Evaluating the ability of a numerical weather prediction model to forecast tracer concentrations during ETEX 2 |
| |
| Authors: | HF Dacre |
| |
| Institution: | 1. School of Civil Engineering and Environmental Science, University of Oklahoma, United States;2. Advanced Radar Research Center, National Weather Center, Norman, OK 73072, United States;3. Department of Natural Resource Ecology and Management, Oklahoma State University, Stillwater, OK 74078, United States;4. NOAA/National Severe Storms Laboratory, Norman, OK 73072, United States;5. State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China;6. Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China;1. School of Earth and Environmental Sciences, Seoul National University, Seoul, South Korea;2. Department of Environmental Science and Engineering, Ewha Womans University, Seoul, South Korea;3. Department of Atmospheric and Environmental Sciences, Gangneung-Wonju National University, Gangneung, South Korea;1. Laboratoire LAMPA, University of Tizi Ouzou, Tizi Ouzou, Algeria;2. School EPMI, EPMI – 13 Boulevard de l’Hautil 95092 CERGY PONTOISE Cedex, Paris, France;3. Novimet, 11 boulevard d’Alembert, 78280 Guyancourt, Paris, France;1. Physics Department, Tecnológico de Monterrey, Av. Eugenio Garza Sada 2501 Sur, Monterrey 64849, Mexico;2. National Renewable Energy Centre (CENER), Ciudad de la Innovación 7, Sarriguren 31621, Spain;1. Institute for Industrial, Radiophysical and Environmental Safety (ISIRYM), Universitat Politècnica de València, 46022, Valencia, Spain;2. Hospital Clínic Universitari de Valencia. Avda. Blasco Ibáñez, 17. 46010, Valencia, Spain;1. Engineering Science and Mechanics, Virginia Tech, Blacksburg, VA, USA;2. Plant Pathology, Physiology, and Weed Science, Virginia Tech, Blacksburg, VA, USA |
| |
| Abstract: | In this paper the meteorological processes responsible for transporting tracer during the second ETEX (European Tracer EXperiment) release are determined using the UK Met Office Unified Model (UM). The UM predicted distribution of tracer is also compared with observations from the ETEX campaign. The dominant meteorological process is a warm conveyor belt which transports large amounts of tracer away from the surface up to a height of 4 km over a 36 h period. Convection is also an important process, transporting tracer to heights of up to 8 km. Potential sources of error when using an operational numerical weather prediction model to forecast air quality are also investigated. These potential sources of error include model dynamics, model resolution and model physics. In the UM a semi-Lagrangian monotonic advection scheme is used with cubic polynomial interpolation. This can predict unrealistic negative values of tracer which are subsequently set to zero, and hence results in an overprediction of tracer concentrations. In order to conserve mass in the UM tracer simulations it was necessary to include a flux corrected transport method. Model resolution can also affect the accuracy of predicted tracer distributions. Low resolution simulations (50 km grid length) were unable to resolve a change in wind direction observed during ETEX 2, this led to an error in the transport direction and hence an error in tracer distribution. High resolution simulations (12 km grid length) captured the change in wind direction and hence produced a tracer distribution that compared better with the observations. The representation of convective mixing was found to have a large effect on the vertical transport of tracer. Turning off the convective mixing parameterisation in the UM significantly reduced the vertical transport of tracer. Finally, air quality forecasts were found to be sensitive to the timing of synoptic scale features. Errors in the position of the cold front relative to the tracer release location of only 1 h resulted in changes in the predicted tracer concentrations that were of the same order of magnitude as the absolute tracer concentrations. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
