EMD-WRF On-Demand ICING: Difference between revisions
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Revision as of 09:33, 1 April 2022
NOTE: This dataset and service is currently being integrated with windPRO 3.6 (beta). Please contact our technical specialist Marie Cecilie Pedersen (mcp@emd.dk) for more information and achedule. We will be attending winterwind 2022 in Skellefteå, Sweden, so you are also welcome to meet with us at that event.
Introduction
EMD-WRF OD ICING is the name of EMD’s icing model. The model is driven by an icing configuration of the standard EMD WRF [1] On-Demand service [2]. The model is run with a spatial resolution of 3x3 km with an hourly temporal resolution and using the ERA-5 reanalysis data from ECMWF as global boundary data [3]. The Thompson microphysics scheme is used for parameterization of the cloud physics and the MYJ scheme for the planetary boundary layer physics [4], [5]. The median volume diameter (MVD) by [6] is used, with a constant droplet concentration (Nc) of (default) 100 cm-3 and the liquid water content (LWC) in kg/m3 [7]. The atmospheric data feeds into the standard cylinder-based model [8], [9] including melting and shedding [10]. The WRF grid point (latitude, longitude) closest to the at mast location or site location is used as a default. The grid point holds a certain elevation above sea level and icing is modelled as a default for 15 heights in the vertical direction above ground level (agl.).
The modelled ice load (kg) is used to identify hours of instrumental icing based on the industry standard thresholds of 10 g [11]. And similar from the modelled ice accretion rate (g/h), hours of meteorological icing [12] is found using the threshold of 10 g/h [9]. The final step of EMD’s modelling chain, is an estimate of the expected production loss of a site which is found by using the IEA Ice Classification system seen in Table 1.
TABLE HERE
The complete list of parameters are seen in the Table 2 further below.
The EMD-WRF OD ICING is available as a time-series product, please see more here: Time-Series - On-Demand.
Please also see the technical note and results from recent validation study on EMD-WRF OD ICING for more information. (add link to note)
How to order?
To get pointwise-timeseries data, you need meso-credits (one credit is worth one month of data). Credits can be ordered here: http://www.emd.dk/windpro/online-ordering/ Please note, that a time period of 10 years will include the complete icing analysis, whereas shorter time periods include only raw timeseries. Complete icing analysis includes:
- Icing reports as pdfs at three hub-heights - 100m, 150m and 200m
- Including predicted AEP loss
- Icing maps at three hub-heights - 100m, 150m and 200m
- IEA ice class, IEA Ice loss (% AEP) and modelled meteorological icing (icing rate > 10 g/h)
- The possibility to use your icing results and timeseries directly in your windPRO project
- Monthly, yearly and seasonal icing analysis and bin-sector analysis as csv-files
- Timeseries of raw WRF data and modelled icing
Data Availability
All EMD-WRF OD ICING is available with global spatial coverage. The temporal availability and update frequency depends on a number of factors such as availability from the boundary data providers, bandwidth and download times, as well as availability on EMD high-performance computing and storage systems. EMD-WRF OD ICING is availability with the ERA5 only, see table below.
Dataset | First date | Most recent date |
---|---|---|
EMD-WRF OD (ERA5) | 1999.01.01 | 2-3 months from present day |
Set of Standard Dataset Parameters for Icing
A large quantity of useful parameters are available directly in WindPRO to aid in your analysis.
The different parameters in each On-Demand ICING dataset is shown in the list below.
Parameter | Unit | Description | Type |
---|---|---|---|
time | UTC time stamp | ||
psfc | Pa | Pressure at site | Instantaneous |
msl | Pa | Pressure at mean sea level | Instantaneous |
wSpeed.x | m/s | Wind speeds at different physical levels (x). Heights for EMD-WRF OD (x): 10m, 25m, 50m, 75m, 100m, 150m, 200m Heights for EMD-WRF Custom Area (x): 10m, 25m, 50m, 75m, 100m, 150m, 200m, 300m, 400m, 500m, 600m, 1000m, 4000m |
Instantaneous |
wDir.x | deg | Wind speeds at different physical levels (x). Heights for EMD-WRF OD (x): 10m, 25m, 50m, 75m, 100m, 150m, 200m Heights for EMD-WRF Custom Area (x): 10m, 25m, 50m, 75m, 100m, 150m, 200m, 300m, 400m, 500m, 600m, 1000m, 4000m |
Instantaneous |
wSpeed.0-30mb | m/s | Wind speeds at pressure level 0-30mb. | Instantaneous |
wDir.0-30mb | deg | Wind speeds at pressure levels 0-30mb. | Instantaneous |
wSpeed.850hpa | m/s | Wind speeds at pressure level 850hPa. | Instantaneous |
wDir.850hpa | deg | Wind speeds at pressure levels 850hPa. | Instantaneous |
temperature.x | celcius | Temperatures at different heights (x) Heights (x): 2m and 100m |
Instantaneous |
waterTemp | celcius | Water temperature | Instantaneous |
soilTemp.0-10cm | celcius | The temperature in the upper 10 cm of the soil | Instantaneous |
relHumidity.2 | % | Relative humidity in height 2m above ground level | Instantaneous |
snowDepth | m | Snow depth (if present) | Instantaneous |
vis.s | m | Visibility at surface | Instantaneous |
sensHeatFlux.s | w/m2 | Sensible Heat Flux at surface | Instantaneous |
totPrecip.s | kg/m^2 | Total Precipitation at surface | 1h Accumulated |
downShortWaveFlux.s | w/m2 | Downward shortwave irradiance at surface | 1h Average |
totalCloudCover.a | % | Total cloud cover in atmosphere | 1h Average |
convCloudCover.a | % | Convective cloud cover in atmosphere | 1h Average |
Data below this line are not shown in a default import of EMD-WRF On-Demand data, but can be made available by clicking on the "+" button in the lower left corner of the import table. | |||
4LFTX | K | N/A | |
rmol | 1/m | Inverse Monin-Obukhov-Length [1] | |
znt | m | Rougnhess length | |
sqrtTKE.x | m/s | Wind speed given as standard deviation in m/s. Derived from the turbulent kinetic energy (TKE). Results available in different physical levels. Heights (x): 10m, 25m, 50m, 75m, 100m, 150m, 200m |
Instantaneous |
cloudWater.100 | mg/kg | Parameter intended for estimating probability of icing.[2] | Instantaneous |
cloudIce.100 | mg/kg | Parameter intended for estimating probability of icing.[2] | Instantaneous |
Footnotes
- ↑ It is still being investigated whether this inverse Monin-Obukhov-Length can be used for stability clasification.
- ↑ 2.0 2.1 CloudWater and cloudIcing values are extracted directly from the WRF meso-scale model and are normal output parameters of the same run as the other parameters (wind, temperature etc.). They are controlled by the WRF microphysics scheme for which Ferrier was used. For further information, please access the numerous internet resources about WRF use. EMD has not done any validation on the parameters, so they are provided as is.