Global Processes, Including C, N Cycles and the Upper Troposphere and Lower

StratosphereGeneral Needs:

To reduce uncertainties for key measurementsTo increase spatial/temporal coverage for key species/parametersTo fill gaps in present suite of surface, remote, airborne measurements

Focus determined by • science needs, • technological advances, and • community cooperation to improve measurement

confidence, data set comparability,and accessibility

Primarily in situ focus, likely a function of group backgrounds

• Surface network measurements (e.g. Ameriflux, Aeronet, GAW)• cross-calibration to link multiple data sets• consistency of coverage, accuracy, precision• contribute a centralized repository of data in a synthesized

form that is/can be made available to other communities• modelling• satellite measuremen

• What to do about undersampled regions?

• LAOF facilities can play a role to link and validate diverse data sets such as surface meaasurements, satellite measurements, and model products

Aerosol measurement

• Science need: still a large uncertainty in IPCC assessment of aerosol indirect effect

• Steps needed:• predict CCN contribution to accumulation mode aerosols• connection between CCN and radiative properties

• Measurement needs: • more frequent CCN measurements or find surrogate correlation

(e.g. CCN-AOD) to link rad effect to present network measurements

• additional supersaturations• reduce incidence of pressure perturbations• method validation exercises

• intercomparisons• compare measurements in specific areas to physical models

Aerosol measurement

• Science need: Better understanding of drizzle genesis processes• Measurement needs:

• scattering aerosol probes inadequate for measuring precipitation sized droplets (1-10 um range)

• new technologies show promise for improvements• phase doppler in situ method• 95 and 220 GHz radar

Carbon and Nitrogen Cycles

Science needs:Climate change characterization, trendsSH underrepresentedCharacterization and effects of land use changeEmission database validation and improvement

Carbon and Nitrogen Cycles

• CO2• surface measurements ok, cross validation a focus area• airborne fluxes can easily develop correlated motion

sensitivity -> artifact• Methane

• more extensive, higher resolution measurements needed, especially fluxes

• Soil moisture, temperature -> N cycle• VOCs to better understand emissions, gas phase transformation,

and the role of VOCs in aersool formation processes• other N species: PANs, NH3, N2O

• Hg: oxidized species measurement a hot new area of research

UT/LS• Science needs:

• composition• mechanisms of exchange• trends with climate change• to what degree does strat O3 contribute to tropospheric levels?

• Measurement need: H2O• many methods, lots of disagreement• increased coordination of validation across organization, but

we need more• community calibration facility needed for absolute and

relative humidity measurements• could be extended to other species (e.g. co2)

• profile measurements: Reference radiosonde development• profile measurements: LIDAR a gap

UT/LS• GPS measurements may be a missed opportunity

• need for more extensive routine measurements covering a broader spatial extent

• either as surface network or deployable facilities• not expensive