Surface characteristics and energy fluxes above different plant canopies

Hurtalova, T.; Matějka, F.

doi:10.1016/s0168-1923(99)00118-5

Cited by 15 publications

(8 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2 which displays the sums of effective soil temperatures above 5 • C in the depth of 0.05 m and describes the dynamics of soil temperatures in the course of time. The presented phenomenon which is related to energy balance and heat flux into the soil for different plant canopies (Hurtalová and Matejka, 1999) was caused by abnormal precipitation, below-average sunshine (sunshine hours) values and high production of biomass. Vegetation cover increased (corrected) the soil surface temperatures at night by reducing convective and radiative heat loss from the ground surface.…”

Section: Resultsmentioning

confidence: 99%

Specifics of soil temperature under winter wheat canopy

Krčmářová

Středová

Pokorný

et al. 2013

Contributions to Geophysics and Geodesy

View full text Add to dashboard Cite

The aim of this study was to evaluate the course of soil temperature under the winter wheat canopy and to determine relationships between soil temperature, air temperature and partly soil moisture. In addition, the aim was to describe the dependence by means of regression equations usable for phytopathological prediction models, crop development, and yield models. The measurement of soil temperatures was performed at the experimental field stationŽabčice (Europe, the Czech Republic, South Moravia). The soil in the first experimental plot is Gleyic Fluvisol with 49-58% of the content particles measuring < 0.01 mm, in the second experimental plot, the soil is Haplic Chernozem with 31-32% of the content particles measuring < 0.01 mm. The course of soil temperature and its specifics were determined under winter wheat canopy during the main growth season in the course of three years. Automatic soil temperature sensors were positioned at three depths (0.05, 0.10 and 0.20 m under soil surface), air temperature sensor in 0.05 m above soil surface. Results of the correlation analysis showed that the best interrelationships between these two variables were achieved after a 3-hour delay for the soil temperature at 0.05 m, 5-hour delay for 0.10 m, and 8-hour delay for 0.20 m. After the time correction, the determination coefficient reached values from 0.75 to 0.89 for the depth of 0.05 m, 0.61 to 0.82 for the depth of 0.10 m, and 0.33 to 0.70 for the depth of 0.20 m. When using multiple regression with quadratic spacing (modeling hourly soil temperature based on the hourly near surface air temperature and hourly soil moisture in the 0.10-0.40 m profile), the difference between the measured and the model soil temperatures at 0.05 m was −2.16 to 2.37 • C. The regression equation paired with alternative agrometeorological instruments enables relatively accurate modeling of soil temperatures (R 2 = 0.93).

show abstract

Section: Resultsmentioning

confidence: 99%

Specifics of soil temperature under winter wheat canopy

Krčmářová

Středová

Pokorný

et al. 2013

Contributions to Geophysics and Geodesy

View full text Add to dashboard Cite

show abstract

“…In these first approaches, the characteristics of the surface elements were used to estimate the roughness parameters for the various canopies. For example, with regard to crop canopies, [42] estimated z 0 according to h and d for harvested wheat; [93] obtained z 0 and d as a function of h for olives orchards; and [41] parameterized z 0 from wind measures using the wind profile. In forests, [100] estimated z 0 and d according to the tree crown and structure, while [63] obtained them from wind observations and canopy structure.…”

Section: Land Cover Databasesmentioning

confidence: 99%

“…Some other works are based on the canopy morphology, such as [12] used in water and saline coverages; [53] in deciduous forests, wetlands and scrubs; and [58] in Aloe Vera crops. Another extended approach is the use of measurements and wind profile: [73] used in cliffs; [13] in screes; [5] in Quaternary lava flow; [18,36,67] in conifers; [83] in rice crops; [41] in crops different from rice; [70] in no citrus fruit Table 2.1: Nominal values and ranges of z 0 and d for the land cover classes provided by SIOSE. The superindex indicates the source:…”

Section: Roughness Length and Displacement Height: Literature Reviewmentioning

confidence: 99%

Characterization of Geographical and Meteorological Parameters

Montero

Rodríguez

Oliver

2018

Wind Field and Solar Radiation Characterization and Forecasting

View full text Add to dashboard Cite

This chapter is devoted to the introduction of some geographical and meteorological information involved in the numerical modeling of wind fields and solar radiation. Firstly, a brief description of the topographical data given by a Digital Elevation Model and Land Cover databases are provided. In particular, the Information System of Land Cover of Spain (SIOSE) is considered. The study is focused in the roughness length and the displacement height parameters that appear in the logarithmic wind profile, as well as in the albedo related to solar radiation computation. An extended literature review and characterization of both parameters are reported. Next, the concept of atmospheric stability is introduced from the Monin-Obukhov similarity theory to the recent revision of Zilitinkevich of the Neutral and Stable Boundary Layers (SBL). The latter considers the effect of the free-flow static stability and baroclinicity on the turbulent transport of momentum and of the Convective Boundary Layers (CBL), more precisely, the scalars in the boundary layer, as well as the model of turbulent entrainment. 2.1 Geographical data The main geographical information for wind and solar radiation modeling may be classified into two general databases, the topographical data related to the orography of the region to be studied and the land cover databases containing the information of the land uses. In this section, both are introduced.

show abstract

“…Mass and energy exchanges at the land surface-atmosphere interface are the most critical components of the climate system (Hurtalová and Matejka 1999), surface latent heat flux (LE) and sensible heat flux (SH) play an especially key role in determining weather and climate at various scales. Therefore, an accurate simulation of LE and SH is of importance to numerical models with regard to weather, climate, hydrology and ecology.…”

Section: Introductionmentioning

confidence: 99%

Seasonal, Diurnal and Wind-Direction-Dependent Variations of the Aerodynamic Roughness Length in Two Typical Forest Ecosystems of China

Zhou¹,

Sun²,

Ju³

et al. 2012

Terr. Atmos. Ocean. Sci.

View full text Add to dashboard Cite

Aerodynamic roughness length (z om ) is an important parameter for reliably simulating surface fluxes. The parameter varies with wind speed, atmospheric stratification, terrain and other factors; however, variations of this parameter are not properly considered in most models, which may result in uncertainties in simulating surface latent heat and sensible heat flux.There have been few studies of the diurnal and wind-direction dependent variations in z om . This study analyzes the seasonal, diurnal and wind-direction-dependent variations in z om calculated from the profile of meteorological data for two forest systems of China, and explores the mechanism underlying these variations.Annually averaged and monthly averaged diurnal variations in z om are obvious and similar at a Changbai Mountain (CBS) site located in northeast China and a Qianyanzhou (QYZ) site located in southeast China. z om is much higher at night than during the day. The diurnal variation in z om is due to a change in atmospheric stratification. The seasonality of z om differs at two sites. z om has sizable seasonal variation and is lower in the leaf-off season than in the growing season at CBS. At QYZ, z om does not have an obvious seasonal pattern. However, at QYZ, the short-term fluctuation is greater than that at CBS. The obvious seasonal variation in z om at CBS is related to the great seasonal change in the leaf area index. The noticeable short-term winddirection-dependent variations in z om at QYZ are attributed to the heterogeneous terrain there.

show abstract

Surface characteristics and energy fluxes above different plant canopies

Cited by 15 publications

References 22 publications

Specifics of soil temperature under winter wheat canopy

Specifics of soil temperature under winter wheat canopy

Characterization of Geographical and Meteorological Parameters

Seasonal, Diurnal and Wind-Direction-Dependent Variations of the Aerodynamic Roughness Length in Two Typical Forest Ecosystems of China

Contact Info

Product

Resources

About