There are several reasons why you should consider purchasing prognostic meteorological model data:
- There are no met stations available in your area - There is no other representative met station site available for your site - The available station data is out of date - The available station data does not have a sufficient number of years - The available station data does not meet data quality standards (e.g. poor treatment of calms)
WRF and MM5 are both mesoscale meteorological models. Both models are still in use today however, WRF was developed as an evolutionary successor to the MM5 model and incorporates current state-of-the-science atmospheric physics improvements. Check with your regulatory agency to verify which model they prefer.
The majority of meteorological data is collected from airport met stations. An airports primary concern is high wind speeds which may affect aircraft. Therefore, low wind speeds are often not recorded with sufficient accuracy for air dispersion modeling purposes. This is of particular concern for air dispersion modeling because low wind speeds often result in higher concentrations. The WRF and MM5 models avoid this issue as all wind speeds are calculated with equal accuracy.
Lakes Environmental can provide one or multiple years of WRF- or MM5-processed met data, depending on what your requirements are. The most common period requested for regulatory purposes is five consecutive years of meteorological data. For information on the years available for each type of data, please visit our met services overview page.
This will depend on the number of orders we are currently processing, and the period the WRF or MM5 data is to cover. Most orders can be completed in 1 to 3 business days. We can provide you with an estimated delivery date at time of order.
The data that we provide to our clients uses meteorological data provided by a vast global network of meteorological stations and satellite data which have been reanalyzed and gridded into a format suitable for input to the meteorological model. They then use state-of-the-science atmospheric physics conservation equations to calculate how the wind field would behave in between grid cells. Many factors additional factors are accounted for in the models including terrain and land use as they also influence the wind field for a given location.
WRF and MM5 use 1km by 1km gridded land use to estimate surface properties (surface boundary conditions). It also uses the pre-processed wind field for the global weather simulations to obtain the initial time boundary condition at t=0 and at other times as well.
Meteorological models including WRF and MM5 use state-of-the-science atmospheric physics conservation equations and account for more refined parameterizations for processes that cannot be simulated directly. For these reasons WRF and MM5 are classified as prognostic models. CALMET uses a simple mass conservation approach and does not solve the momentum, energy, or moisture conservation equations used by MM5 and WRF. CALMET is classified as a diagnostic model.
Our CALMET-Ready data products are the output of the CALWRF and CALMM5 models which format prognostic model output for use in the CALMET diagnostic model. The user is then required to run CALMET in order to produce meteorological data for input to the CALPUFF model.
Our CALPUFF-Ready data has been processed using the USEPA’s Mesoscale Model Interface Program (MMIF) to produce data which can be directly input to CALPUFF thus bypassing CALMET entirely.
The project location coordinates provided by the customer are used as the center point to define the modeling domain for WRF or MM5. The model is executed using a 12km or 4km grid cell domain depending on which option you specify during ordering, and data are extracted for the single grid cell containing the requested coordinate. Since output from the models represent grid cell averages, data from the extracted cell is representative of any point within the bounded grid cell.
AERMINUTE can only be run for Automated Surface Observing System (ASOS) stations where 1-minute and 5-minute wind data are available. If the user-selected station is not an ASOS station, AERMINUTE is bypassed.
Our team of expert meteorologists (including a Certified Consulting Meteorologist certified by the American Meteorological Society) rely on experience and regulatory knowledge to select defensible values for surface moisture condition, snow cover, and additional model options. We also use data from the National Centers for Environmental Information (formerly NCDC) to support our decisions.
Because guidelines on how meteorological data are to be processed are many and have subtle variations, it is the customer’s responsibility to make our team aware of any specific requests for your order. When filling out the quote request, customers can include such information in the Additional Comments section before submittal. Our meteorologists will then review these comments and fulfill your order as requested.