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Eyjafjallajokull eruption
Model simulation
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:
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 primaryPM
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 coarsePM
columns. In order to provide a simple comparison to satelliteAOD
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/
- 2010/meteo-ext201004??_??.nc (EMEP Format)
- 2010_ECMWF/cwf-ext_*_f201004??.nc (retrieved from MARS)
- 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 (inYYYYMMDD
format);date
is the forecasted date and hour (inYYYYMMDDHH
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
- GOME-2, SCIAMACHY & OMI SO2 column
- MODIS AOD
- SEVIRI ASH last 12 hours
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 | ||
2010-04-25 | 115 | zip | ftp | ftp | ||
2010-04-26 | 116 | zip | ftp |
Other model simulations
- SNAP ash dispersion
- MACC SO2 column
- EURAD PM10
- Fall3D ash dispersion
- Flexpart passive tracer and ash
Other
- Time-line wikipedia
Follow up work
ENSEMBLE runs
Model set-up
Meteorology
Domain set up
Domain: [30°N–75°N]×[30°W–45°E]
0.25 degree horizontal resolution
Output variables
For 1 week of eruption beginning 2005:04:14:06:00 ending 2005:04:21:06:00, results written out once per hour.
Concentrations of:
ash < 1 um
ash 1-4 um
ash 4-10 um
SO2
passive tracer
at heights of 0, 100, 500, 1000, 2500, 4000, 6000, 8000, 10000, 12000 m
Dry deposition of:
ash < 1 um
ash 1-4 um
ash 4-10 um
SO2
Wet deposition of:
ash < 1 um
ash 1-4 um
ash 4-10 um
AOD:
500 nm
350 nm
Emission set-up
Emissions are distributed linearly from 1670 m (vent height) to Eruption height in Experiment Tables.
Emissions are divided into the size bins as in Size Bins Table.
Experiment 0050-001
Eruption Height [m asl] | Source Strength [106 g/s] | Start Time [UTC] | Stop Time [UTC] |
---|---|---|---|
8500 | 0.1667 | 2010-04-14 06:00 | 2010-04-18 06:00 |
5000 | 0.01667 | 2010-04-18 06:00 | 2010-04-18 18:00 |
3048 | 0.001667 | 2010-04-18 18:00 | 2010-04-18 09:00 |
4572 | 0.01667 | 2010-04-19 09:00 | 2010-04-21 00:00 |
4572 | 0.001667 | 2010-04-21 00:00 | 2010-02-05 06:00 |
4572 | 0.008335 | 2010-05-02 06:00 | 2010-05-04 06:00 |
6000 | 0.01667 | 2010-05-04 06:00 | 2010-05-05 17:00 |
8000 | 0.1667 | 2010-05-05 17:00 | 2010-05-05 18:30 |
10000 | 1.667 | 2010-05-05 18:30 | 2010-05-06 21:00 |
7000 | 0.08335 | 2010-05-06 21:00 | 2010-05-09 00:00 |
5500 | 0.01667 | 2010-05-09 00:00 | 2010-05-12 21:00 |
6000 | 0.01667 | 2010-05-12 21:00 | 2010-05-13 12:00 |
6500 | 0.01667 | 2010-05-13 12:00 | 2010-05-13 18:00 |
9000 | 0.1667 | 2010-05-13 18:00 | 2010-05-14 07:00 |
7000 | 0.1667 | 2010-05-14 07:00 | 2010-05-14 21:00 |
6500 | 0.1667 | 2010-05-14 21:00 | 2010-05-21 06:00 |
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 |