QUESTION: ARE CURRENT MET OBSERVATIONS ADEQUATE FOR URBAN APPLICATIONS?

1. QUESTION:ARE CURRENT MET OBSERVATIONS ADEQUATE FOR URBAN APPLICATIONS? R. P. Hosker, Jr. NOAA-Air Resources Laboratory Atmospheric Turbulence & Diffusion Division Oak Ridge, TN 37830 ray.hosker@noaa.gov My short answer: mostly NO.

2. CITIES ARE NOT LIKE RURAL AREAS! Sketch by Oke and Rotach, in Piringer et al, 2002: WASP-Focus, 2, pp 1-16.

3. SCIENCE ISSUES WITH CURRENT URBAN OBSERVING SYSTEMS: • Inadequate resolution of spatial scales within urban areas. • Few observations in the vertical – but very important for dispersion predictions in urban areas. • Representativeness a major problem in cities, espec. in complex environments (e.g., terrain, coastal). Remote sensing/averaging an answer? • Limited guidance for siting instruments in urban areas, espec. in CBDs.

4. NON-SCIENCE ISSUES WITH CURRENT URBAN OBSERVING SYSTEMS: • Adequate funding & long-term commitments for urban measurement networks. Need lawmaker understanding and support. • Siting problem #1 – owner permission often driven by liability worries. How to fix? • Siting problem #2 – cities change; site characteristics vary. Need continuity in obs. • Siting problem #3 – some useful instrument systems are not neighbor-friendly. Need to adjust design criteria for urban instrumentation.

5. 5 AREAS OF SPECIAL INTEREST FOR URBAN MET OBSERVATIONS • Severe Weather (storms, floods, heat, cold) • Homeland Security (hazardous releases) • Air Quality (air pollutants and products) • Water Quality (transfer of airborne materials) • Climate (long term changes and trends) A request was made to add fire weather to these; perhaps really a special case of severe weather?

6. Met Requirements For: • Severe Weather. Resolve sub-urban scale spatial variability. Representative sites. Rapid updates; robust comms & power; reasonable accuracy. • Current systems OK? Only in some places. Need more networks.

7. Met Requirements For: • Homeland Security. WD is critical. Resolve local scale variability of wind & T fields both horizontally & vertically. Turbulence info. Rapid updates; robust comms. Ability to recognize CBR release. • Current systems OK? Generally, no. Need specialized integrated networks & vertical data, coupled to modeling.

8. Met Requirements For: • Air Quality. Resolve sub-urban scale variation of winds, T, mixing layer depth. Photochemistry variables important. Concentration data. Hourly updates. Solid calibrations. • Current systems OK? Generally, not quite. Need enhanced networks, vertical data.

9. Met Requirements For: • Water Quality. Resolve sub-urban or smaller scalevariability of precip (location & rate), run-off. • Current systems OK? Perhaps, if using radar obs. to supplement local precip measurements.

10. Met Requirements For: • Climate. Need regionally representative values of T, precip, multi-wavelength solar, etc. Need high accuracy and high precision. Long-term (decades to centuries) unchanging sites. High quality calibrations; extensive metadata; low data loss. • Current systems OK? Only in some places. Need firm commitment to QUALITY. Need more urban sites.

11. Suggested Observation Priorities: • Public Safety. Severe weather obs. & warnings. Homeland security obs & warnings. Design nets (hardware, placement) to reduce human risk. • Public Health, Environment. Air & water quality-related obs. Design integrated networks to assist rational decision-making, so as to reduce urban dweller exposures. • Improved Understanding. Climate obs. Long-term maintenance commitments essential. Urban & other climatically sensitive regions under-represented.