ozone from gome data using neural network technique
TRANSCRIPT
Neural Network based Ozone ProfileRetrieval Using Combined UV/VI
and IR Satellite Data
Anton K. Kaifel, Jasmine Kaptur (ZSW),
Martin Felder (LRZ)
Center for Solar Energy & Hydrogen Research (ZSW), Stuttgart, Germany
Leibniz Computing Center (LRZ), Munich, Germany
ITSC-15, Oct. 2006, Maratea, Italy
Outline
1. Start with TOVS
2. NNORSY and Optimal Estimation (OE)
3. Approach for NNORSY
4. Local error estimation
5. Results of NNORSY-GOME/TOVS
6. Summary and future
Neural Network based Ozone Profile Retrieval Using CombinedUV/VIS and IR Satellite Data
ITSC-15, Oct. 2006, Maratea, Italy
Monthly mean values of56 WOUDC ground stationsalso used for TOMS validation
NNORSY-TOVS L3 (09/79 –12/02)
NNORSY-TOVS Total Ozone
global TOVS TOMSRMS: 9.1 D.U. 8.0 D.U.Bias: 2.0 D.U. -2.8 D.U.
NNORSY-NOAA-TOVS zonal mean 1987 - 2000
Do
bso
n U
nit
s
ITSC-15, Oct. 2006, Maratea, Italy
Op
tim
al
Est
imati
on
x
O3 profile
p(x|y)p(y|x) p(x)
p(y)=
x
"a priori"
y
GOMEspectrum
y
x
… …
k(x,y)
collocated measurements
yx RTM
OptimalEstimation
z.B. FURM, OPERA, ...
NNORSY
~1 min/profile
~1 ms/profile (!)
NN
OR
SY
Co
mp
ari
son
of
retr
ieval
ap
pro
ach
es
ITSC-15, Oct. 2006, Maratea, Italy
Overview NNORSY
operationalreal-time
processing
GOME profiles
Operation
trainingdata
neuralnetworktraining
randomdata
mixing
testdata
eval.data
networkparam.s
qualitycheck
Training
GOMETOVS N14
Level 1data
WOUDCsondes
collocatedspectra/ profiles
collocation
SHADOZsondes
SAGE, POAM, HALOE
profiles
collocation
collocation
Preprocessing
ITSC-15, Oct. 2006, Maratea, Italy
ozonesondes
test data set: 01/1996 – 07/2001, 12000 collocations
POAM III
SAGE II
HALOE
NNORSY: Collocation Example
ITSC-15, Oct. 2006, Maratea, Italy
training data
evaluationdata
y
t
y
t
hiddenlayer
weights w
o(yi)
outputvector
ti
targetvector
"learning process":minimize E=Σi(o(yi)-ti)2
Quality check by cross-validation
test data
y
t
yi
otherinput
param.s
+
inputvector
NNORSY (Neural Network Ozone Retrieval System)
stoppingpoint
Training and Test for NNORSY
ITSC-15, Oct. 2006, Maratea, Italy
NNORSY (Neural Network Ozone Retrieval System)
GOMEspectral
data
geolocation
meteorol. info
climatologicalpredictors
yi
Input data for neural network
NNORSY Input Parameters
270 – 325 nm (O3 Hartley & Huggins)380 – 385 nm (atmosph. window)598 – 603 nm (O3 Chappuis)758 – 772 nm (O2 → cloud info)SZA, SAAsensor scan angleLOS type (east, nadir, west)GEOS4 temperature profileLatitudeSeason and sensor age
HIRSMSU
ITSC-15, Oct. 2006, Maratea, Italy
TOVSTb
Example for NNORSY Ozone Retrieval
y
t
training data 1
y
t
training data 1
o
NNORSYretrieval
|o-t|
training data 2
error networktraining
Estimation of Local Retrieval Error
NNORSYerror estimation
ITSC-15, Oct. 2006, Maratea, Italy
NNORSY NN configurations: training/test
ITSC-15, Oct. 2006, Maratea, Italy
GM: GOMETV: TOVSTp: temperature profile
NNORSY NN configurations: profiles
ITSC-15, Oct. 2006, Maratea, Italy
GM: GOMETV: TOVSTp: temperature profile
NNORSY-GOME Single Ozone Profile I
ITSC-15, Oct. 2006, Maratea, Italy
NNORSY-GOME Single Ozone Profile II
ITSC-15, Oct. 2006, Maratea, Italy
Correlative Analysis: Artic
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Correlative Analysis: 400 S / New Zealand
ITSC-15, Oct. 2006, Maratea, Italy
NNORSY-Climatology (TLLO): Time Series
ITSC-15, Oct. 2006, Maratea, Italy
NNORSY-Climatology (TllO): Single Profiles for Antarctic
ITSC-15, Oct. 2006, Maratea, Italy
NNORSY: Summary and Current
► 10 year NNORSY-GOME ozone profile data set
► comparison/validation with sonde/lidar/satellite and data assimilation
► Using NNORSY for setup of new ozone profile retrieval
MetOp RAO Meeting, May 2006, Frascati, Italy
► NNORSY-OMI for ozone profile retrieval
► NNORSY application to SCIAMACHY nadir
► Combining GOME with TOVS: small improvements in troposphere
► New dynamic ozone profile climatology available
NNORSY-MetOp: Future
► Total ozone column
► ATOVS, IASI, GOME, GOME+IASI
► Ozone profiles
► IASI, GOME, GOME+IASI
ITSC-15, Oct. 2006, Maratea, Italy