scholarly journals The Enviro-HIRLAM online integrated meteorology–chemistry modelling system: strategy, methodology, developments, and applications

2017 ◽  
Author(s):  
Alexander Baklanov ◽  
Ulrik Smith Korsholm ◽  
Roman Nuterman ◽  
Alexander Mahura ◽  
Kristian Pagh Nielsen ◽  
...  
Keyword(s):  
Indirect Effects ◽  
Urban Areas ◽  
Weather Forecasting ◽  
Weather Prediction ◽  
Cloud Microphysics ◽  
Research Strategy ◽  
Integrated Modelling ◽  
Limited Area ◽  
Main Research ◽  
Modelling System

Abstract. The Environment – HIgh Resolution Limited Area Model (Enviro-HIRLAM) is developed as a fully online integrated numerical weather prediction (NWP) and atmospheric chemical transport (ACT) model for research and forecasting of joint meteorological, chemical and biological weather. The integrated modelling system is developed by DMI in collaboration with several European universities. It is the baseline system in the HIRLAM Chemical Branch and used in several countries and different applications. The development was initiated at DMI more than 15 years ago. The first version was based on the DMI-HIRLAM NWP model with online integrated passive pollutant transport and dispersion, chemistry, aerosol dynamics, deposition and indirect effects. To make the model suitable for chemical weather forecasting (CWF) in urban areas the meteorological part was improved by implementation of urban parameterizations. The dynamical core was improved by implementing a locally mass conserving semi-Lagrangian numerical advection scheme, which improves forecast accuracy and model performance. The latest developing version is based on HIRLAM reference v7.2 with a more advanced and effective chemistry, aerosol multi-compound approach, aerosol feedbacks (direct and semi-direct) on radiation and (first and second indirect effects) on cloud microphysics. Since 2004 the Enviro-HIRLAM is used for different studies, including operational pollen forecasting for Denmark since 2009. Following main research and development strategy the further model developments will be extended towards the new NWP platform – HARMONIE. Different aspects of online coupling methodology, research strategy and possible applications of the modelling system, and fit-for-purpose model configurations for the meteorological and air quality communities are discussed.

scholarly journals Enviro-HIRLAM online integrated meteorology–chemistry modelling system: strategy, methodology, developments and applications (v7.2)

2017 ◽  
Vol 10 (8) ◽  
pp. 2971-2999 ◽  
Author(s):  
Alexander Baklanov ◽  
Ulrik Smith Korsholm ◽  
Roman Nuterman ◽  
Alexander Mahura ◽  
Kristian Pagh Nielsen ◽  
...  
Keyword(s):  
Urban Areas ◽  
Weather Forecasting ◽  
Weather Prediction ◽  
Cloud Microphysics ◽  
Research Strategy ◽  
Atmospheric Composition ◽  
Integrated Modelling ◽  
Limited Area ◽  
Main Research ◽  
Modelling System

Abstract. The Environment – High Resolution Limited Area Model (Enviro-HIRLAM) is developed as a fully online integrated numerical weather prediction (NWP) and atmospheric chemical transport (ACT) model for research and forecasting of joint meteorological, chemical and biological weather. The integrated modelling system is developed by the Danish Meteorological Institute (DMI) in collaboration with several European universities. It is the baseline system in the HIRLAM Chemical Branch and used in several countries and different applications. The development was initiated at DMI more than 15 years ago. The model is based on the HIRLAM NWP model with online integrated pollutant transport and dispersion, chemistry, aerosol dynamics, deposition and atmospheric composition feedbacks. To make the model suitable for chemical weather forecasting in urban areas, the meteorological part was improved by implementation of urban parameterisations. The dynamical core was improved by implementing a locally mass-conserving semi-Lagrangian numerical advection scheme, which improves forecast accuracy and model performance. The current version (7.2), in comparison with previous versions, has a more advanced and cost-efficient chemistry, aerosol multi-compound approach, aerosol feedbacks (direct and semi-direct) on radiation and (first and second indirect effects) on cloud microphysics. Since 2004, the Enviro-HIRLAM has been used for different studies, including operational pollen forecasting for Denmark since 2009 and operational forecasting atmospheric composition with downscaling for China since 2017. Following the main research and development strategy, further model developments will be extended towards the new NWP platform – HARMONIE. Different aspects of online coupling methodology, research strategy and possible applications of the modelling system, and fit-for-purpose model configurations for the meteorological and air quality communities are discussed.

scholarly journals Development of an operational modelling system for urban heat islands: an application to Athens, Greece

2013 ◽  
Vol 1 (5) ◽  
pp. 4963-4996
Author(s):  
T. M. Giannaros ◽  
D. Melas ◽  
I. A. Daglis ◽  
I. Keramitsoglou
Keyword(s):  
Weather Forecasting ◽  
Weather Prediction ◽  
Urban Climate ◽  
Mitigation Strategies ◽  
Urban Heat Islands ◽  
Heat Island ◽  
Meteorological Model ◽  
Near Surface ◽  
Urban Heat ◽  
Modelling System

Abstract. The urban heat island (UHI) effect is one prominent form of localized anthropogenic climate modification. It represents a significant urban climate problem since it occurs in that layer of the atmosphere where almost all daily human activities take place. This paper presents the development of a high-resolution modelling system that could be used for simulating the UHI effect in the context of operational weather forecasting activities. The modelling system is built around a state-of-the-art numerical weather prediction model, properly modified to allow for the better representation of the urban climate. The model performance in terms of simulating the near-surface air temperature and thermal comfort conditions over the complex urban area of Athens, Greece, is evaluated during a 1.5-month operational implementation in the summer of 2010. Results from this case study reveal an overall satisfactory performance of the modelling system. The discussion of the results highlights the important role that, given the necessary modifications, a meteorological model can play as a supporting tool for developing successful heat island mitigation strategies. This is further underlined through the operational character of the presented modelling system.

scholarly journals The ALADIN System and its canonical model configurations AROME CY41T1 and ALARO CY40T1

2018 ◽  
Vol 11 (1) ◽  
pp. 257-281 ◽  
Author(s):  
Piet Termonia ◽  
Claude Fischer ◽  
Eric Bazile ◽  
François Bouyssel ◽  
Radmila Brožková ◽  
...  
Keyword(s):  
High Resolution ◽  
Data Assimilation ◽  
Numerical Weather Prediction ◽  
Weather Forecasting ◽  
Weather Prediction ◽  
Forecast Model ◽  
Canonical Model ◽  
Limited Area ◽  
Climate Simulations ◽  
Process Studies

Abstract. The ALADIN System is a numerical weather prediction (NWP) system developed by the international ALADIN consortium for operational weather forecasting and research purposes. It is based on a code that is shared with the global model IFS of the ECMWF and the ARPEGE model of Météo-France. Today, this system can be used to provide a multitude of high-resolution limited-area model (LAM) configurations. A few configurations are thoroughly validated and prepared to be used for the operational weather forecasting in the 16 partner institutes of this consortium. These configurations are called the ALADIN canonical model configurations (CMCs). There are currently three CMCs: the ALADIN baseline CMC, the AROME CMC and the ALARO CMC. Other configurations are possible for research, such as process studies and climate simulations. The purpose of this paper is (i) to define the ALADIN System in relation to the global counterparts IFS and ARPEGE, (ii) to explain the notion of the CMCs, (iii) to document their most recent versions, and (iv) to illustrate the process of the validation and the porting of these configurations to the operational forecast suites of the partner institutes of the ALADIN consortium. This paper is restricted to the forecast model only; data assimilation techniques and postprocessing techniques are part of the ALADIN System but they are not discussed here.

scholarly journals The ALADIN System and its Canonical Model Configurations AROME CY41T1 and ALARO CY40T1

2017 ◽  
Author(s):  
Piet Termonia ◽  
Claude Fischer ◽  
Eric Bazile ◽  
François Bouyssel ◽  
Radmila Brožková ◽  
...  
Keyword(s):  
High Resolution ◽  
Numerical Weather Prediction ◽  
Weather Forecasting ◽  
Weather Prediction ◽  
Forecast Model ◽  
Canonical Model ◽  
Limited Area ◽  
Prediction System ◽  
Climate Simulations ◽  
Process Studies

Abstract. The ALADIN System is a numerical weather prediction system (NWP) developed by the international ALADIN consortium for operational weather forecasting and research purposes. It is based on a code that is shared with the global model IFS of the ECMWF and the ARPEGE model of Météo-France. Today, this system can be used to provide a multitude of high-resolution limited-area model (LAM) configurations. A few configurations are thoroughly validated and prepared to be used for the operational weather forecasting in the 16 Partner Institutes of this consortium. These configurations are called the ALADIN Canonical Model Configurations (CMCs). There are currently three CMCs: the ALADIN baseline-CMC, the AROME CMC and the ALARO CMC. Other configurations are possible for research, such as process studies and climate simulations. The purpose of this paper is (i) to define the ALADIN System in relation to the global counterparts IFS and ARPEGE, (ii) to explain the notion of the CMCs and to document their most recent versions, and (iii) to illustrate the process of the validation and the porting of these configurations to the operational forecast suites of the Partner Institutes of the ALADIN consortium. This paper is restricted to the forecast model only; data assimilation techniques and postprocessing techniques are part of the ALADIN System but they are not discussed here.

scholarly journals Interactions Between the Nocturnal Low-Level Jets and the Urban Boundary Layer: A Case Study over London

2022 ◽  
Author(s):  
Aristofanis Tsiringakis ◽  
Natalie E. Theeuwes ◽  
Janet F. Barlow ◽  
Gert-Jan Steeneveld
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Urban Areas ◽  
Prediction Models ◽  
Weather Prediction ◽  
Urban Boundary Layer ◽  
Limited Area ◽  
Low Level ◽  
Low Level Jets

AbstractUnderstanding the physical processes that affect the turbulent structure of the nocturnal urban boundary layer (UBL) is essential for improving forecasts of air quality and the air temperature in urban areas. Low-level jets (LLJs) have been shown to affect turbulence in the nocturnal UBL. We investigate the interaction of a mesoscale LLJ with the UBL during a 60-h case study. We use observations from two Doppler lidars and results from two high-resolution numerical-weather-prediction models (Weather Research and Forecasting model, and the Met Office Unified Model for limited-area forecasts for the U.K.) to study differences in the occurrence frequency, height, wind speed, and fall-off of LLJs between an urban (London, U.K.) and a rural (Chilbolton, U.K.) site. The LLJs are elevated ($$\approx $$ ≈ 70 m) over London, due to the deeper UBL, while the wind speed and fall-off are slightly reduced with respect to the rural LLJ. Utilizing two idealized experiments in the WRF model, we find that topography strongly affects LLJ characteristics, but there is still a substantial urban influence. Finally, we find that the increase in wind shear under the LLJ enhances the shear production of turbulent kinetic energy and helps to maintain the vertical mixing in the nocturnal UBL.

scholarly journals Dealing with uncertainty: an analysis of the severe weather events over Italy in 2006

2009 ◽  
Vol 9 (6) ◽  
pp. 1775-1786 ◽  
Author(s):  
L. Molini ◽  
A. Parodi ◽  
F. Siccardi
Keyword(s):  
Urban Areas ◽  
Weather Prediction ◽  
Objective Evaluation ◽  
Horizontal Resolution ◽  
Limited Area ◽  
Civil Protection ◽  
Forecast Verification ◽  
Common Definition ◽  
Mediterranean Countries ◽  
Definition Of

Abstract. Forecast verification is a long-standing issue of the whole meteorologists' community. A common definition of a truly satisfying prediction skill has not been achieved so far. Even the definition of "event", due to its spatio-temporal discontinuity, is highly affected by uncertainty. Moreover, decision-making demands numerical weather prediction modellers to provide information about the "inner" uncertainty, i.e. the degree of uncertainty related to the choice of a specific setting of the model (microphysics, turbulence scheme, convective closure, etc.). Most European Mediterranean countries, due to dense development, steep coastal orography and short hydrological response time of the drainage basins, have to deal very frequently with flash floods and sudden shallow land sliding impacting on urban areas. Civil protection organizations are in place to issue early warnings in order to allow local authorities and population to take precautionary measures. To do so in Mediterranean catchments, hydrologists are required to use numerical rainfall predictions in place of rainfall observations on large European catchments. Estimating the measure of uncertainty is for this reason crucial. The goal of this work is to propose an objective evaluation of the performance of the currently operational weather prediction model COSMO-I7 over quite a long time period and to check forecast verification at different space-time scales by the comparison of predictions with observations. Due to large investments in the last years, in fact, Italy has built up one of the most dense hourly-reporting network of rain gauges. The network has a mean space density of about 1/100 km2, very similar to the horizontal resolution of currently operating limited area models. An objective procedure to identify and compare the extreme events of precipitation has been applied to the full set of rainfall observations and over the severe events forecast by COSMO-I7 and announced in official warnings by Italian Civil Protection Department. The procedure allows to classify rainfall events as long-lived and spatially distributed or as having a shorter duration and a minor spatial extent. We show that long-lived events are less affected by overall uncertainty than short-lived ones, yet the inner uncertainty of the event affects both.

Distributed urban drag parameterization in the sub-kilometre scale London Model

2021 ◽  
Author(s):  
Birgit Sützl ◽  
Gabriel Rooney ◽  
Anke Finnenkoetter ◽  
Sylvia Bohnenstengel ◽  
Sue Grimmond ◽  
...  
Keyword(s):  
High Resolution ◽  
Urban Areas ◽  
Prediction Models ◽  
Weather Forecasting ◽  
Weather Prediction ◽  
Urban Environments ◽  
Internal Boundary ◽  
Average Height ◽  
High Rise ◽  
London Model

<p>Urban environments in numerical weather prediction models are currently parameterised as part of the atmosphere-surface exchange at ground-level. The vertical structure of buildings is represented by the average height, which does not account for heterogeneous building forms at the subgrid-level. The use of city-scale models with sub-kilometre resolutions and growing number of high-rise buildings in cities call for a better vertical representation of urban environments.</p><p>We present the use of a newly developed, height-distributed urban drag parameterization with the London Model, a high-resolution version of the Met Office Unified Model over Greater London and surroundings at approximately 333 m resolution. The distributed drag parameterization requires vertical morphology profiles in form of height-distributed frontal area functions, which capture the full extent and variability of building-heights. These morphology profiles were calculated for Greater London and parameterised by an exponential distribution with the ratio of maximum to mean building-height as parameter.</p><p>A case study with the high-resolution London Model and the new drag parameterization appears to capture more realistic features of the urban boundary layer compared to the standard parameterization. The simulation showed increased horizontal spatial variability in total surface stress, identifying a broad range of morphology features (densely built-up areas, high-rise building clusters, parks and the river). Vertical effects include heterogeneous wind profiles, extended building wakes, and indicate the formation of internal boundary layers. This study demonstrates the potential of height-distributed urban parameterizations to improve urban weather forecasting, albeit research into distribution of heat- and moisture-exchange is necessary for a fully distributed parameterization of urban areas.</p>

scholarly journals Observation Operator for Visible and Near-Infrared Satellite Reflectances

2014 ◽  
Vol 31 (6) ◽  
pp. 1216-1233 ◽  
Author(s):  
Philipp M. Kostka ◽  
Martin Weissmann ◽  
Robert Buras ◽  
Bernhard Mayer ◽  
Olaf Stiller
Keyword(s):  
Water Content ◽  
Near Infrared ◽  
Weather Prediction ◽  
Three Dimensional ◽  
Liquid Water Content ◽  
Relative Difference ◽  
Cloud Microphysics ◽  
Small Scale ◽  
Limited Area ◽  
Central Wavelength

Abstract Operational numerical weather prediction systems currently only assimilate infrared and microwave satellite observations, whereas visible and near-infrared reflectances that comprise information on atmospheric clouds are not exploited. One of the reasons for that is the absence of computationally efficient observation operators. To remedy this issue in anticipation of the future regional Kilometer-Scale Ensemble Data Assimilation (KENDA) system of Deutscher Wetterdienst, we have developed a version that is fast enough for investigating the assimilation of cloudy reflectances in a case study approach. The operator solves the radiative transfer equation to simulate visible and near-infrared channels of satellite instruments based on the one-dimensional (1D) discrete ordinate method. As input, model output of the operational limited-area Consortium for Small-Scale Modeling (COSMO) model of Deutscher Wetterdienst is used. Assumptions concerning subgrid-scale processes, calculation of in-cloud values of liquid water content, ice water content, and cloud microphysics are summarized, and the accuracy of the 1D simulation is estimated through comparison with three-dimensional (3D) Monte Carlo solver results. In addition, the effects of a parallax correction and horizontal smoothing are quantified. The relative difference between the 1D simulation in “independent column approximation” and the 3D calculation is typically less than 9% between 0600 and 1500 UTC, computed from four scenes during one day (with local noon at 1115 UTC). The parallax-corrected version reduces the deviation to less than 6% for reflectance observations with a central wavelength of 810 nm. Horizontal averaging can further reduce the error of the 1D simulation. In all cases, the bias is less than 1% for the model domain.

scholarly journals Chemical weather forecasting: a new concept of integrated modelling

2010 ◽  
Vol 4 (1) ◽  
pp. 23-27 ◽  
Author(s):  
A. Baklanov
Keyword(s):  
Chemical Composition ◽  
Weather Forecasting ◽  
Weather Prediction ◽  
Chemical Transport ◽  
Integrated System ◽  
Integrated Modelling ◽  
System Modelling ◽  
Time Step ◽  
Transport Models ◽  
Chemical Transport Models

Abstract. During the last decade a new field of atmospheric modelling – the chemical weather forecasting (CWF) – is quickly developing and growing. However, in the most of the current studies and publications, this field is considered in a simplified concept of the off-line running chemical transport models with operational numerical weather prediction (NWP) data as a driver. A new concept and methodology considering the chemical weather as two-way interacting meteorological weather and chemical composition of the atmosphere is suggested and discussed. The on-line integration of mesometeorological models and atmospheric aerosol and chemical transport models gives a possibility to utilize all meteorological 3-D fields in the chemical transport model at each time step and to consider feedbacks of air pollution (e.g. urban aerosols) on meteorological processes/climate forcing and then on the atmospheric chemical composition. This very promising way for future atmospheric simulation systems (as a part of and a step to Earth System Modelling) will lead to a new generation of models for meteorological, environmental and chemical weather forecasting. The methodology how to realise the suggested integrated CWF concept is demonstrated on the example of the European Enviro-HIRLAM integrated system. The importance of different feedback mechanisms for CWF is also discussed in the paper.

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