# Presentation: 089823

## Overview of GEO-CAPE Capabilities

- _S. R. Kawa_, S. Janz, R. T. Caffrey (NASA Goddard Space Flight Center)
- J. Fishman (NASA Langley Research Center)

-  Decadal Survey Concept
-  - Science Objectives, Instrument Payload, Mission Design
-  Measurements and Requirements

- October 27, 2008

**Notes:**
Drawn from mission concept studies done in anticipation of NAS report about 2 years ago.

## National Academy Decadal Survey

**Notes:**
Combined 2, not completely, but largely, separable sets of objectives in coastal ocean and air chemistry.
Produces 2 mostly independent sets of mmt requirements and, hence, instrument requirements.

## Slide 3

**Notes:**
Only GEO mission in first decade and only atmospheric chemistry mission in first two tiers.
Instruments.
Cost estimate is about factor of 2 lower than successive estimates.

## Science Objectives

**Ocean: **
- quantify the response of marine ecosystems to short-term physical events;
- assess the importance of high temporal variability in coupled biological-physical coastal-ecosystem models;
- monitor biotic and abiotic material in transient surface features;
- detect, track, and predict the location of sources of hazardous materials; and
- detect floods from various sources, including river overflows.
**Air-quality: **
- satisfy basic research and operational needs related to air-quality assessment and forecasting;
- emission of O3 and aerosol precursors, including human and natural sources;
- pollutant transport into, across, and out of North, Central, and South America; and
- large puff releases from environmental disasters.
- Measurements of aerosols from the air-quality instrument can be used to correct aerosol contamination of the high-resolution coastal ocean imager.
- Compatibility with objectives of the terrestrial biophysical sciences should also be explored.

**Notes:**
, such as river plumes and tidal fronts
, such as oil spills, waste disposal, and harmful algal blooms 
to support air-program management and public health
Currently being reformulated in wake of august GEO-CAPE planning meeting organized by HQ program scientists Ken Jucks and Paula Bontempi.  Look for meeting report soon.

## Notional Instrument Suite

- UV/Vis
- - Scanning UV/Visible spectrometer (300 – 480 nm); detect total column O3, NO2, HCHO, SO2, and aerosol; limited efficiency for O3 in the boundary layer.
- CO Detector
-  Gas correlation filter radiometer measuring in reflected near-IR and thermal IR emission; senses atmospheric CO total column to surface and mid- and upper-troposphere weighted; separate boundary layer from free troposphere abundance.
- Multi-Discipline Imager
- - Very high resolution UV-Vis-NIR imaging spectrometer; resolve coastal ocean color variations; capable of focus on environmental emergencies and special events in oceans, atmosphere, and terrestrial regions.

- Measurements need to be made closely in time and space to enable detailed examination of transport and photochemical processes, e.g., O3 production from CO oxidation:
- CO + OH + O2  CO2 + HO2
- HO2 + NO  OH + NO2
- NO2 + h + O2  NO + O3

**Notes:**
Instruments number 1 and 2, Performance of existing instrument technologies is generally adequate for geostationary deployment. 
Adapting heritage sensor technology to GEO does not present a major hurdle.
#3 is higher risk.

## Observatory Concept

-  **Strategic Concept: An Earth-viewing, **
**Hubble-like programmable observatory **
**facility.**
**Combination of medium-**
**resolution (5 km) continental **
**scanning instruments with **
**high-resolution (300-m) regional **
**viewing spectrometer.**
-  Geosynchronous viewpoint provides new and
-   unique approach to satellite remote sensing for
-   atmospheric composition, coastal ocean properties, and terrestrial biosphere.
- - Instrumentation to meet or exceed discipline science measurement requirements.
- Potential ground-breaking new science in each discipline plus synergies.
-  Multi-disciplinary imager is shared resource for regular observations, special observing studies, and emergencies.

- Continuous
- scan of polluted regions

- Programmable high-resolution observations

**Notes:**
Shift to results from HQ mission studies.

## Coastal Ocean Spatial Resolution

- Sample coastal waters at 300-m resolution

- 250 x 500 km scan/15 min

***Measurement Objective:****  *Ecosystem carbon, physiology and functional type with event scale multiple observations per day.

## Science Overview: Local Emissions/Global Impact

- Science Overview: Local Emissions/Global Impact

- Tropospheric O3 from OMI and MLS (June ‘05 avg)

- [Ziemke et al., 2006]

**Local and regional emissions impact ozone and aerosol on local to global scales.**
**Global changes in ozone, aerosol, and other pollutant species impact climate change and affect local air quality.**

- Better understanding of the key processes that connect global and local scales is required to accurately simulate, assess, and project these effects in the future.
- GEO-CAPE is a mission to investigate the _basic science_ of atmospheric composition and transport processes that underlie our ability to forecast air quality.

**Notes:**
How well can we measure tropospheric O3 with GEO-CAPE?

## Why Geostationary Orbit: Temporal Resolution

-  Low earth orbit (LEO/sun sync) affords at best one sample per day at a given location in mid latitudes.  Key processes occur on relatively short time scales that are not accessible from LEO observations.

- Surface NO2 (ppb)

- Column NO2 (1015 mol. cm-2)

- OMI Column Measurements

- Day 1

- Day 2

**     ****June 22          Hour of Day (GMT)     June 23 **

- CMAQ Model Simulation of NO2

**Target continuous hourly sampling of key constituents**

- HCHO

- Mount et al.

**Notes:**
Current process understanding from satellite remote sensing is based on
, e.g., dispersal of point emissions, diurnal photochemistry, planetary boundary layer growth and decay, 
- track plumes, disasters...
Model plot demonstrates the strong relationship between surface abundance and column NO2 such as a geostationary measurement would provide.
 Superimposed on this figure are the actual 2 NO2 column measurements made by OMI over Houston on June 22 and 23, 2005.  The calculations are for a CMAQ simulation over eastern Texas and regional environs using a 12-km grid size for those two days.  The OMI footprint over Houston was comparable for those two days.

These were actually recorded by myself and Dr. Lola Andres-Hernandez and myself plus assistants, as part of a European campaign, which took place  near Ascot race course, within the grounds of Imperial college in 1999.This is on the east side of London - actually the posh side of the Thames valley. It is outside the M25 (London's Beltway) but not that far from it. So it has some resemblance with Goddard but probably a higher population density.It was early August 1999. In the early morning you see the night time boundary layer, probably ~ 50 m, "burn off" and the CO decrease. We had fairly strong photochemical production of O3 as you can see. however the T was not nothing exceptional - remember London is about 52。N. We were also measuring RO2 and NO and were specifically studying the O3 production.Typically when photochemical production of O3 is high in these location the highs and lows are such that the air flow is from continental Europe over the North Sea through the sea east of the UK [Bovensmann et al. 2003].

## Why Geostationary Orbit:

- Coverage and Spatial Resolution

**Coverage:**** **Once per day samples often obscured by clouds.
**Spatial Resolution: **
- - longer Geo time integration allows high SNR/ resolution element
- - higher spatial resolution improves chance of cloud-free pixel

**Target 5 to 7-km pixel resolution over continental field of view.**
- Consistent with that anticipated for regional chemistry/transport models in the next decade.
- Enable boundary layer O3 determination through cloud slicing
- Potential to transform our understanding of atmospheric composition similar to the way GOES imagery has advanced weather analysis and forecasting.

- Tropospheric NO2 from OMI for June 6, 2005

- [Bucsela et al., 2006]

**Notes:**
Current process understanding from satellite remote sensing is based on
, e.g., dispersal of point emissions, diurnal photochemistry, planetary boundary layer growth and decay, 
Basic measurement requirements can be met with spatial resolution of 5-10 km.
Opportunity for Aura to examine emissions over SA?

## Atmospheric Measurement Requirements

| Trace Gas | Needed mixing ratio precision | Needed accuracy | Column density capability* [molecules cm-2] | Instrument Requirement [SNR] | Instrument Implementation |
| --- | --- | --- | --- | --- | --- |
| NO2 | 0.2 ppbv | 20% | 5.0 x 1014 | 2000 (430 nm) | UV/VIS grating spectrograph:
Cost effective broadband measurement at moderate spectral resolution (< 1nm).
High spectral stability and throughput.  Strong heritage. |
| HCHO | 1.0 ppbv | 20% | 2.5 x 1015 | 1500 (350 nm) |  |
| O3
 | 10 ppbv (troposphere) | 10% | 1.3 x 1016
 | 1000 (320 nm) |  |
| SO2 | Not applicable | 20% | 2.2 x 1016 | 500 (312 nm) |  |
| CO  | 10 ppbv | 10% | 1.0 x 1017
 | 2500- 9500 ( 2.3 m)
 (scene dependent) | Gas Filter Correlation Radiometer:
Target gases with very high sensitivity/resolution. Multi-spectral for robust retrieval and to separate PBL from free trop. Strong heritage. |
| CO | 10 ppbv | 10% | 1.0 x 1017
 | 700 (4.67 m) |  |
| Near-surface CO | 10 ppbv | 10% | 1.0 x 1017
 | Not applicable | Inferred from multispectral analysis |
| Near-surface O3 | 5 ppbv  | 10% | 1.3 x 1016
 | Not applicable | Inferred from multispectral analysis |

**Trace gas sensitivity required to meet science goals**

- * Assumes PBL height of 1 km. Additional information on science requirements can be found at http://qp.nas.edu/QuickPlace/decadalsurvey/Main.nsf

**Notes:**
What wavelength bands and spectral resolution?

## Other Considerations

-  Spacecraft and launch vehicle
-  Advanced technology investments
-  Ground system architecture
-  Mission operations
-  Cal/Val requirements, Validation program
-  Supporting research and analysis
-  International cooperation

** ****No show stoppers**

## Outstanding Questions

-  Can the mission be made more affordable?
-  science requirements versus instrument performance/size
-  Do instruments have to fly together?
-  piggy-back on commercial communication satellite?
-  Can other instrument concepts fulfill measurement requirements?
-  cost, benefit, risk assessment
-  Priority and feasibility of boundary layer O3 measurement?

** ****Community input**
** ****Existing data analysis**
** ****Observing system simulation**
** ****Airborne demo measurements**

## Acknowledgements

- K. Jucks, P. Bontempi, J. Crawford, E. Hilsenrath, M. J. Kurlyo, P. DeCola (NASA HQ)
- D. Edwards (NCAR)
- D. Neil (NASA LaRC)
- A. Eldering (JPL)
- J. Herman, K. Pickering, E. Middleton, A. Mannino, J. Gleason, P. K. Bhartia, S. Bidwell, L. Purves, J. Loiacono (NASA GSFC)
- W. H. Brune (Penn State Univ.)
- J. Burrows (Univ. of Bremen)
- Goddard Internal Research and Development

- The consensus report of the Boulder Air Quality from Space community workshop identified a Geo mission as the top priority [Edwards, 2006].

## Elements of The (Atmospheric) Science Question

| 1. What are the emission patterns of the precursor chemicals for tropospheric ozone and aerosols? | 1. Quantify spatial and temporal emissions of ozone and aerosol precursors (NOx, CO, hydrocarbons, SO2, particle emissions). |
| --- | --- |
| 2. What is the evolution of ozone and aerosol through chemical formation and loss, transport, and deposition processes? | 2. Measure distributions of ozone, aerosol, and precursors at high spatial and temporal resolution over the US and surrounding regions. |
| 3. What are the influences of weather in transforming and dispersing emissions, ozone, and aerosol?  | 3. Track transport of aerosol and gases into, across, and out of NA; including large episodic releases from environmental disasters, e.g., fires, volcanoes. |
| 4. What are the regional budgets for air quality criteria pollutants (CO, O3, NO2, SO2, and aerosol) over North America? | 4. Characterize regional air quality for model evaluation, assessment, and forecasting. |

- Mission Science Questions  Mission Science Objectives

**Notes:**
For each question have discussion, motivation, examples, and expected outcomes from GEO mission.
3) Add STE, O3 transported from stratosphere to objectives.

## Science Traceability Matrix for Atmospheres 

| Mission Objectives | Measurement Requirements | Mission Requirements | Instrument Requirements | Mission Concept | Ancillary Requirements |
| --- | --- | --- | --- | --- | --- |
| Quantify spatial and temporal emissions of ozone and aerosol precursors | NO2 and HCHO  tropospheric partial column, CO with sensitivity in the boundary layer (BL) | Cover US and adjoining regions

Simultaneous constituent measurements

Continuous daytime coverage
 | High spatial resolution (5 km) to resolve source locations and sample between clouds; high precision detection (SNR>1000:1)

CO measurement in reflected sunlight | Instruments in geo orbit continuously scan populous N America coast-to-coast.
UV/Visible spectrometer measures O3, NO2, HCHO, SO2, and aerosol column density; plus CO, O3 detectors for BL and free trop | Surface in situ and remote sensing monitoring network; in situ aircraft and balloon mmts; stratospheric O3, NO2, and dynamics

Inverse models for source inference. |
| Measure distributions of O3, aerosol, and precursors at high spatial and temporal resolution over the US and surrounding regions.
 | O3 partial column; O3 with sensitivity in PBL; aerosol optical depth

Measure diurnal changes of constituents | Map sunlit earth at near-nadir

Hourly sampling frequency in polluted regions

View upwind and downwind of the continent

Day/night  CO and O3 sampling
 | Spectrally resolved, high-SNR reflected  UV/Vis radiances

O3 measurement in thermal emission bands (and/or reflected sunlight) 

CO measurement in thermal emission bands | Ability to stare at target region from geo enables high-resolution ground sampling at high SNR. 

Hourly or better sampling frequency during daytime for UV/Vis, and during day and night for free-troposphere CO and O3. | GOES T, H2O profiles, surface, and upper-air weather observations; accurate, detailed meteorological analyses

3-D global chemistry-transport model integrations

Process-oriented research field campaigns |
| Track transport of aerosol and gases into, across, and out of NA; including large episodic releases from environmental disasters | CO in mid-troposphere; O3, NO2 tropospheric partial columns; aerosol optical depth, SO2 column density |  |  |  |  |
| Characterize regional air quality for model evaluation, assessment, and forecasting. | O3, NO2, HCHO, CO partial columns; O3 with sensitivity in PBL; aerosol optical depth | Accommodate large data collection and retrieval rates;
2-5 yr mission lifetime | Continental field of regard; hourly temporal resolution in polluted regions  | High-resolution, frequent sampling maximizes lower troposphere data in presence of clouds | Data assimilation methodology;
Regional mesoscale chemistry-transport modeling |

## Multi Discipline Imager (MDI) 

- Multi Discipline Imager (MDI)

- Mirror stabilization system for image generation will require further development to meet the required precision.
- Large size drives cost, risk; need to optimize for science and feasibility.

- _Instrument Performance Data_

- _Technology Assessment / Development Needs_

- _Instrument Concept_

- Enable scientific objectives of coastal ocean, atmosphere, and biosphere.
- Capable of pointing anywhere on visible Earth hemisphere.
- Measurement parameters adjustable:  dependent on science objective.
- Employs three focal planes/bands
- Two Si: 1k (spectral) x 2k (spatial) Rockwell hybrid focal plane
- One HgCdTe: 256 x 2k Rockwell hybrid focal plane

- Spectral Bands: 300-556, 340-1139, 1240, 1640 nm
- Spectral Resolution: 0.75 (3x sample), 0.8, 40, 40 nm
- SNR:  > 1000 (bands 1, 2); > 500 (bands 3, 4)
- Spatial Resolution: 300 m pixels, Coverage: 500 km
- Temporal Resolution: < 1 hour

## Scanning UV/Vis Spectrometer

- Measurement demonstration and technical feasibility completed under NASA Instrument Incubator Program.
- No technical hurdles to instrument or spacecraft.
- Pointing requirements are commensurate with GOES.
- Detector optimization, single crystal silicon mirror testing, and aircraft demo recommended for technology readiness level 6.

- _Performance Data_

- _Technology Assessment / Development Needs_

- Measure atmospheric pollutants O3, aerosols, and precursors NO2, SO2, HCHO.
- Field of regard: Western Hemisphere with emphasis on continental United State
- Sample revisit time of 1 hour, during sun illumination.
- Mission Design Life:  2 years, goal 5 years (consumables sized for 5 years), launch Sept. 2014.

- _Measurement Concept_

- Star Tracker (1 of 2)

- Calibration Assembly /
- Calibration Aperture

- Optical Bench

- Optics
- Aperture and
- Scanning Mirror

- Gyroscopes

- Thermal Radiator

- 1700 mm

- 860 mm

- 830 mm

- From ISAL

- Single focal plane, continuous band from 300 nm to 480 nm.
- Spectral resolution:  0.8 nm.
- Signal-to-noise ratio of 720 at 320 nm and 1500 at 430 nm.
- Typical scanned  field-of-view:  8° N/S (5000km)  x 8° E/W (5000 km). Can point anywhere on visible hemisphere.
- Pointing stability maintained through active jitter compensation.
- Sample spatial resolution 1.25 km N/S x 5.0 km E/W.

## Carbon Monoxide Detector

- _Instrument Performance Data_

- _Technology Assessment / Development Needs_

- _Measurement Concept_

- Gas correlation filter radiometer measures CO in near-IR reflected sunlight and thermal IR emission.
- Spectral combination approach identifies CO boundary layer distribution from space.
-  Measures CO, an atmospheric pollutant precursor of O3 and primary indicator of combustion.
- Continue outstanding performance of MOPITT; scientific findings based on MOPITT data demonstrate the measurement maturity and technical feasibility.

- Detector: Use of large format 2-D arrays in space (no scanning)
- Data array: 1024 x 1024 pixels for each SWIR & MWIR
- Spatial resolution: 5 x 5 km2; spectral resolution better than 0.1 cm-1 provided by gas filter.
- Each spatial pixel requires frame averages to achieve SNR.
- Onboard calibration: blackbody targets, deep space and solar views

-  Technology for this instrument is at high readiness level.
-  Measurement Heritage: MOPITT, HALOE
-   Beneficial investments:
- - Radiation hard high performance electronics
- - Light weight thermal control and structural materials

- Dimensions: 1.31 x 0.55 x 0.43 m

- From LaRC IDC

##  Satellite Mission Concept

-  Satellite Mission Concept

**   **_**Features**_

_**Technology Development Needs**_

**SC Bus & Launch Vehicle**
**- None (over 20 geostationary launches/year)**

**Instrument Complement: MDI Ins, UV/Vis, CO Detector **
**Launch:  ~FY2014**
**Launch Vehicle: Atlas V 401 or Delta IV 4040-12**
**Orbit Type**
**Geostationary**
**100 Degree W Longitude**
**Real-Time Science Data Downlink with Dedicated Ground Station**
**Disposal into Geo + 300 km Parking Orbit**

**   **_**Performance Data (with margins)**_

**Mass:  1286 kg (payload), 4679 kg (observatory wet total)**
**Power (Average):  930 W (payload), 1625 W (total)**
**Data Rate:  120 Mbps (payload), 179 Mbps (total), **
**Spacecraft Pointing (1 sigma ):  30 arc-sec control, 4 arc-sec knowledge**
**Lifetime (years): 2 (design), 5 (goal & consumables)**

- MDI
- Instrument

- UV/Vis Spectrometer

- CO Detector

- Earth

- Est. Cost: $1.3B

**Notes:**
Concerned that tying atmos composition objectives and instruments to very large coastal ocean instrument will preclude any from flying.
Working under IRAD with interdisciplinary team to better define science requirements that drive size and cost of events imager.
Perhaps we need to consider separating the objectives and instruments into separate payloads, but decadal survey may not agree.

## IASI CO: California Fires July 2008

**IASI CO: California Fires July 2008**

***Cathy Clerbaux, CNRS***