Article
Meteorology & Atmospheric Sciences
Mengjuan Liu, Bowen Zhou
Summary: This study examines the variations of subgrid-scale (SGS) turbulent fluxes in the numerical gray zone, and suggests a mixed model combining scale-adaptive PBL scheme for representing the mean flux and a scale-similarity component to account for gridscale variability would be advantageous for the gray zone.
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2022)
Article
Oceanography
William G. Large, Edward G. Patton, Peter P. Sullivan
Summary: Empirical rules for entrainment and detrainment are developed based on LES of the Southern Ocean boundary layer, taking into account turbulence, stratification, and shear, as well as the influence of diurnal variability and Stokes drift. These rules address the failure of downgradient eddy viscosity and provide parameterizations for momentum flux. The response of the boundary layer to diurnal heating includes collapse and growth, with the depth of the boundary layer empirically related to forcing history. Evaluation against LES fluxes shows that flux profiles are more representative of the diurnal cycle, especially with Stokes drift.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2021)
Article
Geosciences, Multidisciplinary
Xingchi Wang, Tobias Kukulka, J. Thomas Farrar, Albert J. Plueddemann, Seth F. Zippel
Summary: The turbulent ocean surface boundary layer (OSBL) shoals during daytime solar surface heating, developing a diurnal warm layer (DWL). The DWL significantly influences OSBL dynamics by trapping momentum and heat in a shallow near-surface layer. Therefore, DWL depth is critical for understanding OSBL transport and ocean-atmosphere coupling.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Carlos Roman-Cascon, Marie Lothon, Fabienne Lohou, Oscar Hartogensis, Jordi Vila-Guerau de Arellano, David Pino, Carlos Yague, Eric R. Pardyjak
Summary: This study focuses on simulating surface heat fluxes in the interface between the Earth's surface and the atmosphere, and finds that using a more realistic surface representation, exploring mosaic approach, and adjusting vegetation type parameters can improve the model simulated fluxes and enhance the accuracy of the model in representing climate and weather changes.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2021)
Article
Meteorology & Atmospheric Sciences
Huaiyu Wei, Yan Wang, Andrew L. Stewart, Julian Mak
Summary: This study investigates the eddy buoyancy diffusivities across continental shelves and slopes using process-oriented simulations. The simulations show that the cross-slope eddy diffusivity varies significantly with topography, and established scaling frameworks accurately reproduce the diagnosed eddy diffusivities. The predictive skills of these scaling frameworks are insensitive to the presence of along-slope topographic corrugations. This work lays a foundation for improving the parameterization of eddy buoyancy fluxes in coarse-resolution ocean models.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2022)
Article
Agronomy
Eric R. Beamesderfer, Sebastien C. Biraud, Nathaniel A. Brunsell, Mark A. Friedl, Manuel Helbig, David Y. Hollinger, Thomas Milliman, David A. Rahn, Russell L. Scott, Paul C. Stoy, Jen L. Diehl, Andrew D. Richardson
Summary: The atmospheric mixing layer height (MLH) is a critical variable for understanding ecosystem and climate dynamics. Previous estimation methods have relied on data with low temporal or spatial resolutions. This study used continuous measurements from ceilometers and radiosondes to analyze the surface influence on MLH dynamics. The results highlight the difficulty in explaining MLH dynamics with single-point observations.
AGRICULTURAL AND FOREST METEOROLOGY
(2023)
Article
Oceanography
Daniel B. Whitt
Summary: This study characterizes the impacts of rainy days on the surface atmosphere and upper ocean physics in the central equatorial Pacific. It finds that rainfall leads to systematic changes in the surface atmosphere and drives reductions in upper-ocean salinity and temperature, as well as increases in buoyancy. These findings contribute to improving weather and climate observations and predictions in the central Pacific.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2022)
Article
Meteorology & Atmospheric Sciences
Charles Pelletier, Florian Lemarie, Eric Blayo, Marie-Noelle Bouin, Jean-Luc Redelsperger
Summary: The study introduces a method for extending existing turbulent parameterizations to a two-sided framework by explicitly including the ocean surface layer within the parameterizations. The novelties are derived from classical turbulent closures, making them easily implementable in existing formulations. The impact of these two-sided bulk formulations on air-sea fluxes evaluated from settings similar to coupled ocean-atmosphere simulations is investigated.
QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY
(2021)
Article
Geosciences, Multidisciplinary
Jordyn E. Moscoso, Andrew L. Stewart, Daniele Bianchi, James C. McWilliams
Summary: Eastern boundary upwelling systems (EBUSs) are active regions in the ocean with significant impacts on ocean ecology, biogeochemistry, and global fish catch. Studied using models ranging from 2-D to global, the Meridionally Averaged Model of Eastern Boundary Upwelling Systems (MAMEBUS) aims to combine the advantages of 2-D and 3-D approaches by parameterizing key 3-D processes in a 2-D framework. MAMEBUS facilitates future studies to efficiently explore the parameters controlling zonal variations in EBUSs.
GEOSCIENTIFIC MODEL DEVELOPMENT
(2021)
Review
Meteorology & Atmospheric Sciences
Georgios Deskos, Joseph C. Y. Lee, Caroline Draxl, Michael A. Sprague
Summary: This review article discusses existing wind-wave coupling models and parameterizations for large-eddy simulation of the marine atmospheric boundary layer. The models are categorized into wave-phase-averaged and wave-phase-resolved models, and their implementation, validity, and computational efficiency are discussed. Emphasis is placed on their applicability in offshore wind energy problems, with a review of laboratory-scale and field-measurement databases for model validation provided. Knowledge gaps in modeling and computational challenges ahead are also addressed.
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2021)
Article
Meteorology & Atmospheric Sciences
Kota Endo, Adam h. Monahan, Julie Bessac, Hannah m. Christensen, Nils Weitzel
Summary: High-resolution numerical models have been used to develop statistical models of sea surface flux enhancement. The study finds that both the deterministic and stochastic parts of the data-driven parameterization are robust. The statistical features of the stochastic part, including spatial and temporal autocorrelation, are also found to be robust and not sensitive to different models, regions, or time periods.
MONTHLY WEATHER REVIEW
(2023)
Article
Meteorology & Atmospheric Sciences
Domingo Munoz-Esparza, Charlie Becker, Jeremy A. Sauer, David John Gagne, John Schreck, Branko Kosovic
Summary: This study explores the use of artificial neural networks (NN) as an alternative to the widely adopted Monin-Obukhov (MO) similarity theory in atmospheric large-eddy simulation models. The simulations using NN models show consistent predicted flux differences with respect to MO simulations, indicating the skill of NN models in predicting tower observations. These differences have significant impacts on mean and turbulence quantities in the atmospheric boundary layer (ABL). However, careful scrutiny in design and evaluation is necessary to prevent unphysical predictions and establish a robust and generalizable parameterization, considering various factors such as input feature engineering, input sources, climatological fingerprints, and activation function choices.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2022)
Article
Meteorology & Atmospheric Sciences
Luoqin Liu, Srinidh N. Gadde, Richard J. A. M. Stevens
Summary: We develop innovative analytical expressions for mean wind and potential temperature flux profiles in convective boundary layers (CBLs). CBLs are important for weather forecasting, climate modeling, and wind energy applications. We propose an analytical expression for the normalized potential temperature flux profile based on the horizontally homogeneous and quasi-stationary characteristics of the surface and inversion layers, allowing us to capture the velocity profile over the entire boundary layer height.
JOURNAL OF THE ATMOSPHERIC SCIENCES
(2023)
Article
Meteorology & Atmospheric Sciences
Marcin J. Kurowski, Joao Teixeira, Chi Ao, Shannon Brown, Anthony B. Davis, Linda Forster, Kuo-Nung Wang, Matthew Lebsock, Mary Morris, Vivienne Payne, Mark T. Richardson, Richard Roy, David R. Thompson, Robert C. Wilson
Summary: This article introduces a simulation experiment framework for evaluating existing and new measurement techniques for the planetary boundary layer (PBL), highlighting the role of large-eddy simulation (LES) in providing high-resolution synthetic observations. The potential of LES-based PBL retrieval experiments is explored using various instrument simulators, and perspectives for instrument development are discussed.
BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
(2023)
Article
Oceanography
Hieu T. Pham, Sutanu Sarkar, Leah Johnson, Baylor Fox-Kemper, Peter P. Sullivan, Qing Li
Summary: A process study using large-eddy simulations investigates the dominant 1-D processes that affect mixed layer properties during a summer Monsoon Intra-seasonal Oscillations event in the Bay of Bengal. Realistic air-sea fluxes and initial conditions collected during a field experiment are employed to explore the roles of thermal inversion layer and Langmuir turbulence in modulating mixed layer properties. The results show that near-inertial oscillations, solar heating, and precipitation have the most impact on mixed layer depth, sea surface temperature, and sea surface salinity.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Article
Meteorology & Atmospheric Sciences
Camila Gomes Martins Ramos, Haochen Tan, Pallav Ray, Jimy Dudhia
Summary: Precipitation cools the surface due to sensible heat flux, with the highest values found in the Intertropical Convergence Zone and the South Pacific Convergence Zone. The correlation between Q(P) and precipitation is not well established on land, but Q(P) can be larger than Q(SH) and Q(LH) during heavy precipitation events at shorter time scales based on in-situ buoy observations. Future research avenues related to Q(P) implications are discussed.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2022)
Article
Meteorology & Atmospheric Sciences
Mukul Tewari, Fei Chen, Jimy Dudhia, Pallav Ray, Shiguang Miao, Efthymios Nikolopoulos, Lloyd Treinish
Summary: This article investigates the spatio-temporal variability of precipitation during the extreme rainfall event in Beijing in 2012, as well as the uncertainties in short-range weather forecasts. By using high-resolution urban-aware simulations, the authors find that the microphysics parameterizations and model initialization time greatly affect the forecast accuracy. Recommendations for improvement are also proposed.
ATMOSPHERIC RESEARCH
(2022)
Article
Meteorology & Atmospheric Sciences
C. Junquas, M. B. Heredia, T. Condom, J. C. Ruiz-Hernandez, L. Campozano, J. Dudhia, J. C. Espinoza, M. Menegoz, A. Rabatel, J. E. Sicart
Summary: A multi-experiment ensemble using the WRF model was conducted in the Antisana glacier region in Ecuador to identify the best model configurations for simulating atmospheric processes. The model successfully reproduced the complex precipitation gradient between the Amazon and Andean regions, but showed overestimation in the afternoon and at night. Changing the microphysics and cumulus schemes primarily affected nighttime processes, while altering topography forcing and radiation options mainly impacted afternoon processes. Based on the findings, a 1-km resolution configuration with activated cumulus scheme was determined to be the best choice for accurate representation of cloud convection in the region.
Article
Meteorology & Atmospheric Sciences
Haochen Tan, Pallav Ray, Bradford Barrett, Jimy Dudhia, Mitchell Moncrieff, Lei Zhang, David Zermeno-Diaz
Summary: The study analyzes the impact of topography on the diurnal cycle of precipitation over the Islands of the Maritime Continent during the propagation of a Madden-Julian Oscillation event. Results show that realistic topography captures the observed diurnal cycle of precipitation better, while the absence of topography leads to a delay in the arrival of peak precipitation and a reduction in rainfall amount.
Article
Meteorology & Atmospheric Sciences
Pedro A. Jimenez, Jaemo Yang, Ju-Hye Kim, Manajit Sengupta, Jimy Dudhia
Summary: WRF-Solar is a numerical weather prediction model specifically designed for accurate solar irradiance forecasting. This study analyzes the adequacy of the National Solar Radiation Database (NSRDB) to validate and improve the performance of WRF-Solar. The study also examines the forecast errors, sensitivity to grid spacing and radiative effects of unresolved clouds in WRF-Solar. Results show that GHI retrievals have the potential to contribute to increasing the performance of WRF-Solar.
JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY
(2022)
Article
Meteorology & Atmospheric Sciences
Zhongkuo Zhao, Xueyan Bi, Jimy Dudhia, Yali Luo, Jinbao Song, Qingtao Song, Naigeng Wu
Summary: The study investigated the responses of the atmospheric boundary layer at low latitudes (20 degrees N) to forcing by an ocean-mesoscale sea surface temperature (SST) front through ideal numerical experiments. The results showed that the responses were sensitive to the background wind speed and its direction relative to the SST front, and that constructive convergence and divergence could cause strong convergence and divergence in the boundary layer near the SST front.
QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY
(2022)
Article
Energy & Fuels
Ju-Hye Kim, Pedro Jimenez Munoz, Manajit Sengupta, Jaemo Yang, Jimy Dudhia, Stefano Alessandrini, Yu Xie
Summary: This study introduced the WRF-solar ensemble prediction system and a calibration method, showing improvement in forecast quality and reduction of positive bias through ensemble forecasting and analog ensemble calibration, respectively.
IEEE JOURNAL OF PHOTOVOLTAICS
(2022)
Article
Computer Science, Interdisciplinary Applications
Tobias Tolle, Dirk Gruending, Dieter Bothe, Tomislav Maric
Summary: We propose a numerical method for calculating volume fractions from triangulated surfaces immersed in unstructured meshes. The method utilizes geometric calculations of signed distances and an approximate solution of the Laplace equation. It ensures high absolute accuracy and is applicable to triangulated surface models with technical geometrical complexity.
COMPUTER PHYSICS COMMUNICATIONS
(2022)
Article
Engineering, Civil
Hehe Ren, Jimy Dudhia, Shitang Ke, Hui Li
Summary: In this study, hurricane simulation cases were conducted to investigate the wind characteristics of hurricanes at different sea surface temperatures. The results showed a good agreement between the minimum sea surface pressure and the maximum time-averaged wind speed. The maximum tangential wind and radial inflow increased with increasing sea surface temperature. The depth of the inflow layer varied for different intensity hurricanes, and extreme updrafts were found only for intense hurricanes. The study also revealed the average surface inflow angle and the relationship between tangential velocity and radial velocity.
JOURNAL OF WIND ENGINEERING AND INDUSTRIAL AERODYNAMICS
(2022)
Article
Energy & Fuels
Pedro A. Jimenez, Jimy Dudhia, Gregory Thompson, Jared A. Lee, Thomas Brummet
Summary: In this study, a new MAD-WRF model is proposed by combining the MADCast model with the WRF-Solar model, which can improve short-term predictions by integrating cloud initialization and cloud physics parameterization. The experimental results demonstrate that the MAD-WRF model performs better in global horizontal irradiance predictions.
Article
Engineering, Chemical
Suraj Raju, Dirk Gruending, Tomislav Maric, Dieter Bothe, Mathis Fricke
Summary: This study proposes a fast, automated, and rigorously verified open-source solution for computing the hydrodynamic eigenmodes of a two-dimensional channel flow. The numerical results validate analytically derived asymptotic power laws for the leading hydrodynamic eigenmode in the limiting cases of small and large slip.
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
(2022)
Article
Meteorology & Atmospheric Sciences
Hehe Ren, Jimy Dudhia, Hui Li
Summary: In this study, we conducted simulations of four hurricane cases to investigate the size characteristics of the radius of maximum wind (RMW) at different intensity levels. The results show that the distribution of RMW exhibits a similar trend to absolute angular momentum. By considering the physical mechanism of absolute angular momentum, we explained the radial distribution of RMW in different hurricane intensity cases.
ATMOSPHERIC RESEARCH
(2022)
Article
Engineering, Civil
Hehe Ren, Shitang Ke, Jimy Dudhia, Hui Li
Summary: This study investigated wind disasters caused by typhoons that made landfall in China from 2004 to 2020 using the radial integral method. The research analyzed the factors influencing typhoon wind disasters, verified the applicability of the method using existing data, and studied the change patterns of wind disasters before and after landfall in different regions of China. The study provides valuable insights for the assessment and prevention of typhoon wind disasters.
JOURNAL OF WIND ENGINEERING AND INDUSTRIAL AERODYNAMICS
(2022)
Article
Computer Science, Interdisciplinary Applications
Jun Liu, Tobias Tolle, Dieter Bothe, Tomislav Maric
Summary: This study extends a method for handling two-phase flows with different densities and provides a theoretical basis for the numerical consistency between mass and momentum conservation. The proposed method demonstrates exact numerical stability for two-phase momentum advection and performs well in challenging fluid pairings.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)
Article
Environmental Sciences
Ifeanyi Chukwudi Achugbu, Ayorinde A. Olufayo, Ifeoluwa A. Balogun, Elijah A. Adefisan, Jimy Dudhia, Edward Naabil
Summary: This study validated the use of updated MCD12Q1 MODIS LULC data in the WRF model and investigated the effects of LULC change on various climatic factors over West Africa. Results showed that different LULC scenarios had complex impacts on temperature, precipitation, and other parameters, with afforestation leading to decreased temperature and increased rainfall in some areas. Further in-depth analysis of the effects on the general circulation of WA is recommended for future research.
MODELING EARTH SYSTEMS AND ENVIRONMENT
(2022)
