1. NYU/NYC STUDY 10 IOPs – FIVE DAYS EACH (DAY AND NIGHT) – ALL SEASONS 80 SFC WIND SITES  HOURLY FLOW CHARTS PIBALS: – 1- 4 THEODOLITES FOLLOWING 1OR 2 BALLOONS – 15 SEC OBS  37.5 m z-RESOLUTION HELICOPTER SOUNDINGS (ABOUT 1000) – T, Q, & SO2 NOAA TETROONS: ABOUT 200 EMISSIONS – 1 KM X 1 KM – SO2, HEAT, & MOISTURE

2. Sea-breeze frontal (S to N) passage over NYC: 9 March 1966 a. hourly positions (left) b. 1800 EST (right): note urban-induced retardation area

3. NYC daytime sea-breeze sfc div-field during sea breeze frontal (SBF) passage Note: (a) conv area strongest at front (b) div areas over Ocean and Long Island Sound (LIS) D = ∂u/∂x + ∂v/∂y ∂v/∂y Ocean LIS SBF

4. URBAN TURBULENCE DURING A URBAN TURBULENCE DURING A NYC SEA BREEZE FRONTAL PASSAGE: VALUES HIGH ALONG FRONT (LEFT)VALUES HIGH ALONG FRONT (LEFT) AIR STABLE BEHIND FRONT (RIGHT)AIR STABLE BEHIND FRONT (RIGHT) R (deg)

5. Tetroons in sea-breeze flows produce interesting (x, y) and (x, z) trajectories that returns balloon (left) and raises it (right)

6. SEA-BREEZE (SB) EFFECTS ON χ SEA-BREEZE (SB) EFFECTS ON χ AM syn-V pushes χ offhore (right)AM syn-V pushes χ offhore (right) PM sea breeze flow pushes it onshore PM sea breeze flow pushes it onshore & concentrates it in narrow conv & concentrates it in narrow conv zone (lower L) zone (lower L) The SB thus raises χ at coastal JFK & The SB thus raises χ at coastal JFK & lowers it at inland LGA (lower R) lowers it at inland LGA (lower R)

7. KEY IDEA: IDEAL MESO-MET ATM-MODEL CAPTURES ALL BC FORCINGS IN CORRECT ORDER O 3 EPISODES OCCUR ON A GIVEN DAY: – NOT B/C TOPO, EMISSIONS, OR SFC MESO-FORCING (EXCEPT FOR FOG) CHANGES – BUT DUE TO CHANGES IN UPPER-LEVEL SYNOPTIC WX PATTERNS, WHICH COME FROM AN EXTERNAL MODEL & WHICH ALTER MESO SFC-FORCINGS (i.e., TOPO, LAND/SEA, URBAN) VIA MESO-TEMP AND THUS WIND MUST THUS EVALUATE ABOVE FACTORS: – UPPER LEVEL SYN WX Patterns: pressure & then winds – TOPOGRAPHY (via grid spacing): channeling of wind – MESO SFC: temperature & then winds

8. NYC Sea breeze: obs (upper) TVM/URMET (lower)

9. NYC OBS REFERENCES Bornstein, 1968: J. Appl. Met.., 7., 575-82. Born. & Johnson, 1977: At. Env., 11, 597-04 Loose & Born., 1977: MWR, 105, 567-71. Born. & Thompson, 1981: JAM, 20, 843-58 Born., 1987: Modeling the Urban BL, AMS, 53 ‑ 93. Gaffen & Born., 1988: Met. & Atmos. Phys, 38, 185 ‑ 94