UTLS Strategic Initiative Workshop - Meeting

UTLS Strategic Initiative Workshop

Integrated Study of Dynamics, Chemistry, Clouds and Radiation of the Upper Troposphere and Lower Stratosphere

27-28 October 2003

Supported by NCAR director's opportunity fund, the NCAR Integrated Study of Dynamics, Chemistry, Clouds and Radiation of the Upper Troposphere and Lower Stratosphere (UTLS) project steering committee sponsored a community workshop on research opportunities.

The objective of the workshop was to identify the key questions in UTLS research, discuss strategies of integrated studies involving the new NSF aircraft, HIAPER, in conjunction with the new generation of satellite data from the NASA A-Train and with multiple scale models.

The workshop will served to design the NCAR UTLS initiative project in concert with the effort of the broader community and enhance collaborations.

The scientific discussion focused on three main areas:

1. UTLS water vapor, cloud, aerosol and radiation
2. Stratosphere-troposphere exchange in the extratropics
3. Chemistry related to UTLS ozone and radical budgets
4. UTLS aerosol and cirrus clouds

Workshop

Agenda

Workshop objectives:

• To identify the key issues of UTLS research and to define achievable goals.
• To form a science user community for the use of HIAPER in UTLS research, optimizing the synergy with NASA A-train, Aura in particular.
• To work on a science plan and airborne experiment design and to form working groups to implement the plan.
• To form community consensus on instrumentation strategy.

Day 1 (Oct 27, Monday)

Check in registration: (8:00 to 8:30) (pick-up name tags, agenda and mailing list of participants)

Opening session: (8:30-10:20) Laura Pan (NCAR), Chair

1. Introduction to the agenda and objectives (Laura Pan, 10 min.)

2. Welcome by the NCAR Deputy Director (Larry Winter, 5 min.)

3. Welcome by ACD Director (Danny McKenna, 5 min.)

4. Overview of UTLS science issues

• Jim Holton(Univ Washington) / Bill Randel(NCAR), 30 min.

5. Overview of coming opportunities

• SPARC perspective – Ravishankara(NOAA), 10 min.

• NASA activities and interests – Dave Fahey(NOAA)(for Don Anderson and Mike Kurylo(NASA), 10 min.

6. Data from satellite platforms in the UTLS region (I-2 slides, 5 min. each)

• HIRDLS (Alyn Lambert-NCAR)
• MLS (Joe Water-JPL)
• TES (Helen Worden-JPL)
• AIRS (Ann-Marie Eldering-JPL)

• GPS (Bill Kuo-NCAR)

Break (10:20-10:50)

Tropical water vapor, clouds and radiation (10:50-12:00) Andrew Gettelman (NCAR), Chair

1. Ian Folkins(Univ Dalhousie): Structure and issues in the tropical UT/LS
2. Andy Dessler(Univ Maryland): Dessler: Water vapor and clouds in the UT/LS
3. Qiang Fu(Univ Washington): radiation in the UT/LS
4. Eric Jensen(NASA): Clouds and microphysics in the UT/LS
5. Open Discussion

Lunch Break (12:00 - 1:00)

.

STE (1:00– 3:00) Jennie Moody (Univ Virginia), Chair

1. Andreas Stohl(NOAA)-outstanding issues and key measurements (~ 10 min.)
2. Laura Pan(NCAR)–outline of white paper STE section (~ 5 min.)
3. Todd Lane (NCAR)-role of gravity wave in STE (~ 10 min.)
4. Don Lenschow (NCAR)-turbulent processes in the UTLS (~ 5 min.)
5. Pao Wang (Univ Wisconsin)-role of deep convection (~ 5 min.)
6. Owen Cooper(CU/NOAA)-stratospheric intrusions(~ 10 min.)
7. Tim Marcy (NOAA)-quantifying stratospheric influence to UT using HCl measurement (~ 10 min.)
8. Jennie Moody (Univ Virginia)-synergy of satellite and airborne observations (~ 5 min.)
9. John Gille (NCAR)-Synergy of HIRDLS observation with airborne STE studies (~ 5 min.)
10. Open discussions

Break (3:00 - 3:30)

.

UTLS CHEM (3:30-5) Bill Brune (Penn State), chair

1. Bill Brune(Penn State)- outstanding issues in UTLS radical budget and what can we do
2. Jennifer Logan(Harvard)- outstanding issues of UTLS ozone and what can we do in new measurements
3. Mary Barth(NCAR)- outline of the white paper Chem section
4. Darin Toohey(CU)- Halogens in the UT/LS
5. Ron Cohen(Berkeley)- comments
6. Open Discussion (20 min)

Day 2 (Oct 28, Tuesday)

Aerosol and cirrus (8:30-10:00) Steve Massie (NCAR), Chair

1. Chuck Wilson(DU)/Dan Murphy(NOAA)- outstanding issue of UTLS aerosol and key measurements (15 min.)
2. Andy Heymsfield(NCAR)-outstanding issues of cirrus near the tropopause and key measurements (10 min.)
3. Rushan Gao(NOAA)-cirrus-HNO3 interaction near the tropopause (10 min.)
4. Steve Massie(NCAR)/Mike Fromm(Univ Maryland)- satellite synergy
5. convective transport of biomass burning products into stratosphere (10 min.)
6. Tony Clarke(Univ Hawaii)-Airborne in situ measurements of aerosol compositions (10 min.)
7. Open discussions

Hiaper overview (10-10:30) Laura Pan (NCAR), Chair

1. HIAPER – status, NSF MRE, “progressive science period” and other procedures - Dave Carlson
2. Questions and discussions

Break (10:30 - 10:45)

.

Experiment design and strategy (10:45-12:30) Ron Cohen (Berkeley), Chair

1. Paul Wennberg (Cal Tech)-HIAPER and TC4 synergy
2. Brian Ridley(NCAR)- From Soft-start to STE
3. Al Fried(NCAR)/Chris Cantrell(NSF/NCAR)-Radical budget experiment
4. Mike Coffey(NCAR)-PSC studies
5. Andy Heymsfield(NCAR)-Cirrus clouds near the tropopause
6. Jim Whiteway(York Univ)-Measurements to characterize multi-scale dynamics
7. Paul Newman(NASA)/Dave Fahey(NOAA)-AVE
8. Mel Shapiro(NOAA)-Comments and synergy with THORPEX experiment
9. Discussions (20 min)

Lunch Break (12:30 - 1:30)

.

Modeling strategy (1:30-2:30) Danny McKenna -Chair, (NCAR)

1. Ken Pickering(Univ Maryland)- Modeling convection and its contribution to transport and chemistry
2. Jordan Powers(NCAR)-WRF model and mesoscale dynamics
3. Mark Olsen(Univ Maryland)-3D CTM Modeling of STE
4. Andrew Gettelman(NCAR)
5. Peter Hess(NCAR)
6. Discussion

Measurements and Instrumentation Strategy (2:30-4:30, with break in between) Paul Wennberg (Cal Tech), Chair

1. Jeff Stith(NCAR)/Don Lenschow(NCAR)-HIAPER measurements capability and priorities
2. Linnea Avallone(CU)-water vapor measurement
3. John Hair(NASA)/Ed Browell(NASA)-Remote measurements of ozone, water vapor, aerosol, and cloud
4. Christoph Gerbig(Harvard)/Steve Wofsy(Harvard)-Quantum cascade laser spectrometer for measurements of CO, CH4 and CO2
5. Christoph Senff(NOAA)/Mike Hardesty(NOAA)-Doppler lidar measurement capability for studying dynamics in cirrus clouds
6. Rick Shetter(NCAR)-Actinic flux
7. Eric Apel(NCAR)-GC-MS system that measures carbonyls, alcohols, CFCs and NMHCs

Conclusion and action items (4:30- 5) – Laura Pan (NCAR)

1. Implementation plan and working groups
2. Adjourn

Participants

Summary

Laura Pan (NCAR), Brian Ridley (NCAR), Bill Randel (NCAR), Andrew Gettelman (NCAR), Jennie Moody (UVA), Bill Brune (Penn State), Steve Massie (NCAR), Ron Cohen (UC Berkeley), Danny McKenna (NCAR), Paul Wennberg (CalTech)

December 22, 2003

A two-day community workshop on Integrated Study of Dynamics, Chemistry, Clouds and Radiation of the Upper Troposphere and Lower Stratosphere (UTLS), organized by the NCAR UTLS initiative coordinating committee, was held at NCAR on 27 - 28 October. About120 participants attended: ~55 from NCAR and ~65 from 20 universities, NOAA and NASA Labs, and other research organizations nationwide.

The specific objectives of the two-day workshop were

1. to review some of the outstanding problems of the UTLS region and to define achievable goals;
2. to form a science user community for the deployment of the HIAPER aircraft in UTLS research, optimizing the synergy with the NASA A-train satellites, Aura in particular;
3. to form working groups to develop and implement science plans and airborne experiment design;
4. to initiate discussions on the UTLS community’s consensus on instrumentation strategy.

These topics are covered in the sequence of

1. science issues–overview and topical discussions of tropical UT water vapor, clouds and radiation, stratosphere-troposphere exchange (STE), UTLS chemistry and aerosols;
2. initial concepts of airborne experiments centered on HIAPER and the advantages of having large-scale satellite observations (AURA and other satellites);
3. how multi-scale models can help define the science objectives, aid the detailed design and planning of field campaigns, and, of course, aid or stimulate data interpretation and connect the in-situ scale to the much larger scale of satellite observations;
4. categorize instruments that are critical for the success of these studies. This report summarizes what the workshop has accomplished and the issues that require further discussions.

Several categories of experiments are discussed. Working groups are being formed to further develop the plan for field experiments. Initial sign-ups for the working groups consist of around 50 scientists across the community.

The workshop provided a good opportunity to learn of ongoing and current research activities pertaining to the UTLS from a broad perspective. It also provided a good summary of planned activities by other agencies and organizations. Among the specific objectives of the workshop, the first two were well achieved by the workshop. Work on achieving the 3^rd (working groups for designing experiments) and 4^th (instrumentation strategy) objectives are only beginning.

The highlights of the workshop are summarized below.

1. Overviews:
   

   Jim Holton and Bill Randel led the opening session and gave brief overviews of UTLS science issues. The overviews emphasized the importance of convective transport into the UTLS, as illustrated by a simulation of midlatitude convection in Figure 2, plus the interconnection of transport, chemical, microphysical and radiative processes. Ravishankara (Co-chair of SPARC) presented an overview of SPARC perspectives, emphasizing the link of UTLS processes to climate change issues. David Fahey presented NASA plans and activities for UTLS research (on behalf of Don Anderson and Mike Kurylo of NASA Headquarters). This presentation focused on the common scientific objectives of the UTLS initiative and AURA satellite measurements, and potential links to HIAPER deployment with the planned airborne AURA validation missions. This was followed by a series of brief discussions of new generations of satellite data in the UTLS region, given by team members from AURA/HIRDLS (Alyn Lambert), AURA/MLS (Gloria Manney), AURA/TES (Helen Worden), and AQUA/AIRS (Ann-Marie Eldering).

   An overview of the status of HIAPER, funding opportunities for HIAPER instrumentation, and the plan for initial science missions was given by David Carlson (HIAPER PI). He told the community that HIPAER is scheduled to be ready for an initial science payload by the summer of 2005. An initial test period of six months (July to December 2005) has been designated as the “Progressive Science” period. Solicitation for Letters of Intent have now been released, and NSF has just recently announced the funding opportunity for HIAPER aircraft instrumentation.

2. Key issues of the UTLS:
   

   Following are the highlights of the topical discussion of UTLS science issues:

   • Mechanisms controlling tropical UT humidity (presentations by Ian Folkins, Andy Dessler, Eric Jensen, Quang Fu and Andrew Gettelman):
     In the tropics, the “deep convection detrainment layer” spans the 10-14 km altitude range. This is an under-sampled region but critical for understanding the processes that control UTLS humidity, cirrus formation and the radiative impact. Large discrepancies remain between models and observations. A better understanding of how dynamical, microphysical and radiative processes couple is required to reduce the uncertainty in climate models. NASA is planning two multi-aircraft studies (TC⁴) of the tropical UTLS region over the next 4 years and HIAPER would be able to make valuable contributions through in situ measurements within the 10-14 km convective outflow region.

   • Multi-scale dynamics and STE (presentations by Andreas Stohl, Laura Pan, Todd Lane, Jielun Sun (for Don Lenschow), Owen Cooper, Jenny Moody, Pao Wang, Tim Marcy and John Gille):
     The discussions recognized recent progresses in STE climatology using Lagrangian models, but pointed out the need to verify these model results by observations. Stratospheric intrusion and mixing between the stratosphere and troposphere is frequently observed but poorly modeled. Characterization of mixing between the stratosphere and troposphere will require multiscale observations from spaceborne remote sensing to airborne in situ, coupled with multi-scale models. Better characterization of gravity wave breaking and turbulent mixing was emphasized. It was also recognized that there is increasing observational evidence on the importance of vertical transport by mid- to high latitude deep convection, processes that couple the mid- to high latitude lower troposphere to the UTLS. The relative contribution of these processes to the lowermost stratospheric composition, compared to that produced by isentropic mixing, needs to be quantified.

   • UTLS radical budgets, ozone, and convective influence (presentations by Bill Brune, Jennifer Logan, Mary Barth, Darin Toohey and Ron Cohen):
     Discussions focused on ozone and radical budget issues in the tropical and extra-tropical UTLS regions, and the possible impacts of deep convective redistribution, production of ozone, or multiphase uptake of constituents. Much of the discussion reinforced problems described in the White Paper, including the behavior of HO_x at high NO_x mixing ratios, defining possible multiphase interactions of HO_x, defining or identifying the role of OVOCs as HO_x precursors, the sources and sinks of halogen radicals, and the impact of deep convection, cloud processing, and lightning NO_x on the ozone budget.

   • Interaction of chemistry and particle/cirrus formation (presentations by Steve Massie, James Wilson, Dan Murphy, Andy Heymsfield, Rushan Gao, Mike Fromm, and Tony Clarke).
     The composition of UTLS aerosol has an organic content (50%) that is higher than previously realized. It is known that organic aerosol is produced at the Earth’s surface by urban pollution and biomass fires. Boreal forest fires are a (recently recognized) source of particles in the UTLS. Aerosol is potentially a controlling factor for humidity and the cirrus formation criteria near the tropopause. There is observational evidence (INCA) that northern hemisphere cirrus formation nucleates at relative humidities lower than those in the southern hemisphere, a result attributed to the presence of more ice nuclei (IN) in the northern hemisphere, leading to heterogeneous nucleation of cirrus. Furthermore, recent observations from the NASA CTYSTAL-FACE program were interpreted (R-S Gao, D. Fahey) to show that a nitric acid “coating” on ice near the tropopause interferes with H₂O uptake.

3. Airborne experiment strategy

   (presentions by Ron Cohen, Paul Wennberg, Brian Ridley, Al Fried, Joach Kuettner, Jim Whiteway, Andy Heymsfield, and Mike Coffey)

   Initial concepts of several categories of HIAPER-led airborne experiments were discussed, including:

   • Tropical experiments: It is recognized that HIAPER has capability for sampling the 10-14 km altitude range, which is the region of main convective outflow in the tropical UT. A plan for a tropical mission using HIAPER in early 2007, as part of the NASA-led TC4 experiment, was discussed.

   • Mid- to high latitude experiments: A number of mid-to high latitude experimental themes were discussed. They can potentially be combined into joint campaigns. These are considered to be multi-aircraft campaigns, including HIAPER and other platforms. The prospective experiments covered: (a) STE in the extratropics, characterization of the tropopause transition in the region of the subtropical jet and the coupling of the tropics and the extratropics across the jet; (b) Vertical redistribution of chemical species via deep convection, the production and distribution of lightning-produced NO_x, and investigation of the downwind impact on ozone production over several days; (c) detailed process studies of the role of convection on the UTLS radical budgets, particularly the role of peroxides, aldehydes, and OVOCs; (d) Characterization of UT aerosol composition, distributions, and cirrus formation processes near the tropopause; (e) airborne studies of polar stratospheric clouds (PSC’s) in the Arctic.

4. Roles of multi-scale models.

   (presentations by Danny McKenna, Ken Pickering, Jordan Powers, Mark Olson, Peter Hess, and Andrew Gettelman):

   Discussions focused on the range of relevant models, from detailed microphysical/aerosol models, 3-D cloud models, to local and global-scale chemistry transport models. Detailed process studies in the UTLS will be required to quantify dynamical, chemical and aerosol behavior in models. Models can in-turn be used to focus potential field studies, and provide input for the design of aircraft missions.

5. Instrumentation issues

   (presentations by Paul Wennberg, Jeff Stith, Teresa Campos, Linnea Avalone, Christoph Gerbig/Steve Wofsy, John Hair/Ed Browell, Christoph Senff/Mike Hardesty, David Rogers, Rick Shetter, and Eric Apel):

   It is recognized that the success of the HIAPER related science missions critically depends on a strategy for the progressive development of basic instruments to a more complex suite for aerosol and radical studies. Following a review of the HIAPER Advisory Committee (HAC)’s recommendation on instrument development, discussions of critical needs and the status of instrument development were given, including

   • fast sampling in situ O₃ and CO instruments
   • water vapor and total water instruments
   • long lived-tracer instruments
   • cloud microphysics instruments
   • small lightweight LIDARs for aerosol, ozone, water vapor and wind measurements
   • radiation instruments
   • instrumentation for a variety of VOC measurements.
   
   

   The first UTLS HIAPER project needs to be determined in order to define the instrument development priority.

6. Next step:

   Over the next few months, working groups are to be organized to begin the more difficult task of formulating detailed plans for field studies and their links with satellite and modeling partners. We expect a number of instrumentation proposals will be made in response to the NSF’s HIAPER instrumentation opportunity fund. The UTLS project will also coordinate a Letter of Intent for the use of HIAPER during the progressive science time period.