1. GEO-CAPE Atmospheric Science Mission Implementation Analysis of Alternatives FY13 Guidance Letter – Task 1 May 15, 2013

2. Introduction 2  The Geostationary Coastal and Air Pollution Events (GEO-CAPE) mission objective is to make measurements of atmospheric composition and ocean color  ESD acknowledged the impact of TEMPO on GEO-CAPE mission planning: “With the award of the Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument as the first Earth Venture Instrument (EVI-1), a partial change of direction will be needed for the GEO-CAPE activities, as the TEMPO instrument will likely achieve a significant portion of the GEO-CAPE measurement objectives.”  ESD guidance for FY13 GEO-CAPE studies included: “Define the GEO-CAPE atmospheric composition instrument suite in light of the defined science of the TEMPO instrument”  GEO-CAPE atmospheric composition instrument suite may be defined as TEMPO + a GEO-CAPE InfraRed Instrument (GCIRI)

3. Analysis of Alternatives Study 3  This study explored alternatives for achieving all GEO-CAPE Atmospheric Science measurement objectives as defined in the STM, assuming TEMPO will achieve a significant fraction GEO-CAPE requires a set of concurrent UV-Vis-IR measurements at the same spatial and temporal sampling for a period of 3 years TEMPO provides a large fraction of this set of measurements ‒ A critical part of the set includes IR measurements not provided by TEMPO ‒ Ongoing TEMPO, GEO-CAPE, and ESTO activities are advancing the maturity of TEMPO’s planned UV-Vis 2-layer O 3 product  The analysis of alternatives study objectives were to Assess remaining GEO-CAPE atmospheric science implementation architecture based on TEMPO and its expected performance Update GEO-CAPE atmospheric science implementation architecture including schedule options Coordinate with TEMPO team and ASWG Work with SEWG/ESTO on technology needs and recommendations

4. TEMPO Assumptions 4 Assumptions regarding TEMPO used to identify candidate alternatives for a GEO-CAPE InfraRed instrument (GCIRI) a)TEMPO begins making science measurements in 2019 Development and launch schedules are achieved as planned b)The orbit location of TEMPO over mid U.S. enables full CONUS observations Approximately the same GSD for both coasts; no significant differences c)TEMPO makes all GEO-CAPE STM defined UV-Vis measurements O 3 (UV), O 3 (Vis), HCHO, SO 2, NO 2, C 2 H 2 O 2, AOD, AAOD, AI d)TEMPO remains fully operational for its base period of operation (21 mo) Negligible degradation in measurement capability Commercial hosting services contract options for additional periods of operations

5. GCIRI Criteria 5 Criteria used to identify candidate alternatives for a GEO-CAPE InfraRed Instrument (GCIRI) a)GCIRI makes some or all of the GEO-CAPE atmospheric measurements required in the Science Traceability Matrix (STM) that are not made by TEMPO b)GCIRI + TEMPO measurements made at the same time to jointly address the measurement objectives and science questions defined in the GEO-CAPE STM c)GCIRI is a passive optical instrument that measures spectrally resolved radiance in IR spectral bands from GEO d)GCIRI can be accomplished within EV class cost and schedule constraints and Common Instrument Interface guidelines, as a commercially hosted payload like TEMPO

6. GCIRI Implementation Questions Can TEMPO be leveraged to complete GEO-CAPE Atmospheric Science objectives at minimal cost? 6 TEMPO GCIRI GEO Air Quality Mission Over Asia GEO Air Quality Mission Over Europe GEO-CAPE Air Quality Mission Over North America  WHY does GEO-CAPE Atmospheric Science require GCIRI measurements in addition to TEMPO measurements?  WHAT measurement capability must GCIRI have with respect to the defined science of the TEMPO instrument?  WHEN must GCIRI make concurrent observations of N. America with TEMPO?  WHERE in GEO must GCIRI be for geographic coverage compatibility? Science return impact of TEMPO and GCIRI orbit locations

7. WHY: Science Rationale for GCIRI Measurements 7 At a minimum, GCIRI measures CO vertical distribution (as recommended in the DS) to uniquely distinguish emissions, transformation, and long-range transport of pollution GEO-CAPE addresses 6 peer-reviewed science questions regarding the emission, chemical transformation, and transport of air pollutants in a changing climate The minimum set of measurements required to answer these questions, as recommended in the DS, is provided by TEMPO and GCIRI together Emission: NO 2, VOC, CO, aerosol Transformation: O 3 created from NO 2 and VOC (HCHO is proxy for total VOC); CO and aerosol evolve Transport and long-range impact: O 3, CO, aerosol NO 2, VOC, CO, aerosol O 3, NO 2, HCHO, CO, aerosol O 3, CO, aerosol Image adapted from CCSP Strategic Plan (illustrated by P. Rekacewicz) O 3, CO, aerosol

8. WHAT: GEO-CAPE Atmospheric Science Measurement Capability 8 GCIRI = a GEO-CAPE InfraRed Instrument 21% 4% 6% 7% 8% 11% 19% 20% 3% O 3 [2 layers] CO [2 layers] Column NO 2 Column SO 2 Column HCHO Column CH 4 Column NH 3 Column CHOCHO Total STM value = 100% Average contribution to all Questions TEMPO product GCIRI candidate product Aerosols TEMPO+GCIRI together accomplish GEO-CAPE Atmosphere STM measurements GCIRI must provide a multi-layer CO product for minimum GEO-CAPE success GCIRI may provide all GEO-CAPE products requiring IR measurements

9. WHEN: GCIRI Mission Schedule Relative to TEMPO 9  GEO-CAPE Atmospheric Science measurement objectives defined in the STM are to obtain the set of concurrent UV-Vis-IR measurements at the same spatial and temporal sampling for a period of 3 years  The notional GCIRI schedule below illustrates that 3 years of concurrent GCIRI and TEMPO measurements are possible if GCIRI development started in 2014  The longer the duration of concurrent GCIRI and TEMPO measurements, the greater the potential for completing all GEO-CAPE Atmospheric Science objectives and for improving understanding of air pollution around the globe GEO-CAPE science objectives require that GCIRI measurements are concurrent with TEMPO. The international constellation of Air Quality missions extends the science from regional to global.

10. WHERE: Geographic Coverage Compatibility 10  GCIRI and TEMPO orbit locations as close to 100 o W as possible maximizes their science return Provides similar viewing geometries and ground sampling distances for both coasts of North America  Minimal orbital separation between GCIRI and TEMPO maximizes their science return Provides similar viewing geometries and ground sampling distances for any given latitude  Analysis determined that orbit locations between 80 o W and 120 o W are sufficient for GEO-CAPE products GCIRI is not required to be in the same location as TEMPO Geographic coverage from 100 o W Geographic coverage from 120 o W Geographic coverage from 80 o W The large number of anticipated commercial GEO satellites over this longitude range provides adequate opportunities for GCIRI

11. GCIRI Implementation Findings 11  WHY: GCIRI measurements capture critical high value GEO-CAPE species such as CO that are not measured by TEMPO  WHAT: GCIRI measurement capability alternatives a)TEMPO + GCIRI with SWIR-MWIR capability can meet 90-95% of GEO-CAPE Atmospheric Science requirements b)TEMPO + GCIRI with SWIR-MWIR-TIR capability can meet 100%  WHEN: Concurrent GCIRI - TEMPO mission alternatives a)Three years of concurrent observations completes GEO-CAPE Atmosphere Science requirements => Depending on how soon GCIRI can be launched, at least one and possibly more extended-mission phases will be required for TEMPO  WHERE: GCIRI orbit location alternatives a)TEMPO and GCIRI can both accept positions from 80 o W to 120 o W with 100 o W being optimum => No basis for discrimination of GCIRI alternatives; dropped from analysis Based on these findings, the team assessed whether suitable GCIRI alternatives currently exist such that GEO-CAPE Atmospheric Science requirements can be completed at minimal cost

12. Summary: GEO-CAPE Atmospheric Composition Instrument Suite 12  In light of the defined science of TEMPO, the GEO-CAPE Atmospheric Composition Instrument Suite (ACIS) can be TEMPO + a GEO-CAPE InfraRed Instrument (GCIRI) The TEMPO mission will achieve a significant fraction of the GEO-CAPE atmospheric science measurement objectives A GEO-CAPE InfraRed Instrument (GCIRI) observing in IR spectral bands is required to measure the critical high value GEO-CAPE species such as CO which are not measured by TEMPO Concurrent TEMPO and GCIRI measurements are required to meet GEO-CAPE atmospheric science objectives regarding emissions, transport, mixing, and chemical transformation of trace gases and aerosols in a changing climate The science value of GEO-CAPE is extended from regional to global when TEMPO+GCIRI measurements are concurrent with the international constellation of Air Quality missions  The award of TEMPO presents the opportunity to complete the GEO-CAPE Atmospheric Science objectives at minimal cost by a timely start on a GCIRI, briefly outlined on the following slide

13. Alternatives for GCIRI Timely Start 13  Starting GCIRI in time for it to fly during TEMPO’s lifetime would complete GEO-CAPE atmospheric science  Conceptually, GCIRI alternatives could be obtained from: A future EV solicitation ‒ Selection NET FY14, launch NET 2021, after TEMPO Prime Mission is complete A new AO (would require new mission budget line) ‒ GCIRI could probably not launch until several years after TEMPO Prime Mission A new directed mission for immediate implementation ‒ May disrupt competition statistics Previous EV proposals categorized “selectable”  Suitable alternatives exist for possible GCIRI timely start HQ could select a previously competed GCIRI-relevant EV proposal ‒ 4 GCIRI-relevant proposals have been reviewed by ESD (one EV-2 and three EV-I) ‒ 2 of the 4 proposals were rated selectable (EV-2 CHRONOS, EV-I GCPI) with no major TMC weaknesses (no major technical, management, cost weaknesses) At least 2 suitable alternatives currently exist for a timely start of GCIRI such that GEO-CAPE Atmospheric Science requirements can be completed at minimal cost

14. Existing Selectable Options for GCIRI 14 EV-2: CHRONOS (Proposal # 11-EV2-0005) The reviewed concept would meet GEO-CAPE science requirements for hourly SWIR and MWIR measurements of 2-layer CO and column CH 4 over North America Tailoring options ‒ Fit within EV-I cost cap by omitting launch services from the original “full-mission” proposal EV-I-1: GCPI (Proposal # 12-EVI1/12-0014) The reviewed concept would meet GEO-CAPE science requirements for hourly SWIR measurements of column CH 4 over North America Tailoring options ‒ Omit NIR 760nm optical channel (optics, FPA, electronics, etc.) and extend SWIR wavelength range to cover MWIR for making 2-layer CO measurements ‒ Substitute TIR for NIR 760nm optical channel to also obtain NH 3 and additional O 3 information These proposals present attractive options for leveraging TEMPO to complete “Most” to “All” GEO-CAPE Atmosphere Science objectives at minimal cost

15. Summary 15  The TEMPO mission will achieve a significant fraction of the GEO- CAPE atmospheric science measurement objectives  A GEO-CAPE InfraRed Instrument (GCIRI) observing in IR spectral bands is required to measure the critical high value GEO-CAPE species such as CO which are not measured by TEMPO  Concurrent TEMPO and GCIRI measurements are required to meet GEO-CAPE atmospheric science objectives  The science value of GEO-CAPE is extended from regional to global when TEMPO+GCIRI measurements are concurrent with the international constellation of Air Quality missions  Peer-reviewed concepts for a candidate GCIRI exist  Existing selectable EV proposals provide a mechanism for a timely start on GCIRI so that TEMPO and GCIRI together jointly complete the GEO-CAPE Atmospheric Science mission at minimal cost

16. BACK-UP CHARTS 16

17. GCIRI Performance Parameters 17  WHAT GCIRI measurement capability that complements TEMPO measurement capability in a way which provides the full suite of GEO-CAPE atmosphere measurements  WHEN GCIRI mission concurrent with TEMPO to provide the full suite of GEO-CAPE atmosphere measurements GCIRI+TEMPO measurements concurrent with international GEO constellation to provide near global GEO-CAPE atmosphere science  WHERE GCIRI and TEMPO orbit locations to provide the maximum geographic coverage compatibility GCIRI observations Year 1Year 2Year 3 TEMPO observations Overlap GEO-CAPE GCIRI INTERNATIONAL GEO CONSTELLATION TEMPO OCEAN Geographic coverage from 100 o W

18. GEO-CAPE Atmosphere Composition Instrument Suite Summary 18 In light of the defined science of TEMPO, the GEO-CAPE Atmospheric Composition Instrument Suite (ACIS) can be TEMPO + a GEO-CAPE InfraRed Instrument (GCIRI) which measures spectrally resolved radiance in IR spectral bands to provide critical GEO-CAPE species such as CO and CH 4 which are not measured by TEMPO GEO-CAPE ACIS Spectral Region SpeciesRationale TEMPO UV Aerosols Surface AQ, aerosol sources and transport, aerosol plume height, AOD to PM conversion, climate forcing Vis NIR UV O3O3 Surface AQ, transport Vis UVHCHOVOC emissions, chemistry UVSO 2 SO x emissions, chemistry VisNO 2 NO x emissions, chemistry VisCHOCHOVOC emissions, chemistry, aerosol formation GCIRI SWIR COCO emission, transport MWIR SWIRCH 4 CH 4 emissions TIRNH 3 NH 3 emissions TIRO3O3 Surface AQ, transport

19. GEO-CAPE Instrument and Operational Risk Assessment 19  GEO-CAPE mission design team conducted an instrument and operational risk assessment for commercially hosted payloads like TEMPO and GCIRI  16 candidate risks were considered (full info available in supplementary material) 12 risks were accepted; on further discussion 4 were not found to be formal risks L, C Trend IDApproachTitle 2, 31MLack of I & T Oversight 3, 32MEnvironmental Testing Issues 3, 33MDetector Performance Limitations 3, 24MMultispectral Ozone Science Measurements 2, 25MScience Data Rates 3, 46MPointing/Jitter Requirement Instrument Risks L, C Trend IDApproachTitle 3, 38MContamination 3, 29MField-of-View Impingement 3, 310MCalibration 2, 314MLaunch and/or Flight Thermal Affects 2, 315MLaunch Loads 1, 316MOperations Operational Risks 4 2,3 6 5 1 14,15 9 8,10 16 Most risks are low and are being mitigated by the TEMPO development

20. GEO-CAPE Atmospheric Science Questions 20 As published in Fishman, J., and Coauthors, 2012: The United States' Next Generation of Atmospheric Composition and Coastal Ecosystem Measurements: NASA's Geostationary Coastal and Air Pollution Events (GEO-CAPE) Mission. Bull. Amer. Meteor. Soc., 93, 1547–1566. doi: http://dx.doi.org/10.1175/BAMS-D-11-00201.1http://dx.doi.org/10.1175/BAMS-D-11-00201.1 1. What are the temporal and spatial variations of emissions of gases and aerosols important for air quality and climate? 2. How do physical, chemical, and dynamical processes determine tropospheric composition and air quality over scales ranging from urban to continental, diurnally to seasonally? 3. How does air pollution drive climate forcing and how does climate change affect air quality on a continental scale? 4. How can observations from space improve air quality forecasts and assessments for societal benefit? 5. How does intercontinental transport affect air quality? 6. How do episodic events, such as wild fires, dust outbreaks, and volcanic eruptions, affect atmospheric composition and air quality?