Total Solar and Spectral Irradiance Sensor TSIS Rodney Viereck NOAA Space Environment Center Earth Radiation Budget

1. TSIS and ERBS Polar Max 2005 Total Solar and Spectral Irradiance SensorTSISRodney ViereckNOAA Space Environment CenterEarth Radiation Budget SensorERBSJim CoakleyOregon State University

2. TSIS and ERBS Polar Max 2005 NPOESS TSISTotal Solar and Spectral Irradiance Sensor Rodney Viereck NOAA Space Environment Center Peter Pilewskie, Greg Kopp, Jerry Harder Laboratory for Atmospheric and Space Physics, University of Colorado

3. TSIS and ERBS Polar Max 2005 Total Irradiance Monitor (TIM) Total Irradiance Monitor (TIM) Four cavity bolometer Measurment Range 1310 to 1420 W/m2 Long Term Stability 0.002 %/yr Measurement Precision 0.002 %/yr Measurement Accuracy 1.5 W/m2 (0.1 %)

4. TSIS and ERBS Polar Max 2005 Spectral Irradiance Monitor (SIM) Spectral Range 200 – 3000 nm Spectral Resolution l < 280 nm 1 nm 280 nm < l < 400 nm 5 nm l > 400 nm 35 nm Long Term Stability L < 600 nm 0.02%/yr L > 600 nm 0.01%/yr Precision 0.02 %/yr Accuracy 1% Refresh 20 min/orbit

5. TSIS and ERBS Polar Max 2005 TSIS Scan Platform

6. TSIS and ERBS Polar Max 2005 Solar Irradiance:A Critical Component of Climate Modeling

7. TSIS and ERBS Polar Max 2005 Spectral Irradiance: A Critical Component of Climate Variability 11-year Solar Cycle in the Quasi Biennial Oscillation (QBO) The QBO is a semi-periodic shift in the zonal (east-west) stratospheric winds near the equator with an average period of 28 months The QBO seems to be a strong factor in organizing the tropical weather and global climate system. Solar signal emerges from data (stratospheric temperature) when the data is separated into east and west phases of the QBO It is the UV wavelengths that force the stratosphere

8. TSIS and ERBS Polar Max 2005 Critical TSIS Issues NASA SORCE mission TIM and SIM launched in 2003 Five year mission NASA GLORY mission Only TIM Launch in 2008 Three year mission (2011) although TIM is designed for five years (2013). NPOESS C3 TIM and SIM Launch in 2013 (?) GAPS in the Total Solar Irradiance record It is absolutely critical to have overlap between sensors. With overlap, estimating secular trends in TSI is very difficult. Without overlap, estimating secular trends is nearly impossible. Any delays in the launch of NPOESS C3 will increase the possibility of having a gap in the 27-year continuous TSI record Gaps in Spectral Irradiance Record There is no SIM on GLORY Any delays in the launch of NPOESS C3 will add to the existing gap in the spectral irradiance record

9. TSIS and ERBS Polar Max 2005 NPOESS ERBS Earth Radiation Budget Sensor B.A. Wielicki, K.J. Priestley, D.P. Kratz, N.G. Loeb, T.P. Charlock, and P. Minnis NASA Langley Research Center J.A. Coakley, Jr. Oregon State University Shi-Keng Yang NOAA-NCEP/CPC High accuracy broadband radiation budget observations for… Forecast model development and validation Fundamental climate observations Long term, accurate Earth radiation budget, absorbed sunlight and emitted longwave radiation, are key to understanding the variability of climate and climate change which will undoubtedly be accelerating in the decades of the NPOESS era. Inferences of the surface radiation budget as well as the top of the atmosphere radiative fluxes are also finding roles in forecast model development and validation and with the 60-150 min latency, could find their way into assimilation schemes. Current vision from the viewpoint of the OAT is that NPOESS ERBS will continue the current CERES strategy for deriving the ERBS EDRS. In fact, the first instrument to be flown on the afternoon NPOESS orbiter is the CERES Flight Model 5 (FM-5), which needs to be refurbished, as discussed later, to meet IORD II requirements. The CERES observations are themselves a continuation and extension of the ERBE observations which started in the mid 1980’s The CERES strategy incorporates the analysis of multi-sensor data streams, particularly the VIIRS and ERBS, as well as a host of inputs such as analyzed, or even forecast, meteorological variables. Long term, accurate Earth radiation budget, absorbed sunlight and emitted longwave radiation, are key to understanding the variability of climate and climate change which will undoubtedly be accelerating in the decades of the NPOESS era. Inferences of the surface radiation budget as well as the top of the atmosphere radiative fluxes are also finding roles in forecast model development and validation and with the 60-150 min latency, could find their way into assimilation schemes. Current vision from the viewpoint of the OAT is that NPOESS ERBS will continue the current CERES strategy for deriving the ERBS EDRS. In fact, the first instrument to be flown on the afternoon NPOESS orbiter is the CERES Flight Model 5 (FM-5), which needs to be refurbished, as discussed later, to meet IORD II requirements. The CERES observations are themselves a continuation and extension of the ERBE observations which started in the mid 1980’s The CERES strategy incorporates the analysis of multi-sensor data streams, particularly the VIIRS and ERBS, as well as a host of inputs such as analyzed, or even forecast, meteorological variables.

10. TSIS and ERBS Polar Max 2005 Improvement of ERB from the Prognostic Cloud Algorithm An example of the use of CERES data to validate cloud schemes used in the NCEP/CPC forecast model. Broadband fluxes prove to be superior to the traditional narrow channel AVHRR inferences of outgoing longwave radiation in such validations.An example of the use of CERES data to validate cloud schemes used in the NCEP/CPC forecast model. Broadband fluxes prove to be superior to the traditional narrow channel AVHRR inferences of outgoing longwave radiation in such validations.

11. TSIS and ERBS Polar Max 2005 The net radiative flux at the top of the atmosphere is equivalent to heat storage in the ocean. An independent measure of heat storage, based on ocean temperatures and the expansion of water as temperature rises, is compared with long term, accurate measurements of the top of the atmosphere net radiation budget.The net radiative flux at the top of the atmosphere is equivalent to heat storage in the ocean. An independent measure of heat storage, based on ocean temperatures and the expansion of water as temperature rises, is compared with long term, accurate measurements of the top of the atmosphere net radiation budget.

12. TSIS and ERBS Polar Max 2005 CERES Capabilities and IORD-II Requirements Common Requirements: Horizontal Cell Size: 20 km at nadir (meets threshold) Mapping Uncertainty: 1 km at nadir (meets objective) Latency: 1 IBM processor processes a 5-minute orbit granule of data in 20 minutes and produces all four EDRs EDR Specific (CERES in color, Threshold/Objective, Wm-2): Based on thousands of CERES tests over surface sites and multisensor top of the atmosphere consistency checks. IORD-II Requirements and current CERES capabilities. In most instances the current CERES instrumentation and analysis methods meet the IORD-II Requirements. A program is currently underway within the CERES project to provide near real-time radiation budget estimates, so the 60-150 min latency requirement seems achievable. It’s only a matter of money. Where there are exceptions to the IORD-II requirements, strategies have been proposed to improve the observations, although funding limitations are holding up efforts to make the improvements. Crucial to achieving long term stability in the observations are the improvements to the CERES radiometer design and operation required to achieve better in-flight characterizations of instrument performance and calibration and to avoid what appears to be UV degradation of the shortwave filter. IORD-II Requirements and current CERES capabilities. In most instances the current CERES instrumentation and analysis methods meet the IORD-II Requirements. A program is currently underway within the CERES project to provide near real-time radiation budget estimates, so the 60-150 min latency requirement seems achievable. It’s only a matter of money. Where there are exceptions to the IORD-II requirements, strategies have been proposed to improve the observations, although funding limitations are holding up efforts to make the improvements. Crucial to achieving long term stability in the observations are the improvements to the CERES radiometer design and operation required to achieve better in-flight characterizations of instrument performance and calibration and to avoid what appears to be UV degradation of the shortwave filter.

13. TSIS and ERBS Polar Max 2005 CERES processing system as proposed for NPOESS ERBS. Data streams from both VIIRS and ERBS used in generating EDRS. Additional data from NCEP, and other sources, e.g., snow and ice maps, are also used to produce the EDRs. The top of the atmosphere estimates of the shortwave and longwave fluxes are based on the ERBS broadband radiance and the properties of the scene which the ERBS is viewing. The properties of the scene, which include cloud cover, cloud properties, aerosol burden, etc. are derived from the VIIRS and other data streams. Given the observed broadband radiance, the radiative flux is a function of the anisotropy of the radiance field. The anisotropy of the radiance field has been tied through years of CERES observations from the TRMM, Terra, and Aqua satellites. NOTE: The scene properties and the inferred radiance anisotropy are method dependent. NPOESS operational cloud and aerosol products will not necessarily be consistent with the anisotropy of the radiance fields based on the methods used by the CERES project to derive cloud and aerosol properties from imagery data. For the surface radiative fluxes, NCEP, surface, aerosol, and cloud information (derived from VIIRS) are first used in a broadband radiative transfer model to calculate radiative fluxes at the top of the atmosphere. The most uncertain parameters, such as cloud amount, cloud optical depth, water vapor amount, or aerosol optical depth, are adjusted to achieve a match between the top of the atmosphere observed radiative flux and the model calculated flux. The broadband radiative transfer model is then used to predict the surface fluxes.CERES processing system as proposed for NPOESS ERBS. Data streams from both VIIRS and ERBS used in generating EDRS. Additional data from NCEP, and other sources, e.g., snow and ice maps, are also used to produce the EDRs. The top of the atmosphere estimates of the shortwave and longwave fluxes are based on the ERBS broadband radiance and the properties of the scene which the ERBS is viewing. The properties of the scene, which include cloud cover, cloud properties, aerosol burden, etc. are derived from the VIIRS and other data streams. Given the observed broadband radiance, the radiative flux is a function of the anisotropy of the radiance field. The anisotropy of the radiance field has been tied through years of CERES observations from the TRMM, Terra, and Aqua satellites. NOTE: The scene properties and the inferred radiance anisotropy are method dependent. NPOESS operational cloud and aerosol products will not necessarily be consistent with the anisotropy of the radiance fields based on the methods used by the CERES project to derive cloud and aerosol properties from imagery data. For the surface radiative fluxes, NCEP, surface, aerosol, and cloud information (derived from VIIRS) are first used in a broadband radiative transfer model to calculate radiative fluxes at the top of the atmosphere. The most uncertain parameters, such as cloud amount, cloud optical depth, water vapor amount, or aerosol optical depth, are adjusted to achieve a match between the top of the atmosphere observed radiative flux and the model calculated flux. The broadband radiative transfer model is then used to predict the surface fluxes.

14. TSIS and ERBS Polar Max 2005 The first ERBS instrument to fly on NPOESS was an instrument built for the CERES project, FM-5. The instrument requires refurbishment to improve the inflight characterization and calibration of the sensor, and to enhance the redundancy in the longwave and shortwave broadband flux estimates. On orbit operation of the instrument requires attention as the instruments now in space appear to be showing filter degradation in the UV part of the spectrum.The first ERBS instrument to fly on NPOESS was an instrument built for the CERES project, FM-5. The instrument requires refurbishment to improve the inflight characterization and calibration of the sensor, and to enhance the redundancy in the longwave and shortwave broadband flux estimates. On orbit operation of the instrument requires attention as the instruments now in space appear to be showing filter degradation in the UV part of the spectrum.