The measurement campaign, known as EXPORT — short for EXperiments with the Portable Observatory for aeRosol Transport — was led by Andebo Waza, Konrad Kandler, Franz Kanngießer, Stephanie Fiedler, and colleagues from institutions including the GEOMAR Helmholtz Center for Ocean Research Kiel and Technische Universität Darmstadt. Expedition M207 departed Belém, Brazil, on January 3, 2025, and concluded in Mindelo, Cabo Verde, on February 11, 2025, tracing a northbound course directly through the dust corridor. Expedition M208 then began and ended in Mindelo, running from February 15 to March 17, 2025, keeping the ship and its instruments close to the African continent where dust outbreaks are most intense. Together, the two cruises captured continuous aerosol and meteorological observations across three distinct, multi-day Saharan dust events: the first over the tropical mid-Atlantic, and the latter two nearer the African coast.

What makes the EXPORT dataset unusual is its combination of ground-based in-situ sampling and remote sensing of lofted dust layers, all from a moving platform in a region where such measurements are rare. At the heart of the in-situ package was an optical particle counter, or OPC, which measured particulate matter concentrations and particle size distributions for diameters up to roughly 35 micrometers — a size range that includes the coarse dust grains responsible for much of the atmospheric dust mass burden. Complementing the optical counts, the team deployed a flat plate sampler to collect deposited particles, which were then analyzed using scanning electron microscopy coupled with energy-dispersive X-ray analysis, or SEM-EDX. This technique allowed the researchers to determine particle size, morphology, and elemental composition, from which they derived deposition rates — a key quantity for estimating how much dust, and the nutrients it carries, actually reaches the ocean surface.

Above the ship, a battery of remote sensing instruments probed the vertical structure of the atmosphere. CALITOO and MICROTOPS sun photometers measured aerosol optical depth at several wavelengths, providing a column-integrated measure of how much sunlight the dust attenuated. A Vaisala CL61 ceilometer recorded fine-scale layering of aerosol plumes, including depolarization measurements that help distinguish irregularly shaped mineral dust particles from spherical marine aerosols such as sea spray. A wind lidar profiled wind speeds aloft, an optical disdrometer characterized precipitation, and a broadband radiation sensor tracked the radiative effects of the dust. Nearly 90 radiosonde launches — balloon-borne instrument packages that profile temperature, humidity, and winds — stitched these observations into a three-dimensional picture of the dust-laden atmosphere.

The scientific stakes are considerable. Saharan dust influences climate in multiple, competing ways: it scatters and absorbs solar radiation, alters cloud formation by serving as ice-nucleating particles, and fertilizes ocean ecosystems with iron and other micronutrients. Yet climate and weather models still struggle to represent dust transport accurately, in part because ground-truth observations over the remote tropical Atlantic are so sparse. Most long-term dust records come from land-based stations in Africa or from satellite retrievals, which infer column properties but cannot resolve the vertical distribution, particle microphysics, or surface deposition directly. Ship-based campaigns like EXPORT fill precisely this gap, offering calibration points for satellites and validation data for reanalysis products and forecast models.

Indeed, the EXPORT team documented their measurements with a first comparison against reanalysis datasets and the METEOR’s own meteorological sensors, an early sanity check that will help future users judge how well existing models capture the observed dust events. The three dust outbreaks sampled during the cruises serve as illustrative case studies: one plume encountered far from any landmass in the tropical mid-Atlantic, and two others observed closer to West Africa, where fresh outbreaks loft dense dust into the Saharan Air Layer — the hot, dry, elevated air current that carries dust across the basin. Comparing in-situ size distributions and concentrations against model output during these events can reveal where models overestimate or underestimate coarse-particle transport, a persistent problem because large dust grains settle out faster than many models assume.

The winter timing of the campaign is itself scientifically meaningful. Between December and March, the Saharan dust belt shifts southward, and dust transport toward the Amazon becomes most pronounced. This seasonal dust delivery is thought to supply phosphorus and other nutrients that sustain the rainforest’s productivity, compensating for losses from leaching and runoff. Capturing this season with direct measurements — rather than extrapolating from other times of year — matters for quantifying the ocean and land fertilization budgets, for understanding how dust radiative forcing modulates the tropical Atlantic energy balance, and for constraining how dust may respond to changing land use and climate in North Africa.

All of the EXPORT datasets are now publicly available through the PANGAEA data repository, spanning optical particle counter measurements, flat plate sampler collections, sun photometer retrievals, Maritime Aerosol Network observations, radiation and ceilometer profiles, radiosonde soundings, wind lidar data, and disdrometer records for both cruises. The ship’s own meteorological data are archived separately through the dship.o2a-data.de portal operated by Universität Hamburg. This open release means that atmospheric modelers, satellite validation teams, and aerosol researchers worldwide can immediately begin mining the data — comparing it against dust reanalyses, testing transport schemes, or refining retrieval algorithms for spaceborne lidars and imagers.

For a field that has long relied on sparse island stations and satellite proxies, a two-month, instrument-dense transect through the heart of the winter dust corridor is a rare and valuable resource. As the preprint moves through peer review at Earth System Science Data, the EXPORT measurements stand ready to sharpen estimates of how much African dust crosses the Atlantic, at what heights, in what particle sizes, and with what consequences for climate, clouds, and ecosystems on both sides of the ocean.

Subject of Research: Trans-Atlantic transport of Saharan mineral dust measured from a research vessel during two 2025 expeditions

Article Title: Trans-Atlantic aerosol transport from January to March 2025 – measurements from two expeditions on a research vessel

Article References: Trans-Atlantic aerosol transport from January to March 2025 – measurements from two expeditions on a research vessel. (n.d.). https://doi.org/10.5194/essd-2026-733

Image Credits: AI Generated

DOI: 10.5194/essd-2026-733

Keywords: Saharan dust, mineral dust, aerosol transport, tropical Atlantic, R/V METEOR, research expedition, aerosol optical depth, ceilometer, radiosondes, SEM-EDX, dust deposition, Earth System Science Data

The research team, led by Bahar Sürmelihindi of Gaziantep University and colleagues from several Turkish institutions, focused on two very different plants with two very different relationships to the human diet. The first was Hypericum perforatum, commonly known as St. John’s wort, a medicinal herb widely harvested across Anatolia and consumed in teas and herbal preparations. The second was Capsicum annuum, the pepper, a staple vegetable crop grown intensively in the region. By comparing metal concentrations in both species and in the soils beneath them across earthquake-affected Hatay, Kahramanmaraş, Malatya, Adıyaman, and Gaziantep with control samples from Aydın and Manisa, the researchers could isolate the signature of seismic disturbance from the background of ordinary agricultural and industrial contamination.

The analytical backbone of the study was inductively coupled plasma mass spectrometry, or ICP-MS, a technique capable of detecting trace elements at concentrations down to parts per billion. Soil and plant samples were digested and introduced into a plasma torch heated to roughly 10,000 Kelvin, where individual atoms were ionized and sorted by their mass-to-charge ratio. This allowed the team to quantify a broad suite of elements, from essential macronutrients such as calcium, magnesium, and potassium to the notorious toxic quartet of cadmium, chromium, lead, and mercury, along with nickel, which emerged as one of the most striking signals in the dataset.

The results were unambiguous. Concentrations of multiple heavy metals were significantly higher in both soils and plant tissues from the earthquake-affected provinces than in the control sites. Nickel, an element that is toxic to humans at elevated doses and a known carcinogen through inhalation, ranged from 16 to 24 milligrams per kilogram in pepper fruits and reached concentrations as high as 48 milligrams per kilogram in St. John’s wort samples. Translocation factors, which describe the ratio of metal concentration in plant tissues to that in the surrounding soil, indicated a moderate transfer of metals from soil into edible plant parts. In plain terms, the earthquake-affected landscape was not merely contaminated; the contamination was finding its way into the plants that people harvest, eat, and brew.

One of the most intriguing signals came not from the toxic metals but from the benign ones. Elevated levels of calcium, magnesium, and potassium in the leaves of St. John’s wort pointed to an additional and somewhat unexpected source of input: post-earthquake dust deposition and demolition-derived particulates. When thousands of buildings collapse, they release enormous quantities of pulverized concrete, masonry, plaster, and mineral dust that settle on soil surfaces and plant foliage. That dust carries its own elemental fingerprint, rich in the calcium silicates and carbonates of construction materials, and the researchers argue that this deposition contributed measurably to the mineral load observed in plant leaves. It is a reminder that an earthquake’s environmental footprint is not confined to the ground rupture; it extends into the air and settles back down over everything that grows.

The toxic metals told a more complicated story. Increased concentrations of cadmium, chromium, lead, and mercury were detected across the affected region, but they were particularly pronounced in the industrialized provinces. This spatial pattern suggests that the earthquake did not create these contaminants so much as redistribute and remobilize them. Southern Turkey hosts substantial industrial activity, including cement production, metal processing, and textile manufacturing, all of which leave legacy deposits of heavy metals in soils and sediments. Seismic shaking can crack containment structures, disturb buried waste, liquefy waterlogged sediments, and grind contaminated materials into finer, more mobile particles. Previous research on transient seismic stresses has shown that earthquakes can dramatically alter the permeability of soils and aquifers, changing how water and dissolved substances move through the subsurface. The new study is consistent with the hypothesis that such post-earthquake environmental changes, including soil degradation and particle redistribution, can increase the bioavailability of heavy metals and their uptake by plant roots.

The statistical evidence reinforces the pattern. Using one-way analysis of variance, the team found highly significant differences between earthquake-affected and control regions, with a p-value of 0.001, meaning there is only about a one in a thousand chance that the observed differences arose from random variation alone. In environmental monitoring, where natural heterogeneity in soil chemistry often muddies comparisons between sites, a result this clean across multiple elements and two plant species is notable. It suggests the seismic signal is real, systematic, and detectable through the noise of ordinary agricultural variation.

The choice of study plants matters for interpreting the findings. St. John’s wort is a medicinal plant whose dried aerial parts are consumed in concentrated forms, meaning that any metal burden it carries is delivered directly to consumers, often in the name of health. The species is also known from prior research to accumulate metals from soil, making it a useful biological monitor of environmental contamination. Peppers, by contrast, are a fresh food crop, and the detection of nickel at 16 to 24 milligrams per kilogram in the fruits raises immediate questions about dietary exposure thresholds. International food safety standards set limits for cadmium and lead in vegetables, and while the study did not perform a formal health risk assessment, the authors explicitly flag the need for further research into the potential food safety of edible plant tissues from the affected region. That caution is warranted: chronic low-level exposure to cadmium damages kidneys, lead impairs neurological development, and chromium in its hexavalent form is carcinogenic.

The broader significance of the study lies in what it reveals about disasters as environmental events, not just structural ones. Earthquakes are typically assessed in terms of casualties, building damage, and economic loss. But the physical perturbation of a landscape, the fracturing of soil horizons, the pulverization of contaminated building stock, the dust plumes that blanket agricultural land, constitutes a form of geochemical disturbance that science is only beginning to quantify. Comparable concerns have been raised after other major earthquakes, including observations of liquefaction and subsidence during the 2008 Wenchuan earthquake in China, which reshaped soils across vast areas. The Turkish study adds plant uptake to that picture, connecting the geology of a seismic event to the biology of the food chain.

For the affected communities, the practical implications are still taking shape. Much of the agriculture in Hatay, Kahramanmaraş, and the surrounding provinces continues on land that experienced intense shaking and months of demolition activity. Farmers, herbal collectors, and food processors in the region now have an evidence base suggesting that their soils and crops may carry an elevated metal burden, and that this burden reflects a combination of seismic mobilization, dust fallout, and pre-existing industrial contamination. The researchers call for continued monitoring and further investigation into food safety, a recommendation that aligns with a growing recognition among environmental scientists that disaster recovery must include environmental chemistry alongside engineering and reconstruction. The ground beneath southern Turkey was shaken once in a matter of minutes; the chemical consequences, this study suggests, may unfold over years, quietly moving through roots and leaves into the region’s food and medicine.

Subject of Research: Heavy metal mobilization and plant uptake in soils of earthquake-affected regions of Turkey

Article Title: Heavy metal distribution in soils and plants collected from earthquake-affected regions of Turkey: a comparative assessment of Hypericum perforatum L. and Capsicum annuum L.

Article References: Sürmelihindi, B., Gökpinar, B., Morcali, M. H., Yilmaz, Y., Aksan, M. E., Koçer, F., Karakoç, S. B., & Şekeroğlu, N. (2026). Heavy metal distribution in soils and plants collected from earthquake-affected regions of Turkey: a comparative assessment of Hypericum perforatum L. and Capsicum annuum L.. Environmental Monitoring and Assessment, 198(10), Article 1108. https://doi.org/10.1007/s10661-026-15955-1

Image Credits: AI Generated

DOI: 10.1007/s10661-026-15955-1

Keywords: heavy metals, earthquake, Turkey, soil contamination, Hypericum perforatum, Capsicum annuum, ICP-MS, nickel, food safety, plant uptake, dust deposition, environmental monitoring

The central process at work is silicate weathering, a cornerstone of the long-term carbon cycle. When atmospheric carbon dioxide dissolves in rainwater and soil moisture, it forms carbonic acid, a weak acid capable of attacking the crystal lattices of silicate minerals such as feldspars and micas. As these minerals break down, the carbon carried in the acid is transformed into bicarbonate ions dissolved in water. Those ions can then travel through rivers to the ocean, where marine organisms incorporate the carbon into shells and other calcium carbonate structures that eventually settle into seafloor sediments. On geological timescales, this chain of reactions is one of the principal mechanisms by which Earth regulates atmospheric carbon dioxide and, with it, global temperature.

What makes the new analysis striking is its emphasis on drylands as an underappreciated locus for this chemistry. Arid regions receive little rain, so they are often assumed to play a minor role in weathering-driven carbon uptake compared with humid tropical belts where rainfall and vegetation accelerate mineral dissolution. Yet drylands possess distinctive advantages. Intense temperature swings between day and night physically fracture rock surfaces, expanding the reactive area available to chemical attack. Sparse vegetation means that minerals lie close to the surface, exposed to occasional but chemically aggressive runoff events. And, crucially, wind continuously supplies fresh, finely ground dust derived from distant mountain ranges, delivering new reactive material to soils that would otherwise exhaust their weathering potential.

The research team assembled this picture by reconstructing dust deposition and weathering fluxes across eolian archives reaching back to the late Pliocene, an epoch that ended approximately 2.6 million years ago. The late Pliocene is a pivotal interval in Earth’s history: global temperatures were gradually declining, ice sheets were expanding across the Northern Hemisphere, and the modern pattern of arid belts and monsoon circulation was taking shape. By examining the mineralogical and geochemical signatures preserved in dust deposits, the authors were able to track how much silicate material was delivered to dryland soils and how efficiently that material captured carbon dioxide over time.

The results point to persistence rather than volatility. Despite the dramatic climatic oscillations of the past three million years—including the repeated glacial-interglacial cycles of the Pleistocene—the carbon dioxide uptake associated with silicate weathering in eolian drylands appears to have remained remarkably stable. This stability matters because the long-term carbon cycle depends on sinks that behave predictably across changing climates. If a major weathering sink were to weaken abruptly during cold or dry intervals, the balance between volcanic carbon emissions and carbon removal would shift, amplifying climatic swings. The apparent resilience of dryland weathering suggests it has instead acted as a steadying hand, damping rather than reinforcing fluctuations in the global carbon budget.

The mechanistic explanation for this resilience lies in the interplay between supply and demand. In humid regions, weathering rates often saturate: once soils are deeply leached and vegetation covers the landscape, additional carbonic acid cannot significantly accelerate mineral dissolution. Drylands, by contrast, tend to be supply-limited rather than transport-limited. Because chemical reaction rates are slow in arid conditions, freshly deposited dust accumulates in soils awaiting reaction. Even a modest increase in moisture—a stronger monsoon season, a rare intense storm—can mobilize carbonic acid through this stored inventory of fine particles, unlocking weathering that was chemically banked during drier periods. Over thousands to millions of years, this buffering behavior smooths out climatic variability, allowing the carbon sink to persist even as individual decades and millennia fluctuate between dustier and wetter regimes.

The study also carries implications for how scientists model Earth’s climatic future. Most Earth system models represent silicate weathering through simplified parameterizations tuned primarily to temperature, runoff, and lithology, with little explicit treatment of dust supply to arid soils. If eolian drylands contribute a stable and geologically meaningful fraction of global carbon uptake, then changes in dust generation driven by land use, desertification, and shifting wind patterns could subtly alter the trajectory of natural carbon sequestration in the coming centuries. The authors’ reconstruction provides a benchmark against which such model assumptions can be tested, anchoring simulations of deep-time climate in empirical records of dust and weathering chemistry.

There is also a deeper conceptual payoff. For decades, the narrative of drylands in climate science has been dominated by their vulnerabilities: expanding deserts, degrading soils, and human populations exposed to heat and water stress. This research adds a counterpoint, portraying the same environments as engines of planetary regulation. Fine dust lofted from the Sahara, the Gobi, and the world’s other great dust sources does not simply smother ecosystems downwind; it seeds soils with reactive minerals, fertilizes distant oceans with iron, and, according to this study, sustains a chemical removal of carbon dioxide that has operated without interruption since before the Ice Ages began. In that sense, the planet’s dustiest places have been among its most dependable climate stabilizers.

The late Pliocene baseline gives the finding particular weight for understanding the modern atmosphere. Around three million years ago, carbon dioxide concentrations were comparable in broad magnitude to levels considered plausible for the coming decades, and global mean temperatures were warmer than preindustrial values. Reconstructing how weathering sinks behaved under those conditions offers a natural experiment on how the carbon cycle responds to a warmer world. The persistence of dryland silicate weathering through the Pliocene-Pleistocene transition suggests that this sink is robust to the kinds of temperature and hydrological shifts currently under way, though the authors caution that the pace of modern anthropogenic change vastly exceeds the gradual forcing of the late Cenozoic.

As with any reconstruction spanning millions of years, uncertainties remain in translating geochemical proxies into precise fluxes, and the global significance of dryland weathering relative to mountain belts and tropical basins will continue to be debated. But the study’s core message is difficult to ignore: the long-term carbon cycle is woven together by processes operating in places that rarely attract attention. Every dust storm that darkens a distant sky carries within it a shipment of silicate minerals destined to react, slowly and invisibly, with carbonic acid drawn from the air. That humble reaction, repeated across arid landscapes for millions of years, has helped keep Earth’s thermostat within the range that allows oceans, ice sheets, and life to persist. In an era when humanity is rapidly adding carbon dioxide to the atmosphere, understanding the full inventory of natural sinks—including the silent work of wind-blown dust in the world’s drylands—has never been more urgent.

Subject of Research: Long-term silicate weathering and carbon dioxide uptake in eolian drylands since the late Pliocene

Article Title: Persistent silicate weathering and carbon dioxide uptake in eolian drylands since the late Pliocene

Article References: Zhang, C., Wu, H., Hu, B., Qiao, Y., & Guo, Z. (2026). Persistent silicate weathering and carbon dioxide uptake in eolian drylands since the late Pliocene. Communications Earth & Environment. https://doi.org/10.1038/s43247-026-04058-x

Image Credits: AI Generated

DOI: 10.1038/s43247-026-04058-x

Keywords: silicate weathering, eolian drylands, carbon dioxide uptake, long-term carbon cycle, late Pliocene, dust deposition, climate regulation, geochemistry, carbon sequestration, Communications Earth & Environment, Persistent, silicate