Article
Environmental Sciences
Yang Yue, Jingru Cheng, Kang Soo Lee, Roman Stocker, Xu He, Maosheng Yao, Jing Wang
Summary: This study investigated the formation mechanism and influencing factors of sulfate in fine particles during haze episodes in different city environments through experiments and collected samples. The results revealed that relative humidity significantly affects the formation of new CaSO4.2H2O crystals.
ATMOSPHERIC ENVIRONMENT
(2022)
Article
Environmental Sciences
Yuan Zhang, Shaomin Liu, Lisheng Song, Xiang Li, Zhenzhen Jia, Tongren Xu, Ziwei Xu, Yanfei Ma, Ji Zhou, Xiaofan Yang, Xinlei He, Yunjun Yao, Guangcheng Hu
Summary: This study proposes an integrated validation framework for evaluating the accuracy of remotely sensed evapotranspiration (RS_ET) products over different land surfaces. The framework is applied to five widely used RS_ET products in the Heihe River Basin, analyzing their accuracy, spatiotemporal variations, error sources, and uncertainties during the validation process.
Article
Engineering, Electrical & Electronic
Haemi Park, Junghee Lee, Cheolhee Yoo, Seongmun Sim, Jungho Im
Summary: This article proposed machine learning-based models to estimate spatially continuous daily RHns at 1 km resolution over Japan and South Korea under all sky conditions. XGBoost produced slightly better performance than RF, and the spatially continuous RHns model combined based on XGBoost yielded a coefficient of determination of 0.72 and a root-mean-square error of 10.61%. The spatiotemporal patterns of the estimated RHns agreed with in situ observations, reflecting the effect of topography on RHns.
IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING
(2021)
Article
Meteorology & Atmospheric Sciences
P. Prasad, Ghouse Basha, M. Venkat Ratnam
Summary: In this article, the effect of ambient relative humidity (RH) on the optical properties of aerosols in different seasons and RH conditions over India is presented. The results show that aerosol scattering coefficient and total aerosol number concentration increase under high humidity conditions. Except in the monsoon season, an increase in aerosol optical depth (AOD) is observed as surface RH increases. The profile measurements also confirm an overall increase in AOD with increasing RH, with the strongest impact observed during winter. Overall, aerosols within the boundary layer are more sensitive to RH in the winter and monsoon seasons.
ATMOSPHERIC RESEARCH
(2023)
Article
Agricultural Engineering
Chen Zhang, Shuzhuang Sun, Shaojun Xu, Chunfei Wu
Summary: This study investigates the effects of relative humidity and biochar activation on CO2 capture. The findings show that biochar activated by KOH has a high CO2 capture capacity, and both relative humidity and CO2 concentration decrease negatively impact the capture ability of biochar.
BIOMASS & BIOENERGY
(2022)
Article
Chemistry, Physical
Wenxin Wei, Run Li, Niklas Huber, Gonul Kizilsavas, Calum T. J. Ferguson, Katharina Landfester, Kai A. I. Zhang
Summary: Mesoporous organosilica can act as a visible light-active and heterogeneous photocatalyst for efficient synthesis of aryl azolines, showing high conversion and reusability.
Article
Geosciences, Multidisciplinary
Ren Wang, Pierre Gentine, Jiabo Yin, Lijuan Chen, Jianyao Chen, Longhui Li
Summary: This study used a machine learning approach to retrieve global latent heat flux and sensible heat flux for recent decades, finding a decreasing trend in the evaporative fraction and an increase in long-term runoff, indicating the significant impact of surface vegetation on regulating water and energy cycles and aridity variability.
HYDROLOGY AND EARTH SYSTEM SCIENCES
(2021)
Article
Meteorology & Atmospheric Sciences
Xiaocong Wang, Hao Miao, Yimin Liu, Qing Bao, Bian He, Jinxiao Li, Yaxin Zhao
Summary: The study proposes an improved formula for critical relative humidity (RHc), which is essential for cloud parameterization. By incorporating geographic dependence and allowing for non-monotonic variations in the vertical, the new formula provides better estimates for high- and mid-level clouds compared to the conventional globally uniform RHc used in literature. The study also highlights the importance of RHc in influencing cloud feedback and warns modelers to exercise caution when using RHc for model tuning.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2022)
Article
Geochemistry & Geophysics
Qian-Yu Liao, Pei Leng, Zhao-Liang Li, Chao Ren, Ya-Yong Sun, Mao-Fang Gao, Si-Bo Duan, Guo-Fei Shang
Summary: A new method for deriving all-sky relative humidity entirely based on MODIS data was proposed in this study, showing reasonable accuracy under different aridity conditions, with stable linear relationships over time.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2021)
Article
Environmental Sciences
Weiyuan Zhang, Jiming Li, Sihang Xu, Yang Zhao, Bida Jian
Summary: Based on CloudSat and CALIPSO satellite data, this study explores the spatial and temporal distribution characteristics of critical relative humidity (RHc), assesses the ability of different data sources to characterize humidity subgrid variability, and investigates the influence of meteorological factors and aerosols on RHc. The results show significant variations in the spatial distribution of RHc, with large latitude and altitude variations, as well as pronounced monthly variations. Both reanalysis data and climate models reproduce similar distribution patterns but differ in specific values. Aerosols and meteorological conditions affect RHc distribution by influencing cloud fraction at certain relative humidity levels, highlighting the need for their consideration in future parameterization schemes.
Article
Computer Science, Information Systems
Sunanda Bose, Nandini Mukherjee
Summary: This article proposes novel scheduling algorithms for heterogeneous resources with varying capabilities, contexts of usage, and non-uniform performance over time in a sensor-cloud infrastructure. Simulation results demonstrate that the algorithms perform efficiently.
IEEE TRANSACTIONS ON SERVICES COMPUTING
(2022)
Article
Engineering, Aerospace
Boris Rybakin
Summary: The processes occurring in near and far space have a significant impact on the safety of space flights, especially explosions of supernovae and relativistic jets in quasars, black holes, protostars. New star formation involves complex processes in interstellar gas, including turbulence, gravity, molecular cloud collisions, rotation, and other factors. This paper presents results of computer modeling of large-scale filament formation and superdense structurally parallel computation clusters using a modified second-order Godunov method and ultra-high-resolution grids.
Article
Geosciences, Multidisciplinary
Jianglong Zhang, Robert J. D. Spurr, Jeffrey S. Reid, Peng Xian, Peter R. Colarco, James R. Campbell, Edward J. Hyer, Nancy L. Baker
Summary: The study demonstrates that assimilating OMI aerosol index data into the NAAPS model can significantly reduce errors and improve model simulations over cloudy regions and bright surfaces. However, assimilating passive-based AOD data is more effective over cloud-free skies and dark surfaces, although it requires more computational resources.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2021)
Article
Environmental Sciences
Dandan Li, Yajun Huang, Yao Xiao, Min He, Jianguang Wen, Yuanqing Li, Mingguo Ma
Summary: In this study, the accuracy and uncertainty of MuSyQ LAI in mountainous areas were evaluated using a small-scale validation method. The results showed that MuSyQ LAI was significantly underestimated by 53.69% in the study regions due to complex terrain and heterogeneous land cover. This study is important for the application of MuSyQ LAI products and provides a reference for the improvement and application of other high-resolution remotely sensed LAI products.
Article
Environmental Sciences
Kevin Wolf, Nicolas Bellouin, Olivier Boucher
Summary: This study analyzes the potential for contrail and induced cirrus formation based on radiosonde observations in Trappes, France. It finds that adjusting flight altitudes and fuel types can reduce the probability of contrail formation.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2023)
Article
Multidisciplinary Sciences
Jordi Vila-Guerau de Arellano, Oscar Hartogensis, Imme Benedict, Hugo de Boer, Peter J. M. Bosman, Santiago Botia, Micael Amore Cecchini, Kim A. P. Faassen, Raquel Gonzalez-Armas, Kevin van Diepen, Bert G. Heusinkveld, Martin Janssens, Felipe Lobos-Roco, Ingrid T. Luijkx, Luiz A. T. Machado, Mary Rose Mangan, Arnold F. Moene, Wouter B. Mol, Michiel van der Molen, Robbert Moonen, H. G. Ouwersloot, So-Won Park, Xabier Pedruzo-Bagazgoitia, Thomas Roeckmann, Getachew Agmuas Adnew, Reinder Ronda, Martin Sikma, Ruben Schulte, Bart J. H. van Stratum, Menno A. Veerman, Margreet C. van Zanten, Chiel C. van Heerwaarden
Summary: Vegetation and atmosphere processes are interconnected through various interactions, including plant transpiration, carbon dioxide assimilation, turbulent transport, aerosol formation, moist convection, and precipitation. The challenges ahead involve understanding the impact of clouds and canopies on radiation transfer, spatial distribution of radiative energy, interaction between local processes and regional meteorology, and integration of feedbacks between cloud radiative effects and plant physiology. To address these challenges, the proposed methodology combines fine-scale simulations with new observational techniques to study the role of small-scale spatiotemporal processes in weather and climate models.
ANNALS OF THE NEW YORK ACADEMY OF SCIENCES
(2023)
Article
Meteorology & Atmospheric Sciences
Martin Janssens, Jordi Vila-guerau De Arellano, Chiel C. Van Heerwaarden, Stephan R. De Roode, A. Pier Siebesma, Franziska Glassmeier
Summary: Condensation in cumulus clouds plays a key role in structuring the mean trade wind boundary layer. Small anomalies in condensation power circulations that transport moisture and reinforce the condensation anomaly. The positive feedback of mesoscale moisture fluctuations in cumulus clouds is explained as a linear instability, motivating further research into its relevance.
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2023)
Article
Meteorology & Atmospheric Sciences
Mirjam Tijhuis, Bart J. H. van Stratum, Menno A. Veerman, Chiel C. van Heerwaarden
Summary: Most atmospheric models neglect the horizontal transfer of radiation, resulting in incorrect surface radiation fields. In this study, we developed a simple and computationally efficient method to account for the horizontal transfer of diffuse radiation. By applying a Gaussian filter to the surface diffuse radiation field, we successfully simulated cloud enhancements and obtained a bimodal probability distribution of global radiation, consistent with observations. The filter width can be parameterized as a linear function of cloud cover, providing a proof-of-concept for our method to obtain more realistic surface irradiances without complex calculations.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2023)
Article
Meteorology & Atmospheric Sciences
Martin Janssens, Jordi Vila-Guerau de Arellano, Chiel C. C. van Heerwaarden, Bart J. H. van Stratum, Stephan R. R. de Roode, A. Pier Siebesma, Franziska Glassmeier
Summary: Numerical simulations of tropical mesoscales reveal a self-reinforcing feedback between cumulus convection and shallow circulations, leading to the self-aggregation of clouds into large clusters. Large-eddy simulations (LESs) are used to investigate if this feedback can be accurately captured. However, the energetic convective scales involved in self-aggregation are only slightly larger than LES grid spacings, making it difficult to converge even at high resolutions. Therefore, higher resolutions or improved sub-filter scale models may be necessary to faithfully represent trade-wind mesoscale cloud patterns and self-aggregating deep convection.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2023)
Article
Multidisciplinary Sciences
Thomas Karl, Christian Lamprecht, Martin Graus, Alexander Cede, Martin Tiefengraber, Jordi Vila-Guerau de Arellano, David Gurarie, Donald Lenschow
Summary: Nitrogen oxides (NOx) are crucial in the formation of tropospheric ozone. Recent studies have highlighted the importance of nitrogen dioxide (NO2) in air pollution control, indicating a limited understanding of ozone in high-NOx environments. This study utilizes long-term eddy covariance measurements to disentangle the physical and chemical processes involved in ozone, nitric oxide (NO), and NO2 dynamics in an urban area. The findings suggest that chemical conversion of ozone, rather than deposition, is the dominant process near the surface in urban environments, leading to an underestimation of the Leighton ratio and overestimation of primary NO2 emissions.
Article
Agronomy
Mary Rose Mangan, Oscar Hartogensis, Aaron Boone, Oliver Branch, Guylaine Canut, Joan Cuxart, Hugo J. de Boer, Michel Le Page, Daniel Martinez-Villagrasa, Josep Ramon Miro, Jeremy Price, Jordi Vila-Guerau de Arellano
Summary: Irrigation in semi-arid regions induces thermal heterogeneity at different spatial scales, affecting surface energy partitioning, atmospheric boundary layer development, and atmosphere-surface interactions. This study investigates the role of irrigation-induced thermal heterogeneity scales on surface fluxes and diurnal convective boundary layer development using data from the LIAISE experiment and a land-atmosphere model. The observed surface heterogeneity is characterized by Bowen ratios ranging from -0.01 in irrigated areas to -30 in non-irrigated areas. The study finds that surface fluxes and boundary layer dynamics are influenced by spatial scale and non-local processes such as advection play a significant role in energy partitioning at the local scale.
AGRICULTURAL AND FOREST METEOROLOGY
(2023)
Article
Meteorology & Atmospheric Sciences
Francisca Aguirre-Correa, Jordi Vila-Guerau de Arellano, Reinder Ronda, Felipe Lobos-Roco, Francisco Suarez, Oscar Hartogensis
Summary: Observations in the Altiplano region of the Atacama Desert reveal the sudden collapse of the atmospheric boundary layer (ABL) at noon, caused by the arrival of a thermally driven regional flow. Through numerical experiments and modeling, it is found that non-local processes associated with the regional flow, such as mass advection, cold air advection, and subsidence, are the main factors contributing to the ABL collapse. These external forcings dominate over entrainment and surface processes, limiting the growth of the ABL during the afternoon. The relevance of treating large and small-scale processes as a continuum is highlighted to better understand ABL dynamics.
BOUNDARY-LAYER METEOROLOGY
(2023)
Article
Environmental Sciences
Jinyuan Xin, Yongjing Ma, Dandan Zhao, Chongshui Gong, Xinbing Ren, Guiqian Tang, Xiangao Xia, Zifa Wang, Junji Cao, Jordi Vila-Guerau de Arellano, Scot T. Martin
Summary: The interaction between aerosols and the planetary boundary layer has a significant impact on urban air quality. This study focused on the complex feedback of aerosols on the Beijing megacity and found notable distinctions in aerosol properties and vertical distributions among different air masses. Aerosols consistently suppressed the daytime convective boundary layer, indicating the potential complexity of aerosol-PBL interactions in future scenarios and other urban regions.
ENVIRONMENTAL POLLUTION
(2023)
Article
Meteorology & Atmospheric Sciences
Masih Eghdami, Timothy W. Juliano, Pedro A. Jimenez, Branko Kosovic, Marc Castellnou, Rajesh Kumar, Jordi Vila-Guerau de Arellano
Summary: Smoke from wildfires or burning biomass directly affects air quality and weather through modulating cloud microphysics and radiation. A simple wildfire emission coupling of black carbon (BC) and organic carbon (OC) with microphysics was implemented using the Weather Research and Forecasting model's fire module. The influence of background conditions and interactions between atmospheric and fire processes such as fire smoke, ambient moisture, and latent heat release on the formation and evolution of pyroconvective clouds were investigated through simulations inspired by observational data from a specific fire event in Spain.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2023)
Article
Meteorology & Atmospheric Sciences
Wouter B. Mol, Bart J. H. van Stratum, Wouter H. Knap, Chiel C. van Heerwaarden
Summary: This study examines the relationship between solar irradiance variability and cloud size distribution using long-term, high-frequency solar irradiance observations, satellite imagery, numerical simulations, and conceptual modeling. The research finds that both cloud shadows and locally enhanced irradiance occur frequently, mostly driven by boundary layer clouds but distributed over different scales. These findings have significant implications for weather and climate modeling, as well as solar energy and photosynthesis by vegetation.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Energy & Fuels
Frank P. M. Kreuwel, Wouter Knap, Maurice Schmeits, Jordi Vila-Guerau de Arellano, Chiel C. van Heerwaarden
Summary: Accurate forecasts of minute-to-minute irradiance variability are crucial for the large-scale integration of solar PV systems. However, current numerical weather predictions (NWP) provide forecasts at a much coarser temporal resolution, missing important meteorological variability information such as clouds. This study proposes a methodology to forecast minute-to-minute irradiance variability based on hourly NWP results, using statistical postprocessing and machine learning.
Article
Meteorology & Atmospheric Sciences
B. J. H. van Stratum, C. C. van Heerwaarden, J. Vila-Guerau de Arellano
Summary: Global reanalyzes like ERA5 and large-eddy simulation (LES) provide accurate and detailed information about atmospheric processes. This study introduces an open-source Python package called (LS)D-2, which simplifies the downscaling of ERA5 with doubly-periodic LES. The package is validated using observations and demonstrates its usefulness and limitations, particularly in studying surface solar irradiance variability.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2023)
Article
Environmental Sciences
Kim A. P. Faassen, Linh N. T. Nguyen, Eadin R. Broekema, Bert A. M. Kers, Ivan Mammarella, Timo Vesala, Penelope A. Pickers, Andrew C. Manning, Jordi Vila-Guerau de Arellano, Harro A. J. Meijer, Wouter Peters, Ingrid T. Luijkx
Summary: Measuring the concentration and flux of oxygen and carbon dioxide in the atmosphere can provide insights into the carbon budget of forest ecosystems. This study found that measurements at different heights can yield different results, highlighting the importance of using multiple vertical levels to obtain accurate measurements.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2023)
