Eddy‐correlation fluxes are compared to air‐sea fluxes predicted by a widely used bulk flux formulation without wave‐state effects. Systematic discrepancies are found. For example, the model approximately equates the roughness lengths for heat and moisture; however, the observed roughness length for heat (zoh) exceeds that for moisture (zoq) by an...
The 10-m neutral drag coefficient (C[subscript DN10]) over the sea is calculated using a large observational dataset consisting of 5800 estimates of the mean flow and the fluxes from aircraft eddy-covariance measurements. The dataset includes observations from 11 different experiments with four different research aircraft. One of the goals is...
From almost 7000 near-surface eddy-covariance flux measurements over the sea, the authors deduce a new air–sea drag relation for aerodynamically rough flow: u* = 0.0583Uₙ₁₀ 2 0.243. Here u* is the measured friction velocity, and Uₙ₁₀ is the neutral-stability wind speed at a reference height of 10 m. This relation...
This study surveys and evaluates similarity theory for estimating the sea-surface drag coefficient with the bulk aerodynamic method. The most commonly used formulations of the aerodynamic roughness length, required by similarity theory, are examined using data sets from four different field programs. These relationships include the Charnock formulation and the...
An alternative method to Fourier analysis is discussed for studying the scale dependence of variances and covariances in atmospheric boundary layer time series. Unlike Fourier decomposition, the scale dependence based on multiresolution decomposition depends on the scale of the fluctuations and not the periodicity. An example calculation is presented in...
A series of automated tests is developed for tower and aircraft time series to identify instrumentation problems, flux sampling problems, and physically plausible but unusual situations. The automated procedures serve as a safety net for quality controlling data. A number of special flags are developed representing a variety of potential...
Vertical profiles of the time-averaged wind stress, wind speed and buoyancy flux from the off-shore tower site in the Risø Air Sea Experiment are used to evaluate similarity theory in the coastal zone. The observed dependence of the non-dimensional wind shear on stability is compared to the traditional parametrization. Relationships...
Bulk aerodynamic formulas are applied to meteorological data from low-altitude aircraft flights to observational estimates of the subgrid enhancement of momentum, sensible heat, and latent heat the atmospheric–oceanic boundary in light wind, fair weather conditions during TOGA COARE Global Atmosphere Coupled Ocean–Atmosphere Response Experiment). Here, subgrid enhancement the contributions of...
The mixing lengths for heat and momentum are computed from seven levels of eddy correlation data during
the Cooperative Atmosphere–Surface Exchange Study-1999 (CASES-99). A number of formulations of the
mixing length are evaluated, including surface layer similarity theory, several hybrid similarity theories, a
formulation based on the Richardson number, and...
Two distinct nocturnal subcanopy flow regimes are observed beneath a tall (16 m) open pine forest canopy. The first is characterized by weaker mixing, stronger stability, westerly downslope flow decoupled from the flow above the canopy and much smaller than expected ecosystem respiration from the eddy flux plus storage measurements...