Eyjafjallajokull eruption

Model simulation

May 10th forecast for May 11th at 12:00 UTC

Model set-up

The version of the Unified EMEP model correspond to rv3_5_21 on FORECAST mode. The simulation was set up as chain of 6 day forecasts, driven by ECMWF meteorology (IFS, operational 00 UTC forecast). The simulation domain covers only [25W–35E]x[36N–75N] with a 0.2×0.2 resolution. The full extended model domain extends down to 31N, but the simulation goes only down to 36N.

Meteorology

The fields retrieved for the full extended forecast domain [25W–35E]x[31N–75N], from MARS include:

Levels (η=hibrid) Resolution Variables
srf. 0.2×0.2 sshf slhf msl 2t ewss nsss lsp cp ci sd swvl1
η91—η88 0.2×0.2 u v w t q cc
η87—η38 0.8×0.8 u v w t q cc

Emission set-up

Emission set-up for Forecasts and other experiments performed during the eruption.

Maximum plume height comes from London VAAC reports.

Emission rates of PM10 and PM2.5 interpreted from PDF and discussion with Ármann Höskuldsson (University of Iceland). Emission rates for the 14-16 are towards the higher end of the observed mean total ash emissions from the 14-16 and the 17-19 are from the low end of the observed mean total ash emissions from the 14-16 because emissions were reported to have decreased after the first three days. For the 20 it is lower because of reports that there is now less ash in the plume.

Emission rates of SO2 for the 15 are based on OMI SO2. The SO2 then decreases through the 18th consistent with reports of weaker plumes and OMI not observing new puffs clearly and then increases on the 19th. The SO2 values except for on the 15th are not based on total OMI observed SO2, rather they are intended to represent trends in the SO2 emissions.

Eruption emission parameters

PM10 [kg/s] PM2.5 [kg/s] SO2 [kg/s] height [km]
2010-04-14 1E3 2.8E2 15 8
2010-04-15 5E3 1.4E3 46 7
2010-04-16 5E3 1.4E3 15 7
2010-04-17 9E3 2.5E3 10 7
2010-04-18 2E3 5.6E2 10 5
2010-04-19 7E3 2.0E3 20 5
2010-04-20 3E2 8.4E1 15 4
2010-04-21—2010-04-29 3E2 8.4E1 15 3
2010-04-30—2010-05-02 3E2 8.4E1 15 4
2010-05-03—2010-05-04 2E3 5.6E2 15 5
2010-05-05 2E3 5.6E2 70 5
2010-05-06—2010-05-20 2E3 5.6E2 70 6
2010-05-21 1E2 2.8E1 5 3
2010-05-22 1E2 2.8E1 2 3
2010-05-23 0 0 1 2
2010-05-24—today 0 0 0 0

Implementation details

Emissions
  • Volcanic eruption emission are hard-coded into the model.
  • The eruption started on 2010-04-14 at 00 UTC and continues trough the simulation.
  • Emissions are treated as a vertical line source.
  • Emission rates for each day are assumed constant trough the column height.
  • Ash emissions are treated in the model as primary PM emissions.
  • In order to model only the volcanic plume only ash emissions are taken into account as primary PM emissions, i.e. all other primary PM emissions are neglected.
  • Volcanic SO2 emissions are added to the standard model emissions.
  • Standard model emissions are set accordingly to the TNO-MACC-1 emission dataset.
Additional output
  • Under several assumptions, the aerosol optical depth (AOD) can be estimated from the fine and coarse PM columns. In order to provide a simple comparison to satellite AOD observations, the partial contribution of the volcanic particles was calculated (P-AOD) from the primary fine and coarse columns.
Simulation
  • The simulations are run on titan (UiO) on 8×2 processors.
  • The driving bash and perl scripts at:
    • titan:~alvarov/Unify/run/cwf_ext-2010.sh
    • titan:~alvarov/Unify/run/modrun.rv3.CWF-EXT.pl
  • Source and meteorology files are located at:
    • titan:~alvarov/Unify/Unimod.rv3_5_21.CWF-EXT/
    • titan:/data3/metno/emep/Data/FORECAST/metdata/
  • The raw output and images is located at:
    • titan:~alvarov/CWF/output.rv3.CWF-EXT.2010
    • titan:~alvarov/CWF/output.rv3.CWF-EXT.2010/www/images

Results

The latest images (*.png) and animations (*.mpg) for each forecast day can be found in the institute ftp server.

  • All images for a given forecast (or hindcast) are collected in one single zip file, e.g. 20100414.zip contains all images for the forecast starting on April 14th.
  • Each forecast lasts 6 days, starting at 00 UTC (145 hourly records).
  • If emissions estimates improve, past forecast will be re-run (hindcast) and the previous files updated. Zip files for a hindcast include images only for that day (25 hourly records).
  • For consistency, zip files are updated when the graphic layout changes or when additional variables are plotted.
  • Hourly images are named according to the following convention: var_lev_fsdate_date.png, where:
    • var is the variable name (e.g. ppm25 for fine volcanic particles):
    • lev is the level (e.g. tcol for total column);
    • fsdate is the forecast start date (in YYYYMMDD format);
    • date is the forecasted date and hour (in YYYYMMDDHH format);
  • Animations for the whole period are named var_lev_fsdate.mpg.
Variable Model Levels Trop. column
1km 5km tcol
ppm25 fine volcanic particulate matter μg/m3 μg/m3 μg/m2
ppm10 fine+coarse volcanic particulate matter μg/m3 μg/m3 μg/m2
so2 sulfur dioxide du (Dobson units)
p-aod partial aerosol optical depth unitless

Additional resources

Satellite observations

Date SO2 column MODIS AOD
%F %j GOME-2 SCIAMACHY OMI Terra Aqua
2010-04-14 104 zip ftp ftp ftp
2010-04-15 105 zip ftp ftp ftp
2010-04-16 106 zip ftp ftp ftp
2010-04-17 107 zip ftp ftp ftp
2010-04-18 108 zip ftp ftp ftp
2010-04-19 109 zip ftp ftp ftp
2010-04-20 110 zip ftp ftp ftp
2010-04-21 111 zip ftp ftp ftp
2010-04-22 112 zip ftp ftp ftp
2010-04-23 113 zip ftp ftp ftp
2010-04-24 114 zip ftp ftp ftp
2010-04-25 115 zip ftp ftp ftp
2010-04-26 116 zip ftp ftp ftp

Other model simulations

Other

Follow up work

ENSEMBLE runs

Model set-up

Meteorology

  • Domain: [32°N–76°N]×[28°W–36°E] on 0.2° resolution
Experiments
  • 0050-001 - Passive tracer - Emissions are distributed linearly from 1670 m (vent height) to Eruption Height
  • 0050-002 - Passive tracer - Emissions are distributed linearly from 1670 m (vent height) to Eruption Height
  • 0050-003 - Ash - divided into the size bins as in Size Bins Table - Emissions are distributed linearly from 1670 m (vent height) to Eruption Height
  • 0050-004 - SO2 - Emissions are distributed linearly from Base Height to Eruption Height
Time 0050-001 0050-002/3 0050-004
Start Stop Eruption Height Source Strength Source Strength Eruption Height Eruption Base Source Strength
[UTC] [UTC] [m asl] [106 g/s] [106 g/s] [m asl] [m asl] [106 g/s]
2010-04-14 06:002010-04-14 10:0085001.667E-11.340E2 NA NA NA
2010-04-14 10:002010-04-14 16:0085001.667E-11.340E2900050003.584E00
2010-04-14 16:002010-04-14 19:0085001.667E-11.340E2600020008.960E-1
2010-04-14 19:002010-04-14 21:0085001.667E-11.340E2550020006.272E00
2010-04-14 21:002010-04-15 00:0085001.667E-11.340E2550020001.344E00
2010-04-15 00:002010-04-15 12:0085001.667E-11.340E2550020008.960E-2
2010-04-15 12:002010-04-16 00:0085001.667E-11.340E2550020004.480E-2
2010-04-16 00:002010-04-18 06:0085001.667E-11.340E2550020002.240E-1
2010-04-18 06:002010-04-18 18:0050001.667E-21.720E1550020002.240E-1
2010-04-18 18:002010-04-19 09:0030481.667E-32.550E0550020002.240E-1
2010-04-19 09:002010-04-19 12:0045721.667E-21.220E1550020002.240E-1
2010-04-19 12:002010-04-21 00:0045721.667E-21.220E1550020003.584E-1
2010-04-21 00:002010-04-21 06:0045721.667E-31.220E1550020003.584E-1

Size bins

The mass mean diameter and % of ash in size bin data comes from measurements made using laser by Throstur Thorsteinsson (ThrosturTh@gmail.com), Institute of Earth Sciences, University of Iceland. Measurements were made on 15, 17, 18 April and 6-7 May. We are using the average of these four measurement days. The density of the ash particles is a measurement of the bulk ash made by Throstur. The sigma values are the same as what was using in the model previously, just applied to the new size bins.

[um] mass mean diam [um] % of ash in range 0-10 um in bin sigma density [kg/m3]
0-1 0.9 22.0 1.8 2750
1-4 3.0 29.8 1.8 2750
4-10 7.1 48.1 2.0 2750
0-2.5 1.3 32.3 1.8 2750
2.5-10 6.0 67.7 2.0 2750

Required output

  • Domain: [30°N–75°N]×[30°W–45°E] on 0.25° resolution
  • Period: between 2010-04-14 06:00 and 2010-04-21:06:00 (1 week) on 1 h resolution.
  • Levels for concentrations: 0, 100, 500, 1000, 2500, 4000, 6000, 8000, 10000, 12000 m of height
Experiment Output type
ID Variable Concentration Dry deposition Wet deposition Trop. Column
0050-001/2passive tracer
0050-003 ash < 1 μm
0050-003 ash 1–4 μm
0050-003 ash 4–10 μm
0050-003 AOD @ 350 nm
0050-003 AOD @ 500 nm
0050-004 SO2
 
emep/emep_volcano_plume.txt · Last modified: 2011/02/10 14:41 by alvarov
 
Except where otherwise noted, content on this wiki is licensed under the following license: CC Attribution-Noncommercial-Share Alike 3.0 Unported
Recent changes RSS feed Donate Powered by PHP Valid XHTML 1.0 Valid CSS Driven by DokuWiki