Temporal Variations in the Surface Soil Heat Flux over Maize and Grass Surfaces in Northwest China

Abstract Widely used in croplands, plastic mulch can significantly change land surface properties and energy partitioning. However, the magnitude of these modifications caused by plastic mulch (and its variations) on leaf area index remain largely unclear. Field experiments were, therefore, conducted to analyse the differences in energy partitioning between plastic mulch and non-plastic mulch conditions in cotton fields in arid Tarim Basin. Each component net radiation, surface soil heat flux, sensible heat and latent heat was either measured or estimated at different growth stages of the cotton crop. Results showed that the effects of plastic mulch on field energy partitioning was most evident when leaf area index was less than 1.0. During this period, net radiation decreased mainly due to the increase of surface reflectance. Surface soil heat flux and sensible heat were also increased due to the increase of surface temperature. Finally, latent heat decreased after plastic mulch application. As over 20% of net radiation was allocated to the soil surface under plastic mulch at the seedling stage, this suggests that surface soil heat flux should not be ignored for evaluating surface energy balance at the seedling stage under plastic mulch conditions.

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Deriving the Surface Soil Heat Flux from Observed Soil Temperature and Soil Heat Flux Profiles Using a Variational Data Assimilation Approach

Journal of Applied Meteorology and Climatology ◽

10.1175/2008jamc1930.1 ◽

2009 ◽

Vol 48 (3) ◽

pp. 644-656 ◽

Cited By ~ 5

Author(s):

R. J. Ronda ◽

F. C. Bosveld

Keyword(s):

Heat Flux ◽

Data Assimilation ◽

Soil Temperature ◽

Surface Soil ◽

Soil Column ◽

Soil Heat Flux ◽

Variational Data Assimilation ◽

Shortwave Radiation ◽

Model Parameters ◽

Vegetation Canopy

Abstract A novel approach to infer surface soil heat fluxes from measured profiles of soil temperature, soil heat flux, and observations of the vegetation canopy temperature and the incoming shortwave radiation is evaluated for the Cabauw measurement facility in the Netherlands. The approach is a variational data assimilation approach that uses the applied measurements to optimize, on a daily basis, parameter values of a model that describes the heat transport between the vegetation canopy and the surface and within the soil column. Insertion of error characteristics that either are inferred from the field data themselves or are derived from literature leads to valid estimates of the cost function for about 100 days in 2003. The approach gives values of the model parameters that compare well to values derived from the literature, although values for the soil conductivity and the volumetric heat capacity of the soil start to differ from the literature values at the end of 2003, possibly because of specific soil characteristics and the extreme dryness of the summer of 2003. The model gives estimates of the surface soil heat flux that compare well to estimates using the currently operational lambda approach, provided that the latter is adapted to account for the disturbance of the soil heat flux at the locations of the heat flux plates. Only when the surface soil heat flux is very small or very large does the new approach give estimates of the surface soil heat flux that differ from those obtained with the lambda approach.

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Diurnal Variation of Soil Heat Flux at an Antarctic Local Area during Warmer Months

Applied and Environmental Soil Science ◽

10.1155/2016/1769203 ◽

2016 ◽

Vol 2016 ◽

pp. 1-9 ◽

Cited By ~ 3

Author(s):

Marco Alves ◽

Jacyra Soares

Keyword(s):

Heat Flux ◽

Heat Source ◽

Energy Flux ◽

Surface Soil ◽

Local Area ◽

Soil Heat Flux ◽

Energy Balance Equation ◽

Night Time ◽

Simple Method ◽

Soil Layers

Soil heat flux (G) is one term in the energy balance equation, and it can be particularly important in regions with arid, bare, or thinly vegetated soil surfaces. However, in remote areas such as the Antarctic, this measurement is not routinely performed. The analysis of observational data collected by the ETA Project at the Brazilian Antarctic Station from December 2013 to March 2014 showed that, for the total daily energy flux, the surface soil flux heats the deeper soil layers during December and January andGacts as a heat source to the outer soil layers during February and March. With regard to daytime energy flux,Gacts as a source of heat to the deeper layers. During the night-time, the soil is a heat source to the shallower soil layers and represents at least 29% of the net night-time radiation. A relatively simple method—the objective hysteresis method (OHM)—was successfully applied to determine the surface soil heat flux using net radiation observations.A priori, the OHM coefficients obtained in this study may only be used for short-time parameterizations and for filling data gaps at this specific site.

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