Details

Autor(en) / Beteiligte

• Hicks, Bruce B.
• Pendergrass, William R.
• Vogel, Christoph A.
• Artz, Richard S.

Titel

On the Drag and Heat of Washington, D.C., and New York City

Ist Teil von

• Journal of applied meteorology and climatology, 2014-06, Vol.53 (6), p.1454-1470

Ort / Verlag

Boston: American Meteorological Society

Erscheinungsjahr

2014

Quelle

EZB Free E-Journals

Beschreibungen/Notizen

• Data from a network of micrometeorological instruments, mostly mounted 10m above the roofs of 12 buildings in Washington, D.C., are used to derive average values and spatial differences of the normalized local friction velocity u * / u ≡ ( − u ' w ' ¯ ) 1 / 2 / u (withubeing the wind speed reported at the same height as the covariance is measured,wbeing the vertical wind component, primes indicating deviations, and the overbar indicating averaging). The analysis is extended through consideration of two additional sites in New York City, New York. The ratiou*/uis found to depend on wind direction for all locations. Averaged values ofu*/uappear to be best associated with the standard deviation of local building heights, with little evidence of a dependence on any other of the modern building-morphology indices. Temperature covariance data show a large effect of nearby activities, with the consequences of air-conditioning systems being obvious (especially at night) in some situations. The Washington data show that older buildings, built largely of native limestone, show the greatest effects of air-conditioning systems. The assumption that the nighttime surface boundary layer is stable is likely to be most often incorrect for both Washington and New York City—the sensible heat flux resulting from heating and cooling of building work spaces most often appears to dominate.