Monin–Obukhov Similarity Functions for the Structure Parameters of Temperature and Humidity

Li, Dan; Bou‐Zeid, Elie; Bruin, H.A.R. de

doi:10.1007/s10546-011-9660-y

Cited by 77 publications

(87 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As was shown by Maronga (2014), C 2 q no longer follows MOST if this ratio >1. The entrainment of dry air is then the dominant process that affects C 2 q in the surface layer, in agreement with the assumption of Li et al (2012). The present study supports this finding so that it is impossible to derive a value for A q .…”

Section: Monin-obkuhov Similarity Relationshipssupporting

confidence: 89%

“…However, often it is found that R T q = 1 (e.g. Beyrich et al 2005) and it was shown by Li et al (2012) and Maronga (2014) that f T = f q can be observed in such situations. The latter showed that C 2 T usually follows MOST, whereas C 2 q is often affected by entrainment of dry air at the top of the mixed layer and thus does not follow MOST.…”

Section: Monin-obukhov Similarity Relationshipsmentioning

confidence: 99%

“…If both C 2 T and C 2 q follow MOST, then f T and f q should be universal functions of z/L. So far it has not been possible to derive a precise form for f T and f q , but several empirical formulations have been proposed for unstable conditions from experimental data (Wyngaard et al 1971b;Wesely 1976;Andreas 1988;Thiermann and Grassl 1992;Hill et al 1992;De Bruin et al 1993;Li et al 2012). Most suggest the following form…”

Section: Monin-obukhov Similarity Relationshipsmentioning

confidence: 99%

“…Much more data points for conditions with higher geostrophic winds and lower surface fluxes would be required in order to cover the whole stability range from free convective down to near-neutral conditions with −z/L ≈ 0.01 (see e.g. Li et al 2012). Nevertheless, we can derive the function f T from this dataset.…”

Section: Monin-obkuhov Similarity Relationshipsmentioning

confidence: 99%

“…The measurement of the area-averaged fluxes at a regional scale is necessary both for a better understanding of the meteorological and hydrological processes as well as for the validation of parametrizations in numerical weather prediction (NWP) and climate models (De Bruin et al 1993;Li et al 2012;Beyrich et al 2012;Braam et al 2012). The grid resolution in NWP models is usually of the size of several km.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

The Effect of Surface Heterogeneity on the Structure Parameters of Temperature and Specific Humidity: A Large-Eddy Simulation Case Study for the LITFASS-2003 Experiment

Maronga

Hartogensis

Raasch

et al. 2014

Boundary-Layer Meteorol

View full text Add to dashboard Cite

We conduct a high-resolution large-eddy simulation (LES) case study in order to investigate the effects of surface heterogeneity on the (local) structure parameters of potential temperature C 2 T and specific humidity C 2 q in the convective boundary layer (CBL). The kilometre-scale heterogeneous land-use distribution as observed during the LITFASS-2003 experiment was prescribed at the surface of the LES model in order to simulate a realistic CBL development from the early morning until early afternoon. The surface patches are irregularly distributed and represent different land-use types that exhibit different roughness conditions as well as near-surface fluxes of sensible and latent heat. In the analysis, particular attention is given to the Monin-Obukhov similarity theory (MOST) relationships and local free convection (LFC) scaling for structure parameters in the surface layer, relating C 2 T and C 2 q to the surface fluxes of sensible and latent heat, respectively. Moreover we study possible effects of surface heterogeneity on scintillometer measurements that are usually performed in the surface layer. The LES data show that the local structure parameters reflect the surface heterogeneity pattern up to heights of 100-200 m. The assumption of a blending height, i.e. the height above the surface where the surface heterogeneity pattern is no longer visible in the structure parameters, is studied by means of a two-dimensional correlation analysis. We show that no such blending height is found at typical heights of scintillometer measurements for the studied case. Moreover, C 2 q does not follow MOST, which is ascribed to the entrainment of dry air at the top of the boundary layer. The application of MOST and LFC scaling to elevated C 2 T data still gives reliable estimates of the surface sensible heat flux. We show, however, that this flux, derived from scintillometer data, is only representative of the footprint area of the scintillometer, whose size depends strongly on the synoptic conditions.

show abstract

Section: Monin-obkuhov Similarity Relationshipssupporting

confidence: 89%

Section: Monin-obukhov Similarity Relationshipsmentioning

confidence: 99%

Section: Monin-obukhov Similarity Relationshipsmentioning

confidence: 99%

Section: Monin-obkuhov Similarity Relationshipsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

The Effect of Surface Heterogeneity on the Structure Parameters of Temperature and Specific Humidity: A Large-Eddy Simulation Case Study for the LITFASS-2003 Experiment

Maronga

Hartogensis

Raasch

et al. 2014

Boundary-Layer Meteorol

View full text Add to dashboard Cite

show abstract

Contribution of impervious surfaces to urban evaporation

Ramamurthy

Bou‐Zeid

2014

Water Resources Research

105

View full text Add to dashboard Cite

Observational data and the Princeton urban canopy model, with its detailed representation of urban heterogeneity and hydrological processes, are combined to study evaporation and turbulent water vapor transport over urban areas. The analyses focus on periods before and after precipitation events, at two sites in the Northeastern United States. Our results indicate that while evaporation from concrete pavements, building rooftops, and asphalt surfaces is discontinuous and intermittent, overall these surfaces accounted for nearly 18% of total latent heat fluxes (LE) during a relatively wet 10 day period. More importantly, these evaporative fluxes have a significant impact on the urban surface energy balance, particularly during the 48 h following a rain event when impervious evaporation is the highest. Thus, their accurate representation in urban models is critical. Impervious evaporation after rainfall is also shown to correlate the sources of heat and water at the earth surface, resulting in a conditional scalar transport similarity over urban terrain following rain events.

show abstract

On the variability of the Priestley‐Taylor coefficient over water bodies

Assouline

Tyler

et al. 2016

Water Resources Research

Self Cite

View full text Add to dashboard Cite

Deviations in the Priestley-Taylor (PT) coefficient a PT from its accepted 1.26 value are analyzed over large lakes, reservoirs, and wetlands where stomatal or soil controls are minimal or absent. The data sets feature wide variations in water body sizes and climatic conditions. Neither surface temperature nor sensible heat flux variations alone, which proved successful in characterizing a PT variations over some crops, explain measured deviations in a PT over water. It is shown that the relative transport efficiency of turbulent heat and water vapor is key to explaining variations in a PT over water surfaces, thereby offering a new perspective over the concept of minimal advection or entrainment introduced by PT. Methods that allow the determination of a PT based on low-frequency sampling (i.e., 0.1 Hz) are then developed and tested, which are usable with standard meteorological sensors that filter some but not all turbulent fluctuations. Using approximations to the Gram determinant inequality, the relative transport efficiency is derived as a function of the correlation coefficient between temperature and water vapor concentration fluctuations (R Tq ). The proposed approach reasonably explains the measured deviations from the conventional a PT 5 1.26 value even when R Tq is determined from air temperature and water vapor concentration time series that are Gaussian-filtered and subsampled to a cutoff frequency of 0.1 Hz. Because over water bodies, R Tq deviations from unity are often associated with advection and/or entrainment, linkages between a PT and R Tq offer both a diagnostic approach to assess their significance and a prognostic approach to correct the 1.26 value when using routine meteorological measurements of temperature and humidity.

show abstract

Monin–Obukhov Similarity Functions for the Structure Parameters of Temperature and Humidity

Cited by 77 publications

References 62 publications

The Effect of Surface Heterogeneity on the Structure Parameters of Temperature and Specific Humidity: A Large-Eddy Simulation Case Study for the LITFASS-2003 Experiment

The Effect of Surface Heterogeneity on the Structure Parameters of Temperature and Specific Humidity: A Large-Eddy Simulation Case Study for the LITFASS-2003 Experiment

Contribution of impervious surfaces to urban evaporation

On the variability of the Priestley‐Taylor coefficient over water bodies

Contact Info

Product

Resources

About