Comparison of Evapotranspiration from Alfalfa Estimated by Soil Moisture Depletion (Neutron and Capacitance Probes), Surface Renewal Analysis of Sensible Heat Flux and Production Function Yield Loss.

2008 ◽  
Author(s):  
Blake L Sanden ◽  
B R Hanson ◽  
R L Snyder ◽  
D H Putnam
Keyword(s):  
Heat Flux ◽  
Soil Moisture ◽  
Production Function ◽  
Yield Loss ◽  
Sensible Heat Flux ◽  
Sensible Heat ◽  
Surface Renewal

<i>Estimating sensible heat flux from Camellia sinensis using the Surface renewal method</i>

2019 ◽  
Author(s):  
Noman Ali Buttar ◽  
Yongguang Hu ◽  
Imran Ali Lakhiar ◽  
Ahmad Azeem ◽  
Muhammad Zaman ◽  
...  
Keyword(s):  
Heat Flux ◽  
Camellia Sinensis ◽  
Sensible Heat Flux ◽  
Sensible Heat ◽  
Surface Renewal ◽  
Renewal Method

Latent and sensible heat flux predictions from a uniform pine forest using surface renewal and flux variance methods

1996 ◽  
Vol 80 (3) ◽  
pp. 249-282 ◽  
Author(s):  
Gabriel Katul ◽  
Cheng-I Hsieh ◽  
Ram Oren ◽  
David Ellsworth ◽  
Nathan Phillips
Keyword(s):  
Heat Flux ◽  
Sensible Heat Flux ◽  
Pine Forest ◽  
Sensible Heat ◽  
Surface Renewal

Studies on lichen-dominated systems. XX. An examination of some aspects of the northern boreal lichen woodlands in Canada

1977 ◽  
Vol 55 (4) ◽  
pp. 393-410 ◽  
Author(s):  
K. A. Kershaw
Keyword(s):  
Heat Flux ◽  
Soil Moisture ◽  
Latent Heat ◽  
Latent Heat Flux ◽  
Higher Plants ◽  
Sensible Heat Flux ◽  
Subsequent Development ◽  
Sensible Heat ◽  
Early Recovery ◽  
Lichen Woodland

The existence of two major types of lichen woodland in Canada, Cladonia stellaris woodland and Stereocaulon paschale woodland, is discussed in relation to their seral nature and their rarely developed theoretical climax type.Our own observations, coupled with previous descriptions from a wider area, suggest that Stereocaulon paschale woodland replaces Cladonia stellaris woodland in a more or less continuous zone from just west of Churchill across to Great Slave Lake, immediately north and south of latitude 60° N. Both woodland types are often typical of sandy soils (pH 6 or less) and almost always represent the final recovery phase after fire. Rarely, the lichen surface is replaced by a continuous moss cover as the spruce canopy closes. The lichen surface is thus dependent on the lack of competition from higher plants, the absence of which is characteristic of the climate of this northern boreal region. Cladonia stellaris woodland also occurs on palsas and peat plateaux where, again, lack of higher plant competition and a suitable pH exist.The recovery sequence after fire is a highly complex process and as yet only the following parameters have been categorized. In the early recovery phases, limited soil moisture and hence a reduced summer latent heat flux enhance the sensible heat flux. The surface conditions are analogous to those of a hot desert with very high surface temperatures and extremely large diurnal temperature fluctuations. The physiology of these initial moss and lichen colonizers presumably enables them to tolerate these harsh conditions. The establishment of a few spruce seedlings and the subsequent development of open lichen woodland modulates the harsh summer temperature regime and allows the further development of a vegetated surface. After humus accumulation, which acts as an effective mulch, summer soil moisture is elevated, enhancing the latent heat flux and correspondingly reducing the sensible heat flux. This probably allows the full development of mature lichen woodland with its almost monospecific ground cover of either Cladonia stellaris or Stereocaulon paschale. Limited data suggest that the net photosynthetic responses of these two species is favoured by the relatively warm mesic conditions established by the open spruce canopy. Good accumulation of snow in the winter is probably also important for protection of the lichen surface from low temperatures. The open nature of mature lichen woodland is apparently maintained by an active inhibition of spruce seedling establishment by the lichen mat, although the mechanism is not entirely clear.

scholarly journals How Does Soil Moisture Influence the Early Stages of the South American Monsoon?

2008 ◽  
Vol 21 (2) ◽  
pp. 195-213 ◽  
Author(s):  
Estela A. Collini ◽  
Ernesto H. Berbery ◽  
Vicente R. Barros ◽  
Matthew E. Pyle
Keyword(s):  
Boundary Layer ◽  
Heat Flux ◽  
Soil Moisture ◽  
Latent Heat ◽  
Sensible Heat Flux ◽  
South American ◽  
Sensible Heat ◽  
The South ◽  
Early Stages ◽  
Initial Soil

Abstract This article discusses the feedbacks between soil moisture and precipitation during the early stages of the South American monsoon. The system achieves maximum precipitation over the southern Amazon basin and the Brazilian highlands during the austral summer. Monsoon changes are associated with the large-scale dynamics, but during its early stages, when the surface is not sufficiently wet, soil moisture anomalies may also modulate the development of precipitation. To investigate this, sensitivity experiments to initial soil moisture conditions were performed using month-long simulations with the regional mesoscale Eta model. Examination of the control simulations shows that they reproduce all major features and magnitudes of the South American circulation and precipitation patterns, particularly those of the monsoon. The surface sensible and latent heat fluxes, as well as precipitation, have a diurnal cycle whose phase is consistent with previous observational studies. The convective inhibition is smallest at the time of the precipitation maximum, but the convective available potential energy exhibits an unrealistic morning maximum that may result from an early boundary layer mixing. The sensitivity experiments show that precipitation is more responsive to reductions of soil moisture than to increases, suggesting that although the soil is not too wet, it is sufficiently humid to easily reach levels where soil moisture anomalies stop being effective in altering the evapotranspiration and other surface and boundary layer variables. Two mechanisms by which soil moisture has a positive feedback with precipitation are discussed. First, the reduction of initial soil moisture leads to a smaller latent heat flux and a larger sensible heat flux, and both contribute to a larger Bowen ratio. The smaller evapotranspiration and increased sensible heat flux lead to a drier and warmer boundary layer, which in turn reduces the atmospheric instability. Second, the deeper (and drier) boundary layer is related to a stronger and higher South American low-level jet (SALLJ). However, because of the lesser moisture content, the SALLJ carries less moisture to the monsoon region, as evidenced by the reduced moisture fluxes and their convergence. The two mechanisms—reduced convective instability and reduced moisture flux convergence—act concurrently to diminish the core monsoon precipitation.

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