bluuebunny/crossref_metadata_2025 huggingface dataset:
Maximising information in open source health data: A statistical approach for modelling aggregated time series of health outcomes
Authors: Economou Theodoros
Published: July 2024

One of the major concerns of climate change is the impact on human health. To that end, there is a lot of research on quantifying the effects of environmental exposure such as heat and air pollution on human health. The main challenge encountered in such research is the availability of health data. For short-term exposure effects, such as the impact of heat on daily mortality, daily data is required which can be obtained at country-level, but is generally not open-source or available at at a wider spatial extend (e.g., at continent or global scale).It is also true however, that open-source repositories do contain health-related data at a large spatial scale, albeit at non-optimal temporal resolution. A bright example is Eurostat, which contains (but is not limited to) health data (e.g., mortality) at weekly time steps for the EU member states but also other countries peripheral to Europe.The primary tool for quantifying the effect from various exposures on mortality and morbidity is the framework of Distributed Lag Non-linear Models (DLNMs). These models, applied to daily data, can capture the effects from environmental exposure across many days (lags). In this work, we exploit the mathematical properties of the Poisson distribution to enable the implementation of DLNMs on temporally aggregated data, and demonstrate that the loss of information is minimal, particularly when the goal is to understand aggregated quantities such as the attributable number of deaths. Using simulated data, we demonstrate that using the framework of Generalized Additive Models enables the application of DLNMs to weekly data, to emulate the situation of using data from databases such as Eurostat. We further illustrate our framework using real mortality data from the city of Thessaloniki, Greece and from Cyprus.Another implication of our suggested framework is that large scale studies (e.g., at continental or global scale) can be made more optimal when the goal is to estimate aggregate risk measures. For instance, aggregating daily data to weekly data, reduces the amount of data by a factor of 7. We present a sensitivity analysis to the level of aggregation that can be performed before significant loss of information in the estimates starts to occur.
Thunderstorm Intensification from Mountains to Plains: The TIM Campaign
Authors: Fischer Jannick , Groenemeijer Pieter , Holzer Alois , Eisenbach Stefan , Partners Campaign
Published: July 2024

Observational data of thunderstorm hazards, such as hail reports in the European Severe Weather Database, suggest that severe convective storms are especially frequent over the surrounding slopes of mountain ranges. The same geographic regions are also projected to experience the strongest increases in severe weather occurrence as a result of global warming. Given the potential high impact of intensifying severe convection in these densely populated parts of Europe (and other regions of the world), it is critical to better understand where and why these storms become more severe. While a number of field campaigns has investigated either terrain effects on the atmospheric boundary layer or severe storm dynamics away from terrain, their topical overlap, severe convection dynamics near terrain, is less researched.For these reasons, ESSL is currently coordinating efforts to plan an international field campaign on severe convective storms surrounding the Alps and lower mountain ranges in central Europe from the Pyrenees to the West to the Tatras mountains to the East. A network of over 20 partner institutions across these countries has already been engaged. The research focus is on high-resolution data collection of the pre-convective environment and within individual severe storms. However, the field campaign will also provide wider opportunities to validate recent innovations in forecasting, nowcasting, and measurements, such as new instruments on the Meteosat Third Generation satellite, numerical model parametrizations of terrain-related processes, drone-based surveys and profiling, and polarimetric radar algorithms. This presentation will give a short review of the scientific literature on the topic of severe convective storms near complex terrain and summarize the most important research questions. Based on that, the current plans for the TIM field campaign are presented to invite collaborations from the EMS community.
Multi-season analysis of the boundary layer structure and evolution in a high-altitude valley in Colorado
Authors: Adler Bianca , Cox Christopher J , Intrieri Janet , Bianco Laura , Butterworth Brian , de Boer Gijs , Gallagher Michael R. , Gutmann Ethan , Meyers Tilden , Sedlar Joseph , Turner David D. , Wilczak James M
Published: July 2024

Comprehensive atmospheric measurements were conducted in the East River Valley in Colorado for a nearly 2-year period from 2021 through 2023 in the framework of the NOAA Study of Precipitation, the Lower Atmosphere, and Surface for Hydrometeorology (SPLASH) and the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) program Surface Atmosphere Integrated Field Laboratory (SAIL) campaigns. The main focus of these research initiatives is to enhance weather and water prediction capabilities by measuring, evaluating, and understanding integrated atmospheric and hydrologic processes relevant to water resources. The East River Valley is embedded in the East River Watershed which is a representative mountainous headwater catchment of the Colorado River Basin and is a primary source of water for much of the southwestern United States. The valley floor is located at more than 2500 m above mean sea level and the surrounding ridges extend above 4000 m.In this study, we used temperature, humidity, and wind profiles from ground-based remote sensing instruments and radiosondes in the upper part of the valley, as well as near-surface meteorological observations from 5 sites distributed along the valley axis. Temperature and humidity profiles with high temporal resolution were retrieved from infrared spectrometer radiances with the optimal estimation physical retrieval TROPoe. The data set allows one to investigate the seasonal and diurnal cycle of the boundary layer and to investigate the impact of varying spatial snow coverage including the melt period. We show that the diurnal cycle of the boundary layer conditions on many days is very different from a typical thermally driven wind system, especially when snow coverage is low, and we discuss possible factors contributing to the boundary evolution.
Improving offshore wind forecasts off the coast of New England in the United States – The Third Wind Forecast Improvement Project (WFIP3)
Authors: Adler Bianca , Wilczak James M , Turner David D , Krishnamurthy Raghavendra (Raghu) , Kirincich Anthony , Bianco Laura , Myers Timothy
Published: July 2024

Offshore wind energy development in the United States is accelerating, with projects currently representing 40 gigawatts of proposed installed capacity. However, there are still substantial, unsolved challenges with forecasting winds and turbulence over the ocean. To help overcome the challenges, the US Department of Energy (DOE) and the National Oceanic and Atmospheric Administration (NOAA) are currently conducting a multi-seasonal offshore field campaign off the coast of New England in the Eastern United States. In collaboration with public and private partners, WFIP3 aims to boost offshore wind generation through better forecasting for existing, constructed, and planned wind farms in the area. WFIP3 builds on the success of the first and second wind forecast improvement projects (WFIP1 and WFIP2) which collected data to improve the accuracy of short-term wind forecasts over land. WFIP3 seeks to improve the understanding of the physical phenomena in the marine atmospheric boundary layer that impact wind and turbulence within turbine rotor planes that are critical for wind energy.  Since November 2023, a comprehensive set of remote sensing and in situ meteorological instruments have been installed at several sites at the coast and on islands. These continuous land-based observations are complemented by observations on a barge and ship during several multi-week-long periods. The observations will be used to evaluate and improve NOAA’s currently operational High-Resolution-Rapid-Refresh model as well as its successor the Rapid Refresh Forecast System. We present an overview of the campaign, research questions, and measurement strategy and will show some preliminary results from the ongoing campaign.
Machine learning approach to predict mortality reduction from summer heatstroke and heart disease through urban modification scenarios for climate change adaptation
Authors: Ohashi Yukitaka , Nakajima Ko , Takane Yuya , Kikegawa Yukihiro , Ihara Tomohiko , Oka Kazutaka
Published: July 2024

A hot summer or heatwave event induces heat stress-related human deaths. Reducing the number of those deaths is stated on one of social issues for urban resilience and sustainability. This study aims to evaluate a change in the deaths if energy-saving or temperature-decreasing measures in urban modifications would be installed as the climate change adaptation in the whole urban area, from a novel approach combined machine learning (ML) techniques with meteorological model simulations. In this study, the WRF-CMBEM (the WRF, the urban multi-layer, and building energy models) was used to simulate spatiotemporally urban meteorological conditions, while the ML was applied to perform and predict daily heat stress-related deaths in an urban area.We covered the most populated Tokyo's 23 wards in Japan and demonstrated the extremely hot summer of 2018. As expected urban modification scenarios, the cases of a ground surface greening (GRN), no anthropogenic heat from buildings to atmosphere (noAH), rooftop photovoltanic (PV), and cool roofs (CRF) were evaluated in this study.The ML performed well for heat-related daily deaths from heatstroke (HS) and ischaemic heart disease (IHD) by detecting important meteorological factors. After meteorological changes from a control case to four urban modification scenarios were predicted by the WRF-CMBEM, potential reductions in heat-related deaths were estimated using previous successful ML-trained models. As a result in July–August 2018, the GRN case performed the most effective decreases of 0.28 °C (50%ile), 0.37 °C (90%ile), and 0.56 °C (Max) in the outdoor surface air temperature of all grids resolved at 1 km. The temperature changes reduced HS deaths by 43% and IHD deaths by 18% during a peak period of the deaths in the summer 2018. The second effective modification was the CRF case, which showed temperature decreases of 0.23 °C (50%ile), 0.31 °C (90%ile), and 0.36 °C (Max), and a 14% reduction in HS deaths and a 13% reduction in IHD deaths. These demonstrations suggest that the combined implementation of urban modifications is more effective in reducing heat stress-related deaths, especially during heatwaves and extreme hot summers.
Can Observation Targeting Be a Wild Goose Chase? An Adjoint-Sensitivity Study of a U.S. East Coast Cyclone Forecast Bust
Authors: Durran Dale , Lloveras Daniel , Doyle James
Published: July 2024

We use a moist adjoint model to compute the initial-condition perturbations that minimize the significant 48-72-h synoptic-scale forecast errors associated with the 15 November 2018 cyclone over the East Coast of the United States. These adjoint-optimal perturbations, which have a maximum amplitude of about 2 K in potential temperature, are widespread, extending throughout the troposphere and across much of North America. We investigate the most impactful subsets of the perturbations by truncating them in physical and spectral space and rescaling them to be equal in an energy norm to the full, unmodified perturbations. When the perturbations are confined to localized target regions, including those with the highest adjoint sensitivity or the strongest convective instability, they have weaker impacts on the forecast than when the perturbations within the target regions are removed and the rest of the perturbations are retained. Additionally, when the perturbations are filtered to retain only wavelengths longer than 1000 km, they have greater impacts on the forecast than when the perturbations are filtered to retain only wavelengths shorter than 1000 km. These results suggest that the 15 November 2018 forecast bust was strongly sensitive to widespread, large-scale uncertainties in the initial conditions, rather than those in localized, small-scale regions that could more feasibly be reduced by targeted observations.Left: 600-hPa potential-temperature adjoint perturbations (color fill every 0.5 K) for the (b) box, (d) full, and (e) hole experiments. GFS analysis for 600-hPa geopotential height (black contours, contoured every 15 dam). Green box in (b), (e) bounds the box and hole regions.Right: 72-h SLP errors (color fill, contoured at 3.5 hPa) for (a) control (unperturbed) simulation and for the adjoint perturbations (b) box, (d) full, and (e) hole. SLP contours from the GFS analysis (black) and the forecast (magenta) contoured every 6 hPa.
Simulation of Flow Fields in Complex Terrain with WRF-LES: Sensitivity Assessment of Different PBL Treatments
Authors: Liu Yujue , Liu Yubao , Munoz-esparza Domingo , Miao Shiguang
Published: July 2024

A multiscale modeling study of a real case has been conducted to explore the capability of WRF-LES over the Xiaohaituo Mountain (a game zone for the 24th Beijing-2022-Winter-Olympic-Games). Comparing WRF-LES results with observations collected during the MOUNTAOM (MOUNtain Terrain Atmospheric Observations and Modeling) field campaign, it is found that at 37 m resolution with LES settings, the model can reasonably capture both large-scale events and microscale atmospheric circulation characteristics. Employing SRTM1 (≈30 m) high resolution topographic dataset instead of traditional USGS_30s (≈900 m) dataset effectively improves the model capability for reproducing fluctuations and turbulent features of surface winds. Five sensitivity experiments are conducted to investigate the impact of different PBL treatments, including YSU and SH PBL schemes and LES with 1.5TKE, SMAG and NBA subgrid-scale (SGS) stress models. In this case, at gray zone scales, differences between YSU and SH are negligible. LES outperform two PBL schemes which generate smaller turbulence kinetic energy, and increase the model errors for mean wind speed, energy spectra and probability density function of velocity. Another key finding is that wind field features in the boundary layer over complex terrain are more sensitive to the choice of SGS models than above the boundary layer. With the increase of model resolution, the effects of SGS model become more significant, especially for the statistical characteristics of turbulence. Among these three SGS models, NBA has the best performance compared to observation. Overall, this study demonstrates that WRF-LES is a promising tool for simulating real weather flows over complex terrain.
The Future Responses of Tropical Extreme Convection to Climate Change based on GCRM simulation
Authors: Wu Xueke , Fu Qiang , Jia Ding , Kodama Chihiro
Published: July 2024

The tropics are the most active regions of convective activity on earth, which plays a crucial role in global atmospheric energy and water cycle. Climate change due to increases of greenhouse gas concentrations has led to a substantial increase in intense convection and extreme precipitation.  We use simulations from a global cloud-system resolving model, Nonhydrostatic Icosahedral Atmosphere Model (NICAM), to study the future changes of extreme convection include overshooting deep convection (ODCs) and the most intense convection (MICs) at the end of the 21st century. Combining TRMM satellite observations with ERA5 reanalysis data, we find that the NICAM well reproduces the spatio-temporal distributions of TRMM observed extreme convection and atmospheric environment. The results show that future extreme convection will show a globally increasing trend with climate warming. However, the trends vary either between different convective property thresholds or between different regions. For example, the future occurrences of ODCs with cloud top height above 15.5 km, 16.9 km and 18.3 km scaled by the global temperature increase will increase by 7%/K, 27%/K and 90%/K, respectively, over ocean where the atmosphere becomes warmer and wetter in a warming world. The corresponding changes are -1%/K, 10%/K and 37%/K over land where the atmosphere is hotter but drier. In the other hand, the frequency of MICs will increase significantly in the Atlantic and central Pacific, while decrease slightly in central and northern Africa. Specifically, the frequency of MICs in the Northern Hemisphere will increase significantly in boreal summer and decrease in boreal winter. Nevertheless, the GCRM simulations also show some discrepancies compare to the observations, i.e., the simulated convection over northeast of the South America was significantly less, which still need a further improvement. However, GCRM will be a crucial tool for studying global climate change and will undoubtedly provide important assistance for us to better address future climate change.
Possible impact of sudden stratospheric warming on the intraseasonal reversal in winter
Authors: Yan Hongming
Published: July 2024

Abstract：The intraseasonal reversal of the temperature over East Asia and the sudden stratospheric warming (SSW) are two abrupt events during the winter of 2020/21. The characteristics of these two events and their relationship are the focused issues in this paper. In winter 2020/21, there was a transition from cold to warm over East Asia. The surface air temperature (SAT) in East Asia suddenly changed from cold to warm with long duration. The cold period lasted from 21 November 2020 to 11 January 2021, while the warm period lasted from 19 January to 28 February 2021. And the transition of the cold to the warm was from 12 to 18 January 2021.There are significant differences of the atmospheric circulations between the cold and warm periods in the upper and lower troposphere. During the cold period, both of Ural Mountain High(UH) and Siberian High(SH) were stronger than normal, the Westerly Jet (WJ) was weakened and located to the area farther southerly than usual, the northerly wind anomalies and the cold advection occurred in East Asian; vice versa during the warm period. The mutations of the atmospheric circulations in the upper and lower levels were obvious during the transition period, especially for UH and SH. A strong SSW event occurred in the stratosphere at the beginning of 2021. As a result, the stratospheric polar vortex was largely weakened and deviated to the areas over Ural Mountains and nearby, the polar westerly wind turned to easterly wind and the temperature gradient reversed. The abnormal changes of the temperature and the geopotential height over the Ural Mountains area in the stratosphere were closely related to the SSW. These abnormal signals caused by the SSW gradually transmitted from stratosphere to troposphere over the Ural Mountains and the polar region, leading to the weakening and collapse of tropospheric UH and further caused the transition from cold to warm in East Asia. The SSW may be the most critical factor leading to the turning from cold to warm over East Asia during the winter of 2020/21.
Evaluation of two turbulence schemes in representing UTLS turbulence generated by orographic gravity waves
Authors: Siri Jagan Roshny , Schmidli Juerg , Goecke Tobias
Published: July 2024

Interactions within the upper troposphere/lower stratosphere (UTLS) region of the atmosphere play a crucial role in shaping climate change predictions by affecting the distribution of greenhouse gases. The transport of such tracers across this area is governed by a range of dynamic processes operating on multiple scales. On the smallest scales, turbulence is responsible for the irreversible mixing of tracers. Acting on subgrid scales, turbulence needs to be parameterized in weather and climate models. Turbulence within the UTLS region differs from that in the atmospheric boundary layer (ABL) due to stable stratification and the absence of a solid boundary. Various sources contribute to UTLS turbulence, including jet streams, overshooting convection, unbalanced flows, and gravity wave breaking.  With its unique characteristics, turbulence in the UTLS region is still relatively poorly understood when compared to its counterpart in the ABL. Traditional turbulence parameterizations, developed for the ABL, do not take into account the complex, non-homogenous, anisotropic, and patchy nature of the stratified UTLS turbulence. Hence there is a need for adapting ABL turbulence schemes to reflect the characteristics of turbulence in the UTLS region. As a first step, our study compares the characteristics of mountain-wave generated UTLS turbulence for two turbulence schemes: the operational turbulence scheme in the ICOsahedral Non-hydrostatic (ICON) model and a new scheme, the two-turbulence energies scheme coupled to the assumed probability density function method (2TE+APDF). We assess the performance of the two schemes in capturing turbulence features by simulating mountain waves during two field campaigns, the DEEPWAVE campaign over New Zealand and the SouthTRAC campaign over South America. Our goal is to improve the 2TE+APDF scheme for the representation of UTLS turbulence related to mountain waves and to develop an optimized setup for UTLS mountain wave simulations with the ICON model.
Assessing the impact of climate change on solar energy production on the Italian peninsula
Authors: Bonanno Riccardo , Collino Elena
Published: July 2024

This study aimed to assess the impact of climate change on solar energy production up to 2100 on the Italian peninsula by focusing on the key variables of global solar irradiance (GHI) and temperature and examining the photovoltaic (PV) energy production by means of the capacity factor (CF). Regional Climate Models (RCM) simulations from Euro-CORDEX models assimilating time-evolving aerosols were selected to ensure accurate estimations of solar radiation trends in future RCP scenarios. A bias correction was applied using the SARAH-3 solar radiation dataset for GHI and MERIDA reanalysis for 2 m temperature data to enhance the accuracy of CF estimation.The trend analysis revealed a slight decrease in the GHI under RCP 2.6, while the other RCPs exhibited significant increases, especially over the mountain regions in central Italy. The opposite trend is foreseen in the Alpine region, particularly under RCP 8.5. Moreover, temperature is projected to increase, notably under RCP 4.5 and RCP 8.5, with potential implications for production efficiency and snow cover reduction in the Alps, with subsequent decreases in solar irradiance related to the diffuse component.Analyzing the trend of the ensemble mean CF for the 2021–2100 span across the different RCPs, under RCP 8.5, a significant decrease is predicted, particularly in the Alps, due to the reduced GHI. Despite the general increase in the GHI, a decrease in the CF is likely for most of Italy due to rising temperatures potentially reducing solar panel efficiency. RCP 4.5 and RCP 2.6 showed less pronounced decreases in solar production, with RCP 2.6 being the scenario with the lowest magnitude of the climate signal.Seasonal cycle analysis revealed variations primarily linked to changes in GHI throughout the year. RCP 8.5 exhibited a significant decrease in production during winter, followed by a slight increase in summer, which was likely dampened by increasing temperatures. RCP 4.5 maintained similar characteristics, with a less pronounced decrease in winter and stable production in other months. RCP 2.6 showed a slight increase in spring and generally stable production throughout the year.In conclusion, climate change is expected to marginally influence photovoltaic power production in the Italian peninsula under different RCP scenarios, with temperatures playing a predominant role, particularly under the RCP 4.5 and RCP 8.5 scenarios, dampening the effect of increased solar radiation on PV production. The Alpine region represents an exception, with marked solar radiation decreases likely associated with reduced snow cover expected by the end of the century, leading to a significant decrease in the CF. The future expansion of photovoltaic installations should consider these findings, especially those in the Alpine region.
Enhancing meteorological report access and response time: How the Meteorological Service of Catalonia addresses the rise in weather-related claims
Authors: Aparicio Garcia Albert , Rius Anna , Barbería Laura , Miró Anna , Peña Juan Carlos , Ruiz Adrián
Published: July 2024

In recent years there has been an increase in the interest and number of users demanding meteorological data. From individuals to private companies and public administrations, the Climate Services Team (CST) of the Meteorological Service of Catalonia is responsible for addressing this surge in data requests. Among these inquiries, weather-related insurance claims have been particularly prominent, monopolizing a significant portion of the team’s operational time in preparing these on-demand reports and lengthening the response time. 

A web application tool has been developed to streamline the process of weather report generation. This application integrates a wide range of data into a user-friendly interface, including derived remote-sensing products (radar rainfall estimation and hail probability) and data retrieved from automatic and manual weather stations. Consolidating all this information in a single interface simplifies the process of determining which data are the most representative for a given municipality and date. Meteorological certificates can also be generated from the same application and are then freely available on the SMC website. 

Furthermore, an algorithm that combines daily wind gust, rainfall rate and accumulated precipitation with population data has been formulated. This algorithm identifies the municipalities from which it is most likely to receive weather insurance-related requests in the upcoming days. This proactive approach allows the CST to anticipate the influx of requests and prepare all potential weather data certificates that may be requested for each locality well in advance, using the previously mentioned application tool, even before affected individuals request them. 

This new operational workflow has not only significantly reduced response time but also enhanced the representativeness of the data provided for each municipality and weather event. It has also improved the accessibility for end-users, who need only to choose their locality from the SMC website and all available weather data certificates can be downloaded for free. 
Additional parameters in TRANSLATE: A standardized Climate change dataset for Ireland
Authors: Samala Basanta Kumar , O'Brien Enda , Nolan Paul
Published: July 2024

The TRANSLATE project has already generated a first set of standardised climate projections, based on a selection of CMIP5 global model projections using 3 different forcing scenarios (RCP 2.6, 4.5 and 8.5).  For each scenario, a 6-member ensemble of CMIP5 simulations were dynamically downscaled to high-resolution (4 km) over Ireland using the COSMO and WRF regional models, while a larger ensemble (up to 30 members, depending on scenario) were downscaled to 12 km by the EURO-CORDEX project.  The rest of the 21st century was divided into three 30-year periods (2021-2050, 2041-2070, and 2071-2100), and for each of these the downscaled simulations were detrended and bias-corrected (using quantile-delta mapping), and further statistically downscaled to a high-resolution observational grid. This project is now adding several more parameters like wind speed  and direction, relative humidity, and downward shortwave radiation  at the surface. The method remains much the same as used by O’Brien E and Nolan P (2023). These variables may be combined with temperature projections produced earlier to compute projections of derived indices such as evapotranspiration or renewable energy potential. A high resolution (2km X 2km) reanalysis dataset is used in lieu of reference observations from 1981 to 2010. These data were generated using the WRF regional model down-scaling the ERA Interim dataset. These 30 year daily observations were used to validate the corresponding variables in regional climate models output for the same historical period (1981-2010). Ensembles of reconstructed i.e., detrended, bias-corrected, and further downscaled daily timeseries for all three parameters are now completed. Using these data, future climate change scenarios from both COSMO and Cordex ensembles are analysed relative to the historical baseline period. The most interesting selected results will be presented.We also plan to repeat these analyses using CMIP6  based projections.
How does the novel EDMF-AERO model help to study Aerosol-PBL Interactions? Initial testing and results
Authors: Florczyk Grzegorz , Markowicz Krzysztof , Witek Marcin
Published: July 2024

Understanding the interactions between atmospheric aerosols and the evolution of the planetary boundary layer (PBL) is of paramount importance for human health, climate, and forecasting models. In this study, an eddy-diffusivity mass-flux (EDMF) model is coupled with a radiative transfer model (RTM) to investigate the effects of aerosol optical properties on the growth and thermodynamics of the PBL, or the so-called aerosol-PBL interactions (API). The developed model, called EDMF-AERO, is first extensively validated against in-situ radiosonde and microwave radiometer (MWR) observations, showing very good performance. Having established the model’s satisfactory accuracy, we investigated the impact of aerosol properties and model parameters on PBL evolution. In particular, we studied and confirmed the previously identified positive feedback loop between PBL growth and aerosol absorptivity known in the literature as the stove and dome effects (Ma et al. 2020). For the stove case higher 𝜏500 and lower 𝜔 cause PBL to grow and heat up faster. In extreme cases (𝜏500 = 1.5, 𝜔 = 0.8), the PBL growth speeds up ~40% and warms up ~40% faster compared to the reference. For the dome case higher 𝜏500 and lower 𝜔 cause PBL to grow and heat up slower. In extreme cases (𝜏500 = 1.5, 𝜔 = 0.8), the PBL growth slows down ~30% and warms up ~30% slower compared to the reference. In both cases, the feedback loop severely impacts surface PM concentrations and enhances heat index. Based on the sensitivity runs, a parameterization relating the τ500 and 𝜔 on the PBL heating rate and PBL growth is suggested, which could be easily employed in atmospheric and chemical transport models. The EDMF-AERO model developed in this study proves to be a valuable tool for studying API.
PYRENEES4CLIMA: A New Project to Provide More Reliable Climate Information for the Pyrenees
Authors: Prohom Marc , Cunillera Jordi , Soubeyroux Jean-Michel , Vicente-Serrano Sergio , Esteban-Alonso Xabier , Garcia-Balaguer Eva , Terrádez Juan
Published: July 2024

Mountains, custodians of unique biodiversity, are undergoing remarkable transformations at an unprecedented pace due to anthropogenic climate change. The Pyrenees are deeply affected by this phenomenon, threatening ecosystem services, ranging from water sources and natural habitats to forest resources.Thanks to cross-border cooperation, 46 entities from Spain, France, and Andorra have joined together in a new LIFE – SIP PYRENEES4CLIMA project with the objective of strengthening resilience in the Pyrenees through the implementation of measures to adapt to climate change. This 7.5-year project (October 2023- April 2031), with a total budget of almost €20 million, marks the starting point for the implementation of the Pyrenean Climate Change Strategy (EPiCC), the first European cross-border climate change strategy. It will accelerate climate policies in the region and reinforce governance based on territorial climate cooperation.The project is based on five fundamental pillars: (1) Understanding climate impacts, (2) Improving the resilience of natural spaces, (3) Adapting the mountain economy, (4) Safeguarding the population and territory from natural-climate risks and resource deterioration, and (5) Promoting an innovative system of climate governance involving citizens, socio-economic sectors, the scientific community, and political decision-makers.Working Group 1 (Climate) is composed of five beneficiary partners and four associated partners, led by the Meteorological Service of Catalonia and Météo France. The main objective of this group is to provide high-quality and reliable information and data to reduce the inherent uncertainty of the spatial and temporal variability of climate (and climate change), both observed and projected, in the Pyrenees. To achieve this objective, several tasks have been planned and described in depth:Update and expand the availability of observed climate data in the Pyrenees.
Generation of high-resolution climate projections in the Pyrenees for atmospheric and snow variables.
Development of climate change indices for sector-specific applications based on both observations and climate projections for the Pyrenees.
Development of a climate services platform providing real-time information on climate risks: droughts and heatwaves.
Comparison of cloud cover measurement techniques
Authors: Ben Slama Mehdi , Liandrat Olivier , Balmes Kelly A. , Riihimaki Laura D. , Hodges Gary B. , Schmutz Nicolas
Published: July 2024

Clouds are vital for Earth's radiative balance and affect industrial sectors like solar energy, airports, and ground-to-space optical communication. Cloud cover day and night measurement uncertainties persist due to subjective observations. Various ground instruments like radiometers and ceilometers offer improved accuracy, while infrared all-sky cameras like the Sky InSight™ offer more granular cloud cover descriptions. We aim to compare cloud cover data from these methods and suggest ways to address any disparities. We analyze cloud cover time series from the NOAA Surfrad Radiation Budget Network (SURFRAD) Table Mountain site in Boulder, Colorado, USA, for 2023. Data are collected using a pyrgeometer (Eppley’s PIR), pyranometers (diffuse - Eppley 8-48, global - Spectrosun SR-75), a ceilometer (Vaisala’s CL51), and an infrared all-sky camera (Reuniwatt’s Sky InSight™). Different methodologies are applied depending on the instrument used. For the radiometers, we utilize the existing NOAA RadFlux product (Riihimaki et al. 2019). For the ceilometer, we calculate a weighted average of low-mid cloud occurrences over the previous 30 minutes following the approaches in Wagner et al. (2015). With the Sky InSight™, we employ the provided cloud mask image and compute the ratio of cloudy pixels over the total number of pixels with a zenith angle below 70°, as well as on a narrow view close to the zenith used to emulate a ceilometer. The predominant readings are clear skies (0 and 1 octa) or overcast (7 or 8 octas), accounting for 70.1% of cases for the pyrgeometer, 87.8% for the ceilometer, and approximately 76.1% for the Sky InSight™ hemispherical and ground cloud covers. Overall, cross-instrument accuracy within one octa across all methods ranges between 70% and 75%, although this must be considered in the context of the high occurrence of clear and overcast skies at the site. For partial cloud cover cases (octas 2-6), cross-instrument accuracies drop to 25%-46%, with the ceilometer showing the most divergence and the camera and pyrgeometer tending to agree more often. The camera emulation of a ceilometer significantly improves agreement between the two instruments, suggesting between 25% and 35% of the ceilometer’s variance is due to the reduced field of view and averaging window.  Analysis reveals that ceilometer measurements often miss cloud edges or gaps in the cloud cover due to their narrow spatial constraints, making partial cloud cover readings less frequent. They are also more sensitive to optically thin clouds than the other instruments. Conversely, while both the camera and pyrgeometer are sensitive to the entire sky dome, the latter tends to underestimate cloud cover for thin overcast skies (altostratus), whereas the former may miss some high-altitude cirrus clouds. 
Coastal fog and its formation: Insights for the Catalonia Coastline
Authors: Álvarez Téllez Manuel
Published: July 2024

Saving properties and lives are one of the premises of a weather forecaster. Coastal fog presents significant challenges not only for daily life but also for the correct functioning of infrastructures such as airports, ports, and even roads. Therefore, accurately forecasting these events is crucial. However, fog remains a relatively unpredictable meteorological phenomenon. Thus, it is essential to know the geography well and understand which types of situations are favourable to its formation and anticipate them.In this study, various episodes from long series of spot observations along the Catalan coast have been analysed. More specifically, eight events from 2008 were chosen because they could be compared to Barcelona sounding, HRV satellite images, and buoy database. Only those which affected almost all parts of the Catalan coastline have been analysed in order to avoid a specific situation.The conclusions show that fog events are more frequent in spring, but not exclusively. A strong subsidence inversion close to the surface is also necessary, due to the stability caused by the high-pressure system. Furthermore, the position of the anticyclone over the Mediterranean is crucial to the formation of fog. The wind path, from south to north, is determinant in acquiring humidity. Additionally, crossing from warmer to colder maritime surface temperatures helps to saturate the air mass, and also the bigger the difference between air mass temperature and sea surface temperature, the more chances there will be for its formation.Last but not least, the more persistent the anticyclone is, the more favourable the conditions and the persistence of the event will be because the air mass acquires characteristics from the Mediterranean Sea.
A WRF-LES study of turbine inflow and wake characterization
Authors: Peña Alfredo , Angelou Nikolas
Published: July 2024

Measurements of both the wind turbine inflow and its wake from a floating wind turbine are here analyzed to understand the role of the vertical wind shear and the veer on both inflow and wake characteristics. The inflow measurements correspond to those from a nacelle-mounted Doppler wind lidar that retrieved radial velocities up to three rotor diameters in front of the turbine, measuring thus within a large portion of the atmosphere. The wake measurements correspond to those from a scanning lidar that measured up to ten rotor diameters in both plan position indicator and range height indicator modes, thus covering spatially a good portion of the wake. For a significant number of periods, both inflow and wake measurements reveal the presence of a clear low-level jet (LLJ) with noses close to turbine hub height (about 100 m). The presence of LLJs complicates inflow modeling as, depending on the inflow model and measurement coverage, negative wind shears might appear.We therefore study the ability of the Weather Research and Forecasting (WRF) model in simulating similar inflow conditions as those observed under the above LLJ episodes. Since turbulence and the presence of the turbine itself are highly important, we use the ability of the WRF model to perform large-eddy simulations (LES) for these conditions and we model the turbine by using a generalized actuator disk (GAD). The WRF-LES simulations reveal the turbulence and atmospheric stability conditions that are required to replicate the inflow conditions that lead to these shallow LLJs. Further, after similar LLJ conditions (as those measured) are achieved with the WRF-LES simulations, a similar turbine as the real floating turbine is implemented in the simulation via the GAD. Here, we then analyzed the differences and similarities between the wake measurements and the wake simulations  and their characteristics.
Periodic Characteristics and Cause Analysis of Continuous Heavy Rainfall Induced by Typhoon Yagi (1814) in Shandong
Authors: Sun Shasha , Chen Boyu , Sun Jun , Sun Yi , Diao Xiuguang , Wang Qian
Published: July 2024

The Best Track from China Meteorological Administration (CMA) tropical cyclone database as well as the observation data of high level and surface stations, minute precipitation, radar, satellite and reanalysis data were used to analyze both periodic characteristics and cause of continuous heavy rainfall induced by the “north going” landing Typhoon Yagi(1814) in Shandong. The results show: During the period under the influence of Yagi, the torrential rain has distinct phases. The precipitation of typhoon body and the cold air and typhoon interaction are much stronger than those of two other stages. The precipitation formed by the typhoon body has larger range but weaker intensity than that of the heavy rain phase when the cold air interacted with the typhoon. The typhoon body precipitation phase has low-centroid tropical precipitation features, while the cold air and typhoon interaction phase shows high-centroid frontal precipitation features. During the northward movement of Yagi, the water vapor transport conditions were significantly abnormal compared with those of normal years, which was favorable for persistent heavy rainfall. During the typhoon body precipitation stage, the main heavy precipitation area is located in the forward direction of the typhoon, while in the cold air interacted with the typhoon stage, the main heavy precipitation area is located in the direction of the typhoon and the spiral rain band on the right side of Yagi. The top of low-level jet, vertical wind shear in the low and middle troposphere and convergence line above ground surface together determine where the main heavy precipitation area occurs. The moving direction of typhoon is consistent with both the long axis direction of isentropic potential vorticity (IPV) and the moving direction of high value center of IPV. During the typhoon movement, the IPV has a significant increase, which is caused by the transfer from the higher-level atmosphere that has high potential vorticity (PV) cold air to the lower level atmosphere. During the later period of Yagi landfall, the spiral rain band developed, while the mesoscale convection characteristics were significant. This is related to frontogenesis induced by the cold air invasion as well as high-altitude terrain. On the one hand, the frontogenesis in the cold air and typhoon interaction phase is obvious. On the other hand, the high-altitude terrain in the central and eastern regions of Shandong which plays an uplifting role and the frontogenesis of the weather system are conducive to the convective system enhancement, therefore promote the spiral rain band to develop.（This paper has been published in Plateau Meteorology）
Analysis of the potential of CML data for nowcasting forecasts in Poland
Authors: Pasierb Magdalena , Bałdysz Zofia , Szturc Jan , Nykiel Grzegorz , Jurczyk Anna , Ośródka Katarzyna , Figurski Mariusz , Wojtkowski Cezary , Wojtczak Marcin
Published: July 2024

The growing network of telecommunication stations and commercial microwave links (CMLs) in last years has opened a window into a new way of rainfall estimation. This is a relatively new approach in precipitation estimation field, and it gives reasonably good results, and so have become a valuable source of precipitation information which can successfully supplement other existing observations. The potential of CMLs lies in their high temporal resolution (reaching one minute) and high abundance, so they are increasingly used for short‐term forecasting (nowcasting). Like any type of data, data from commercial microwave links are subject to quality control to isolate non-functioning stations and those links that systematically give erroneous results. Such a pilot analysis and quality control was recently carried out on 66 CMLs from the Opole Voivodeship, Poland. It was analysed to what extent the precipitation derived from CML attenuation data is useful in estimation of the precipitation field with the high temporal and spatial resolution required in nowcasting models. Several methods were used to estimate precipitation field based on data from available links. The CML-based estimates were compared to point observations from manual rain gauges and multi-source precipitation fields using daily and half-hourly accumulations. The analyses conducted show that the CML-based precipitation fields are much worse than radar-derived estimates. At the same time, they had slightly poorer reliability than spatially interpolated telemetric rain gauge data and significantly higher reliability than satellite estimates. There is seen potential for precipitation forecasting using CML data, for example in regions where there is no weather radar. But on the other hand there a challenge to validate data in regions where there is no ground-truth data available.