# Presentation: 316951

## Solar Irradiance(Swiss contributions to ILWS)

- 4th ILWS general meeting, Beijing, June 22-23, 2006

- Werner Schmutz, PMOD/WRC, Switzerland
- (representing Swiss Space Office)

## Overview

- Why are solar irradiance measurements required?
- Future Swiss Irradiance experiments
- The future of Total Solar Irradiance

## What is the influence of the Sun on the climate? 

- Graphics: Dr. J. Beer EAWAG, Switzerland

**?**

## Solar irradiance variation between maximum and minimum – spectral dependance

## Rozanov et al. 2001:   what UV-wavelength should be observed? 

- Ozone mixing ratio changes (%) due to a 10% increase of the spectral solar flux in 1 wavelength bin (1 nm).

## Filter Radiometers:LYRA/PROBA2 (launch 2007)PREMOS-PFR/PICARD (launch 2008)

- LYRA: 	7-20, 20-70, 125,	215 nm
- PREMOS: 		215, 268, 535, 782 nm

## C. Fröhlich et al.	SOVIM/ISS	
	2008(?) - 2010
J.-F. Hochedez et al.	LYRA/PROBA2	
	2007 - 2008
W. Schmutz et al. 	PREMOS/PICARD
	2009 - 2019	

- 	2008(?) - 2010
- J.-F. Hochedez et al.	LYRA/PROBA2
- 	2007 - 2008
- W. Schmutz et al. 	PREMOS/PICARD
- 	2009 - 2019

- Future PMOD/WRC Irradiance Measurements (phase C/D)

## SOVIM on ISS (launch 2008?): Hardware, tests and calibration finishedacceptance review passed (almost)

## LYRA (Status: FM April 2005)

## LYRA (Status: FM March 2006)

- BESSY synchrotron calibration at PTB

## PICARD (PI G. Thuillier)PREMOS – SOVAP – SODISM

- PICARD (PI G. Thuillier)PREMOS – SOVAP – SODISM

- Total Solar Irradiance

- Filter Radiometers

## Summary

- SWAP (0.1 Hz) + LYRA (60 Hz) on PROBA2 provide the EUV equivalent in Europe of the NOAA SXI + GOES X-ray monitor 2007-2008
- SODISM + PREMOS on PICARD will continue in the near UV and visual (+TSI) 2008/2009-2011

**Notes:**
Equivalent or rather complementary
Technology demonstration for solar orbiter

## Total Solar Irradiance measurements 

- present :
- 	VIRGO on SoHO (since 1996)
- 	ACRIM III on ACRIM-sat (since 2000)
- 	TIM on SORCE (since 2003)
- future:
- 	SOVIM (CH/B experiments on ISS 2008)
- 		PREMOS-TSI (CH experiment on PICARD 2008)
- 		SOVAP (B experiment on PICARD 2008)
- planned:
-  	RAD (CN/CH experiment on KuaFu-A 2012)

## TSI comparison with observations: cycle 21 – 23Wenzler et al. 2005, A&A 432, 1057

*I*TSI = q*I*quite sun + n*I*network + f*I*faculae + s*I*sun spot

- Minimum-*I*TSI = *I*quite sun

*Is this approach supported by observations?*

## Absolutely calibrated TSI measurements

**TIM/SORCE**
**2003 - **

## TSI – latest update

## TSI – comparisons of different composites

## PMOD composite of the Total Solar Irradiance 

- the aim is to get ***experimental*** long-term information about the TSI

## Total Solar Irradianceobservations between 2006 and 2012

- ACRIM III             2000 - ?
- VIRGO/SOHO  1996 -	           2007 -   ?
- TIM/SORCE	2003 –  	2008 - (?)
- SOVIM/ISS 		2008 – 2009 ?
- PREMOS-TSI/PICARD	2008 – 2011
- SOVAP/PICARD
- (SDO 2008-2012 has no TSI instrument)
- NPOESS			2012
- National Polar Orbiting Operational Environmental Satellite System may have TSI instrument – but are planned to start not earlier than 2009 (?), more likely as late as 2012

## Total Solar Irradianceobservations between 2006 and 2012

- ACRIM III             2000 - ?
- VIRGO/SOHO  1996  	                   -          2009 (?)
- TIM/SORCE	2003        -	2008 - (?)
- SOVIM/ISS 		2008 – 2009 ?
- PREMOS-TSI/PICARD	2008 – 2011
- SOVAP/PICARD
- (SDO 2008-2012 has no TSI instrument)
- NPOESS			2012
- National Polar Orbiting Operational Environmental Satellite System may have TSI instrument – but are planned to start not earlier than 2009 (?), more likely as late as 2012

- TSI on NPOESS canceled June 2006

## Total Solar Irradianceobservations between 2006 and 2012

- ACRIM III             2000 - ?
- VIRGO/SOHO  1996 -	           2007 -          2009
- TIM/SORCE	2003 –  	2008 -     (GLORY?)
- SOVIM/ISS 		2008 - 2009 ?
- PREMOS-TSI/**PICARD**	2008 -                   **2013**
- SOVAP/PICARD
- (SDO 2008-2012 has no TSI instrument)
**KuaFu-A**			**2012**
- RAD comprising:
- SIM = Solar Irradiance Monitor (CN)
- DOR = Davos Observatory Radiometer (CH)

## Summary 2

- Continuation of ***long term ***TSI-measurements requires overlapping missions
- *	**There should be always at least two independent operational experiments *
- TSI is most likely observed by two experiments until 2009/2010
- The gap 2010-2012 is probably covered by an experiment (extended PICARD and/or GLORY)
- There is no approved TSI mission after 2009, but:  good chance for RAD on KuaFu-A 2012
- Other options for 2nd TSI experiment: 		DynaMICS ?
- 			(proposed by Sylvaine Turck-Chièze, F)

- PICARD

**Notes:**
Equivalent or rather complementary
Technology demonstration for solar orbiter