1 MIDDLE ATMOSPHERE RESEARCH HIRDLS: The High Resolution Dynamics Limb Sounder –Future potential in remote sensing for the UT/LS region. –Benefit to

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MIDDLE ATMOSPHERE RESEARCH

HIRDLS: The High Resolution Dynamics Limb Sounder – Future potential in remote sensing for the UT/LS

region.– Benefit to the community

UT/LS Research Initiative– Building upon existing strength, anticipation of new

capabilities (HIAPER)– opportunity for the greater role for university

community. WACCM: Whole Atmosphere Community Climate Model

– An inter-Divisional Community modeling effort that benefits from a National Center setting.

John C. Gille The High Resolution Dynamics Limb Sounder (HIRDLS) Experiment 2

Atmospheric Chemistry DivisionNational Center for Atmospheric Research

24-26 October 2001 NSF ReviewThe High Resolution Dynamics

Limb Sounder (HIRDLS) A Joint US-UK Experiment

John Gille – US PI John Barnett – UK PIUniversity of Colorado/NCAR Oxford University

Objectives: Measure temperature, 10 species, aerosols and PSC’s from 8-80 km with SPECIAL EMPHASIS ON UT/LS.

BETTER VERTICAL AND HORIZONTAL RESOLUTION THAN PREVIOUSLY AVAILABLE GLOBALLY.


HIRDLS Science Team

U.S. U.K.Principal Investigators J. Gille, CU/NCAR J. Barnett, OXF

Instrument Design, Management M. Coffey, NCAR C. Mutlow, RALW. Mankin, NCAR J. Seeley, Reading

J. Whitney, OXF

Dynamical modeling and Analysis B. Boville, NCAR R. Harwood, EdinburghJ. Holton, UW D. Andrews, OXFC. Leovy, UW M. McIntyre, Cambridge

H. Muller, CranfieldG. Vaughan, AberystwithA. O’Neill, Reading

Chemical Measurements & modeling L. Avallone, CU J. Pyle, CambridgeG. Brasseur, MPI

Aerosol Science O. B. Toon, CU

Radiative Transfer F. Taylor, OXF

Data Handling, Retrieval, Gridding K. Stone, CU C. Rodgers, OXFE. Williamson, OXF


HIRDLS Science Objectives

• Understand stratosphere-troposphere exchange of radiatively and chemically active constituents (inc. aerosols) down to small spatial scales

• Understand chemical processing, transports and mixing in the upper troposphere/lowermost stratosphere/lower overworld

• Understand budgets of quantities (momentum, energy, heat and potential vorticity) in the middle atmosphere that control stratosphere-troposphere exchange

• Determine upper tropospheric composition (with high vertical resolution)

• Provide data to improve and validate small scales in models

• Measure global distributions of aerosols and PSC’s and interannual variations


Summary of Measurement Requirements

Temperature <50 km 0.4 K precision

1 K absolute

>50 km 1 K precision

2 K absolute

Constituents O3, H2O, CH4, H2O, HNO3, NO2, N2O5, 1-5% precision

ClONO2, CF2Cl2, CFCl3, Aerosol 5-10% absolute

Geopotential height gradient 20 metres/500 km (vertical/horizontal)(Equivalent 60oN geostrophic wind) (3 m s-1)

Coverage:Horizontal - global 90oS to 90oN (must include polar night)Vertical - upper troposphere to mesopause (8-80 km)Temporal - long-term, continuous (5 years unbroken)

Resolution:Horizontal - profile spacing of 5o latitude x 5o longitude (approx 500 km)Vertical - 1-1.25 km

Temporal - complete field in 12 hours

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Limb Technique and Coverage

Infrared radiance emitted by the

earth’s atmosphere, seen at the

limb, is measured as a function of

relative altitude.

Technique previously applied by

LIMS and ISAMS

HIRDLS measures in 21 spectral

channels.

12-hour coverage

IR Limb Scanning Technique


Measurement Capabilities

.

PRECISIONMIXINGRATIO

(%)TEMP

(K)

1 .25

3 .5

5 1.

10

15

20

40

60

80

TEMP

O3

H O2

CH4

N O2

NO2

N O2 5

HNO3

CFCl3

CF Cl2 2Aerosol

PSC

CloudTops

HIRDLS CAPABILITIES

Effects

Alt

itu

de (

km

)

LocationsNO2ClO

ALTITUDE


H2O (Model) H2O (Retrieval Error)

O3 (Model) O3 (Retrieval Error)

HIRDLS Retrievals of 1 Orbit of Data Simulated from MOZART 3 Model


Future Plans

• Oversee completion of Instrument Integration• Participate in EM calibration development• Participate in PFM testing and calibration• Oversee integration and testing on spacecraft and

launch• Complete algorithms, include additional features• Finalize and test operational codes• Intensify planning for use of data in science studies• LAUNCH (Scheduled June 2003)• Process data, find and correct artifacts• Validate data• Apply data to studies, notably of the UT/LS

Sue Schauffler UT/LS 14


Upper TroposphereLower Stratosphere

(UT/LS)

Sue SchaufflerAssociate Scientist IV

Stratosphere/Troposphere Measurements Project

24-26 October 2001, NSF Review


Importance of the UT/LS region

• “The tropopause region exhibits a complex interplay between dynamics, transport, radiation, chemistry, and microphysics.

This is particularly highlighted in the case of ozone and water vapor, which provide much of the climate sensitivity in this region.” (SPARC Tropopause Workshop, April, 2001).

• Transition region between the troposphere and stratosphere, both of which have mechanisms of ozone production and loss that are fundamentally different.

• Strong gradients in many trace constituents including water vapor and ozone.

• Transport processes occur on a multitude of scales including global, synoptic, and subsynoptic.


UT/LS ChemistryProduction and Destruction of Ozone

• Seasonal variations in ozone and water vapor

• HOx and NOx budgets• ClOx and BrOx budgets

• PAN, organic nitrates, HNO3 contributions to NOy

• Heterogeneous processes associated with aerosols and cirrus clouds

• Aerosol formation and composition

• Influence of the summer monsoon and convection on UT/LS chemistry


Seasonal Variation in Water Vapor

Randel et al., JGR, 106, 13, 14,313, 2001

Figure 8. Horizontal structure of water vapor at 390K in July. Dark and light shading denote maxima (>4.6 ppmv) and minima (<3.6 ppmv) in water vapor, respectively.

Pan et al., JGR, 105, 21, 26,519, 2000

Plate 2. Comparisons of middle world water vapor from SAGE II, MLS, and ER-2 in-situ measurements for 350 K.


UT/LS Annual Cycle in Ozone

Logan: JGR, 104, 13, 16,115, 1999 An Analysis of Ozonesonde Data for the Troposphere

Figure 8. Annual cycle at the tropopause (middle), 1 km below the tropopause (bottom) and 2 km above the tropopause (top) for four Canadian stations. Monthly median values are shown.


1.5

1.0

0.5

0.0

frac

tions

of N

Oy

140120100806040Day Number (from 1 January 2000)

PAN+PPN HNO3

Alkyl Nitrates NOx

1:1 line Sum

Frank Flocke: TOPSENOy balance during TOPSE, north of 58 degrees, upper troposphere

(>6km flight altitude)

TOPSE: NOy UT budget

A. Weinheimer, NCARB.A. Ridley, NCARB. Talbot, UNHJ. Dibb, UNHD. Blake, UC IrvineR. Cohen, UC Berkeley


UT/LS Transport

• Processes that maintain sharp gradients in constituents across the tropopause.

• Influence of various transport processes, such as convection, on gradients of VOCs, halogens, nitrogen compounds, and other constituents.

• Magnitude of irreversible exchange from transient baroclinic waves and large/small scale transport in midlatitudes.


J. Atmos. Sci., 37, 994, 1980 Shapiro, M.A.

Tropopause Folding Event

Tropopause fold observed during TOPSE: Browell et al., NASA Langley.

Pot

enti

al T

emp.

(K

)

PV (PVU)J. Beuermann, et al., 2001, Julich.


Evidence of Convective Transport: E. Atlas (NCAR), H. Selkirk (NASA)

0

5

10

15

20

20 40 60 80 100 120 140

ACCENTPEM TROPICS B (Equatorial Pacific)(CO data from G. Sachse et al.)

Me

thyl N

itra

te (

pp

tv)

CO (ppbv)

Continental Outflow

Tro

pic

al

Ma

rin

e E

mis

sio

n

Convective Outflow Over Gulf of Mexico

Figure 1. Back-trajectories calculated along the WB-57 flight track intersect regions of strong convection in the tropical Pacific Ocean. Figure 2. CO – Methyl nitrate relationship observed during ACCENT (23 April) over the Gulf of Mexico (blue dots), and same relationship from PEM TROPICS (over tropical Pacific Ocean (red dots). The measurements and modeling of the Gulf data suggest convective redistribution over the Pacific followed by 2 day transport to the east.

Convection

WB-57Flight


Future: NSF/NCAR HIAPER up to 14-15 km

Current: NSF/NCAR C-130 up to 7-8 km

NCAR Aircraft


Tropopause Location

Holton et al., Reviews of Geophysics, 33, 4, 403, 1995 (figure courtesy of C. Appenzeller)


Tools in ACD for UT/LS Studies

• Aircraft Instruments: Apel - Oxygenated hydrocarbons; Atlas - Halocarbons, Hydrocarbons, Alkyl nitrates, Oxygenated hydrocarbons; Cantrell – RO2; Coffey/Mankin – N2O, CO, FTIR; Eisele – OH, HNO3, Sulfur species; Fried – Formaldehyde; Ridley – NOx, NOy, Fast O3; Shetter – SAFS; Flocke/Weinheimer – PAN, PPN, MPAN, PiBN, APAN; Guenther – VOCs; Campos/ATD CO2, O3, CO, H2O, and aerosol instruments.

• Models: Garcia/ Kinnison – WACCM/MOZART; Madronich – MM, TUV; McKenna – CLaMS; Hess - HANK

• Satellite observations and analysis: Gille – HIRDLS, MOPITT; Randel – HALOE, TOMS; Massie - UARS

• Ground based remote sensing: Mankin/Coffey – FTIR spectrometer; Newchurch - RAPCD


UT/LS Field Campaign

• Initial field campaign to study Photochemistry at mid to high latitudes out of Jeffco using HIAPER.

To formulate details of the field campaign, ACD will convene a community workshop to solicit ideas and input from colleagues at universities and other government sponsored agencies.

• Integrate aircraft measurements, satellite observations, and modeling efforts.

• Use simultaneous observations of key active and tracer species as constraints for testing and improving atmospheric models.

Rolando Garcia WACCM: Whole Atmosphere Community Climate Model 27


WACCM:

Whole Atmosphere

Community Climate Model

Rolando GarciaSenior Scientist, Modeling Group

(special thanks to D. Kinnison)

NSF Review, 24-26 October 2001


WACCM MotivationRoble, Geophysical Monographs, 123, 53, 2000

•Coupling between atmospheric layers:

- Waves transport energy and momentum from the lower atmosphere to drive the QBO, SAO, sudden warmings, mean meridional circulation

- Solar inputs, e.g., auroral production of NO in the mesosphere and downward transport to the stratosphere

- Stratosphere-troposphere exchange

• Climate Variability and Climate Change:

- What is the impact of the stratosphere on tropospheric variability, e.g., the Artic oscillation or “annular mode”?

- How important is coupling among radiation, chemistry, and circulation? (e.g., in the response to O3 depletion or CO2 increase)

Jarvis, “Bridging the Atmospheric Divide”

Science, 293, 2218, 2001


WACCM Motivation

• Response to Solar Variability:

- Recent satellite observations have shown that solar cycle variation is:

0.1% for total Solar Irradiance

5-10% at 200nm

- Radiation at wavelengths near 200 nm is absorbed in the stratosphere

=> Impacts on global climate may be mediated by stratospheric chemistry and dynamics

• Satellite observations:

- There are several satellite programs that can benefit from a comprehensive model to help interpret observations

- e.g., UARS, TIMED, EOS Aura

UARS / SOLSTICE

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Chronology of Model Development

• 1999: Scientists in ACD, CGD, HAO agree on the need for a comprehensive ground-to-thermosphere model

• 1999-2001: NCAR Director’s fund provides “seed money” to support 1.3 new FTE’s. Allows software development and “proof of concept”

• 2001: Initial work on model completed (chemistry calculations are currently “offline”)

• 2001: Preliminary scientific results presented at the CCSM Workshop in Breckenridge, CO, and at the IAMAS Assembly in Innsbruck, Austria

• 2001: Responsibility for support of 1.5 new FTEs transferred to the scientific divisions. Leveraged by proposals to NASA (LWS, ROSS Theory and Modeling)

• 2002: WACCM workshop in connection with CEDAR meeting; model released to community

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WACCM ComponentsCollaboration between 3 NCAR Divisions

MOZART

MACCM3

WACCM

TIME GCM

+Chemistry

Dynamics + Physical processes

Mesospheric + Thermospheric Processes

CGDB. Boville F. Sassi

ACDR. Garcia

D. Kinnison S. Walters

HAOR. RobleB. Foster

(Middle Atmosphere CCM)

(currently offline)


WACCM and the NCARCommunity Climate System Model

Atmosphere

LAND

OCEAN

ICE

+

WACCM

WACCM uses the software framework of the NCAR CCSM. May be run in place of the standard

CAM (Community Atmospheric Model)

dynamics,chemistry


Dynamics Module

• A parameterization of non-LTE IR (15 m band of CO2 above 70 km) merged with CCSM IR parameterization (below 70 km)

• Short wave heating rates (above 70 km) due to absorption of radiation shortward of 200 nm and chemical potential heating

•Gravity Wave parameterization extended upward, includes dissipation by molecular viscosity

• Effects of dissipation of momentum and heat by molecular viscosity (dominant above 100 km)

• Diffusive separation of atmospheric constituents above about 90 km

• Simplified parameterization of ion drag

Additions to the original MACCM3 code:


WACCMZonal Winds, Temperature

Gross diagnostics (zonal mean behavior) Complete climatological analysis is planned


Solstice Temperature Distribution (K)

January July

note cold Antarctic winter stratosphere


Chemistry Module (50 species; 41 Photolysis, 93 Gas Phase, 17 Heterogeneous Rx)(50 species; 41 Photolysis, 93 Gas Phase, 17 Heterogeneous Rx)

(Taken from Brasseur and Solomon, 1986)

Our goal was to represent the chemical processes considered important in the:

• Troposphere, Stratosphere, and Mesosphere:

• Ox, HOx, NOx, ClOx, and BrOx

• Heterogeneous processes on sulfate, nitric acid hydrates, and water-ice aerosols

• Thermosphere (limited):

• Auroral NOx production

• Currently do not include ion-molecule reactions


WACCM Chemical Species

Long-lived Species: (17-species, 1-constant)

– Misc: CO2, CO, CH4, H2O, N2O, H2, O2

– CFCs: CCl4, CFC-11, CFC-12, CFC-113

– HCFCs: HCFC-22

– Chlorocarbons: CH3Cl, CH3CCl3,

– Bromocarbons: CH3Br

– Halons: H-1211, H-1301

– Constant Species: N2

Short-lived Species: (32-species)

- OX: O3, O, O(1D)

- NOX: N, N(2D), NO, NO2, NO3, N2O5, HNO3, HO2NO2

- ClOX: Cl, ClO, Cl2O2, OClO, HOCl, HCl, ClONO2, Cl2

- BrOX: Br, BrO, HOBr, HBr, BrCl, BrONO2

- HOX: H, OH, HO2, H2O2

- HC Species: CH2O, CH3O2, CH3OOH


Heterogeneous Chemistry Module

>200 K

Sulfate Aerosols (H2O, H2SO4) - LBSRlbs = 0.1 m

Sulfate Aerosols (H2O, HNO3, H2SO4) - STSRsts = 0.5 m

Nitric Acid Hydrate (H2O, HNO3) – NAD, NAT

Rlbs = 0.1 mRNAH= 2-5 m

k=1/4*V*SAD* (SAD from SAGEII)

Thermo. Model (Tabazadeh)

188 K(Tsat) ICE (H2O, with NAH Coating)

Rice= 20-100 m185 K(Tnuc)


Computational Demands

• Using the MOZART3 framework:

• Resolution of 2.8 x 2.8 degrees horizontal, ~2 km vertical

• Calculations at >500,000 grid cells; time step of 20 minutes

• Coded to run on massively parallel architectures (IBM Blackforest at NCAR)

• 16 nodes x 4 processors per node (64 processors)

• 1 model year = 1.25 wall clock days

• Near Future… Advanced Research Computing System (ARCS)

• Expect a 5-fold increase in computational resources

• 4 model years = 1 wall clock day


CH4 (ppmv), March

WACCM / MOZART3UARS / HALOE+CLAES Data


NOx (ppbv), March

WACCM / MOZART3UARS / HALOE Data


Total Column Ozone (Dobson Units)

Earth Probe TOMS, 1999 (daily) WACCM (daily)


Equatorial H2O (ppmv), UARS HALOE

Strat / Trop Exchange of Water Vapor:

A Key Question for Chemistry and Radiative Transfer

The observed “tape recorder” signal in the lower stratosphere

is shown at left(imprint of the sesonal cycle in

tropopause temperature)


Calculated Equatorial H2O (ppmv)

Semi Lagrangian advection Lin and Rood advection (now used in WACCM)


WACCM Science Application

Middle Atmosphere Variability due to Planetary Waves Propagating from the Troposphere:

• Changes in tropical sea surface temperature (SST) alter the forcing of large-scale waves that propagate into the middle atmosphere

•This can impact the structure and intensity of the winter polar night vortex

Model Simulation:

• WACCM was run with time-dependent SST from 1979 through 1998 specified from observations

• Model results grouped according to whether the SST distribution corresponds to El Niño or La Niña years


500 mb Geopotential (JAN) Ensemble Difference El Niño – La Niña

“canonical” tropospheric

response(PNA pattern)

Response in the Troposphere


Response in the Lower Stratosphere

• ENSO effects extend into the stratosphere (and above)

• At high latitudes, a large warm anomaly is shown which corresponds to a more disturbed polar vortex during El Niño years relative to La Niña years

• A disturbed polar vortex is accompanied by polar temperatures colder by several degrees.

• Could have significant impact on polar heterogeneous processes

JANT (K) at 100 mb: El Niño – La Niña


Coming Attractions...

• Community workshop will be organized for 2002

• WACCM to be released as community model

Dynamics

--------------------------------

Chemistry

Dynamics

--------------------------------

Chemistry

Specified O3 drives Qsw Calculated O3 drives Qsw

Current

(Offline Chemistry)

Under development

(Coupled Chemistry)

Future Work and PlansInteractive Dynamics and

Chemistry

–> Coupled model allows feedbacks between Qsw and dynamics

Documents

1 MIDDLE ATMOSPHERE RESEARCH HIRDLS: The High Resolution Dynamics Limb Sounder –Future potential in remote sensing for the UT/LS region. –Benefit to