Air-Sea%20Interaction%20in%20NYC:%20Urbanized%20Mesoscale%20Modeling%20for%20CB%20Threats

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Air-Sea Interaction in NYC Urbanized Mesoscale
Modeling for CB Threats

• Julie Pullen Teddy Holt
• Naval Research Laboratory
• Monterey, CA

with Alan Blumberg, SIT Bob Bornstein, SJSU
24 UTC
03 UTC
09 UTC
15 UTC
2
Motivation Ocean Urban Impacts

• Building morphology and heating effects from
  urban areas impact the weather and contaminant
  dispersion

• Local SST gradients due to urban discharges (such
  as power plants), river discharges and coastally
  upwelled water can alter overlying atmosphere
  (e.g., sea breeze fronts)

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Mesoscale Overview

• COAMPS data-assimilating modeling system
• 5 nests (36 km to 0.44 km)
• urbanization and time-varying (hourly) realistic
  SSTs on nests 4 (1.33 km) 5 (0.44 km)

sea breeze forecast (nest 5)
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Model Configuration
N
1
Midtown Manhattan
2
3
4
Brooklyn
Staten Island

• nest 1 (36 km)
• nest 2 (12 km)
• nest 3 (4 km)
• nest 4 (1.33 km)
• nest 5 (0.44 km)

S
Nests 4 5 use an urban canopy parametrization
and hourly time-varying model-derived SSTs
Building height AGL (km)
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Realistic High-Resolution SSTs
nest 4 (1.33 km)
model SST
control SST
Observed SST
control SST
model SST
nest 5 (0.444 km)
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Upwelling-favorable Wind Regime
13 UTC July 4 to 12 UTC July 9
Plumb Beach
ALSN6
Sandy Hook
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Model/Observation Statistics
13 UTC 4 July - 12 UTC 9 July, 2004 (5 days)
Wind speed (m/s) MB RMSE CC
Plumb Beach uses control SST uses model SST -2.16 -1.90 2.79 2.50 0.38 0.39
Sandy Hook uses control SST uses model SST -0.38 -0.16 1.86 1.75 0.49 0.54
ALSN6 uses control SST uses model SST -0.80 -0.42 2.28 2.25 0.63 0.62
Wind speed (m/s) N mean standard dev
Plumb Beach observed uses control SST uses model SST 120 120 120 2.99 5.15 4.89 1.35 1.77 1.60
Sandy Hook observed uses control SST uses model SST 120 120 120 4.56 4.94 4.72 2.01 1.55 1.54
ALSN6 observed uses control SST uses model SST 120 120 120 6.38 7.18 6.80 2.43 2.55 2.64
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Modification of Urban Heat Island
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Offshore Wind Regime
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NYC Mesoscale Modeling
10-m winds 2-m air temperature (C)
12-h forecast valid 00 UTC 5 Aug 2004
COAMPS NYC Nest 5 (0.444 km)
LGA
JFK
ALSN6
Winds every 5th grid point