ATD Facilities in Support of Biogeosciences

1. ATD Facilities in Support of Biogeosciences Biological processes play key roles in the dynamics of the Earth system, modulating global and local carbon, nitrogen, trace-gas, water, and energy cycles. In turn, ecosystems and biogeochemical cycles are sensitive to physical and chemical forcing and the growing influence of human activities.

2. Common theme of scaling from global and local to regional scale fluxes (NRCS/USDA, 1997) TEMPERATURE (C) (IPCC, 2001) (NRCS/USDA, 1997)

3. Model-data fusion is critical for advances • Measurements to elucidate responses, couplings, and feedbacks, on local to regional scales, for inclusion into process models • Measurements on all scales made in a way such that they are useful in inverse and assimilation models • Measurements on all scales designed to test and validate predictive models • Models to aid in local to regional experiment planning and regional to global observing system design

4. U.S. Carbon Cycle Planning Documents(Current U.S. carbon cycle expenditures $40-50M/yr) CCSP, 1999: +$135-300M (2000-2005) $200-250M/yr (2005- ) LSCOP, 2002: $250M (2002-2006) $150M (2007-2011) NACP, 2002: +$40-70M/yr (2002-2005) +$50-100M/yr (2005- ) Others (list incomplete): Nitrogen Cycle Science Plan, NACP-CH4, Ocean Carbon Cycle and Climate (OCCC) Plan, U.S. Climate Change Science Program (CCSP)

5. Organizing Topic 1: Local scale fluxes • Science Needs: • Improve our understanding of the response of local terrestrial exchange of carbon, nitrogen, reactive species, and aerosols to relevant environmental, climatic, and anthropogenic drivers. • Investigate coupling between terrestrial carbon and nutrient cycling and associated non-linear feedbacks. • Resolve how complex terrestrial landscapes interact with physical processes in the atmosphere to influence biogeochemical and physical ecosystem processes, land-atmosphere exchange, and local climate. • Characterize biases in tower flux measurements due to horizontal tracer transport. • Measurement Needs: • Tower based eddy flux measurements for CO2 and H2O. Flux measurements of reactive biogeochemical species and particles should be considered, but technology transfer from ACD to universities for long term measurements may be more appropriate. • In situ instrumentation for CO2 isotopes. • Medium arrays of towers (order 10-20) and instruments to sample local heterogeneity, environmental gradients, and complex terrain for CO2 and other species, along with more complete characterization of the wind, radiation, and scalar field within vegetated canopies. • Large (order 100-1000) arrays of intelligent sensors for sampling high variability environmental parameters. • Advanced tethered balloon instrumentation for multi-species boundary layer profiles. • Enclosure techniques for measuring soil and plant exchange of CO2 and reactive species. • Relatively autonomous instrumentation with capacity to support regular annual cycle length campaigns.

6. Organizing Topic 2: Regional scale fluxes • Science Needs: • Understand relationships between regional terrestrial and oceanic exchange of carbon and other biogeochemically important gases and the underlying ecosystems and imposed climatic and land-use perturbations. • Develop methods to quantify terrestrial and oceanic anthropogenic CO2 uptake on regional scales. • Assess impacts of regional atmospheric N deposition and ozone pollution on ecosystem function. • Investigate transport of biogeochemical aerosols from the continents and their influence on marine productivity. • Measurement Needs: • Airborne instrumentation for fast-response, precise, and accurate measurements of CO2, CO, H2O, O3, O2/N2, CO2 isotopes, radon, and photochemically active species. • A flask system or systems for collection of discrete, dried samples for laboratory analyses of these and other gases or isotopes. • Airborne instrumentation for eddy flux measurements of CO2, CO, O3, and H2O. In the case of CO2, and possibly others, this instrument should be independent from the concentration instrument. • Airborne disjunct eddy accumulator to enable flux measurements of a wide range of compounds. • Airborne remote sensing instrumentation, including hyperspectral imaging for both atmospheric and surface biogeochemical observations, CO2 LIDAR, microwave soil moisture measurements, and accurate surface IR temperature imaging. • Regional scale instrument networks for background concentration gradients and associated flux constraints.

7. Organizing Topic 3: Continental to global scale fluxes • Science Needs: • Partition global anthropogenic CO2 uptake between ocean and land, and partition continental anthropogenic CO2 uptake between continents and ocean basins at similar latitudes (e.g. N. America from Europe, Asia, N. Atlantic, and N. Pacific). • Characterize global, hemispheric, and continental budgets of other greenhouse gases, such as CH4 and N2O. • Constraints on global cycling of nitrogen, reactive species, and biogeochemical aerosols. • Investigate how biogeochemical coupling of carbon, nitrogen, iron, and sulfur cycles affect climate, air quality, radiative forcing and ecosystem function on continental to global scales. • Measurement Needs: • Much of biogeoscience on these scales requires long term monitoring of multiple species. For monitoring purposes, technology transfer from ATD to universities or other government labs, as for example in the case of background O2 instrumentation, may be the most appropriate contribution. • An airborne flask sampling system capable of sampling UTLS or stratospheric air without fractionation, to allow investigation of global isotope budgets for various species. • In situ instrumentation for upper tropospheric airborne measurements to characterize convective outflow sources and tropical continental exchange signals. The combination of radon and CO2 would be particularly useful.

8. Other considerations • Training Needs: • The biogeosciences community has relatively less experience utilizing ATD facilities and less infrastructure for advanced instrument development and airborne science. NCAR should partner with universities and agency programs to entrain BGS students and postdocs into earth system observing technique development, and provide internship and summer opportunities and curricular material. • Internal Facilities: • Many biogeoscience measurements require high levels of precision and accuracy that can only be achieved through rigorous calibration procedures, including the maintenance and propagation of calibration scales based on suites of high-pressure gas cylinders. In these cases, internal facilities are required to support the community facilities. An example is the NCAR CO2 and O2/N2 Calibration Facility, consisting of gas cylinders, an insulated horizontal storage unit, valves and high-precision instruments under automated control to provide calibration gases for the airborne and surface deployments of ATD and other divisions. • Community Biogeosciences Instrumentation Workshop: • The NCAR Biogeosciences Initiative will host a two day workshop in fall ’04 to solicit community feedback on the BGS component of the ATD Facilities Strategic Plan and to engage university scientists in the planning and use of ATD BGS facilities.

9. Example Case: Carbon in the Mountains Experiment (CME, ACME) Planned NCAR Resources: ISFF: Array of CO2 flux and concentration, wind, and environmental parameter measurements. Subset maintained over annual cycle. C130: CO2, CO, O3, H2O concentration measurements. Fluxes for those available. O2/N2, 13C, and remote sensing in future deployments. CO2 Calibration Facility Intelligent Sensor Array PTRMS (ACD) Many people GPP gC m-2 day-1

10. The Case for Research Science in ATD • Motivations (apply to BGS and other fields): • The quality of the observational facilities ATD provides to the community will suffer if those providing them are not themselves involved in using the same or similar measurements in their own scientific research. • As experts in the collection of state-of-the-art observations, ATD scientists have insights into their interpretation valuable to the community. • Therefore, in addition to research into development of advanced instruments and platforms, ATD should foster and encourage research of the facility providers themselves, addressing current scientific questions, by: • Allowing ATD scientists significant time to pursue their own scientific interests (additional support staffing required in some areas). • Hiring scientists in underrepresented or new facility areas. • Drafting scientists from other NCAR divisions to serve in community instrumentation support roles (would also help to expand facility).