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Wednesday, September 09, 2026

The kissing bug that crossed the Atlantic

New study details the finding of the first known live kissing bug in Europe

University of Delaware

On an August morning last year, an American couple soon to embark on a European river cruise awoke in a luxury hotel in Lisbon.

Staring back at them from the headboard was a bloodsucking insect.

They’d later learn the culprit was an adult female kissing bug.

More than half of all kissing bugs travel with an accomplice — a parasite called Trypanosoma cruzi. The parasite causes Chagas disease which can lead to serious heart problems. T. cruzi is transmitted through the insect’s feces rather than its bite.

But how did this particular species of kissing bug, native to the southwestern U.S. and northwestern Mexico for its dry, desert-like climate, get to Portugal?

That question became the centerpiece of a scientific investigation led by UD assistant professor and medical entomologist Jennifer K. Peterson and her team of Blue Hen sleuths. Students in her Fall 2025 Medical Entomology (ENWC 410/610) class donned their detective hats and helped investigate what appears to be the first documented live kissing bug in Europe. Their findings were recently published in the journal Parasites and Vectors.

A bug’s life

“When they first contacted me, I was super skeptical,” Peterson said. “My first response was, ‘Is there a Lisbon, Delaware? Because they can’t be referring to Lisbon, Portugal.’”

Peterson and colleagues identified the insect as a species of kissing bug, Hospesneotomae protracta, native to the southwestern U.S. and northwestern Mexico.

The insect traveled a 5,000-mile transatlantic journey. Could it have stowed away aboard a cargo shipment? Did it hitchhike in somebody’s suitcase and take an international flight?

No one knows how it got to Portugal.

Medical entomologists in training

Rather than simply presenting the case to her students, Peterson turned it into a collaborative class research project.

She gave her class the basic facts and challenged students to investigate the insect’s biology, identify other hitchhiking cases and explore how the kissing bug might have reached Europe. She then combined the strongest elements of their work into one research paper.

“Writing, peer review and publishing are such a huge part of being a researcher,” Peterson said. “As university academics, it’s our bread and butter. I wanted students to experience that process from beginning to end.”

Increasing awareness

The Lisbon case illustrates how easily this insect (and others) can travel across the globe.

Peterson said when any insect that can transmit pathogens or parasites journeys outside of its usual range, there can be medical consequences. Especially if the insect is able to lay eggs and start an infestation. In the case of the adventurous kissing bug, it was not carrying the parasite that causes Chagas disease.

The next one might.

“This particular kissing bug was not infected with T. cruzi, but others could be,” Peterson said. “What we don’t want is to see kissing bug populations in places where they aren’t. Because once that takes off, they’re really tough to eliminate.”

She hopes customs officials, border patrol agents and others who monitor for agricultural pests will become more familiar with kissing bugs.

To speak with Peterson more about this extraordinary discovery, email mediarelations@udel.edu.

Journal

Parasites & Vectors

DOI

10.1186/s13071-026-07464-4

Method of Research

Experimental study

Subject of Research

Animals

Article Title

Live triatomine bug, vector of Trypanosoma cruzi , found engorged in Lisbon hotel room: A first for Portugal and for Europe

Taylor Swift becomes bugs

Newly discovered herbivorous insects named in tribute

University of California - Riverside

image:
*Swiftiephylus amator*
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Credit: Sarah Schroeder/UCR

She’s a Grammy Award-winning international superstar, and now, Taylor Swift is also a genus of plant-feeding insects from Australia that were previously unknown to science.

Sarah Schroeder, a UC Riverside doctoral student in entomology, hopes that by naming these insects after the singer, both the insects, specifically, as well as the concept of insect conservation more generally will shine with a little of her reflected light.

“It felt authentic to me as a lifelong Swiftie to honor Taylor in this way, as well as bring attention to the diversity of insects that has yet to be discovered,” Schroeder said.

A paper describing 12 new species of insects was published today in the journal Insect Systematics and Evolution. Of these, one genus has been named Swiftiephylus, and it contains four species whose names are inspired by the artist herself as well as several of her albums: Swiftiephylus taylorae, Swiftiephylus amator, Swiftiephylus intrepidus, and Swiftiephylus poetorum.

The names are Latin versions of Taylor, lover, fearless, and poets, respectively. The genus name combines “Swiftie,” the term for Swift’s fans, with Phylus, a name commonly used for this group of insects.

These new insects are not known to be pests to either humans or animals. They are part of a family called Miridae, the largest family of true bugs, with more than 11,000 described species worldwide. The family includes plant feeders and predators, as well as insects with highly specialized lifestyles.

The newly described species are closely associated with Australian she-oaks, trees and shrubs adapted to environments ranging from tropical forests to coastal dunes and extreme heat. Many plant bugs spend their entire lives on a particular host plant, from hatching through adulthood and egg laying. Though they feed off the trees, they aren’t known to cause them harm.

One of the reasons Schroeder dedicated the names of the new insects to Swift also has to do with their appearance. She believes their coloring helps them camouflage among she-oak flowers, which feature spindly red to orange structures. The paper notes that similar cream-and-red coloration has been observed in distantly related bugs living on the same plants, suggesting camouflage may have evolved independently multiple times.

“Taylor Swift’s iconic look is her blonde hair and red lips. These insects are pale yellow with accents of red throughout,” Schroeder said. “In the paper I refer to them as blonde.”

Though the insects are new to science, the specimens themselves have been waiting decades to be formally described.

They were among the plant bug specimens collected between 1995 and 2004 during a large biodiversity effort involving researchers from the American Museum of Natural History and Australian collaborators. The collecting effort yielded more than 50,000 specimens, many of which have required years of taxonomic work to sort, study, and describe.

A key member of that effort was Schroeder’s advisor and paper co-author, Christiane Weirauch, a UCR entomology professor who participated in the project as a postdoctoral researcher before coming to Riverside. Years later, knowing that there were still many undescribed insects from those Australian collection efforts, Weirauch suggested Schroeder investigate them as part of her dissertation.

Schroeder and Weirauch ultimately examined 593 specimens borrowed from the American Museum of Natural History and Australian Museum. The insects fall into distinct evolutionary groups despite sharing host plants and similar coloration.

For Schroeder, their long journey from Australian she-oaks to museum drawers and finally into the scientific record illustrates why the science of identifying and naming organisms, called taxonomy, remains essential.

Despite centuries of biological exploration, there may be as many as 30 million insects that remain undocumented.

Schroeder studies the evolution of this particular subfamily of plant bugs using both traditional taxonomy and genomic data. By reconstructing their evolutionary relationships, she hopes to better understand how the insects spread around the world, developed specialized relationships with plants, and diversified over time. Ultimately, she wants to connect that knowledge to conservation.

Naming the insects for an artist whose music has accompanied Schroeder from childhood through graduate school offered an opportunity to connect that scientific mission with something deeply personal.

Though it has been done for centuries, there is some controversy in entomological circles around naming parts of the natural world for humans. However, Schroeder felt strongly that the practice of doing so can be used in a positive way.

“Taxonomy is the cornerstone of conservation,” Schroeder said. “If we don’t describe species, we don’t know they exist and can’t conserve them. Honoring Taylor through naming these species after her is a way to honor conservation science and bring attention to all the unknown diversity.”

Journal

Insect Systematics & Evolution

DOI

10.1163/1876312x-bja10090

Article Title

New genera and species of Australian sheoak-associated plant bugs (Hemiptera: Miridae: Phylinae: Pilophorini and Semiini)

Article Publication Date

9-Sep-2026

Denisovan radius discovered for first time in Southwest China

Chinese Academy of Sciences Headquarters

image:
The geographical location of the Bianfu Cave and the morphology of the two human teeth and three newly discovered Denisovan bones.
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Credit: Image by IVPP

Scientists recently discovered various Denisovan remains in Southwest China dating back to the late Middle Pleistocene, including the first Denisovan radius—one of two long bones in the forearm.

Denisovans are a genetically identified archaic hominin group believed to have been widely distributed across Asia. However, due to the limited number of fossil remains, especially postcranial bones—those below the skull—a distribution gap has long existed in Southwest China. Therefore, little is known about the physical traits that allowed Denisovans to adapt to different environments.

In a new study, researchers employed a novel proteomic strategy to identify additional hominin bones from a Paleolithic site called Bianfu Cave in Southwest China’s Yunnan Province. Paleoproteomic analysis confirmed five hominin remains as Denisovans, helping fill the distribution gap of Denisovans in Southwest China.

According to the researchers, the discovery of the first Denisovan radius provides crucial insights into Denisovan postcranial phenotype.

The study, published in Nature on September 9, was conducted by a research team led by Professor FU Qiaomei from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences (CAS), in collaboration with multiple institutions.

New Strategy

ZooMS (Zooarchaeology by Mass Spectrometry) has recently become an important tool for large-scale screening of hominin fossils due to its advantages of micro-invasive sampling, methodological simplicity, rapid identification, and low cost. However, the recovery rate of hominin fossils has been extremely low—only 0.1% at sites such as Denisova Cave and Baishiya Karst Cave. Given that Bianfu Cave yielded more than 60,000 bone fragments, conducting ZooMS analysis on all specimens would be both costly and inefficient.

To overcome this challenge, the researchers developed a novel “morphological pre-screening + ZooMS identification” strategy. This combined approach significantly improved screening efficiency and provided a replicable methodological framework for discovering hominin remains at similar Paleolithic sites with abundant bone fragments.

Through morphological pre-screening, the researchers selected 22 potential hominin remains from the large assemblage of bone fragments. Subsequent ZooMS analysis confirmed that two parietal bone fragments (BFD767 and BFD769) and one proximal radial fragment (BFD771) were derived from hominins.

Among the three newly identified hominin specimens, BFD767 and BFD771 originated from Layer 7, which also contained four hominin teeth. This layer was dated to approximately 148,000–134,000 years ago. BFD769 came from the older Layer 9, dated to approximately 167,000–150,000 years ago.

In addition to the three hominin bones, the research team also analyzed two hominin teeth excavated from Layer 7, including a lower fourth premolar (YHB3518) and a lower second molar (YHB3075).

To obtain comprehensive proteomic profiles of the five specimens, the team extracted and analyzed proteins from multiple fractions of different tissues, including bone, dentine, and enamel. Six to 16 endogenous proteins were identified from each specimen, covering 1,972 to 4,076 amino acid residues. Notably, abundant specific peptides from the amelogenin Y isoform were identified in the enamel of the two teeth, indicating that both teeth belonged to male individuals.

Population Assignment

To determine the population assignment of these hominin specimens, the research team systematically screened for single amino acid polymorphisms (SAPs) within the endogenous proteomes.

They found that all five samples carried the Denisovan-specific variant COL1A2 R996K, indicating their Denisovan identity. Three additional informative SAPs were identified in the enamel of two Bianfu Cave teeth: the Denisovan-related variant AMBN M273V; AMELY 179L, a variant shared by modern humans, Neanderthals, and Denisovans; and AMBN 253A, a variant that distinguishes the Bianfu Cave individuals from Middle Pleistocene Homo erectus in East Asia.

Using the consensus sequences of endogenous proteins from each sample, the researchers constructed Bayesian phylogenetic trees with topologies highly consistent with those obtained from nuclear genome studies. The trees placed modern humans as the sister group to the Neanderthal-Denisovan clade. Each Bianfu Cave sample formed a monophyletic clade with Denisova 3, with a posterior probability of 100 percent. This result aligns with the SAP assignments, supporting the reliable attribution of these specimens as Denisovans.

Morphological Phenotype

Comprehensive morphological analysis was conducted on the two Denisovan parietal bones (BFD767 and BFD769) and one partial radius (BFD771). The cranial vault thickness pattern of Bianfu Cave hominins is most similar to that of H. heidelbergensis and East Asian late Middle Pleistocene archaic Homo.

Notably, BFD771 is the only confirmed Denisovan radius to date. Although it has large proximal dimensions and a likely medially oriented radial tuberosity, similar to Neanderthal radii, its overall external shape and mid-neck cross-sectional geometry align more closely with modern humans. According to the researchers, the first identified Denisovan radius fragment is of exceptional importance. Its mosaic features indicate unique biomechanical demands and behavioral adaptations in Denisovans, differing from those inferred for Neanderthals and modern humans.

Based on their results, Bianfu Cave has the richest Denisovan fossil record currently known outside Denisova Cave. The study fills a critical geographical gap in the known distribution of Denisovans. The Denisovan remains were derived from two different stratigraphic layers dating to Marine Isotope Stage 6. During this glacial period, the relatively warmer climate and abundant food resources may have enabled the Yunnan-Guizhou Plateau to serve as a favorable habitat for hominins and supported the long-term survival of the Bianfu Cave population.

Journal

Nature

DOI

10.1038/s41586-026-10976-9

Article Title

Ancient proteins identify various Denisovan remains from Southwest China

Article Publication Date

9-Sep-2026

As El Niño looms, study finds rapid growth in climate extremes are hitting an unexpected region of the Amazon hardest

Lancaster University

The central north Amazon, with extensive areas of high forest cover, natural savannas and vast and important indigenous territories, was not previously considered as being the most affected by climate change.

However, this region, which is considered critical to Amazonia’s cultural and biodiversity wealth has unexpectedly found itself at the forefront of rapid growth in climate extremes, a new study reveals.

Findings, published today in Communications Earth & Environment, identify Amazonia as experiencing rapid growth in extreme temperatures and water stress – with 10% of the basin, an area larger than 700,000 square kilometres (bigger than Afghanistan), witnessing increases in extreme temperatures during the dry season of at least 0.75°C a decade and more than 3.22°C since 1981.

The findings reveal that climate extremes in the Amazon have been getting increasingly worse over the last 43 years. These changes do not show up in assessments of average Amazon temperatures, which are rising at 0.21°C a decade and are in line with the global average warming.

With the El Niño of 2026 expected to be the largest in living memory, the Amazon might suffer with extremely high temperatures and droughts just two years after the last big drought in 2024. Scientists fear that if these rapid increases in extreme climate events continues, it could risk pushing the Amazon past critical thresholds.

The discoveries are among the findings of a study led by researchers at Lancaster University, in partnership with WWF UK and an international team of more than 50 scientists, which sheds new light on climate extremes within the Amazon. Their paper provides an up-to-date comprehensive assessment of Amazonia’s changing climate across more than four decades and at a high-resolution for the whole biome.

Climate extremes are responsible for some of the most harmful climate-linked impacts on nature and people, driving increased mortality, losses of forest species and damage to ecosystems. In the Amazon, recent exceptionally hot or dry periods have led to extensive forest fires, large-scale animal and tree deaths as well as impacts to human health from heat and air pollution.

By dividing the Amazon into 11km cells and using high resolution temperature and rainfall data from sources that combine information from satellites and local weather stations, the research team was able to identify dry seasons for each individual area of the Amazon.

Using this, as well as a new measure of water deficit that accounts for the effects of temperature on water loss, the researchers modelled temperature changes and water stress across the entire Amazon from 1981 to 2023. Temperature and water deficit were recorded as the averages from across the dry season or the whole hydrological year (dry and wet seasons combined).

The rate of climate change was assessed in two different ways. First, the authors used the ‘central tendency’, the most commonly used measure to date which emphasises average rates of temperature and water deficit change across all years. Second, the authors then used ‘extreme tendency’, which emphasises the most exceptional years. This therefore provides a more accurate indication of the changes in the exceptional hottest or driest time periods.

“We are most interested in things when they are at their hottest and driest as that is when the most harm can be caused by high temperatures,” said Professor Jos Barlow of Lancaster University and lead author of the report. “While this has been assessed in the Southern Amazon, which shares a largely similar dry season, it has never been assessed across the whole of the Amazon – which includes regions north of the equator which have a different dry season period.”

The Southern Amazon, which has experienced significant deforestation and land-use change, is confirmed as the fastest warming region when looking at average temperature changes.

However, the central north Amazon is identified as experiencing the most rapid growth in climate extremes.

“The rates of change in climate extremes are much higher than the rates of change of average climate in the Amazon, and the most affected regions are also different for extremes and average climate,” said Dr Nathália Carvalho, post-doctoral research associate at Lancaster Environment Centre. “This is important because we show that Amazonia’s climate is not changing uniformly. This information will be crucial when planning and implementing climate change adaptation strategies.”

Professor Barlow said: “Extreme climate is a primary concern, contributing to forest fires, exceptional river levels, air pollution and high temperatures that can harm people as well as animals and the forest trees. The rates of change that we are seeing in the most affected regions are very alarming.

“Given the area that is experiencing the fastest growing in extreme temperature is far from the arc of deforestation, these rapid rises cannot be explained by local changes such as deforestation and land-use changes. It’s showing how the Amazon is being affected by global climate change. It’s the world’s emissions that are responsible.”

There is evidence from recent studies that climate extremes are impacting the region including the first observed mass death of mammals in the Amazon, where sloths and other mammals were found on the forest floor or hanging dead from understorey trees, reductions in the size of bird populations, and changes to bird lifespans, appearance and behaviour. The region has also experienced extensive forest fires, extreme heat and drought, contributing to megafires which have led to air pollution in the Amazon city of Manaus, and drying rivers have affected the health of people living in the forests.

Dr Joice Ferreira, at the Brazilian Agricultural Research Corporation (Embrapa) highlights the social concerns. “Extreme climate events are impacting local livelihoods in many ways, affecting key products like açaí. This removes the safety net that forests provide, threatening food security and weakening their role in a growing socio-bioeconomy. Most concerning, it could derail public policies currently being designed and implemented by Brazilian and state governments to drive positive transformation in the region, such as forest restoration plans. This scenario demands global action to halt climate change in the name of climate justice.”

Professor Barlow added: “Adaptation measures are urgently required to address the impacts of these rapidly changing climate extremes, including preventing factors that amplify climate risks such as deforestation. We also need to bring in measures to support the fighting of forest fires as well as supporting local people when the rivers they rely on for navigation dry up, especially in a year like 2026 with the arrival of a super El Niño.”

Mike Barrett, chief scientific adviser at WWF-UK, said: “The rapidly increasing climate extremes revealed in this study highlight the urgent need for global action on climate change. However, the new regions of risk also demonstrate the need to support other measures, including an end to deforestation and support for measures such as the Tropical Forest Forever Facility if we are to avoid critical tipping points and environmental collapse."

The study, ‘Rapid increase of climate extremes reveals new areas of concern in Amazonia’, has been published by Communications Earth & Environment. The maps with the rates of change in temperature, vapour pressure deficit and precipitation can be assessed interactively at this platform.

Journal

Communications Earth & Environment

DOI

10.1038/s43247-026-03975-1

Method of Research

Data/statistical analysis

Subject of Research

Not applicable

Article Title

Rapid increase of climate extremes reveals new areas of concern in Amazonia

Article Publication Date

9-Sep-2026

Saturday, September 05, 2026

Satellites spot forest stress two years before bark beetle die-offs become apparent

A faint signal emitted during photosynthesis may reveal physiological stress well before tree mortality appears in aerial surveys, potentially giving forest managers more time to prepare before mortality becomes widespread

University of Utah

Categorizing pixels of forests from satellite observations — image:
Pixels of forested lands that were categorized as a) control (low tree mortality by wildfire and bark beetles from 2011 through 2023), b) wildfire (fire-driven mortality in 2020 and 2021) and c) bark beetle (insect-driven mortality for 2021 and 2022).
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Credit: Kunik et. al. Rem Sen Enviro (2026)

Satellite measurements detected declining photosynthetic activity in Western U.S. forests two years before bark-beetle mortality appeared in aerial detection surveys, according to new University of Utah-led research.

The first-of-its-kind study suggests that satellite-observed chlorophyll fluorescence (SIF), a measure of plant photosynthesis, could provide an early warning of forest stress. As drought, wildfire and insect outbreaks occur with increasing frequency across the American West, the technology could also help scientists understand how these disturbances affect forests’ ability to absorb and store carbon from the atmosphere.

“I don't know of any other tool that can detect this type of signal before tree mortality becomes obvious at a scale large enough to assess the health of entire forests,” said lead author Lewis Kunik, who recently completed his doctorate at the U. Kunik’s doctorate was jointly advised by study co-authors and U professors John Lin in the Department of Atmospheric Sciences and David Bowling in the School of Biological Sciences.

“The ultimate goal isn't to predict the exact tree that will die. Rather, the technology could identify areas of concern early enough for land managers to investigate, mobilize crews, allocate funding or otherwise prepare before mortality becomes widespread.”

The study is online ahead of its publication in the October issue of Remote Sensing of Environment.

Fluorescence provides an early warning signal

Many satellites monitor forest health using signals such as greenness and canopy structure because some when some trees become stressed, they might wilt or drop their leaves. But pines, spruces, firs and other evergreen trees present challenges for satellite monitoring: they can keep their needles even while photosynthetically dormant, such as during winter or under other high-stress conditions. This matters for Western U.S. forests, which are largely dominated by evergreens.

Fortunately, several next-generation satellites carry specialized instruments which detect a faint red glow that plants emit during photosynthesis, the process by which plants convert sunlight into energy. This signal is known as solar-induced fluorescence (SIF)—when a leaf’s chlorophyll molecules absorb radiation, some radiation re-emits at longer, red wavelengths known as fluorescence.

When plants get stressed, they absorb more light than they can use, reducing their efficiency and dimming their red glow. By tracking SIF relative to the amount of light absorbed over time, the researchers could identify subtle physiological changes in in evergreen trees that conventional satellite metrics can miss.

The authors used SIF observations from TROPOMI, the instrument on the European Sentinel-5P satellite, to compare changes in fluorescence patterns in forests affected by wildfire- and insect-caused tree mortality with non-affected control areas with similar biogeographic characteristics in forests across the American West.

In forests that would later experience bark-beetle mortality, the researchers detected a significant SIF decline roughly two years before mortality was seen in aerial surveys conducted by the USDA Forest Service. Drought stress alone couldn’t explain the signal. While nearby healthy forests experienced similar levels of drought, the decline in SIF from healthy forests was 10-20% less severe than the decline in the bark beetle-infested forests.

SIF can change for many reasons, including drought, insect infestation, canopy dieback, changes to seasonal timing of growth, reduced sunlight and changes in the mix of plants growing from the forest floor to the top of the canopy. The researchers accounted for these factors, but the complexity of forest ecosystems makes year-to-year changes in SIF difficult to interpret.

In this case, however, their analysis revealed a clear pattern. The findings suggest that SIF signal could provide an early warning of forest stress that precedes widespread tree mortality.

The researchers validated their approach using wildfire mortality as a testbed for detecting SIF changes from a wide range of mortality severities. They saw declines in SIF that scaled proportionally with the amount of vegetation lost due to fire.

“Wildfire mortality has more predictable impacts to forest productivity than bark beetle mortality. There is also a lot more wildfire-affected land to study, and we can use established tools to estimate the severity of those events. Testing our method on wildfires really helped build confidence in our bark beetle assessment,” Kunik said.

The researchers were also able to use SIF to monitor how the ecosystem recovered from wildfire, highlighting the technology’s potential for tracking how disturbances alter forest productivity and carbon cycling over time. Because forests store massive amounts of carbon, tracking these changes will help scientists better understand how disturbances affect the carbon balance of western forests.

“SIF is an emerging tool that Earth scientists can use to show the fingerprint of plant CO2 uptake at regional or global scales,” said Kunik. “Drought, wildfire and bark beetle outbreaks can weaken a forests’ ability to absorb carbon and may release the carbon stored in the trees. Tracking these changes will help us understand whether these disturbances potentially turn forests from carbon absorbers to carbon sources.”

SIF outperformed the other satellite metrics

While other SIF-observing satellites exist, the authors used data collected by TROPOMI due to its coverage and sampling frequency.

The study tested the sensitivity of SIF measurements against several forest-health and vegetation-productivity remote-sensing measures. These included other frequently used satellite signals like land surface temperature, as well as vegetation indices like the Normalized Difference Vegetation Index (NDVI).

SIF showed greater sensitivity to bark beetle mortality than the other canopy remote sensing products tested. It also showed significant stress-related declines earlier than the other products, and roughly two years before aerial surveys first detected mortality.

“The results are exciting because they show the potential of SIF to provide information on forest health over a large spatial region,” said Lin. “Future satellites, such as the European Space Agency’s FLEX mission, will provide SIF at much higher spatial resolution and add to the growing record of SIF that will reveal more patterns in the future.”

The authors are excited for SIF’s potential. The project began through conversations with USDA Forest Service collaborators who have long wanted an early warning system to help them manage forests.

“They want to know as soon as possible when forests may cross a threshold of stress that leave it vulnerable to pests, pathogens or other drought-related impacts,” said Kunik. “We still can’t predict if, or where, mortality will occur just based on SIF observations, but our work shows that SIF could be another powerful tool for identifying areas of concern.”

******

Other co-authors of the study include Brett Raczka, University of Utah and National Center for Atmospheric Research; Jeffrey Hicke, University of Idaho; Christian Frankenberg, California Institute of Technology; Rui Cheng, Claremont McKenna College; and Michèle Slaton, Inyo National Forest, USDA Forest Service.

This research was funded by the NASA Carbon Monitoring Systems program (Award (80NSSC20K0010), the National Science Foundation Graduate Research Fellowship Program (award #2139322) Wilkes Center for Climate Science & Policy at the University of Utah and by the USDA Forest Service Western Wildland Environmental Threat Assessment Center (Agreement #22-JV-11261994–036-M2).

The publication:

Kunik, Lewis et al. (2026). Characterizing effects of tree mortality from wildfire and bark beetles using satellite observations of solar-induced chlorophyll fluorescence. Remote Sensing of Environment, 334(October special issue), 10.1016/j.rse.2026.115550.

Multimedia access

https://www.youtube.com/watch?v=bAhXV6ntsZg

Visualization tracking the Earth’s carbon cycle from 2015 to 2026 using observations from NASA’s Orbiting Carbon Observatory missions. The animation shows the relationship between atmospheric carbon dioxide levels (blue regions contain less CO2 than the baseline, red regions contain more) and photosynthetic activity of terrestrial vegetation. The left map shows atmospheric carbon dioxide; The right map shows solar induced chlorophyll fluorescence (SIF) levels.

Credit: Christian Frankenberg/Caltech

A) the average insect-induced mortality from 2022-2023 USDA aerial surveys and C) 2021 late-summer mean solar induced fluorescence relative to 2019 levels, a low insect-mortality year. Redder hues represent lower levels SIF, a sign of lower photosynthetic activity.

Credit

Adapted from Kunik et. al. Rem Sen Enviro (2026)

Journal

Remote Sensing of Environment

DOI

10.1016/j.rse.2026.115550

Method of Research

Observational study

Subject of Research

Not applicable

Article Title

Characterizing effects of tree mortality from wildfire and bark beetles using satellite observations of solar-induced chlorophyll fluorescence

Article Publication Date

1-Oct-2026

New study demonstrates TanSat-2's potential to distinguish human carbon emissions from ecosystem carbon sinks

Institute of Atmospheric Physics, Chinese Academy of Sciences

As the world works toward a clearer picture of where carbon is emitted and absorbed, satellites are becoming increasingly important tools for tracking the global carbon cycle. China is preparing to launch its next-generation carbon monitoring satellite, TanSat-2, which is designed to provide global and regional observations of column-averaged carbon dioxide (CO2) and methane (CH4).

One of the major challenges in satellite-based carbon monitoring is distinguishing CO2 released by human activities from the carbon exchanged between the atmosphere and terrestrial ecosystems. Atmospheric CO2 observations contain signals from both processes, making it difficult to determine how much of the observed CO2 originates from fossil fuel emissions and how much is associated with ecosystem carbon uptake and release.

A recent collaborative study by Chinese and UK researchers published in Advances in Atmospheric Sciences explores how TanSat-2 could help address this challenge.

This study introduces a newly developed carbon flux inversion approach that combines atmospheric CO2 measurements with solar-induced chlorophyll fluorescence (SIF), an observational proxy closely related to vegetation photosynthetic activity. By bringing these two complementary measurements together, the approach can simultaneously constrain net primary productivity (NPP) and fossil fuel combustion emissions (FF).

To further improve the separation of natural ecosystem carbon fluxes and fossil fuel emissions, the researchers applied empirical orthogonal function (EOF) analysis to prior NPP and FF inventories. This identifies their dominant spatial and temporal patterns while reducing the number of variables that need to be optimized in the inversion.

The researchers then put the proposed TanSat-2 observing strategy through a virtual test using Observing System Simulation Experiments (OSSEs). Under idealized conditions in which observational biases are effectively controlled, the results show that TanSat-2 CO₂ and SIF observations could lead to an NPP error reduction of up to 95% over Siberia and the Amazon, and to error reductions of about 80% for FF emissions in regions including Siberia, northern Asia, the United States, and South Africa.

The study, however, also highlights an important challenge. Even small systematic biases in satellite-derived column-averaged dry-air mole fractions of CO2 (XCO2) can substantially distort inferred CO2 sources and sinks—or even lead to their misattribution. Such biases could ultimately compromise the reliability of carbon flux estimates, underscoring the importance of carefully identifying and correcting systematic errors in satellite retrievals and subsequent data applications.

The researchers also investigated whether increasing TanSat-2’s cross-track swath width could strengthen its carbon-monitoring capability. Their results indicate that a wider observational swath can improve the robustness of CO2 flux estimates. The study further develops an error-matrix analysis framework that could help evaluate observing strategies and support the design and optimization of future carbon-monitoring satellite missions.

“Reliable monitoring of carbon fluxes at both global and regional scales cannot rely on satellites alone.” The lead author, Dr. YANG Dongxu from the Institute of Atmospheric Physics at the Chinese Academy of Sciences concluded their study and emphasized, “Instead, it requires the integration of satellite, ground-based, airborne, and in situ observations. Together, these complementary observing systems will be essential for building a more accurate and comprehensive picture of Earth’s carbon sources and sinks.”

DOI

10.1007/s00376-026-6150-1

Article Title

A step forward to global segment CO2 flux estimation benefiting from large swath of coordinated CO2 and SIF measurement from TanSat‑2 mission

Article Publication Date

2-Sep-2026