Physikalisch-Meteorologisches Observatorium Davos
Space experiments of PMOD/WRC
to measure the solar constant and
the influence of the solar irradiance
on the terrestrial climate
Werner Schmutz
PMOD/WRC
ISPMSRS'07 12-14 March 2007 Davos, Switzerland
PMOD 1907-2007
WRC since 1971
Two activities:
Operational Service
Guided tour at PMOD/WRC
for ISPMSRS'07
participants
„World Radiation
Center“
Energy balance and influence
of radiation on the terrestrial
climate
¾ Green house effect
¾ Sun-Earth connection
12.3.2007
= calibration of meteorological
instruments
Monday measuring
2 pm
radiation
Tuesday 2 pm
Research
Overview
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Physikalisch-Meteorologisches Observatorium Davos
Overview
• Past observations of the Total Solar
Irradiance (TSI) and the TSI-composite
• Why irradiance measurements
• Why continue to measure TSI
12.3.2007
• Future irradiance observations
Absolutely calibrated
TSI observations
TIM/SORCE
12.3.2007
2003 -
Overview
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Physikalisch-Meteorologisches Observatorium Davos
A side note: Need for
improved Quality Assurance!
Difficulties:
- Bias between sensors
MISR, MODIS, AVHRR …..
ƒ On-board calibration systems
expensive! Reliable? Traceable?
BIPM and WMO are proposing
ƒ Inter-team / manufacturer /agency
on launch
andpreparing
degrade
and
adebate
meeting in 2008
in-orbit
ƒ Need for
agreement
orspectral)
2009 dedicated
to International
calibration
(gain and
ƒ No
consistent statements of
and traceability
problems
uncertainty or “degrees of
- Instruments change
12.3.2007
confidence”.
Courtesy of Nigel Fox
Traceable Radiometry Underpinning
Terrestrial- & Helio- Studies
Mission proposal: TRUTHS
Nigel Fox
NPL
Nigel.Fox@npl.co.uk
U of Alab.
Mike Sandford
RAL
Plym Mar Lab
Michael Schaepman U of Zur
Xavier Briottet
ONERA
Werner Schmutz
PMOD/WRC
John Barnett
Ox univ.
Keith Shine
Uni of Read
Steve Groom
Plym Mar Lab
Phil Teillet
CCRS
Claus Frohlich
PMOD/WRC
Theo Theocharous
NPL
Jo Haigh
Imp Coll
Kurtis Thome
U of Ariz
Olivier Hagolle
CNES
Terry Quinn
BIPM
Hugh Kieffer
USGS
Michel Verstraete
JRC(Italy)
Judith Lean
NRL
Emma Woolliams
NPL
John Martin
NPL
Ed Zalewski
U of Ariz
12.3.2007
James Aiken
David Pollock
Overview
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Physikalisch-Meteorologisches Observatorium Davos
TSI – including TIM/SORCE
Absolute measurements cannot be used to
construct a long-term record
12.3.2007
Æ Merge to a relative composite
TSI –
comparisons of
different
composites
12.3.2007
Different composites predict
different long-term trends:
Overview
Courtesy of Claus Fröhlich
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Physikalisch-Meteorologisches Observatorium Davos
Why irradiance measurements?
IUGG
2007:
On
short
term,
the T.,
solar
influence
on the
terrestrial
Rozanov
E.,
Egorova
Schmutz
W., Peter
T., 2006:
• Space
Weather:
atmosphere
dominated
by the
variations
Session MS020
Simulation
ofisthe
stratospheric
ozone
and of the
Monitoring
of220
thenm
solar
Totalband)
and Spectral
UV
(Ly-α
and
Herzberg
temperature
to the solar
Solar Activityresponse
and its Influences
onirradiance
the Earth's
irradiance
variability
during
sun rotation
Weather
Climate
(IRC)
Influenceand
of the
short-term
(dayscycle
to months) variations on
JASTP
68, 2203composition of the upper terrestrial atmosphere
the chemical
12.3.2007
• Space Climate:
Long
term
record
the Solar
On long
term,
it is notofknown
what Irradiance
dominates,
Influence
of the long-term
variations
on the chemical
secular
change
of Total Solar
Irradiance
or
composition of the upper terrestrial atmosphere and its
spectral
(UV)
variations
propagation to the troposphere changing the terrestrial
climate
But:
although UV variations are much larger (up to
100%) all spectral variations are highly correlated
to TSI variations
What is the influence of
the Sun on the climate?
12.3.2007
?
Overview
Graphics: Dr. J. Beer EAWAG, Switzerland
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Physikalisch-Meteorologisches Observatorium Davos
Climate Anomalies versus
solar influence
River Thames in London 1813/1814
200
Maunder
Dalton
150
100
12.3.2007
50
0
1600
1650
1700
1750
1800
YEAR
1850
1900
1950
2000
illustration: Dr. J. Beer EAWAG, Switzerland
Predicted long-term trend of TSI
100 years
12.3.2007
Different “educated”
guesses!
Overview
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Physikalisch-Meteorologisches Observatorium Davos
Predicted long-term trend of TSI
400 years
Suspected secular change of TSI
needs to be confirmed
observationally
Different “educated”
Æ requires long term observation
of several decades!
12.3.2007
guesses!
Three minima in the latest
(August 2006) version of the
PMOD-composite
The present minimum is
It is essential 0.15
to design
W/m (= 110the
ppm)
lower than the previous
irradiance
measurements
at the
twoagree
minimain their value to
The three minima
highest
possible
accuracy!
or 60 ppm)
within ±0.08
W/m2 (0.006%
2
12.3.2007
Î Solution: twin instrument
experiment as VIRGO on SoHO
and PREMOS+SOVAP on PICARD
Overview
The latest (updated) composite is published on the PMOD/WRC web site
http:www.pmodwrc.ch
follow the links:
Æ projects Æ Solar Constant / Solar Irradiance
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Physikalisch-Meteorologisches Observatorium Davos
VIRGO/SoHO:
operational since 1996
12.3.2007
• Two absolute radiometers:
- PMO6V (A & B)
- DIARAD (L & R)
• Precision Filter Radiometer (blue, green, red)
• Image of the Sun in the green light in low resolution
(12 pixels): 1 minute sampling
SoHO launch 2. December 1995
DIARAD
PMO6
SPM
LOI
VIRGO instruments
Future TSI experiments
¾ GLORY (USA: no launch date – ready to be
used as gap-filler)
¾ SOVIM/ISS and
¾ PREMOS+SOVAP/PICARD
approved TSI experiments of PMOD/WRC
12.3.2007
¾ RAD/KuaFu-A only future TSI experiment
presently being considered
Overview
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Physikalisch-Meteorologisches Observatorium Davos
12.3.2007
Space experiments are being
built in house at PMOD/WRC
Space experiments of PMOD/WRC
12.3.2007
today
Overview
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Physikalisch-Meteorologisches Observatorium Davos
PICARD (PI G. Thuillier)
PREMOS – SOVAP –
SODISM
12.3.2007
Filter Radiometers
Total Solar Irradiance
Total Solar Irradiance
observations until 2012
ACRIM III
2000 - ?
VIRGO/SOHO 1996
TIM/SORCE
2003
-
2009 (+?)
2008 - (?)
12.3.2007
SOVIM/ISS
2008 – 2009 ?
PREMOS/PICARD
2009 – 2011
SOVAP/PICARD
(SDO 2008-2012 has no TSI instrument)
Overview
NPOESS
2012
TSI o
National Polar
Orbiting
n NPO Operational Environmental Satellite
E Sc
ancele – but are planned to start
System may have TSI Sinstrument
d June
not earlier than 2009 (?), more likely
as20late
06 as 2012
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Physikalisch-Meteorologisches Observatorium Davos
Total Solar Irradiance
observations until 2012
ACRIM III
2000 - ?
VIRGO/SOHO 1996 2007 2009
TIM/SORCE
2003 –
2008 - (GLORY?)
SOVIM/ISS
PREMOS-TSI/PICARD
SOVAP/PICARD
2007 - 2009 ?
2009 -
2013
(SDO 2008-2012 has no TSI instrument)
KuaFu-A
irradiance measurement experiment comprising:
2012 -
12.3.2007
Æ SIM = Solar Irradiance Monitor (CN: PI Daren Lu)
Æ DOR = Davos Observatory Radiometer (CH: Werner Schmutz)
Conclusions
Short-term irradiance variations (days) are closely related
to variations of the chemical composition of the upper
atmosphere
Æ space weather: operational monitoring of TSI
•
Long-term irradiance variations (tens to thousands of
years) are probably (!) related to climate variations
Æ space climate: secular long term change of TSI
•
TSI observations are most likely continuous and
overlapping until about 2012
•
RAD/KuaFu-A would be a matching continuation
12.3.2007
•
Overview
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Physikalisch-Meteorologisches Observatorium Davos
Thank you for your attention!
Integration of LYRA
on PROBA2
5.3.2007
Overview
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