Real-Time Estimation of Volcanic Ash/SO2 Cloud Height from Combined

UV/IR Satellite Observations and Numerical Modeling

Gilberto A. VicenteNOAA National Environmental Satellite, Data, and Information Service (NESDIS)

Office of Satellite Data Processing and Distribution (OSDPD)

CICS Science Team MeetingSeptember 8th 2010 College Park, MD

Eric HughesUniversity of Maryland - College Park

Cooperative Institute for Climate and Satellites (CICS)

Wilfrid Schroeder University of Maryland - College Park

Cooperative Institute for Climate and Satellites (CICS)

Source1: How volcano chaos unfolded: in graphics, BBC News (http://news.bbc.co.uk/2/hi/europe/8634944.stm)

Volcanic emissions damage aircraft

British Airways Flight 9 - (1982)Experienced full engine failure mid-flight (flame-out of all four engines)

Ash

Ash melts and forms glassy coating

Clogs Jets fuel and cooling systems

Source1

Source1

The effects on volcanic ash on airplanes:

Several reports of Airplane-Ash interactions occurred in the 1980’s and early 1990’s. The results of such interactions were: severe damage to airplanes and often mid-flight engine failure.

Volcanic EruptionsHazards to Aviation

“Ladies and gentlemen, this is your captain speaking. We have a small problem. All four engines have stopped. We are doing our damnedest to get them under control. I trust you are not in too much distress.” - Cpt. Eric Moody

In the 1990’s, a global network of 9 Volcanic Ash Advisory Centers (VAACs) were established.

The Role of the VAACs

Monitoring and tracking volcanic ash in their areas of attention.

Coordinate the Meteorological Watch Offices (MWO’s), Volcano Observatories, and Area Control Centers/Flight Information Centers (ACC/FIC) for the prompt notification and distribution of volcanic ash information and warnings.

Still high demand for more accurate monitoring/forecasting techniques. Uncertainties in monitoring/forecasting lead to the closure of large air spaces.

$1.7 Billion: Estimated airspace closure cost from Iceland's Eyjafjallajokull volcanic eruption2

Source2: IATA

Map of global VAAC coverage

Monitoring/forecasting improvements have lead to few hazardous Airplane/Ash interactions since the early 1990’s.

Ash forecasts from the London VAAC The ash height was understood to be between 2km – 11km

[ April 15th 06:00 UTC ]

Satellite Observations

Dispersion Models

Reports:

IR: AIRS, AVHRRUV: OMI, GOME-2Vis: GOES, MODIS (multi)Vis/IR: MSG(SEVERI)

PUFFHySPLITNAMESFlex-Part

SIGMETs Airlines News Volcanologists (Observatories, USGS, Smithsonian) Volcano Cameras etc …

VAAC ResourcesProducing Ash Forecasts

UV Sensors - Polar

OM

I

SO2

IR – Polar/Geo

April 15th 13:30 UTC

Measurement Technique Measurement Technique 320- 380 nm difference from Rayleigh spectrum

Advantages

Effective over land or sea

No water cloud interference

Disadvantages Day time only

Smoke and dust have same signature

Longer latency time

Advantages Day and Night Times Operational Satellites Geo: High spatial/temporal res.

Disadvantages Misses detections due to water vapor interference and cold clouds – false alarms Geo: Poor observations at high latitudes

10 – 12 m BTD - Split Window

April 15th 12:00 UTC

MODIS (Terra)

April 15th 11:35 UTC

AIR

SAI (Ash) Ash

Ackn

ow

led

gm

en

ts to

Arlin

Kru

eg

er

April 16th 16:00 UTC

MSG RGB

VIS/IR – Polar/Geo

VAAC ResourcesSatellite Observations

Ash Forecasts (Washington VAAC)Hybrid Single Particle Lagrangian Integrated Trajectory Model (HySPLIT)Simulations for 4 altitude regions and 6 and 12 hour forecast

PUFF (Alaska - VAAC)

NAMES (London - VAAC)

FLEX-PART (NILU)

HySPLIT (Washington, DC - VAAC)

Simulate the dispersion and transport of volcanic ash into the atmosphere using meteorological forecast data

Approaches: Lagrangian, Eulerian or both

VAAC ResourcesDispersion Models

Using Models and Satellite Observations to Forecast Ash Transport

Even with current capabilities, there are several unknown “variables” in ash forecasting:

• Ash density (size distribution)• Ash height• Start and stop eruption times

An understanding of the ash height and concentration are the most important variables needed in airline rerouting.

These VAAC resources are typically used as follows: Reports: Find information about eruptions time/duration and

injection altitude (when available)Satellites: Locate and track ash plumes Models: Forecast ash transport

Volcano MonitoringCreate a platform that allows users to view near real-time volcanic data products.

Volcanic Cloud Height EstimationConstruct a system which compares near real-time data with model simulation data.

Project Overview

Our Approach Run various dispersion model simulations and see which initial height conditions reconstruct satellite observations.

Volcano Monitoring

Volcanic Cloud Height Estimation

Retrieve satellite data*

SO2/AI Retrieval*

Place SO2/AI maps and data files on our web server

These project parts were developed independently, but work together as a set of tools for users.

Model Initialization

Run model simulations

Post-Processing

Compare to satellite observations

Users

* Pro

cesse

d a

t NA

SA

GS

FC

Project Overview

Volcano Monitoring The NOAA/NESDIS OMISO2 product delivery and visualization user interface

http://satepsanone.nesdis.noaa.gov/pub/OMI/OMISO2/

Global compositesGlobal composites

Volcano sectorsVolcano sectors

Satellite orbitSatellite orbit

Digital imagesDigital images

SO2 Cloud (Reflectivity) AI

Volcanic Sector ImageryVolcano Monitoring

Input data Gridded data

Compare overlap

AIRS (Ash)

PUFF (2km Simulation) Overlapping region:

Estimating Cloud Heights: Implementation

Compare the results from the various simulations to satellite observations.

Run the dispersion model (PUFF) using various initial height conditions

Bas

ic C

on

cep

tVolcanic Cloud Height Estimation

Statistical comparison:

A = Number of Coincident Satellite and Model points

B = Number of Satellite points NOT coincident with model data

C = Number of Model points NOT coincident with satellite data

Compute two statistic variables:

Probability of Detection (PoD): PoD = A / (A+B)

False Alarm Rate (FAR): FAR = C / (A+C)

Probability of Detection

Sim

ula

tio

n H

eig

ht

(km

)

Currently algorithm uses only PoD

Model-Satellite Comparisons

Volcanic Cloud Height Estimation

Volcanic Cloud Height Estimation:Online Model

OMI-AI

April 15th 12:00 UTC

Input Data

PUFF Simulation

OMI AI

All profiles show two distinct peaks in height: 8-10 km and 5-4 km.All profiles show two distinct peaks in height: 8-10 km and 5-4 km.

OMI – AI/SO2 AIRS-Ash

The Eyjafjallajokull eruption Analysis Summary

Observations from April 15th 2010

8 km

2 km

OMI-AI

Vertical profile Visual AnalysisApril 15th 12:00 UTC

The statistical and visual analysis do not match exactly

The statistics predicts the 10km and 4km simulations heights

A visual analysis suggests the 8-7km and 2-3km heights

False Alarm Rate (FAR) analysis should improve the statistics

The Eyjafjallajokull eruption Limitations

Description of an automated system to compare dispersion model outputs with Near-Real-Time (NRT) satellite observations of volcanic emission

Generate a series of maps overlaying various model simulations atop of satellite observations

Perform a statistical analysis on the simulation/satellite data to determine which simulation injection heights

produce the best match to satellite observations

Perform these tasks quickly, requiring little input from the analyst

Summary and Conclusions

Compare the model simulations with volcanic ash products from other satellites/sensors: GOES, MSG (SEVERI) AVHRR, MetOp-A (IASI), MODIS, etc.

Generate automated volcanic ash height forecast based on the statistical analysis of the simulation/satellite data.

Future plans

Arlin Krueger, Simon Carn, and Keith Evans: JCET/UMBC

George Serafino: NOAA/NESDIS

Nick Krotkov and Kai Yang; GEST/UMBC

Jerry Guo: Perot Systems Government Services

Pieternel Levelt: KNMI

Acknowledgements

USER/WEB SERVER DATA SERVER MODEL SERVER

Submit request(User)

Check to see if a request has been

submitted

…

Retrieve the request,then submit the request

to PUFFRun the PUFF

simulations and perform the

height analysis.Generate output images w/ IDL

Retrieve output images and data files. Submit

them to the USER SERVER (web)

Display the results

Firewall

… show the status of the analysis …

Online model setup

MISR Team, JPL and GSFC

MISR Stereo-Derived Ash Plume HeightsPlume HeightsApril 14th, 2010

MISR derived heights:The leading part of the ash cloud is around 7.3 km and the trailing part around 2.3 km

Visual analysis: Closely agrees with the MISR derived heights

Statistical analysis: Higher than the MISR derived heights, but agrees the VAAC reports (cited the max height ~11km)

Comparison with other height measurements

The Eyjafjallajokull eruption