NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and...
-
Upload
tamsyn-pope -
Category
Documents
-
view
235 -
download
0
Transcript of NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and...
![Page 1: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/1.jpg)
NORTRIP: Kjeller meeting
NILU: Generalised road dust emissions model (GRD-2)
Bruce Rolstad Denby
andIngrid Sundvor
![Page 2: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/2.jpg)
Contents (1)• Expectations from the meeting• Model overview
o Conceptso Road dust model (GRD-2)o Comparison between emission models (GRD-2/SMHI)o Surface moisture model (GRD-2)o Road dust and surface moisture linkageso Model documentation
• Some first resultso Hornsgatan (2009)o Hornsgaten (2010)o RV4 (2005)o NB (2002)
![Page 3: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/3.jpg)
Contents (2)• Demonstrations
o Suspension factor sensitivity (Hornsgatan)o Comparison of evaporation schemes (Hornsgatan)o Demonstration of cleaning (Hornsgatan)o Demonstration of salting (RV4)
• Datasets• Plans
![Page 4: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/4.jpg)
Expectations this meeting
• Demonstrate some aspects of the model• Improve the parameterisations in regard to
– wear parameters (VTI)– suspension parameters (DMU)– sanding and the sand paper effect (FMI)– impact of salting (NILU)– traffic induced turbulence parameterisation (DMU)– splash/spray parameterisation (SMHI)
• Plan and encourage– provision of data sets– inter-comparison (models and parameterisations)– develop application studies of the models
![Page 5: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/5.jpg)
GRD-2 concept
• A structure within which road dust emission processes can be quantified and can interact
• Mass loading based on:– wear (road, tire and break)– addition of external mass
• Emissions based on:– direct wear– suspension
• Surface retention based on surface moisture process
• Described in documentation (v5)
![Page 6: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/6.jpg)
Dust and salt surface mass balance
• Production through:– retained wear (road, tires, brakes) – ambient air deposition– salting and sanding– sand paper effect
• Removal through:– traffic induced suspension of surface mass– wind induced suspension of surface mass– drainage– spray/splash
• Distributed over road and shoulder surfaces
![Page 7: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/7.jpg)
• Emission through direct wear– inhibited by surface moisture
• Emission through suspension– traffic induced suspension– wind induced suspension– inhibited by surface moisture
• Size fraction:– fixed size distributions of emissions
• Emitted from road and shoulder surfaces
Dust and salt emissions
![Page 8: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/8.jpg)
GRD-2
![Page 9: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/9.jpg)
Road dust (M)
Wear W(N,V) .f0,direct . fq . fPM10
PM101-f0,direct . fq
Direct emissions
fsuspend (V2,3).fq.fPM10
Suspended emissions
f0,direct = Fraction of wear emitted directly(0.5)f0,suspend = Fraction of mass suspended (Veh-1hr-1) (1x10-4)fq = Retention factor(0 – 1)fPM10 = PM fraction emitted as PM10 (0.2)
GRD-2
Removal
![Page 10: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/10.jpg)
Road dust (l)
Wear + sanding
PM10ast
.fq . ewinter ref
Suspended emissions
ast = Fraction with studded tires(0.7)ewinter ref = Reference emission factor (g/km)(1200 )l = Normalised road dust loading (0 – 1)kdecay = Decay rate for road dust (Veh-1hr-1) (2x10-6)
Omstedt et al.
fq . kdecay
Mass loading and sanding are normalised quantities
Road dust removal not coupled to suspension
![Page 11: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/11.jpg)
Surface moisture mass balance • Production through:
– precipitation (rain/snow)– snow melt– condensation (affected by salting)– wetting during salting/cleaning
• Removal through:– evaporation (affected by salting)– drainage– spray/splash
• Includes snow mass balance– removal by ploughing and by snow melt
![Page 12: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/12.jpg)
Dust and moisture model linkages
• Surface moisture (and snow) retention:– retention of direct wear producing surface mass– retention of direct wear reducing emissions – retention of surface mass through inhibited suspension
• Drainage and spray of water, dust and salt– mixing of dust and salt in surface water– removal of mixed layer through drainage and spray
• Evaporation/condensation affected by salt– reduced vapour pressure
• Melting point affected by salt– reduced melting point
![Page 13: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/13.jpg)
Retention based on surface moisture
• Surface moisture retention (fq) is given by
• gthresh is the threshold surface moisture above which full retention occurs (fq = 0) .– simple formulation– may be different for direct and suspended emissions– may be different for different wear sources– may be different for shoulder and road
• How wet is a dry road?
sourceemisthresh
surfsourceemisq g
gf
,, 1 ,0max
![Page 14: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/14.jpg)
Documentation and model code
• All model processes are described in the documentation (v5.0)– still in development (v5.1)
• Model is coded in MatLab– easy visualisation and development possibilities– will be transferred to FORTRAN when complete– will be available to NORTRIP
• Input data and model input parameters– model parameter excel sheets (dust model only)– model input data excel sheets (RV4, NS, Hornsgaten)
• All code/data uploaded to the NORTRIP ftp site
![Page 15: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/15.jpg)
Example of model output for Hornsgatan: (Daily means for winter 2009)
• Traffic data• Meteorological data• Mass balance and emissions• Surface wetness• Other factors• Energy balance• Concentrations
• 60% studded tires, 27 000 veh/day at 45 km/hr
![Page 16: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/16.jpg)
![Page 17: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/17.jpg)
Example of model output for Hornsgatan: (Daily means for 2010)
• Meteorological data• Mass balance and emissions• Surface wetness• Concentrations• 40% studded tires in winter, 2% in summer• 22 000 veh/day at 45 km/hr
![Page 18: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/18.jpg)
![Page 19: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/19.jpg)
Example of model output for RV4 (2004)
• Meteorological data missing– wind, radiation, cloud cover
• 27% studded tires• 44 000 veh/day• 80 km/hr• Known to have significant contributions from salt,
around 30% for the whole period.
![Page 20: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/20.jpg)
![Page 21: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/21.jpg)
Example of model output for NB (2002)
• Meteorological data missing– radiation, cloud cover
• No PM2.5 data• Only daily mean average background PM10• 32% studded tires• 35 000 veh/day at 94 km/hr
![Page 22: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/22.jpg)
![Page 23: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/23.jpg)
Suspension concepts/questions
• Suspension is the combined effect of grinding and emission.– creates ‘suspendable’ particle sizes from larger particles ( V?)– ejects these particles mechanically or through turbulence ( V?)
• Is it necessary to divide the surface mass into >TSP and <TSP size distributions? – better suspension description– better road cleaning description– better sanding and sand paper effect description
• How to determine suspension parameters from measurements?– road dust loading under dry conditions– fitting the model to observed concentrations
![Page 24: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/24.jpg)
f0,direct = 1.0f0,suspend = 1x10-4
f0,direct = 0.0f0,suspend = 1x10-4
f0,direct = 0.5f0,suspend = 1x10-5
f0,direct = 0.5f0,suspend = 1x10-4
(default)
Suspension factor sensitivity
![Page 25: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/25.jpg)
Stop
![Page 26: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/26.jpg)
Surface moisture mass balance • Production through:
– precipitation (rain/snow)– snow melt– condensation (affected by salting)– wetting during salting/cleaning
• Removal through:– evaporation (affected by salting)– drainage– spray/splash
• Includes snow mass balance– removal by ploughing and by snow melt
![Page 27: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/27.jpg)
• Basis for Penman and energy balance equations
• Penman does not know the surface flux but requires as input. Also uses parameterisation of net long wave radiation.
• Energy balance solves for surface temperature and outgoing radiation using
snets RG ,2.0
Surface energy balance
sssnets LHRG ,
soutsinroadsinsnet RLRLRSR ,,,, )1(
ssnet GR ,
s
s
ss
s
z
G
ct
T
1
![Page 28: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/28.jpg)
Penman modified
Energy balance
![Page 29: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/29.jpg)
Comparison of evaporation/condensation
1. Fixed evaporation time scale (48 hours)2. Penman-Omstedt (surface RH = 100%)
– potential evaporation from a wet surface– evaporation reduced with a fixed factor (fevap= 0.075, 0.3)
– no information on surface heat flux
3. Penman modified (surface RH = gsurf/gthresh)– no information on surface heat flux– reduces surface relative humidity for gsurf < 0.2 mm
4. Bulk energy balance method (surface RH)– prognoses surface temperature and surface heat flux– reduces surface relative humidity for gsurf < 0.2 mm
![Page 30: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/30.jpg)
1. Constant time scale (48 hr)
2. Penman - Omstedt (f=0.075)
4. Penman – modified (G=0.2*net rad)
5. Energy balance
3. Penman - Omstedt optimised (f=0.3)
Evaporation demonstration
![Page 31: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/31.jpg)
Surface moisture mass balance • Drainage– Drainage time scale (4 hours)– Drainage stops at a threshold value (1 mm)– Also removes mass, assuming a well mixed layer
• Splash and spray– not implemented– should remove significant amounts, down to a threshold of
X mm?
• Snow mass balance– degree hour model for snow melt (can also use EB model)– removal by ploughing
![Page 32: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/32.jpg)
1. Without road cleaning
2. With road cleaning
Road cleaning demonstration
![Page 33: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/33.jpg)
Road salting demonstration
1. Without salting
2. With dry salting(3 days, -10 < T < 0)
![Page 34: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/34.jpg)
• Road surface moisture– Meteo data, surface temperature, surface moisture, salt content, cleaning
and salting activities, splash and spray data
• Concentration data– Street level and background for PM and NOx
• Activity data– Salting activities– Cleaning activities– Ploughing activities– Sanding activities
• Mass balance data– Road dust and salt loading– Concentrations in surface water and drainage water
Data sets required
![Page 35: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/35.jpg)
• Model development– Implementation of new parameterisations– Develop code and interface using excel sheets (executable)– Division of road dust into > TSP and < TSP size categories?
• Database– Add Kirkeveien and RV4 2005, 2006 to database (Other?)– Supplement with other meteorological data
• Apply the models– Use a range of input data sources for model inter-comparisons– Speed reduction studies– Salting impact on surface moisture– Contribution of salting and sanding to PM concentrations
Plans for 2011 (1)
![Page 36: NORTRIP: Kjeller meeting NILU: Generalised road dust emissions model (GRD-2) Bruce Rolstad Denby and Ingrid Sundvor.](https://reader036.fdocuments.net/reader036/viewer/2022062305/56649ebf5503460f94bc90d9/html5/thumbnails/36.jpg)
• Reports– Complete and QC model documentation– Model users guide
• Possible publications– A review of road dust emission data– GRD-2 description and validation – Inter-comparison of road dust emission models– Impact of speed reduction, salting on road dust emissions– Model applications to road surface management
Plans 2011 (2)