2025

1. [Spengler et al. 2025] Mensaje de las conferencias y consejos episcopales católicos de África, América Latina y el Caribe, y Asia con ocasión de la cop30
   Cambio climático, Iglesia

2. [Fernández-Castillo et al. 2025] Snow cover can significantly alter the energy fluxes that take part on the surface energy balance (SEB), which subsequently affects surface air temperature. However, studies of the influence of snow cover on the SEB are scarce due to limited observational data and usually constrained to high altitudes or mountainous areas. In this study, the SEB is analysed under two differentiated land surface conditions: with and without snow cover, for a non-mountainous region in the midlatitudes. This is done in order to analyse the physical processes leading to one of the most extreme and disruptive cold waves of the present century in Spain. The cold wave took place in January 2021 after historical snowstorm Filomena left widespread snowfall amounts of 30–50 cm in the interior of Spain. By means of analysis of in-situ observational data from a micrometeorological tower and synoptic fields, we determine the contribution of synoptic and microscale processes to the extremely cold surface air temperatures recorded. The SEB analysis reveals the decisive role of snow cover in the cold wave. Surface albedo increased from 20 % to 80 %, leading to a 60 % decrease in the surface net radiative flux. Together with weak turbulence conditions due to weak synoptic forcing, this allowed extraordinarily low surface air temperatures. Thus, this event stands out from the typical pattern leading to cold waves in this region, characterised by cold air advection. This study highlights the importance of having observational data of micrometeorological variables, which have proven very insightful into the physical mechanisms contributing to the cold wave.
   Microvariability, Filomena

3. [Langille et al. 2025] Abstract The High-altitude Aerosols, Water vapour and Clouds (HAWC) mission is an observing system, with a planned launch around 2031, that is being developed by the Canadian Space Agency to provide co-located global measurements of aerosols, water vapour, and thin ice clouds in the upper troposphere and lower stratosphere with vertical coverage that extends into the troposphere in the polar regions. The mission is the Canadian contribution to NASA’s Atmospheric Observing System (AOS, aos.gsfc.nasa.gov); a satellite constellation that will include multiple instruments to monitor aerosols, clouds, and precipitation as part of the Earth System Observatory (ESO,https://science.nasa.gov/earth-science/missions/earth-system-observatory). The HAWC mission includes three innovative Canadian instruments: the Aerosol Limb Imager (ALI), the Thin Ice Clouds and Far InfraRed Emissions (TICFIRE) instrument, and the Spatial Heterodyne Observations of Water (SHOW) instrument. ALI and SHOW will provide limb profiles of aerosol and water vapour with high spatial resolution (vertical and along-track) and high sensitivity to fine aerosols and dry conditions. TICFIRE will provide nadir measurements of infrared radiation, thin ice cloud content, and cloud microphysical properties. These coordinated measurements will help build a more comprehensive picture of high-altitude aerosols, clouds, and water vapour in the atmosphere. In this paper, we present the HAWC concept and discuss the primary science objectives and requirements of the mission. The instrument payloads and data products are introduced and synergies between HAWC and other AOS instruments are identified.
   Iphone Hugo

4. [Molina et al. 2025] Abstract: The anthropogenic nature of global environmental change demands that it is viewed not only as a scientific, technological, and economic issue, but as a philosophical, religious, and ethical one. In this article, we intend to explore Biology-Based Mimetic Ethics (BBME) as a subdiscipline of ethics that seeks to learn, adapt, implement, and evaluate models of response observed in living organisms to help social agents make pro-environmental decisions. Based on this the- oretical foundation, we aim to explore the relationship between moral and environmental education by presenting this teaching proposal as an innovative tool for bridging both disciplines, while reframing the global socio-environmental crisis as an ethical and educational one. The proposal rests on two premises. First, it recog- nizes that nature operates amorally, rendering ethological value judgments inappropriate. Second, it emphasizes, nevertheless, that any insight derived from a scientific analysis requires rational and ethical scrutiny. Finally, by providing both a theoretical framework and practical examples, this article aims to guide university educators —particularly those working in faith-based institutions—aspiring to develop character-based environmental education programs.
   Environmental ethics

5. [Nakamura et al. 2025] Reanalysis goes back to the dawn of modern operational numerical weather prediction (NWP). Relying on using a consistent data assimilation system for an extended period back in time at reduced resolution to manage cost, reanalysis integrates historical observations into physically consistent gapless fields and, in the case of an atmospheric reanalysis, provides a comprehensive picture of the historical global atmospheric circulation. There have been con- tinued efforts to improve data quality and to include not only the atmosphere but also other Earth system components (e.g., land, ocean, and cryosphere). Demands for higher resolution and quality have become a driving force of regional reanalysis. The increasing usage across successive Intergovernmental Panel on Climate Change (IPCC) assessment cycles attests to the improvement in the quality and comprehensiveness of reanalysis. Reanalysis data have enabled significant contributions not only to research on the climate system concerning its variability and predictability but also to operational services such as the Copernicus Climate Change Service (C3S) and the Copernicus Marine Service (CMEMS), offering great potential for applications in socioeconomic activity. Reanalyses’ recent usage as training datasets for machine learning (ML) activities may revolutionize the provision of weather forecasts and how weather/ocean forecasts benefit from reanalysis.

   The Sixth World Climate Research Program (WCRP) International Conference on Reanalysis (ICR6) took place in Tokyo from 28 October to 1 November 2024 and brought together reanalysis producers, observation data providers, numerical modelers, and members of the user community to discuss progress, applications, challenges, and future priorities in the field. The ultimate aim was to guide the development and use of reanalysis data in science, public services, policymaking, and socioeconomic activity.
   Global and regional reanalyses, recommendations of a WCRP conference on reanalysis.

6. [Soukissian et al. 2025] Abstract. The Copernicus European Regional Reanalysis (CERRA) was released in August 2022, providing a continental atmospheric reanalysis, and, in addition, the New European Wind Atlas (NEWA) is a recently released hindcast product that can be used to create a high temporal and spatial resolution wind resource atlas of Europe. In order to demonstrate the suitability of the NEWA and CERRA wind datasets for offshore wind energy applications, the accuracy of these datasets was assessed for the Mediterranean Sea, a basin with a high potential for the development of offshore wind projects. Long-term in situ measurements from 13 offshore locations along the basin were used in order to assess the performance of the CERRA and NEWA wind speed datasets in the hourly and seasonal time scales by using a variety of different evaluation tools. The results revealed that the CERRA dataset outperforms NEWA and is a reliable source for offshore wind energy assessment studies in the examined areas, although special attention should be paid to extreme value analysis of the wind speed.
   Newa and Cerra evaluation over the Mediterranean

7. [Zuo et al. 2025] Abstract. Accurate surface wind speed data are vital for atmospheric science, climatology, and energy applications. European Centre for Medium-Range Weather Forecasts Reanalysis v.5 (ERA5), as one of the most widely used global reanalysis datasets, has insufficient assessment of its applicability across diverse landform types. Using the gridded observational dataset over China (CN05.1) and the Global Basic Landform Units dataset, this study evaluated the surface wind speed data from ERA5 over various altitudinal zones and undulating terrains in China via root-mean-square differences (RMSD) and mean absolute percentage error (MAPE) against CN05.1 observations. Results reveal significant regional variations, with ERA5 effectively capturing the spatial distribution of mean wind speeds but systematically underestimating magnitudes, particularly in plateau and mountainous regions. ERA5 reanalysis fails to reproduce the observed altitudinal increase in surface wind speed. Elevation-dependent biases are prominent, with RMSD and MAPE increasing from low-altitude to high-altitude areas. Terrain complexity exacerbates errors, showing maximum deviations in high-relief mountains and minimum deviations in hilly regions. These biases evolve seasonally, peaking in spring and reaching minima in winter. In summary, discrepancies between observations and ERA5 vary with altitude, topographic relief, and season. The most significant deviations occur for spring surface winds in high-altitude, high-relief mountains, with mean RMSD reaching 3.3 m/s and MAPE 553%. The findings highlight the limitations of ERA5 reanalysis data in scientific and operational contexts over complex terrains.
   Wind, reanalyses, China