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EDUCE IGF PAS PARTICIPATION
WPX1 ESTIMATE OF THE NATURAL LEVEL AND VARIABILITY OF
SURFACE UVR OVER POLAND
J.W. Krzyścin, J. Borkowski, J. Jarosławski, and P. SobolewskiInstitute of Geophysics, Polish Academy of Sciences, 01-452 Warsaw, Poland
1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003
Year0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
AO
D 3
20 n
m
Daily means of aerosol optical depth at 319.8 nm for the period 1992-2002
Belsk
Retrieval of Aerosol Optical Depth from the UV Direct Sun Intensity Measured by the Brewer during total ozone calculation procedureThe method uses the Langley plot estimation of extraterestrial constants
article in press J.Geophys.Res.
-10
-5
0
5
alfa
Your text aYour textYour text
440-670 nm
-10
-5
0
5
alfa
340-380 nm
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
AOD 320 nm
-10
-5
0
5al
fa
310-320 nm
Ǻngström Formula: Aerosol Optical Depth =
Visible range α = 1.3 0.6
Ǻngström Exponent αversus AOD at 320 nm
for selected pair of wavelength
α < 0 ! →
100 150 200 250 300
-10
0
10
20
30
40
Nor
mal
ize
d D
evi
atio
ns
(%)
-20
020
4060
80100
120
140160
180200
220240
260280
IrradianceActinic Flux
(%)
Julian Day of 2002
Comparison of the surface irradiance and actinic flux at 310 nm by LibRadtran model for various input:
-full input (total ozone-Brewer, ozone profile-Dobson Umkehr,temperature-rawind sonde, AOD-Brewer, SSA+ phase function-CIMEL,
-classic input (total ozone-Brewer, standard profiles for NH midlatitudes,AOD at 550 nm-CIMEL, Ǻngström Exponent=1.3, rural aerosol model)
Biomassburning←
Biometr Irradiances (SL 501A)for the period 1993-2002
-30 -10 10 30 50
Total Ozone Fractional Deviations-60
-20
20
60
-60
-20
20
60
UV
Fra
ctio
nal
Dev
iati
on
s RAF(total ozone) = 1.19
(%)
Total Ozone = 330 DU
(%)
-100 0 100 200 300
Aerosol Optical Depth Fractional Deviations-50
-30
-10
10
30
-50
-30
-10
10
30
UV
- U
V(o
zon
e)
Fra
ctio
nal
Dev
iati
on
s RAF (aerosol) = 0.12 0.01 (1)
AOD (320 nm) = 0.39
(%)
(%)
Belsk SZA=600
Ozone Vertical Profiles by Umkehr Observations
14 3 14 57 3 57 810 3 810
* 2 * 2 * 2 * 214 3 14 57 3 57 810 3 810
( ( )) ( , ) ( , ) ( , ) ( )
( , ) ( , ) ( , ) ( )
UV t O O O AOD
O O O AOD
Partial Radiation Amplification Factors (RAF), , for ozone profile impact on UV and
Radiation Amplification Factor due to aerosol,
Model applied for broadband irradiances taken at SZA=60 and 80 by SL501 A over Belsk for the cloudless period 1993-2002
Partial RAFs depend on SZA UV more sensitive to ozone content in upper levels for large SZA
RAF due to aerosols almost constant
Our Findings
• Brewer Spectrophotometer – instrument providing spectral aerosol optical depth
• No long-term aerosol forcing on the surface UV at Belsk• Aerosol properties in the UV range can not be
extrapolated from those in the visible range• Partial Radiation Amplification Factor (RAF) due to
ozone changes in selected Umkehr layers depend on SZA - empirical evidences for the ozone profile impact on UV.
• Significant impact of day-to-day changes in aerosols on UV irradiance – RAF due to aerosols ~0.12 (weak dependence on SZA)
EDUCE IGF PAS PARTICIPATION
WPX1EXAMINATION OF SURFACE VARIABILITY AT DIFFERENT TIME SCALES IN SURFACE UVR
METHOD FOR RECONSTRUCTION OF UVR TIME SERIES AT EUROPEAN SITES
MULTIRESOLUTION DECOMPOSITION OF THE DATA
SERIES USING WAVELETS.
The wavelet expansion of a time series f(t) enables us to perform a multiresolution decomposition, which separates the series into components: f(t)=SJ(t)+DJ(t)+DJ-1(t)+…….. D1(t).where functions SJ and Dj(t) are called the smooth and detail components respectively. The advantage of wavelet methods is that wavelets provide exact scale-based decomposition results, and can be applied for nonstationary processes.
1977 1982 1987 1992 1997 2002
-5
-1
3
7
S6 [%
]
UV smooth componentozone smooth component
SMOOTH AND DETAILED COMPONENTS OF UV AND OZONE SERIES
UV radiation responds differently to ozone and cloudiness at different time scales.....
cloudiness component
1979.0 1979.5 1980.0 1980.5 1981.0
-30-20-10
010
D1
[%]
UV componentozone component
month
1979.0 1979.5 1980.0 1980.5 1981.0
-20-10
01020
D1
[%]
UV componentcloudiness component
D1 COMPONENTS OF UV AND TOTAL CLOUDINESS
month
1977 1982 1987 1992 1997 2002
-1
3
S6
MODELLED AND OBSERVED S6 COMPONENTS OF UV SERIES
observedmodelled
The mean difference between observed and modelled UV doseis 44%
1977 1982 1987 1992 1997 2002year
-30
-20
-10
0
10
20U
V f
ract
ional d
evi
atio
ns
%
UV observedUV modelled
MODELLED AND OBSERVED UV SERIES
Our Findings:
• Components of the wavelet multiresolution decomposition represent variations at time scales from 2 to 64 months and „smooth” variations
• UV responds differently to ozone and cloudiness variations at different time scales
• Modeling different components separately results in good agreement between modeled and observed values particularly for longer time scales
• The smooth component can be perfectly reconstructed with ozone and cloudiness as explanatory variables only
Annales Geophysicae, 2003, 21, 1887-1896Non-linear (MARS) modelling of long-term variations of surface UV-B
radiation:As revealed from the analysis of Belsk, Poland, data for the period 1976-2000
1 2 3 4 5 6 7 8 9 10Model Version
50
60
70
80
90
Ad
just
ed V
aria
nce
Exp
alin
ed b
y M
od
el
LO
CA
L:
NO
INT
ER
AC
TIO
NS
LO
CA
L+
NO
N-L
OC
AL
: IN
TE
RA
CT
ION
S
LO
CA
L+
SU
N+
NA
O+
QB
O:
INT
ER
AC
TIO
NS
LO
CA
L +
SU
N+
QB
O:
INT
ER
AC
TIO
NS
LO
CA
L +
NO
N-L
OC
AL
: N
O IN
TE
RA
CT
ION
S
LOC
AL
+ S
UN
+Q
BO
: N
O IN
TE
RA
CT
ION
S
LO
CA
L +
SU
N:
INT
ER
AC
TIO
NS
LO
CA
L:
NO
INT
ER
AC
TIO
NS
LO
CA
L +
NO
N-L
OC
AL
: IN
TE
RA
CT
ION
S
:LO
CA
L+
NO
N-L
OC
AL
: N
O IN
TE
RA
CT
ION
S
STEPWISE REGRESSION MARS(%) (a)
1 2 3 4 5 6 7 8 9 10Model Version
50
60
70
80
90
50
60
70
80
90
Ad
just
ed V
aria
nce
Exp
lain
ed b
y M
od
el
LO
CA
L:
NO
INT
ER
AC
TIO
NS
LO
CA
L+
NO
N-L
OC
AL
: IN
TE
RA
CT
ION
S
LOC
AL+
SU
N+
NA
O+
QB
O:
INT
ER
AC
TIO
NS
LO
CA
L +
NA
O+
QB
O:
IN
TE
RA
CT
ION
S
LO
CA
L +
NO
N-L
OC
AL
: N
O IN
TE
RA
CT
ION
S
LO
CA
L +
NA
O+
QB
O:
NO
INT
ER
AC
TIO
NS
LO
CA
L +
NA
O:
INT
ER
AC
TIO
NS
LO
CA
L:
NO
INT
ER
AC
TIO
NS
LO
CA
L +
NO
N-L
OC
AL
: IN
TE
RA
CT
ION
S
LO
CA
L+
NO
N L
OC
AL
: N
O IN
TE
RA
CT
ION
S
STEPWISE REGRESSION
MARS (b)(%)
Regressors: Belsk’s Dobson total ozone,Cloud cover from NCEP/NOAA Reanalysis,Teleconnection Indices (QBO+NAO+ENSO). 11-year solar cycle
Regressors: Belsk’s Dobson total ozoneTotal solar radiation from Belsk’s pyranometerTeleconnection Indices (QBO+NAO+ENSO) 11-year solar cycle
↕ ↕
Comparison the model-observation simulation of the interannual changes in the UV data
1976 1980 1984 1988 1992 1996 2000
Year-30
-20
-10
0
10
20
30
40 ObservationsSmoothed ObservationsModelled ValuesSmoothed Values
(%)
1976 1980 1984 1988 1992 1996 2000
Year-30
-20
-10
0
10
20
30
40 ObservationsSmoothed ObservationsModelled ValuesSmoothed Values
(%)
BELSK: Monthly means for May-October subperiods in 1976-2000
The simplest model The most sophisticated model
Our Findings
• Nonlinear Regression Model-MARS resolves larger part of month-to-month variations but small improvement of the long-term fit to the observed UV radiation
• Long-term Cloud Effects from Reanalysis-1 Data Base – UV reconstruction for any site (if ozone data available)
• NAO and SOI effects on UV by MARS model (impact on atmospheric optical depth over Belsk)
EDUCE IGF PAS PARTICIPATION
WPX1Verification and Extension of UV
Climatology at Selected European Sites
Objectives
Belsk
Toravere
Hradec K.
- Calibration
- UV Doses Climatology
- Long-term Changes of UV dose
- Clouds and Total Ozone Effects on UV Doses long-term changes
Results based on the article submitted to Journal Geophysical Research
Model Verification
CRF –Cloud Reduction Factor
IGF PAS model:
RIVM model:
• Gl - measured daily sum of total solar
radiation• Gl*- modelled clear-sky sum of total solar
radiation
1976 1980 1984 1988 1992 1996 2000
Year
-20
-15
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-5
0
5
10
15
20
25
Fra
ctio
nal
Dev
iati
on
s
(%)MeasurementsSmoothed MeasurementsSmoothed Model Data
1 2 3 4 5 6 7 8 9 10 11 12
Month0
4
8
12
0
4
8
12(MED)
UV
Do
seModeled MeansObserved Means
Monthly Mean Doses - Belsk (1976-2001)
_ *all sky clear skyUV CRF UV
1/*(1 (1 / ) PCRF A GL GL
2* * 2
1 2/ ( / )CRF a Gl Gl a Gl Gl
UV-Climatology
1 2 3 4 5 6 7 8 9 10 11 12
Month0
4
8
12
0
4
8
12
(MED)
UV
Do
se
Monthly Mean (1970-2001) Doses
Belsk - 51.7 NHradec Kralove - 50.1NToravere - 58.3N
1 2 3 4 5 6 7 8 9 10 11 12
Month
0.6
0.7
0.8
0.9
1.0
0.6
0.7
0.8
0.9
1.0
UV
Tra
nsm
itta
nce
BelskHradec KraloveToravere
Cloud/Albedo Effects on UV
Long-term UV variations from the reconstructed UV data Hradec Kralove 1964-2001 (April-September)
1964 1968 1972 1976 1980 1984 1988 1992 1996 2000
Year-30
-25
-20
-15
-10
-5
0
5
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15
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25
30
Fra
cti
on
al
De
via
tio
ns
Monthly mean doses - model IGF PASSmoothed Doses - model IGFPASSmoothed Doses - model RIVM
(%)
1964 1968 1972 1976 1980 1984 1988 1992 1996 2000
Year
-20
-15
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-5
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10
15
20
25
-20
-15
-10
-5
0
5
10
15
20
25
(Ob
se
rva
tio
n -
Mo
de
l)/M
od
el
*10
0% Daily Sum of Total Solar Radiation
Smoothed Data
1964 1968 1972 1976 1980 1984 1988 1992 1996 2000
Year-30
-25
-20
-15
-10
-5
0
5
10
15
20
25
30
Fra
ctio
nal
Dev
iati
on
s
Montlhy mean doses - model IGF PANSmoothed doses - model IGF PANSmoothed doses - model RIVMSmoothed Global Radiation Data - Measurements
(%)
1964 1968 1972 1976 1980 1984 1988 1992 1996 2000
Year-30
-25
-20
-15
-10
-5
0
5
10
15
20
25
30
Fra
ctio
nal
Dev
iati
on
s
(%)Monthly UV dose - model IGFPANSmoothed Doses - model IGF PANSmoothed total ozone
Monthly UV doses
UV daily doses –clear skies
Monthly UV doses cloud effects
Monthly UV doses – ozone effects
Our Findings:
• Reconstruction of the UV time series from historical time series of total ozone and global solar radiation
• Delineation and correction method for the instrument drift in historical time series of global solar and UV radiation
• Establishing the UVR climatology for Central Europe (seasonal profile of UVR and the clouds forcing on UVR )
• Estimations of the clouds and total ozone long-term effects on the surface UVR since mid 1960s
EDUCE IGF PAS PARTICIPATION
WPX2
Estimation of trend variability in Belsk at least 2 other sets
I. There is no precise, commonly accepted definition of a trend.
II. Pristley [1981] refers to trend as “…tendency to increase (or decrease) steadily over time”
Kendall [1976] -“the essential idea of trend is that it shall be smooth”.
III. Most popular approach
y(t)=C*t +e(t)
C depends on time period considered, and does not show variations of the trend within the time period
TREND DETERMINATION
WAVELET APPROACH
1. The „smooth” component of the signal is extracted with the use of wavelet multiresolution decomposition
2. Trend is defined as time derivative of the smooth component of the signal.
1975 1980 1985 1990 1995 2000 2005Year
-30
-20
-10
0
10
20
30F
ract
ional d
evi
atio
ns
[%]
FRACTIONAL DEVIATIONS OF THE UV RADIATION (BELSK)
UV fract. dev.UV smooth
linear trend 1.9%/decade0.9
1975 1980 1985 1990 1995 2000 2005year
-10
-7
-4
-1
2
5
8
% p
er
deca
de
UV trend
1980 1985 1990 1995 2000year
-30
-20
-10
0
10
20
30F
ract
ional d
evi
atio
ns
[%]
FRACTIONAL DEVIATIONS OF THE UV RADIATION (NORRKOPING)
UV fract. dev.UV smooth
1982 1984 1986 1988 1990 1992 1994 1996 1998year
-50
-40
-30
-20
-10
0
10
20
% p
er
deca
de
UV trend
linear trend 6.42.7% per decade
Conclusions:
• Trend is function of time
• Trend determined from smooth component is not contaminated by fluctuations with short time scale
• The problem of the influence of the kind of wavelets on trend is beeing investigated
EDUCE IGF PAS PARTICIPATION
WPX3Submission of spectra and broad-band measurements
The data sets from Belsk in the UV data base:
The 1993-2003 UV spectra from the Brewer spectrophotometer ( ~ 86000 spectra)
Erythemal irradiances by SL 501A biometer (resolution 5 minut) – 1993-2003
Global Solar irradiances by Kipp@Zonen CM1 pyranometer
(resolution 5-minut) – 1994-2003 Total ozone from the Dobson spectrophotometer (daily
representatives 1993-2002)
