Aircraft icing: in-cloud measurements and sensitivity to physical parameterizations

The prediction of supercooled cloud drops in the atmosphere is a basic tool for aviation safety, owing to their contact with and instant freezing on sensitive locations of the aircraft. One of the main disadvantages for predicting atmospheric icing conditions is the acquisition of observational data. In this study, we used in‐cloud microphysics measurements taken during 10 flights of a C‐212 research aircraft under winter conditions, during which we encountered 37 regions containing supercooled liquid water. To investigate the capability of the Weather Research and Forecasting model to detect regions containing supercooled cloud drops, we propose a multiphysics ensemble approach. We used four microphysics and two planetary boundary layer schemes. The Morrison parameterization yielded superior results, whereas the planetary boundary layer schemes were essential in evaluating the presence of liquid water content. The Goddard microphysics scheme best detected the presence of ice water content but tended to underestimate liquid water content

Aircraft icing: in‐cloud measurements and sensitivity to physical parameterizations

The prediction of supercooled cloud drops in the atmosphere is a basic tool for aviation safety, owing to their contact with and instant freezing on sensitive locations of the aircraft. One of the main disadvantages for predicting atmospheric icing conditions is the acquisition of observational data. In this study, we used in‐cloud microphysics measurements taken during 10 flights of a C‐212 research aircraft under winter conditions, during which we encountered 37 regions containing supercooled liquid water. To investigate the capability of the Weather Research and Forecasting model to detect regions containing supercooled cloud drops, we propose a multiphysics ensemble approach. We used four microphysics and two planetary boundary layer schemes. The Morrison parameterization yielded superior results, whereas the planetary boundary layer schemes were essential in evaluating the presence of liquid water content. The Goddard microphysics scheme best detected the presence of ice water content but tended to underestimate liquid water content.This research was carried out in the framework of the SAFEFLIGHT project, financed by MINECO (CGL2016‐78702) and LE240P18 project (Junta de Castilla y León)

Comparison of the WRF and HARMONIE models ability for mountain wave warnings

Mountain lee waves usually involve aircraft icing and turbulence events. These weather phenomena, in turn, are a threat to aviation safety. For this reason, mountain lee waves are an interesting subject of study for the scientific community. This paper analyses several mountain lee waves events in the south-east of the Guadarrama mountain range, near the Adolfo Suarez Madrid-Barajas airport (Spain), using the Weather Research and Forecasting (WRF) and the HARMONIE-AROME high-resolution numerical models. For this work, simulated brightness temperature from the optimum WRF parametrization schemes and from the HARMONIE are validated using satellite observations to evaluate the performance of the models in reproducing the lenticular clouds associated to mountain lee waves. The brightness temperature probability density shows interesting differences between both models. Following, a mountain wave characterization is performed simulating some atmospheric variables (wind direction, wind speed, atmospheric stability, liquid water content and temperature) in several grid points located in the leeward, windward and over the summit of the mountains. The characterization results are compared for both numerical models and a decision tree is developed for each to forecast and warn the mountain lee waves, lenticular clouds and icing events with a 24 to 48 h lead time. These warnings are validated using several skill scores, revealing similar results for both models

Dataset for Subtropical cyclone formation via warm seclusion development: The importance of surface fluxes

In the related manuscript, the importance of surface heat fluxes is evaluated by means of the Weather Research and Forecasting (WRF) model. To that end, two WRF simulations are compared considering the presence and absence of these heat fluxes. Due to the huge size of the assessed cyclone which generated an extense domain to analyze and due to its long life-cycle, the obtained WRF model outputs are of considerable size. Therefore, only the WRF run files are provided here. Furthermore, the post-processing NCL and Matlab scripts are provided here with which the different analyzed variables have been plotted for the two analyzed dates considering the presence and absence of surface heat fluxes

Dataset for Subtropical cyclone formation via warm seclusion development: The importance of surface fluxes

In the related manuscript, the importance of surface heat fluxes is evaluated by means of the Weather Research and Forecasting (WRF) model. To that end, two WRF simulations are compared considering the presence and absence of these heat fluxes. Due to the huge size of the assessed cyclone which generated an extense domain to analyze and due to its long life-cycle, the obtained WRF model outputs are of considerable size. Therefore, only the WRF run files are provided here. Furthermore, the post-processing NCL and Matlab scripts are provided here with which the different analyzed variables have been plotted for the two analyzed dates considering the presence and absence of surface heat fluxes

Analysis of the October 2014 subtropical cyclone using the WRF and the HARMONIE-AROME numerical models: Assessment against observations

Subtropical cyclones (STCs) are low-pressure systems characterized by having a thermal hybrid structure and sharing tropical and extratropical characteristics. These cyclones are widely studied due to their harmful impacts, in some cases, similar to those caused by hurricanes or tropical storms. From a numerical modeling point of view, they are considered a challenge on account of their rapid intensification. That is the reason why this paper analyzes the simulations of the STC that occurred in October 2014 near the Canary Islands through two highresolution numerical models: Weather Research and Forecasting (WRF) and HARMONIE-AROME. In this study, the simulations obtained with both models of this STC are analyzed versus different observational data. METAR data are used to validate some surface simulated variables throughout the STC life while soundings are chosen to study the tropospheric behavior. Finally, MSG-SEVIRI satellite brightness temperature is used to be compared to those brightness temperatures simulated by both models to give information of the cloud top spatial structure of this atmospheric system. The 2 m temperature, 2 m dew-point temperature, and 10 m wind speed variables do not show significant deviations when carrying out the validation of both models against the available METAR data. It is outstanding the good results found for the HARMONIE-AROME model when analyzing the temperature sounding for both analyzed dates. Additionally, regarding the wind speed sounding, better results are presented in general by the HARMONIE-AROME model, being the WRF model slightly better during the pre-STC stage. Moreover, the skillfulness of the HARMONIE-AROME model is highlighted when simulating the infrared brightness temperature and cloud distribution compared to the WRF model