1. Geostationary satellite mission for air quality and coastal ecosystems One of 15 missions recommended to NASA for the next decade by the U.S. National Research Council Atmospheric Planning Team: J. Al-Saadi, K. Chance, R. Chatfield, S. Christopher, J. Crawford, B. Duncan, D. Edwards, A. Eldering, J. Fishman, S. Kondragunta, D, Jacob, L. Iraci, R. Kawa, X. Liu, D. Neil, M. Newchurch, K. Pickering, J. Rodriguez, R. Scheffe, J. Szykman, O. Torres, J. Wang Science Traceability Matrix (STM) sub-team: D. Neil and D. Jacob, co-leads Upcoming GEO-CAPE Science WG workshop: 22-24 Sept.

2. The NRC vision for GEO-CAPE Mission Objective Statement proposed by atmospheric STM sub-team: “To Observe, Understand, and Predict Air Quality, Coastal Ecosystem Health, and Climate Forcing in North and South America”

3. Building the Science Traceability Matrix for GEO-CAPE Flow from objectives to requirements Trace requirements to their objectives; define “trade space”

4. Measurement requirements are to be guided by five Science Questions (in priority order): 1.What are the emissions of gases and aerosols important for air quality and what are the processes controlling these emissions? 2.How do atmospheric transport, chemical evolution, and deposition determine tropospheric composition over scales ranging from urban to continental? 3.How can we improve air quality forecast and assessment models? 4.How do changes in air quality drive climate forcing on a continental scale? 5.How does intercontinental transport affect air quality? Preliminary Science Traceability Matrix for the atmospheric component of GEO-CAPE

5. Proposed GEO-CAPE viewing domain Orbit centered at 95 o W 8x8 km 2 pixels Observe North America land and coastline with hourly resolution Observe North Pacific, North Atlantic, and South/Central America with daily resolution Still very tentative! Awaiting input from GEO-Cape Oceanic Planning Team Asian and European geostationary mission partners

6. Preliminary measurement requirements for GEO-CAPE SpeciesPriorityRequired sensitivity (cm -2 ) Temporal frequency (1) Science Question O3O3 12x10 16 (2)1h2,3,4,5 PM10.1 AOD1h (SZA<70)1,2,3,4,5 CO13x10 17 (2)1h1,2,3,5 NO 2 11x10 15 1h (SZA<70)1,2,3 SO 2 11x10 16 3h (SZA<50)1,2,3,4 HCHO11x10 16 3h (SZA<50)1 CH 4 22x10 16 daily1,4 NH 3 25x10 15 daily1,2 CH 3 OH35x10 15 daily1 CHOCHO34x10 14 daily1 (1)For North American land and coastlines only; daily for rest of domain (2) 2 pieces of information in troposphere including sensitivity in boundary layer Instrument requirements to flow from measurement requirements but still TBD

7. Diurnal difference between SCIAMACHY (10 am) and OMI (1:30pm) for different seasons SCIAMACHY – OMI difference: DJF 2006 JJA 2006 maximum vehicle use in daytime would result in higher NO 2 at 13:30 than at 10:00; This is more than compensated in summer by high chemical loss in daytime Boersma et al. [ACP 2009] Israel Cairo Diurnal variation of NO 2 in Israeli cities, Mar-Nov Data show how hourly measurements with sufficient precision can significantly increase information on NO x sources and chemistry

8. 0-60 ppb 61-79 ppb 80-99 ppb 100-110 ppb 111-124 ppb 125+ ppb OMI Measurements over Houston Shows Correlation between Daily Satellite and Surface Measurements Surface O 3 Concentrations Elevated TOR from OMI Elevated NO 2 from OMI Elevated Surface O 3 from EPA Sites Tropospheric O 3 Residual from OMI NO 2 Column from OMI from Jack Fishman

9. OSSE of ozone measurement requirements for GEO-CAPE Take hourly ozone simulation by MOZART CTM for summer 2001 to represent the true atmosphere to be sampled by GEO-CAPE; Attempt to reproduce this true atmosphere by assimilating GEO-CAPE pseudo-observations into a GEOS-Chem CTM simulation for the same period using a Kalman filter MOZART (1.9 o x1.9 o, NCEP) GEOS-Chem (1 o x1 o, GEOS-3) 700 hPa surface July 2001 Peter Zoogman, work in progress “Truth” a priori

10. Preliminary OSSE results using a GEO-CAPE TIR instrument with TES averaging kernels truthGEOS-Chem a priori GEOS-Chem + daily obsGEOS-Chem + hourly obs Mean July 2001 ozone (ppbv) at 700 hPa Hourly observations (daytime clear-sky only) provide successful correction, much better than daily

11. Preliminary OSSE results using a GEO-CAPE TIR instrument with TES averaging kernels (cont.) Mean July 2001 ozone (ppbv) at surface TES sensitivity to boundary layer is insufficient to correct model at the surface ; need to do better to inform ozone surface air quality GEOS-Chem a priori GEOS-Chem + daily obs GEOS-Chem + hourly obs Truth

12. Next step: test a multispectral UV+IR ozone instrument for GEO-CAPE in the same OSSE framework Combination of UV+IR provides increased sensitivity in the boundary layer (J. Worden et al., 2007)

13. Also need to explore retrieval in the visible (Chappuis), polarization in UV X. Liu, NASA/GSFC