The North Atlantic Oscillation (NAO) affects precipitation, temperature, and many other climate parameters over large areas. Previous studies indicate a statistically significant relationship between NAO and drought in several countries within the Mediterranean Basin. In recent years, the NAO Index has remained predominantly in its positive phase. During positive NAO phases, winter precipitation in Türkiye decreases, and the tendency toward drought increases. This study aims to identify the relationships between NAO, drought, and vegetation conditions in Türkiye. Standardised precipitation (SP) was derived from ERA5 precipitation data for seven stations across Türkiye to analyse the NAO influence on drought occurrence. Additionally, Normalised Difference Vegetation Index (NDVI) from the GIMMS dataset provided by the NOAA AVHRR satellite was used to evaluate the driver effect of NAO on vegetation dynamics. Analyses were performed using statistical methods, such as Pearson correlation and linear trend analysis with the Mann-Kendal. Principal Component Analysis (PCA) and Cluster analyses were applied to these datasets. Results show a statistically significant positive NAO trend in the last 40 years related to an increasing drought trend for a substantial part of Türkiye. During many periods of positive NAO, Türkiye experienced a marked reduction in precipitation. Conversely, negative NAO months often coincide with notably wetter conditions across all precipitation regions in the country. Moreover, vegetation activity (NDVI values) in the western and northern regions of Türkiye significantly declined from 1982 to 2022. The results reveal that vegetation does not respond much to drought conditions due to the positive phase of the NAO, especially in the central and eastern regions of Türkiye, thanks to increased agricultural irrigation projects.
More intense wildfire seasons have increased the need for earlier indicators of vegetation stress and wildfire potential. Seasonal prediction of live fuel moisture content (LFMC) can support anticipation of fuel dryness weeks to months ahead of the fire season. Here, we develop a seasonal LFMC forecasting framework by forcing the LFMC-SFX modelling chain with the European Centre for Medium-Range Weather Forecasts (ECMWF) seasonal ensemble forecasts (SEAS5) and apply it to mainland Portugal, using the 2022 fire season as a proof-of-concept case study. Forecast skill is evaluated against an independent weekly LFMC reference dataset for Portugal using spatial error maps and distributional diagnostics. SEAS5 captures the broad seasonal evolution and associated regional patterns but exhibits a systematic positive bias in absolute LFMC values. Typical errors (Mean Absolute Error/Root Mean Square Error) are on the order of 10–20%, with localized hotspots exceeding 25%, and correlations are moderate (r ≈ 0.56–0.74, p < 0.001) across initialization dates. These results indicate that SEAS5 provides useful probabilistic information on the timing and spatial extent of seasonal fuel drying, while also highlighting the need for forecast-aware calibration and improved evaluation datasets for operational deployment. We discuss how seasonal LFMC outlooks could complement existing fire-danger indices within multi-horizon early-warning systems to support preparedness and resource allocation.
The largest and longest ocean bottom seismometer (OBS) experiment so far in the Atlantic Ocean occurred as part of the UPFLOW project to better constrain upward mantle flow, which is crucial to understanding global mantle flow. UPFLOW deployed 50 and recovered 49 OBSs in a ∼ 1,000 × 2,000 km2 area in the Azores-Madeira-Canary islands region with a station spacing of ∼110-160 km between June 2021 and August 2022. Most instruments had three-component broadband seismic sensors and hydrophones, and three different designs of OBS frames were used. Our analysis shows ∼91 % data completeness. Vertical-component long-period noise (T>∼30s) is reduced compared to previous experiments. The orientations of horizontal components were estimated from the polarisation of long-period body and surface waves from teleseismic events. Earth’s free oscillations with frequencies as low as ∼1.8 mHz are observed following two Mw > 8 earthquakes, and the signal-to-noise ratio of these observations is enhanced after applying tilt and compliance corrections. We show illustrative recordings and spectrograms of teleseismic and local events as well as non-seismic signals (whales, instrument resonances), demonstrating the wide variety and richness of UPFLOW data and their potential to address many outstanding questions in solid Earth sciences, oceanography, and marine biology.
Body tactile stimulation (TS) is a sensory enrichment that benefits mammals' welfare. It has also been reported to reduce stress, aggression, and enhance growth in some fish species. However, response to this enrichment may vary across species, suggesting that species-specific preferences should be considered when designing enrichment strategies to improve welfare. This study investigated behavioural responses to TS in two marine fish species: gilthead seabream (Sparus aurata) and white seabream (Diplodus sargus), which belong to the same family but differ in social behaviour. Over eight days, groups of three fish were exposed to a rectangular PVC frame with silicone bristles that promote TS when fish pass through them. Following this, each fish underwent a preference test in a neutral tank with a tactile apparatus on one side and a control apparatus on the other. White seabream spent more time in the area with TS and more frequently choose this area first, showing a behavioural pattern consistent with preference for the TS area. In contrast, gilthead seabream showed no clear preference pattern, however neither species appeared to avoid the TS apparatus. The preference index based on entries into each area indicated that 78% of white seabream and 33% of gilthead seabream showed preference for the TS area. Overall, these findings suggest that behavioural responses to TS may vary between species and individuals, possibly associated with differences in socio-ecological traits. These results highlight the importance of considering species-specific responses when designing enrichment strategies for fish.
The stable isotope values of seawater (delta 18O and delta 2H) provide valuable information on the exchange of water between the ocean, atmosphere, and cryosphere and on ocean mixing processes. As such, observational seawater delta 18O and delta 2H data place powerful constraints on hydrologic changes in the modern ocean. Seawater delta 18O data are also essential for calibrating paleoclimate proxies based on the delta 18O of marine carbonates and are an increasingly critical diagnostic tool for assessing model performance and skill in isotope-enabled climate models. Despite their broad value, no centralized and actively-curated database for this type of data exists, even though a growing number of new seawater delta 18O datasets have been generated over the last decade. As such, many seawater delta 18O datasets remain "hidden". To improve the accessibility of seawater delta 18O data for the Earth Science research community, the Past Global Changes (PAGES) CoralHydro2k project has created a new, machine-readable, and metadata-rich database of observational seawater delta 18O data, paired with seawater delta 2H and salinity data, that is compliant with findability, accessibility, interoperability, and reusability (FAIR) standards for digital assets. The data has been collected from public databases and repositories, direct researcher data submissions, scientific papers, and student theses. In total, the PAGES CoralHydro2k Seawater delta 18O Database contains over 18 600 data points with extensive metadata that makes the database suitable for a myriad of research applications. For hidden data, we searched for and included all datasets within the global ocean. For public data, our data collation efforts were focused on the upper 50 m from 35 degrees N to 35 degrees S (to aid in CoralHydro2k's seawater delta 18O reconstruction studies using delta 18O and Sr/Ca in tropical-subtropical coral skeletons). We also provide a set of best practices to the community for reporting seawater isotope data in the future. The database is available on the NOAA NCEI World Data Service for Paleoclimatology landing page: https://www.ncei.noaa.gov/access/paleo-search/study/34575 (last access: 11 February 2026; 10.25921/ap7d-2k16, Atwood et al., 2026). A Seawater Oxygen Isotopes Community was also developed within the EarthChem Library (https://www.earthchem.org/communities/seawater-oxygen-isotopes/, last access: 20 February 2026) to help researchers submit new datasets and obtain a dataset DOI. This template is aligned with the CoralHydro2k Seawater delta 18O Database to facilitate future updates to the database.
