAL SIGNATURE OF COMPONENTS ACCURATELY AND PRECISELY EVEN IN THE GASEOUS PHASE. view more
CREDIT: PHOTO/©: LYKOURGOS BOUGAS, JGU

The chiral signature of a fragrance can reveal whether a perfume is genuine or fake. Similarly, the chiral signature of the emissions of a plant can provide information on whether the plant is healthy or sick. Researchers at Johannes Gutenberg University Mainz (JGU) and the Max Planck Institute for Chemistry (MPIC) have developed an innovative approach capable of identifying and monitoring such chiral signatures. Most natural chiral substances are found in two mirror-image forms present in different relative quantities. Therefore, every plant and every perfume must have its own individual chiral hallmark. Using their new approach, the research team has been able, for the first time, to identify chiral compounds within complex mixtures of gases with a high level of sensitivity and in real time.

"Our new technique has enormous potential, specifically in agriculture and the chemical industry," said Dr. Lykourgos Bougas of JGU. Professor Jonathan Williams of MPIC added: "In addition to commercial applications, this technique will also make it possible for us to decode chiral signals in the air around us, enabling us to better understand the chemistry of the atmosphere." The cooperating partners have already applied for a patent for their technique.

Naturally occurring odors differ from synthetic ones

Chirality is a fundamental property of nature. Our right and left hands are a manifestation of this. Most importantly, several biomolecules exist in two mirror-image forms that are non-superimposable – in the same way that a right hand will not fit in a left-handed glove. This can affect the bio-chemical activity of these molecules. A unique example is the emissions of plants. These contain several chiral compounds that are naturally present in both chiral forms, the D- and L-isomers or enantiomers. A prominent example is the chiral molecule pinene, which is responsible for the characteristic scent of conifers and pines. The relative ratios of the two enantiomers of pinene naturally vary in the emissions of such plants, but they critically depend on the state of health of the plant.

The same principle applies in the case of complex blends of natural and synthetic components, as in the case of perfumes. Any chiral ingredients will occur in both the D- and L-isomers but in differing relative quantities, depending on whether these originate from natural sources or from synthetic ones. As it is often the case that natural components are replaced by synthetic substances in fake or counterfeit perfumes, fake perfumes will have a chiral signature that differs from that of the originals.

Research under the aegis of the ULTRACHIRAL project funded by the European Union

The Mainz-based researchers have developed a cavity-enhanced polarimetric method for optical chiral analysis as part of the EU-sponsored ULTRACHIRAL project. They were able to detect the differing optical rotation effects of chiral molecules under polarized light. For this they transferred a sample of a plant or perfume scent to a small chamber which they exposed to polarized light. They then used a novel chirality-sensitive optical polarimeter to measure precisely and accurately the induced rotation of the polarized light. The researchers have been able to achieve a sensitivity that is better than that of the current state-of-the-art equipment by several orders of magnitude.

"Our new chiral-analysis approach provides us with precise results, faster and at better sensitivities than traditional techniques, without the need for any calibration before each measurement run. Additionally, our technique has been combined with gas chromatography for the first time to separate the individual components in a complex mixture. As a result, the chiral form of each constituent present in a complex blend of gases can be directly and accurately identified," explained JGU physicist Dr. Lykourgos Bougas, lead author of the paper that has recently been published in Science Advances. In their publication, the team of authors proposes a whole range of possible new applications for their detection method.

Among these is the quality control of perfumes, currently a particularly complex process as perfumes contain several hundreds or even thousands of different – natural and synthetic – compounds. To demonstrate the effectiveness of their technique, the researchers compared four authentic high-quality commercial perfumes with their low-cost counterfeits. The Mainz-based team was able to differentiate the high-quality original perfumes from their imitations on the basis of their chiral signatures with the help of a single rapid measurement.

CAPTION

Plant emissions contain several chiral compounds that significantly contribute to their characteristic aromas. The researchers were able to directly observe in real time how the chirality of emissions from a young conifer changed when the plant was damaged.

CREDIT

photo/©: Lykourgos Bougas, JGU

Potential use in crop cu

CAPTION

The resin secreted by a damaged conifer to protect the site of the damage has its own characteristic chiral signature within that of the overall emissions of the plant.

CREDIT

photo/©: Lykourgos Bougas, JGUltivation to monitor plant health and pest infestation

The technique might also be of considerable interest in the field of agriculture. Taking a young coniferous plant, the team was able to show that the chiral signature of the plant's emissions suddenly changed as soon as the plant was damaged. Similar chiral signatures have already been observed in plants subject to drought or disease. These signatures can be employed in practice, for example, to continuously monitor crop plants and trigger an alarm if these are infested by insects, suffer from a shortage of water, or become unhealthy.

The method may also assist in acquiring further insights into the physical and chemical processes that occur in our atmosphere. It is known that forests release vast quantities of volatile organic compounds (VOCs) into the environment, many of which are chiral. These molecules have an effect not only on the chemistry and physics of the air around us but also on our climate. VOCs can also be the precursor substances of secondary organic aerosols that influence the Earth's solar radiation budget. "We are still largely unaware of the role chirality plays in all these processes. In order to better understand this, we need new instruments and new approaches, such as that delivered by our research," concluded Bougas.

In order to enable the new method to be implemented in the various areas of application more easily, Dr. Lykourgos Bougas and Professor Jonathan Williams hope that a portable version of the device will be developed in future.

Related links:
https://www.mpic.de/2285/en – Max Planck Institute for Chemistry ;
https://cordis.europa.eu/project/id/737071 – ULTRACHIRAL project

Read more:
https://www.uni-mainz.de/presse/aktuell/13510_ENG_HTML.php – press release "Metabolite fumarate can reveal cell damage: New method to generate fumarate for MRI presented" (27 April 2021) ;
https://www.uni-mainz.de/presse/aktuell/13224_ENG_HTML.php – press release "Hyperpolarized proton magnetic resonance imaging used to observe metabolic processes in real time" (11 March 2021) ;
https://www.uni-mainz.de/presse/aktuell/13025_ENG_HTML.php – press release "Venus flytraps found to produce magnetic fields" (2 Feb. 2021) ;
https://www.uni-mainz.de/presse/aktuell/11825_ENG_HTML.php – press release "New NMR method enables monitoring of chemical reactions in metal containers" (15 July 2020) ;
https://www.uni-mainz.de/presse/aktuell/11370_ENG_HTML.php – press release "New simple method for measuring the state of lithium-ion batteries" (7 May 2020) ;
https://www.uni-mainz.de/presse/20145_ENG_HTML.php – press release "EU funding for excellent young researchers in physics" (23 Feb. 2016)