Houlry and daily air quality forecast
QWeather is pleased to announce today that we have cooperated with the AIR forecast team to develop daily and hourly air quality forecast data for the next 7 days in China, which is now online.
Different from the traditional air quality forecast, the new generation forecast system is based on the WRF-CHEM model, developed by the US NOAA Forecast System Laboratory (FSL), and is a new generation of fully coupled weather model (WRF) and chemical model (CHEM) online Regional air quality model. At the same time, the most comprehensive pollutant emission inventory in the country has been adopted to achieve an accuracy of grid points per kilometer.
Compared with the traditional WRF model, WRF-CHEM is a brand-new atmospheric chemistry model concept. It is designed based on a brand-new atmospheric chemistry model concept in which meteorological and chemical processes are simultaneously coupled with each other. The meteorological model and the chemical model are fully coupled and run at the same time. Its chemical and meteorological processes use the same horizontal and vertical coordinate system, the same physical parameterization scheme, there is no time interpolation, and the feedback effect of chemistry on the meteorological process can be considered Changes in meteorological factors can affect the chemical process in time, and the chemical process can also immediately give feedback to the meteorological process. The following figure shows the feedback mechanism of the chemical process to the meteorological process in the WRF/Chem mode. Different from the previous atmospheric chemistry modes, such as SAQM mode, CALGRID mode, MODEL3/CAMQ mode, etc., their meteorological process and chemical process are separated. Generally, the mesoscale meteorological mode is run first to obtain the meteorological field at a certain time interval. Then provide it to the chemical model. After separate processing in this way, there are some problems: First, because the coordinate system used in the usual weather model and chemical model is different, using such a weather field to drive chemical processes requires time and space interpolation; second, it loses some less than the weather model Output interval meteorological processes, such as a short-term precipitation, and these processes may be very important to chemical processes; again, the physical parameterization schemes used in the meteorological model and the chemical model may be different; finally, it The feedback effect of chemical processes on meteorological processes cannot be considered. In fact, in the actual atmosphere, chemical and meteorological processes occur at the same time and can influence each other. For example, aerosols can affect the radiation balance of the earth-atmosphere system. Aerosols, as cloud condensation nuclei, can affect precipitation, while temperature, cloud and precipitation affect each other. Chemical processes also have a very strong influence. Therefore, WRF-CHEM can simulate and reproduce a more realistic atmospheric environment.
Refined pollution source emission inventory
Our AIR forecasting expert team, relying on a large amount of air pollution data, lasted more than 2 years, finally compiled a national regional pollution source emission inventory. The main species in the emission source list include VOC, SO2, PM10, PM2.5, OC, NOX, NH3, CO2, CO, BC, CB5, etc. The accuracy of the emission source inventory in the whole country reaches 1 km accuracy. The national regional emission source inventory has been verified by data uncertainty analysis. After a period of actual simulation of the model, it is proved that this set of source inventory can better represent the situation of air pollution.