OSA1.6 | The Weather Research and Forecasting Model (WRF): development, research and applications
The Weather Research and Forecasting Model (WRF): development, research and applications
Convener: Gert-Jan Steeneveld | Co-convener: Arianna Valmassoi
| Thu, 07 Sep, 09:00–10:15 (CEST)|Lecture room B1.02
| Attendance Thu, 07 Sep, 16:00–17:15 (CEST) | Display Wed, 06 Sep, 10:00–Fri, 08 Sep, 13:00|Poster area 'Day room'
Orals |
Thu, 09:00
Thu, 16:00
The Weather Research and Forecasting model (WRF) is a widely used high-resolution meteorological model for operational weather forecasting, fundamental and applied research in meteorology, air quality, wind energy engineering, and consultancy studies. Its user’s community consists of universities, weather forecasters, and consultancy agencies world-wide. The goal of this session is to create a European forum to discuss research results concerning all aspects of the WRF and MPAS modelling frameworks.
Papers are invited on:
• Initialization, and meteorological and land surface boundary conditions.
• Numerical and grid spacing aspects
• Studies concerning data assimilation.
• Development of physical parameterization schemes.
• Model evaluation and validation against a broad range of available observations.
• Future WRF development.
• Tailored WRF versions, e.g. polar WRF, WRF-LES, WRF-Chem, H-WRF, the WRF single-column model
• WRF applications in weather forecasting, air quality studies, wind energy engineering.
• Regional climate studies
• Mesoscale meteorological phenomena studied with WRF.
• Analogous studies using Model for Prediction Across Scales (MPAS)

Orals: Thu, 7 Sep | Lecture room B1.02

Chairpersons: Gert-Jan Steeneveld, Arianna Valmassoi
Onsite presentation
András Peterka and István Geresdi

Operative forecasting of the fog is still a challenge. The numerical weather prediction (NWP) models frequently miss the spatial and temporal location or onset and the dissipation the fog. Even the recently developed microphysics schemes (e.g. Thompson Aerosol Aware scheme (hereafter TAAS)), evaluate the rate of the activation of the hygroscopic aerosol particles as a function of the vertical velocity. However, in the case of fog, the updraft is usually negligible, therefore this method is physically inconsistent.

A novel parameterization technique was developed to evaluate the rate of aerosol activation in fog. This novel scheme was implemented into WRF, TAAS microphysical module. The novel parametrization calculates the activation rate as a function of local cooling rate, and as a function of local change of water vapor content. Furthermore, a diagnostic variable was introduced to evaluate the visibility reduction due to the formation of haze droplets.

A well observed radiative fog event was used, to demonstrate the capabilities of the novel parametrization. Data from standard meteorological stations, and a measurement campaign at Budapest are available to test the numerical model.

The results are as follows: (i) While the original TAAS activates the aerosols homogeneously throughout the fog (the prescribed minimum value for the updraft velocity is constant in both space and time), the novel parameterization scheme results in significant spatial and temporal variability of the droplets concentration. The impact of the cooling is well demonstrated by the enhanced activation rate at the top of the fog. (ii) In the dissipation period the spatial extension of the fog simulated by novel parameterization fit better to the satellite data than that of calculated by the updraft based parameterization. The novel activation scheme increases the life time of the fog by 30 – 60 min. (iii) Gradual decrease and increase of the visibility can be simulated by calculating of the visibility reduction due to the haze (iv) Comparison of the observed and simulated data shows that the early dissipation of the simulated fog not necessarily the consequence of the overestimation of downward short wave flux.

The results of further case studies for different types of fog are planned to present.

How to cite: Peterka, A. and Geresdi, I.: Improvement of numerical simulation of fog: Implementation of a novel scheme in WRF Thompson Aerosol Aware module to simulate the activation of aerosol particles, EMS Annual Meeting 2023, Bratislava, Slovakia, 4–8 Sep 2023, EMS2023-61, https://doi.org/10.5194/ems2023-61, 2023.

Onsite presentation
Michael Matějka, Kamil Láska, and Stachoň Zdeněk

Antarctic Peninsula (AP) glaciers experiencing mean summer air temperature near the melting point are highly sensitive to both long‑term climate variability and short-term but intense warm air advection events. Large scale flow during these events could be further modified by interaction with topography, e.g., by foehn development at the eastern coast of 1000 – 2000 m high AP mountain range. Foehn effect on glacier melt was extensively studied at the Larsen C Ice Shelf region. However, less attention was given to ablation events occurring at the northeastern coast, where AP mountains are less prominent, and where flow interacts also with complex topography of western Weddell Sea islands. In this contribution, we present an analysis of three pronounced melt events in summer 2022/2023 observed on the Davies Dome glacier (514 m a.s.l.) and a cirque-based Triangular Glacier (180 m a.s.l.), both located on Ulu Peninsula, northern James Ross Island. Melt events were identified and their intensity was quantified with an ultrasonic depth sensor data supplemented by snow and ice density observations. The selected events induced total snow/ice melt of ~1.19 m water equivalent (Triangular Glacier) and ~0.28 m water equivalent (Davies Dome) and significantly contributed to an anomalous ablation season 2022/2023 in this region. In-situ air temperature, wind speed, albedo, and net radiation observations allowed identification of crucial meteorological factors leading to snow and ice melt. Differences in melt regime of studied glaciers were further discussed. In addition to in-situ measurements, the Weather Research and Forecasting (WRF) model was run in a very high resolution for investigated events. The model output allowed analysis of synoptic-scale advection patterns leading to enhanced glacier ablation. An attention was given also to the effects of AP mountains and James Ross Island topography on incoming flow characteristics and possible foehn development.

How to cite: Matějka, M., Láska, K., and Zdeněk, S.: Meteorological forcing of unusually high glacier melt on James Ross Island, Antarctic Peninsula in summer 2022/2023:  in-situ observations and WRF model simulations, EMS Annual Meeting 2023, Bratislava, Slovakia, 4–8 Sep 2023, EMS2023-223, https://doi.org/10.5194/ems2023-223, 2023.

Online presentation
Jon Ander Arrillaga, Ivan R. Gelpi, Aurelio Diaz de Arcaya, Antonio Castaño, and Santiago Gaztelumendi

The summer of 2022 in the Basque Country was characterized by extremely dry and hot conditions. In a major part of the region, precipitation levels were 50% below average, and the mean temperature was 2.4 ºC higher than the 1981-2010 climatology. This made it the warmest summer on record, second only to 2003. In the midst of this arid and sweltering season, a historic persistent and high temperatures event occurred between July 13th and 18th. During the episode, maximum temperatures exceeded 40 ºC in some areas for several consecutive days, with the highest recorded temperature reaching 43.6 ºC. Minimum temperatures were also persistently high, with some stations not dropping below 20 or even 25 ºC during the warmest days.

Given the extreme and challenging context in terms of surface heating and evapotranspiration, we assessed the ability of the WRF model with a operational forecasting configuration to reproduce the observed atmospheric conditions during the estudied case. Although wind patterns and hourly temperature evolution where generally well-reproduced, maximum temperatures were slightly underestimated and minimum temperatures were greatly overestimated in some areas. Specifically, the WRF configuration did not accurately capture the local weakening of wind at night and the subsequent formation of surface-based thermal inversions on days when offshore southerly winds prevailed.

In this work we present different aspects related with the fine-tune temperature prediction during this significant heatwave episode. We present results from different sensitivity experiments on the operational configuration. We tested various dynamics options, finer land-use databases, and physical parameterizations. We also include some comparison results with other forecast systems available in Euskalmet as other mesoescale models or statistical prediction systems.

How to cite: Arrillaga, J. A., R. Gelpi, I., Diaz de Arcaya, A., Castaño, A., and Gaztelumendi, S.: Evaluating the WRF model’s ability to predict extreme temperatures :  a record-breaking high temperatures case in the Basque Country, EMS Annual Meeting 2023, Bratislava, Slovakia, 4–8 Sep 2023, EMS2023-255, https://doi.org/10.5194/ems2023-255, 2023.

Online presentation
Impacts of Soil Moisture Retrievals in the Strongly Coupled Atmosphere-Land Data Assimilation System
Sujeong Lim, Seon Ki Park, and Milija Zupanski
Online presentation
Aurelio Diaz de Arcaya, Ivan R. Gelpi, Jon Ander Arrillaga, Antonio Castaño, and Santiago Gaztelumendi

In this work, we present a system developed by Tecnalia and Euskalmet for air quality forecast at local level, the system runs since 2019 in order to provide different air quality products to support some operational task in Basque Meteorology Agency (Euskalmet).  

The air quality prediction multi-model system developed is based on two main modelization strategies, one using CHIMERE and another one based on WRF-CHEM.  The system  have been implemented for the hourly prediction of air quality for the pollutants CO, NO2, O3, PM10, PM2.5 and SO2 in the domain of the Basque Country. Both models are executed daily with a prediction horizon of up to 4 days and with resolutions around 1 km. In the case of the CHIMERE chemical transport model, four nested domains are considered, being the coarser domain Western Europe and the finer one the Autonomous Community of the Basque Country (CAE), WRF model meteorological fields are included offline. In the case of WRF-CHEM, three nested domains are implemented, the first one being Western Europe and the last one the CAE, in this case meteorology given by the WRF model and the pollutant transport module, are executed online. In both cases, the WRF meteorological model starts from the initial and boundary conditions given by the one-degree GFS global prediction model. The emissions used by both models are those given by the EMEP emissions inventory for the CHIMERE model and EDGAR for the anthropogenic emissions required by WRF-CHEM. Subsequently, for the domain of the Autonomous Community of the Basque Country, a proprietary emissions inventory has been used.

In this contribution, main results of the implementation of the system are shown, including post-processing, products generation and validation. Finally, some conclusions from pre-operational and operational experiences are presented.

How to cite: Diaz de Arcaya, A., R. Gelpi, I., Arrillaga, J. A., Castaño, A., and Gaztelumendi, S.: An air quality multi-model prediction system for the Basque Country, EMS Annual Meeting 2023, Bratislava, Slovakia, 4–8 Sep 2023, EMS2023-261, https://doi.org/10.5194/ems2023-261, 2023.

Posters: Thu, 7 Sep, 16:00–17:15 | Poster area 'Day room'

Display time: Wed, 6 Sep 10:00–Fri, 8 Sep 13:00
Chairpersons: Arianna Valmassoi, Gert-Jan Steeneveld
Juan José Rosa-Cánovas, Matilde García-Valdecasas, Emilio Romero-Jiménez, Yenny Marcela Toro-Ortiz, Sonia Raquel Gámiz-Fortis, Yolanda Castro-Díez, and María Jesús Esteban-Parra

The Mediterranean regions are expected to experience an increase in temperature under the climate change scenario along the ongoing 21st century. Thus, the development of instruments to predict the evolution of this field is crucial to adequately assess the challenges we are called to face in the upcoming decades. Decadal climate predictions (DCPs), alongside seasonal predictions, play a fundamental role at time scales in which this kind of information is being actively requested by institutions and governments.

This study aims at assessing the prediction skill of maximum and minimum temperatures in the Iberian Peninsula (IP) by using DCPs at a very high resolution. The experiments have been conducted by following a dynamical downscaling (DD) approach with the Weather Research and Forecasting model (WRF) version as the regional model, and the Decadal Prediction Large Ensemble (DPLE) providing the initial and boundary conditions. The DPLE encompasses a set of decadal experiments initialized every year in November from 1954 to 2017. For each initialization date, an ensemble composed of 40 members generated by randomly perturbing the initial atmospheric conditions. In this study, the DD simulations have been performed for a subensemble of 4 members and 13 initialization dates (from 1987 to 1999). Two nested domains have been considered: one, coarser, covering the EUROCORDEX region at a resolution of 50 km approximately, and another, finer, spanning the IP at a resolution of about 10 km. The prediction skill has been assessed for different forecast ranges to analyze the dependence of the skill on the lead time along the decade.

The results of this study will contribute to the collective efforts of the scientific community in the development of mitigation and adaptation strategies to climate change. This is particularly relevant in the IP, where the consequences of the increase in temperature, such as an increment in droughts and heat waves frequency and intensity, are already causing human, environmental and economic losses.


Keywords: maximum temperature, minimum temperature, Weather Research and Forecasting Model, Iberian Peninsula, Decadal Prediction Large Ensemble.

Acknowledgments: J. J. Rosa-Cánovas acknowledges the Spanish Ministry of Science, Innovation and Universities for the predoctoral fellowship (grant code: PRE2018-083921). This research has been carried out in the framework of the projects P20_00035, funded by FEDER/Junta de Andalucía-Consejería de Transformación Económica, Industria, Conocimiento y Universidades, CGL2017-89836-R, funded by the Spanish Ministry of Economy and Competitiveness with additional FEDER funds, the project LifeWatch-2019-10-UGR-01 co-funded by the Ministry of Science and Innovation through the FEDER funds from the Spanish Pluriregional Operational Program 2014-2020 (POPE), LifeWatch-ERIC action line, and the project PID2021-126401OB-I00 funded by MCIN/AEI/ 10.13039/501100011033/FEDER Una manera de hacer Europa.

How to cite: Rosa-Cánovas, J. J., García-Valdecasas, M., Romero-Jiménez, E., Toro-Ortiz, Y. M., Gámiz-Fortis, S. R., Castro-Díez, Y., and Esteban-Parra, M. J.: High-resolution decadal climate prediction of maximum and minimum temperatures in the Iberian Peninsula, EMS Annual Meeting 2023, Bratislava, Slovakia, 4–8 Sep 2023, EMS2023-294, https://doi.org/10.5194/ems2023-294, 2023.

Matilde García-Valdecasas Ojeda, Feliciano Solano-Farías, David Donaire-Montaño, Luna Cepeda-Ventura, Emilio Romero-Jiménez, Juan José Rosa-Cánovas, Yolanda Castro-Díez, Sonia Gámiz-Fortis, and María Jesús Esteban-Parra

The climate of Sierra Nevada affects many relevant aspects for the living systems that inhabit it as well as the water resources of a region with semi-arid characteristics. Climate change in the Sierra Nevada can be especially exacerbated by its condition of mountainous region and its location in the Mediterranean area, which makes it a double climate change hotspot. Monitoring and studyng its present and future climate are crucial to define adaptation strategies to climate change and the use of very high-resolution regional models becomes a useful tool in this area of complex topography.

In this work we evaluate climate simulations at a resolution of 1 km using the Weather Research and Forecasting (WRF) model as a convection permitting model and we analyze the added value of these simulations with respect to another with a resolution of 5 km for the Sierra Nevada area. The simulations cover the period 2001-2020 and the analysis focuses on the study of precipitation. The simulated precipitation is compared with observational data mainly from the Climanevada database (https://climanevada.obsnev.es/).

In addition to analyzing the mean precipitation values and some extreme indices, the evaluation is also focused on the comparison of the simulated data for some extreme events in order to analyze both the increasing improvement in the spatial and temporal resolutions.

Keywords: Sierra Nevada, precipitation, WRF, convection permitting model, added value.


This research was financed by the project “Thematic Center on Mountain Ecosystem & Remote sensing, Deep learning-AIe-Services University of Granada-SierraNevada” (LifeWatch-2019-10-UGR-01), which has been co-funded by the Ministry of Science and Innovation through the FEDER funds from the Spanish Pluriregional Operational Program2014-2020 (POPE), LifeWatch-ERIC action line, the project P20_00035 funded by FEDER/Junta de Andalucía-Consejería de Transformación Económica, Industria, Conocimiento y Universidades, and by the project PID2021-126401OB-I00 funded by MCIN/AEI/ 10.13039/501100011033/FEDER Una manera de hacer Europa.

How to cite: García-Valdecasas Ojeda, M., Solano-Farías, F., Donaire-Montaño, D., Cepeda-Ventura, L., Romero-Jiménez, E., Rosa-Cánovas, J. J., Castro-Díez, Y., Gámiz-Fortis, S., and Esteban-Parra, M. J.: Added value of WRF as a convection permitting regional climate model in simulating precipitation over a mountain region in Southern Europe, EMS Annual Meeting 2023, Bratislava, Slovakia, 4–8 Sep 2023, EMS2023-433, https://doi.org/10.5194/ems2023-433, 2023.