scholarly journals Towards improving the simulation of meteorological fields in urban areas through updated/advanced surface fluxes description

2008 ◽  
Vol 8 (3) ◽  
pp. 523-543 ◽  
Author(s):  
A. Baklanov ◽  
P. G. Mestayer ◽  
A. Clappier ◽  
S. Zilitinkevich ◽  
S. Joffre ◽  
...  
Keyword(s):  
Air Pollution ◽  
Urban Areas ◽  
Prediction Models ◽  
Weather Prediction ◽  
Surface Fluxes ◽  
Surface Exchange ◽  
Urban Meteorology ◽  
Recent Developments ◽  
Urban Roughness ◽  
Meteorology And Air Pollution

Abstract. The increased resolution of numerical weather prediction models allows nowadays addressing more realistically urban meteorology and air pollution processes. This has triggered new interest in modelling and describing experimentally the specific features and processes of urban areas. Recent developments and results performed within the EU-funded project FUMAPEX on integrated systems for forecasting urban meteorology and air pollution are reported here. Sensitivity studies with respect to optimum resolution, parametrisation of urban roughness and surface exchange fluxes and the role of urban soil layers are carried out with advanced meso- or sub-meso meteorological models. They show that sensible improvements can be achieved by higher model resolution that is accompanied with better description of urban surface features. Recommendations, especially with respect to advanced urban air quality forecasting and information systems, are given together with an assessment of the needed further research and data.

scholarly journals On the parameterisation of the urban atmospheric sublayer in meteorological models

2005 ◽  
Vol 5 (6) ◽  
pp. 12119-12176 ◽  
Author(s):  
A. Baklanov ◽  
P. Mestayer ◽  
A. Clappier ◽  
S. Zilitinkevich ◽  
S. Joffre ◽  
...  
Keyword(s):  
Air Pollution ◽  
Urban Areas ◽  
Prediction Models ◽  
Weather Prediction ◽  
Surface Exchange ◽  
Urban Meteorology ◽  
Recent Developments ◽  
Urban Roughness ◽  
Meteorological Models ◽  
Meteorology And Air Pollution

Abstract. The increased resolution of numerical weather prediction models allows nowadays addressing more specifically urban meteorology and air pollution processes and forecasts. This has triggered new interest in modelling and describing experimentally the specific features and processes of urban areas. Recent developments and results performed within the EU-funded project FUMAPEX on integrated systems for forecasting urban meteorology and air pollution are reported here. Issues of optimum resolution, parameterising urban roughness and surface exchange fluxes and the role of the urban soil layers are addressed with advanced meso- or sub-meso meteorological models. Recommendations, especially with respect to advanced urban air quality forecasting and information systems, are given together with an assessment of the needed further research and data.

scholarly journals ECLand: The ECMWF Land Surface Modelling System

2021 ◽  
Author(s):  
Souhail Boussetta ◽  
Gianpaolo Balsamo ◽  
Gabriele Arduini ◽  
Emanuel Dutra ◽  
Joe McNorton ◽  
...  
Keyword(s):  
Land Surface ◽  
Urban Areas ◽  
Weather Prediction ◽  
Open Water ◽  
Surface Fluxes ◽  
Atmospheric Composition ◽  
Flexible System ◽  
Wide Range ◽  
Forecasting System ◽  
The One

The land-surface developments of the European Centre for Medium-range Weather Forecasts (ECMWF) are based on the Carbon-Hydrology Tiled Scheme for Surface Exchanges over Land (CHTESSEL) and form an integral part of the Integrated Forecasting System (IFS), supporting a wide range of global weather, climate and environmental applications. In order to structure, coordinate and focus future developments and benefit from international collaboration in new areas, a flexible system named ECLand which would facilitates modular extensions to support numerical weather prediction (NWP) and society-relevant operational services, e.g. Copernicus, is presented . This paper introduces recent examples of novel ECLand developments on (i) vegetation, (ii) snow, (iii) soil, (iv) open water/lake (v) river/inundation, and (vi) urban areas. The developments are evaluated separately with long-range, atmosphere-forced surface offline simulations, and coupled land-atmosphere-ocean experiments. This illustrates the benchmark criteria for assessing both, process fidelity with regards to land surface fluxes and reservoirs of the water-energy-carbon exchange on the one hand, and on the other hand the requirements of ECMWF’s NWP, climate and atmospheric composition monitoring services using an Earth system assimilation prediction framework.

scholarly journals Variance-Based Sensitivity Analysis: Preliminary Results in COAMPS

2014 ◽  
Vol 142 (5) ◽  
pp. 2028-2042 ◽  
Author(s):  
Caren Marzban ◽  
Scott Sandgathe ◽  
James D. Doyle ◽  
Nicholas C. Lederer
Keyword(s):  
Sensitivity Analysis ◽  
Prediction Models ◽  
Theoretical Calculations ◽  
Weather Prediction ◽  
Surface Fluxes ◽  
Cumulus Parameterization ◽  
Convective Precipitation ◽  
Primary Concern ◽  
Total Precipitation ◽  
Parameter Values

Abstract Numerical weather prediction models have a number of parameters whose values are either estimated from empirical data or theoretical calculations. These values are usually then optimized according to some criterion (e.g., minimizing a cost function) in order to obtain superior prediction. To that end, it is useful to know which parameters have an effect on a given forecast quantity, and which do not. Here the authors demonstrate a variance-based sensitivity analysis involving 11 parameters in the Coupled Ocean–Atmosphere Mesoscale Prediction System (COAMPS). Several forecast quantities are examined: 24-h accumulated 1) convective precipitation, 2) stable precipitation, 3) total precipitation, and 4) snow. The analysis is based on 36 days of 24-h forecasts between 1 January and 4 July 2009. Regarding convective precipitation, not surprisingly, the most influential parameter is found to be the fraction of available precipitation in the Kain–Fritsch cumulus parameterization fed back to the grid scale. Stable and total precipitation are most affected by a linear factor that multiplies the surface fluxes; and the parameter that most affects accumulated snow is the microphysics slope intercept parameter for snow. Furthermore, all of the interactions between the parameters are found to be either exceedingly small or have too much variability (across days and/or parameter values) to be of primary concern.

scholarly journals The role of urban boundary layer investigated by high resolution models and ground based observations in Rome area: a step for understanding parameterizations potentialities

2013 ◽  
Vol 6 (3) ◽  
pp. 5297-5344
Author(s):  
E. Pichelli ◽  
R. Ferretti ◽  
M. Cacciani ◽  
A. M. Siani ◽  
V. Ciardini ◽  
...  
Keyword(s):  
Boundary Layer ◽  
High Resolution ◽  
Urban Areas ◽  
Prediction Models ◽  
Weather Prediction ◽  
Sonic Anemometer ◽  
Lower Atmosphere ◽  
Area Of Interest ◽  
The Impact

Abstract. The urban forcing on thermo-dynamical conditions can largely influences local evolution of the atmospheric boundary layer. Urban heat storage can produce noteworthy mesoscale perturbations of the lower atmosphere. The new generations of high-resolution numerical weather prediction models (NWP) is nowadays largely applied also to urban areas. It is therefore critical to reproduce correctly the urban forcing which turns in variations of wind, temperature and water vapor content of the planetary boundary layer (PBL). WRF-ARW, a new model generation, has been used to reproduce the circulation in the urban area of Rome. A sensitivity study is performed using different PBL and surface schemes. The significant role of the surface forcing in the PBL evolution has been verified by comparing model results with observations coming from many instruments (LiDAR, SODAR, sonic anemometer and surface stations). The crucial role of a correct urban representation has been demonstrated by testing the impact of different urban canopy models (UCM) on the forecast. Only one of three meteorological events studied will be presented, chosen as statistically relevant for the area of interest. The WRF-ARW model shows a tendency to overestimate vertical transmission of horizontal momentum from upper levels to low atmosphere, that is partially corrected by local PBL scheme coupled with an advanced UCM. Depending on background meteorological scenario, WRF-ARW shows an opposite behavior in correctly representing canopy layer and upper levels when local and non local PBL are compared. Moreover a tendency of the model in largely underestimating vertical motions has been verified.

scholarly journals Turbulence-permitting air pollution simulation for the Stuttgart metropolitan area

2020 ◽  
Author(s):  
Thomas Schwitalla ◽  
Hans-Stefan Bauer ◽  
Kirsten Warrach-Sagi ◽  
Thomas Bönisch ◽  
Volker Wulfmeyer
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Metropolitan Area ◽  
Urban Areas ◽  
Single Layer ◽  
Urban Canopy ◽  
Surface Fluxes ◽  
Residential Areas ◽  
Near Surface ◽  
Air Quality Forecast

Abstract. Air pollution is one of the major challenges in urban areas. It can have a major impact on human health and society and is currently a subject of several litigations at European courts. Information on the level of air pollution is based on near surface measurements, which are often irregularly distributed along the main traffic roads and provide almost no information about the residential areas and office districts in the cities. To further enhance the process understanding and give scientific support to decision makers, we developed a prototype for an air quality forecasting system (AQFS) within the EU demonstration project Open Forecast. For AQFS, the Weather Research and Forecasting model together with its coupled chemistry component (WRF-Chem) is applied for the Stuttgart metropolitan area in Germany. Three model domains from 1.25 km down to a turbulence permitting resolution of 50 m were used and a single layer urban canopy model was active in all domains. As demonstration case study the 21 January 2019 was selected which was a heavy polluted day with observed PM10 concentrations exceeding 50 µg m−3. Our results show that the model is capable to reasonably simulate the diurnal cycle of surface fluxes and 2-m temperatures as well as evolution of the stable and shallow boundary layer typically occurring in wintertime in Stuttgart. The simulated fields of particulates with a diameter of less than 10 µm (PM10) and Nitrogen dioxide (NO2) allow a clear statement about the most heavily polluted areas apart from the irregularly distributed measurement sites. Together with information about the vertical distribution of PM10 and NO2 from the model, AQFS will serve as a valuable tool for air quality forecast and has the potential of being applied to other cities around the world.

Reviewing operational and near operational progress in surface water flood forecasting for urban areas

2020 ◽  
Author(s):  
Linda Speight ◽  
Michael Cranston ◽  
Laura Kelly ◽  
Christopher White
Keyword(s):  
Surface Water ◽  
Urban Areas ◽  
Prediction Models ◽  
Rapid Development ◽  
Weather Prediction ◽  
Flood Forecasting ◽  
Water Flooding ◽  
Environment Protection ◽  
Probabilistic Forecasting ◽  
Protection Agency

<p>Surface water flooding is caused by intense rainfall before it enters rivers or drainage systems. As the climate changes and urban populations grow, the number of people around the world at risk of surface water flooding increases. Although it may not be possible to prevent such flooding, reliable and timely flood forecasts can help improve preparedness and recovery. Unlike river and coastal flooding where flood forecasting methods are well established, surface water forecasting techniques that address the challenges around predicting the location, timing and impact of events are still in their infancy.</p><p>Over the past five years there has been a rapid development of convection permitting numerical weather prediction models and probabilistic forecasting. Combined with an increase in computational ability, this has meant that it is potentially feasible to develop operational surface water forecasting systems for urban areas. The ability to make flood risk management decisions based on such forecasts depends on an interdisciplinary understanding of their strengths and limitations.</p><p>In 2019, the Scottish Environment Protection Agency (SEPA) commissioned a systematic review of UK and international surface water forecasting capabilities to inform the development of forecasting capabilities for Scotland (Speight et al, 2019). As part of the review process a literature review of international examples of operational surface water forecasting tools was conducted alongside discussion with a number of industry experts and leading academics to incorporate emerging capabilities.</p><p>This PICO will summarise the three approaches to surface water forecasting identified as part of this review; empirical based rainfall scenarios, hydrological forecasts linked to pre-simulated impact scenarios, and, real time hydrodynamic simulation. International examples of each type of approach will be presented along with discussion of their ability to meet the varying needs of decision makers. It will conclude by identifying ‘grand interdisciplinary challenges’ that still need to be addressed to provide effective solutions for reliable and timely surface water forecasts. For example although the emergence of new meteorological and hydrological capabilities is promising there is a scientific limit to the predictability of convective rainfall. To overcome this challenge re-thinking of the established role of flood forecasting is needed alongside developing interdisciplinary solutions for communicating uncertainty, making the best use of all available data and increasing preparedness.</p><p> </p><p><em>Speight, L., Cranston, M., Kelly, L. and White, C.J. (2019) Towards improved surface water flood forecasts for Scotland: A review of UK and international operational and emerging capabilities for the Scottish Environment Protection Agency. University of Strathclyde, Glasgow, pp 1-63, doi:10.17868/69416 Available online at https://strathprints.strath.ac.uk/69416/</em></p>

scholarly journals Parametrizing Horizontally-Averaged Wind and Temperature Profiles in the Urban Roughness Sublayer

2019 ◽  
Vol 173 (3) ◽  
pp. 321-348 ◽  
Author(s):  
Natalie E. Theeuwes ◽  
Reinder J. Ronda ◽  
Ian N. Harman ◽  
Andreas Christen ◽  
C. Sue B. Grimmond
Keyword(s):  
Wind Speed ◽  
Numerical Weather Prediction ◽  
Prediction Models ◽  
Weather Prediction ◽  
Roughness Sublayer ◽  
Vertical Profiles ◽  
Flux Boundary Condition ◽  
Numerical Weather ◽  
Urban Roughness Sublayer ◽  
Urban Roughness

Abstract Tower-based measurements from within and above the urban canopy in two cities are used to evaluate several existing approaches that parametrize the vertical profiles of wind speed and temperature within the urban roughness sublayer (RSL). It is shown that current use of Monin–Obukhov similarity theory (MOST) in numerical weather prediction models can be improved upon by using RSL corrections when modelling the vertical profiles of wind speed and friction velocity in the urban RSL using MOST. Using anisotropic building morphological information improves the agreement between observed and parametrized profiles of wind speed and momentum fluxes for selected methods. The largest improvement is found when using dynamically-varying aerodynamic roughness length and displacement height. Adding a RSL correction to MOST, however, does not improve the parametrization of the vertical profiles of temperature and heat fluxes. This is expected since sources and sinks of heat are assumed uniformly distributed through a simple flux boundary condition in all RSL formulations, yet are highly patchy and anisotropic in a real urban context. Our results can be used to inform the choice of surface-layer representations for air quality, dispersion, and numerical weather prediction applications in the urban environment.

scholarly journals Effect of urbanization on the urban meteorology and air pollution in Hangzhou

2015 ◽  
Vol 29 (6) ◽  
pp. 950-965 ◽  
Author(s):  
Hongnian Liu ◽  
Wanli Ma ◽  
Junlong Qian ◽  
Juzhen Cai ◽  
Xianman Ye ◽  
...  
Keyword(s):  
Air Pollution ◽  
Urban Meteorology ◽  
Meteorology And Air Pollution
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