mapping science to measurement requirements for geo-cape presented by annmarie eldering jet...

Mapping Science to Measurement Mapping Science to Measurement Requirements for GEO-CAPERequirements for GEO-CAPE

Presented by Annmarie Eldering

Jet Propulsion LaboratoryCalifornia Institute of Technology

TES Science Team MeetingFebruary 24, 2009, Boulder, CO

Contributors: Kevin Bowman, Meemong Lee, Zheng Qu, Mathew Yeates, Paul Hamer, Changsub Shim, John Worden

JPL Clearance: N/A

Last Modified: 2/24/2009

National Aeronautics and Space AdministrationNational Aeronautics and Space Administration

www.nasa.govwww.nasa.gov Jet Propulsion LaboratoryJet Propulsion Laboratory11 California California

Institute of TechnologyInstitute of Technology Pasadena, CAPasadena, CA

National Aeronautics and Space Administration

Jet Propulsion Laboratory - California Institute of Technology 2

Introduction to GEO-CAPEIntroduction to GEO-CAPE

From the decadal survey, GEO-CAPE science objectives -


Jet Propulsion Laboratory - California Institute of Technology 3

GEO-CAPE Science ObjectivesGEO-CAPE Science Objectives

Atmospheric Science

Air quality assessments several times daily and forecasting to support air program management and public health

Measure emission of ozone and aerosol precursors including human versus natural sources

Monitor pollutant transport into, across, and out of North, Central, and South America

Detect, track, and predict the location of extreme pollution events such as large puff releases from environmental disasters, and plumes from wildfires

Ocean Science

Quantify response of marine ecosystems to short-term physical events, such as passage of storms and tidal mixing

Assess importance of variability in coupled biological-physical coastal ecosystem models

Monitor biotic and abiotic material in transient surface features, such as river plumes and tidal fronts

Detect, track, and predict the location of hazardous materials, such as oil spills, ocean waste disposal, and harmful algal blooms

Detect floods from various sources including river overflows

Geostationary orbit enables continuous continental & regional observations


Jet Propulsion Laboratory - California Institute of Technology

Practically designing a missionPractically designing a mission

Take broad science objectives and …..

Develop specific measurement requirements (species, precision, accuracy, vertical resolution, temporal resolution)

Develop instrument designs that can meet the measurement requirements

Identify strategy for using instrument to meet science goals (observation scenario and mission design)

OSSE: The ozone case 4


Jet Propulsion Laboratory - California Institute of Technology OSSE: The ozone case 5

Why GEO-CAPE needs advances:Why GEO-CAPE needs advances: GEO-CAPE science questions with societal impacts push us

towards a new way of measuring ozone

– Improve air quality forecast skill

– Quantify impacts of pollution transport on regional to continental scales

– Monitor pollution emissions

CMAQ Using TES Boundary Conditions

CMAQ Prior to use of TES Current measurements fall short

for these science goals

– Limited sensitivity to the lower layers of the atmosphere

– Observations at best twice per day



Key Questions for GEO-CAPEKey Questions for GEO-CAPE

Vertical resolution and boundary layer sensitivity, especially with regard to ozone – do we need it, can we do it?

Is rule of thumb of hourly resolution driven by science?

Toolsets:

– Simulated retrievals and sensitivity tests

– OSSEs that marry retrievals and assimilation to see impact of measurements

– adjoints to quantify relationships of measurement variables and science variables




Suggestions in the literatureSuggestions in the literature

Simulations based on existing instrument configurations (TES+OMI) show that combination of UV/vis and IR should have better sensitivity to the boundary layer (Worden et al, 2007; Landgraf & Hasenkamp, 2007). We have extended this

to test in wide range of atmospheric conditions, range of mission designs, and in end-use science applications



Assimilation System

Referencemodelfields

Spatio-temporalsampling

Propagationto instrument

Instrumentmodel Observations

Geophysicalparameter estimation

Sampledgeophysical

fields

Estimated fieldsor parameters

-

Comparesciencemetrics

Model prediction

Estimate modelfields or parameters

Update model

-

Observationoperator

Exploiting OSSEs in the Mission Design Process



Our experimentsOur experiments

First phase focused on getting the right instrument sensitivity

In second phase, will study mission design in more detail

How we compare instrument & mission ideas:

Averaging kernels - are they sensitive in the region of interest?

Bias statistics - does the bias meet the requirements?

Maps of characteristics - will the spatial characteristics meet science goals?

Assimilate into model - assess ability to capture features of interest

Air quality forecast - test ideas against forecast skill



Instrument designs evaluatedInstrument designs evaluated

Using instrument designs in the realm of EOS capabilities.

First plots focus on 6 combinations

IR: 970-1080 cm-1

UV/vis: 312-344 nm

better

OMI

AIRS

TES

IR instrumentsUV instruments



SimulationSimulationSamplingSampling

Use GEOS-CHEM and regional model fields and geostationary viewing

Assimilate into GEOS-CHEM



Metrics in our AnalysisMetrics in our Analysis

Pdf of truth – retrieved

-Used to derive bias (mean value of pdf)

- And rms (rms of distribution)



Can we design an instrument to measure O3 to 5ppb Can we design an instrument to measure O3 to 5ppb at 825 hPa??at 825 hPa??

UV only

IR only



CombinationsCombinations

Combo - high noise, low res

Combo - low noise, high res



Looking over the range of casesLooking over the range of cases

Lower spectral resolution IR instrument (used alone or in combination with UV/vis) have large bias and rms

Combined high-spectral resolution IR and uv/vis have low bias and rms

bia

sR

ms



Next StepsNext Steps

Complete analysis of cross-over region (3.2 and 3.6 micron) for ozone

Extends to other molecules – how important is SO2 to the science of GEO-CAPE, can a joint retrieval improve sensitivity??

Concept extends beyond GEO-CAPE to many molecules

– CO – explored by MOPITT

– CO2 and CH4 – we may see some interesting information from GO-SAT




Assimilation of Simulated DataAssimilation of Simulated Data

Current OSSE includes assimilation into GEOS-CHEM (2 by 2.5 degrees).

We can look at impact of simulated measurements on ozone at various levels of the atmosphere – will the measurements help us answer our science questions?

What is the impact of only a GEO measurement versus GEO plus a LEO??

Assimilation opportunities – multiple species (ozone and precursors) and regional models




Sensitivity between states or Sensitivity between states or parametersparameters

The sensitivity between states can be calculated this way

or that way

00 y

y

yy

N

N ∂∂

∂∂

=∂∂ ψψ



Sensitivity Analysis: August 1st, 2006, sensitivity Sensitivity Analysis: August 1st, 2006, sensitivity of NY ozone at 2:30 pm to its precursors of NY ozone at 2:30 pm to its precursors

target regionregion of maximum sensitivity of boundary layer ozone in New York to free tropospheric NOx

The sensitivity of ozone in NY to free tropospheric NOx on 7/29/06 over Chicago is roughly half of the sensitivity to local NOx on 08/01/06



How sensitive is ozone to local NOHow sensitive is ozone to local NOxx??

Boundary layer ozone is sensitiveto local NOx up to 3 days before

Strong diurnal variation

Highest sensitivity to morning NOx



The maximum sensitivity of ozone in NY to free troposphericozone is roughly .2 two days before.

Does knowing free tropospheric ozone improve Does knowing free tropospheric ozone improve boundary layer ozone prediction?boundary layer ozone prediction?



Does knowing ozone today improveDoes knowing ozone today improveozone predictability for the following day?ozone predictability for the following day?

The sensitivity of ozone to ozone on 07/31/08 is about half of ozone on 08/01/08



ConclusionsConclusions

It is critical to tie the science questions to measurement requirements and then instrument requirements for GEO-CAPE

We have toolset for quickly making a relative comparison of nadir viewing instruments designs for atmospheric composition with simulated retrievals, assimilation, and adjoints

Analysis suggests that boundary level ozone can be measured with UV/vis paired with high spectral resolution (0.06) IR with good noise characteristics

Mission design (footprint size, frequency of measurements) to be evaluated in geostationary framework

More analysis by atmospheric sciences community important to develop consensus and move GEO-CAPE forward



BACKUPBACKUP




Outline:Outline:

• Motivation: Measuring tropospheric pollution and air quality from space for GEO-CAPE

• Approach: Evaluation of possible approaches for ozone – focused on 825 hPa

• Conclusion• There are instrument designs that can measure boundary

layer ozone

• Use of uv/vis and high spectral resolution IR wavelengths together are needed to have low bias and low rms in 825 hPa ozone

• GEOS-CHEM adjoint being used to quantify spatial and temporal relationships



Comparing statistics: varying width of IR windowComparing statistics: varying width of IR window

UV only


IR only UV + IR

Narrow window

1043-1075

wider window

970-1080

Bias: 1.46 rms: 14.6 Bias: -4.42 rms: 16.9 Bias: 0.87 rms: 6.03

Bias: -2.44 rms: 15.4 Bias: -0.02 rms: 6.51



Preparing to include 3.6 micronsPreparing to include 3.6 microns

Need to perform radiative transfer calculations with both solar terms and thermal emission




Verifying RT calculations in LIDORTVerifying RT calculations in LIDORT


Wavenumber (2778 cm-1 = 3.6 microns)



Next StepsNext Steps

Complete characterizations of 3.6 micron window

combine with UV/vis and IR

break down UV/vis into more specific bands (as Kelly Chance has outlined)




Sampling the field + retrievalsSampling the field + retrievals

Can select orbit parameters and footprints, profiles then selected from field.

Generate radiance, apply instrument function, and use linearized optimal estimation to generate simulated retrievals and error characterization (as well as averaging kernels).

Orbiter-2D



Comparing requirements Comparing requirements to simulated performanceto simulated performance

Focus on the ozone requirements from the NRC white paper - JANZ

All figures for 825 hPa

Yellow box marks requirement

Mean bias @ 825hPa for all simulated instruments

For one simulation, histogram of error

For one simulation, distribution of error



Where do we go from here?Where do we go from here? Important science questions with societal impacts push us

towards a new way of measuring ozone (GEO-CAPE)

– Improve air quality forecast skill

– Quantify impacts of pollution transport on regional to continental scales

– Monitor pollution emissions

CMAQ Using TES Boundary Conditions

CMAQ Prior to use of TES Current measurements fall short

for these science goals

– Limited sensitivity to the lower layers of the atmosphere

– Observations at best twice per day



Suggestions in the literatureSuggestions in the literature

Simulations based on existing instrument configurations (TES+OMI) show that combination of UV/vis and IR should have better sensitivity to the boundary layer.

We have extended this to test in wide range of atmospheric conditions, range of mission designs, and in end-use science applications



Using OSSEs to more fully evaluate possible Using OSSEs to more fully evaluate possible approaches (getting to the right design for the approaches (getting to the right design for the INSTRUMENT and the MISSION):INSTRUMENT and the MISSION):

Science question used to define measurement requirements

Instrument designed to meet measurement requirements (sensitivity)

Mission designed to meet measurement requirements (frequency of samples)

Thoroughly test in simulated science analysis



Measuring ozone from SpaceMeasuring ozone from Space

We have a long history of space based measurements

Many nadir viewing approaches, key for tropospheric measurements

– Total column ozone from SBUV, TOMS, and OMI based on uv/vis

– GOME, SCIAMACHY, GOME-2

– Infrared sounder measurements

» AIRS total column

» TES - profiles with ability to differentiate the upper and lower troposphere

» IASI - total columns and some thick layer vertical information

mapping science to measurement requirements for geo-cape presented by annmarie eldering jet...

Documents

geocape science questions

geocape vertical resolution

mapping science

broad science objectives

ozone case

river plumes

shortterm physical events

societal impacts