noaa observations of solar irradiance - |lasp|cu...

14 Sept 2005 SORCE Meeting 1

NOAA Observations of SolarIrradiance

Rodney ViereckNOAA SEC

A presentation of the past, present, and futureobservations of solar irradiance made by NOAA

GOES XRS GOES 8-12 XRSX-Ray

EUV

UV

UVVISIR

Total1970 1980 1990 2000 2010 2020 . . . . . .

Year

GOES NOP XRS

GOES NOP EUVS

POES (and NIMBUS) SBUV POES SBUV NPOESS OMPS and SIM

NPOESS SIM

NPOESS TIM

Spec

tral B

and

GOES

NOAA POES

NPOESS

GOES R+ XRS

GOES R+ EUVS


0.1 1.0 10010 1000 10000Wavelength (nm)

Sola

r Irr

adia

nce

0.1

10

1000

105

Solar Variability(m

ax min)/m

in

IRVISUVEUVX-RAY

GOES XRS

GOES SXI (Imager)

GOES EUV*

POESSBUV

NPOESS(SIM)*

NPOESS(TIM)*

Overview of NOAA Solar Observations:Spectral Coverage

NOAA is monitoring, or plans to monitor, much of the solarspectrum.

Solar Spectrum

Solar Variability

* Planned for future NOAA satellites


GOES X-Ray Sensor (XRS)

Operational Requirement(Space Weather)Detect onset of flareMeasure flare magnitude

Expanded Utility (SpaceClimate)Long-term measure of solar x-ray irradiance

Planed inclusion in theSolar2000 EUV irradiance andflare model (Tobiska andBouwer)

X-Ray Sensor IssuePresently adjusting irradianceto match earlier spacecraft

XRS Long * 0.7 XRS Short * 0.85

Very Large (X17) Flare of Last WeekHF Radio Wave Absorption

Impacted Location and Frequencies

Solar X-Ray Daily Background


GOES R+ XRS

GOES XRS

Past Data is Available at the NOAA National Geophysical DataCenter http://spidr.ngdc.noaa.gov/spidr/

Presently, GOES 10 and 12 are operational, GOES 11 is stored on-orbit. GOES N will be launched in October 2005, GOES O and P are in final stages of assembly. GOES R is in initial planning stage

XRS will remain very similar into the foreseeable future

GOES NOP XRS

GOES

Sat

ellit

eSe

ries

1970 1980 1990 2000 2010 2020 . . . . . . Year

Toda

y

GOES 8-12 XRSEarly GOES XRS


GOES EUV Irradiance(new for GOES NOP: Launch Oct. 2005)

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140

1

10

100

1000

10000

100000

1000000

1E7

EUVEEUVD

EUVC

EUVB

EUVA

Inst

rum

ent R

espo

nse

Wavelength (nm)

-200

-180

-160

-140

-120

-100

-80

-60

-40

-20

0

20

40

60

80

100

120

Atmospheric Heating Rate Hea

ting

Rat

e(d

eg/h

r)

100

150

200

250

300

350

400

450

500

0 20 40 60 80 100 120

Energ

y D

eposi

tion (

W/m

3

)

1E-12

1.9E-12

3.8E-12

7.3E-12

1.4E-11

2.7E-11

5.3E-11

1E-10

2E-10

3.9E-10

7.5E-10

1.5E-9

2.8E-9

5.5E-9

1.1E-8

2.1E-8

4E-8

Alti

tud

e (

km)

Wavelength (nm)

Space WeatherRequirements driven by Ionospheric models

(Communications,Navigations)

Thermospheric models(Satellite drag)

Original GOES N EUVS Bands


GOES R+Bands or Lines?

The next generationof GOES EUV sensorsis under development. What is the best

compromise between fullspectral coverage andcost?

Can we model the entirespectrum with just a fewspectral lines ratherthan bands?

TIMED SEE data showthat we can measure afew spectral lines andmodel the rest of theEUV spectrum

0 20 40 60 80 100 120

0.0

0.1

0.2

F10 + F10(81 day Avg)

Mg II + F10 + F10(81 day Avg)

Five Bands + Mg II + F10 + F10(81 day Avg)

Five Lines + Mg II + F10 + F10(81 day Avg)

Sta

ndard

Devia

tion

Wavelength (nm)

0 20 40 60 80 100 12010

-10

10-9

10-8

10-9

10-8

10-7

10-6

10-5

10-4

10-3

10-2

EUV-A EUV-B EUV-C EUV-D EUV-E

Wavelength (nm)

FeIX

/X

HeI

I

FeXV

IM

gIX

HI

TIMED SEE Solar Spectrum

GOES N EUVS Bands


EUV Irradiance:Relevant to Climate Change Research?

Climate change in the upperatmosphere.

Upper atmosphere is a driven systeminternal variability is small compared tothe response to external forcing.

EUV variability and upper atmosphericresponse vary by factors of 10.

Upper atmospheric response toanthropogenic forcing is negative(cooling)

Upper atmospheric response toanthropogenic forcing is smallcompared to the response to solarforcing.

Removing the natural (solar) signal toobserve the secular or anthropogenicsignal requires very good solar data.

Solar MaxSolar Min

Keating380 km

Roble400 km

Marcos 400km

Akmaev200 km

Emmert530 km

NOV time = 19 UTC

1940 1950 1960 1970 1980 1990 2000

80

100

120

140

Kp

1940 1950 1960 1970 1980 1990 2000

1.5

2.0

2.5

3.0

3.5

foF2 - solar removed

1940 1950 1960 1970 1980 1990 2000

-15

-10

-5

0

5

10

foF2 in percent - solar removed

1940 1950 1960 1970 1980 1990 2000

-10

0

10

NOV time = 20 UTC

1940 1950 1960 1970 1980 1990 2000

80

100

120

140

Kp

1940 1950 1960 1970 1980 1990 2000

1.5

2.0

2.5

3.0

3.5


1940 1950 1960 1970 1980 1990 2000

-15

-10

-5

0

5

10


1940 1950 1960 1970 1980 1990 2000

-15

-10

-5

0

5

10

15

NOV time = 21 UTC

1940 1950 1960 1970 1980 1990 2000

60

80

100

120

140

Kp

1940 1950 1960 1970 1980 1990 2000

1.5

2.0

2.5

3.0

3.5


1940 1950 1960 1970 1980 1990 2000

-10

-5

0

5

10


1940 1950 1960 1970 1980 1990 2000

-10

-5

0

5

10

Trends in the Thermosphere

Trends in the IonosphereBoulder (Nov 1900UT)

From Akmaev (2005)

From Weatherhead (2004)


SORCE XPS

GOES R+ EUVS

NOAA EUV Sensor

Starting in 2005 (or sometime after), NOAA will begincontinuous monitoring of solar EUV irradiance.

Planned GOES N Schedule: Launch October 2005 Post Launch Test To May 2006 On Orbit Storage ???? Begin Operations 2007, 2008, 2009, ???

1970 1980 1990 2000 2010 2020 . . . . . . Year

Toda

y

Sate

llite SOHO SEM

TIMED SEE

SDO EVE

GOES NOP EUVSAEROS

-A

AEROS-A

SM-5

AE-E

SOLRAD 11

EUV

Hole


Solar UV Observationsfrom NOAA POES SBUV and SBUV2

(see publications and presentations by Matt DeLand)

The Solar Backscatter UltraVioletSensor (SBUV) Scanning monochrometer Nadir viewing (Designed to measure

ozone) Periodically (daily), a diffuser directs

sunlight into sensor Daily measurements

Continuous scan mode (170-405 nm, 1.1nm resolution)

Discrete mode, sampling 12wavelengths around the 280 nm Mg IIabsorption feature.

Primary solar product is the Mg IIcore-to-wing ratio a measure ofsolar chromospheric activity. Proxy for UV Proxy for EUV Proxy for Total Solar Irradiance

Models

Solar UV Spectrum from the SBUV


Calculating the Mg II Core-to-Wing Ratio

277 278 279 280 281 282 283Wavelength (nm)

1.0E5

1.5E5

2.0E5

2.5E5

3.0E5

3.5E5

Rel

ativ

e In

ten s

i t y 791011 5 4 3 12612 8

(Allen et al., 1978)

SBUV Discrete Grating Steps

Wavelength (nm)

h (280.27 nm)

k (279.56 nm)

Rel

ativ

e In

tens

ity

SBUV Scan Data

The h and k Mg II emission lines (core)are highly variable while the adjacentsolar spectral features (wings) are morestable

Even though the SBUV does not resolvethe lines, the bottom of the spectralfeature is still more variable than thewings

The SBUV Mg II ratio is the ratio ofthe sum of the core values to the wingvalues

(6 + 7 + 8)(1 + 2 + 11 + 12)

Mg II = Core/Wings

=

12 11 10 9 8 7 6 5 4 3 2 1


Mg II Observations:Creating a Composite Mg II Index

Rodney A. Viereck(1), Linton E. Floyd, L.(2), Patrick C. Crane(2), Thomas N. Woods(3), Barry G. Knapp(3), GaryRottman(3), Mark Weber(5), Lawrence C. Puga(1), Matthew T. DeLand(6)

In spite of large variations in the absolute values of the Mg II observations,the measurements are highly correlated. This allows simple linear scaling ofeach dataset to a common value.


Cross Correlations Between Mg II Data Sets

Linear correlationsbetween UV sensorswith

differentresolutions

measuring atdifferent timesof the day

from differentsatellites.

Combining thesemeasurements into asingle time series isfairly straightforward.

0.260 0.265 0.270 0.275 0.280 0.285 0.290

0.260

0.265

0.270

0.275

0.280

0.285

0.290

0.295

0.260 0.265 0.270 0.275 0.280

0.260

0.265

0.270

0.275

0.280

0.285

0.265 0.270 0.275 0.280 0.285 0.290

0.265

0.270

0.275

0.280

0.285

0.290

0.255 0.260 0.265 0.270 0.275 0.280 0.285 0.290 0.295

0.255

0.260

0.265

0.270

0.275

0.280

0.285

0.290

0.295

NOAA9

N7N9

R = 0.99737

a

c

SUSIM

NOAA9

R = 0.99147

d

NOAA16

SUSIM

R = 0.99540

R = 0.99628

SUSIM

GOME


UV Applications:Mg II Core-to-Wing Ratio

Mg II Index is a measure of solar chromospheric variability used as a proxy for EUV and UV variability and in models of TSI. one of the longest records of solar variability.

1978 1982 1986 1990 1994 1998 2002 2006

0.260

0.265

0.270

0.275

0.280

0.285

0.290

0.295

Mg II In

dex

Year


NOAA SBUV Sensors

1970 1980 1990 2000 2010 2020 . . . . . . Year

NOAA 16 SBUV

Toda

yUARS SUSIM

UARS SOLSTICE

UMETSAT GOME

SORCE SOLSTICE

NOAA 17 SBUV

NOAA N SBUV

NOAA 18 SBUV

NPP OMPS

NPOESS OMPS and SIM

NIMBUS 7 SBUV

NOAA 9 SBUV

NOAA 11 SBUV

The present SBUV/2 instrumentsNOAA-14 Launched Dec 1994NOAA-16 Launched Sept 2000NOAA-17 Launched June 2004NOAA-18 Launched May 2005NOAA-N Launch-ready in 2008

The Future NOAA UV Solar ObservationsNPP OMPS Launch 2009NPOESS OMPS Launch 2011NPOESS SIM Launch 2013

Not measuring Mg II


TSIS measures the solar input into the Earths energy balance -- a key factor inunderstanding the change in climate

NPOESS TSIS consists of

Two sensors:

Total Irradiance Monitor (TIM): Measures total solar irradiance

Spectral Irradiance Monitor (SIM): Measures spectral irradiance in the 200 to 2000 nm range

A Thermal Pointing System (TPS) that integrates thermal and mechanical designs forsun-staring and calibration, and includes

A Fine Sun Sensor (FSS)

Associated Electronic Modules

TIM and SIM are based on heritage SORCE (Solar Radiation and ClimateExperiment)

TSIS is procured from the University of Colorado, Laboratory for Atmosphericand Space Physics (CU LASP)

TSIS will be located on 1730 satellite aft nadir deck and will be launched firston NPOESS C3 (2013?) and later on NPOESS C6 (2018??)

Total and Spectral Irradiance onNPOESS TSIS

(National Polar orbiting Operational Environmental Satellite System Total and Spectral Irradiance Sensor)


NPOESS TSIS

SpectralIrradianceMonitor (SIM)

TotalIrradianceMonitor (TIM)

Electronics Modules

PointingPlatform

SupportStructure


NPOESS C6 TIM

NPOESS C6 SIM

NPOESS C3 TIM

NOAA Total and Spectral Irradiance Sensors

Total Irradiance and Spectral Irradiance Requirement for long-term solar irradiance trends and information Long accurate records require instrument-to-instrument overlap

Gaps in record create much larger uncertainties in the trends Gap in SIM data seems inevitable unless SORCE lasts for a long long time Gap in TIM will not occur if all sensors operate longer than planned and

launches are not delayed (lots of ifs)

2002 2004 2006 2008 2010 2012 2014 2016 2018 2020 2022 Year

GLORY TIM

NPOESS C3 SIM

Toda

y

SIM Data Gap

SORCE TIM

SORCE SIM


Summary

NOAA has been monitoring the x-ray irradiance for more than 20years

NOAA has been monitoring the UV solar irradiance for more than20 years

NOAA will begin to monitor the EUV solar irradiance in a few weeks

NOAA will monitor total and spectral solar irradiance on NPOESSsome time in the future (2013?)

Total Solar Irradiance (TIM)

Spectral Irradiance (SIM) of the UV, Visible, and IR wavelengths

All of these observations will continue into the foreseeable future.

noaa observations of solar irradiance - |lasp|cu...

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