scholarly journals Sub-soil temperature variation and estimation of soil heat flux at Pune

MAUSAM ◽  
2021 ◽  
Vol 42 (4) ◽  
pp. 357-360
Author(s):  
A. CHOWDHURY ◽  
H. P. DAS ◽  
A. D. PUJARI
Keyword(s):  
Experimental Data ◽  
Heat Flux ◽  
Soil Temperature ◽  
Temperature Variation ◽  
Heat Balance ◽  
Thermal Wave ◽  
Heat Storage ◽  
Soil Heat Flux ◽  
Temperature Ranges ◽  
Maximum Minimum

Utilising experimental data from 23 November to 8.December 1989. temperature and heat storage variations at Pune have been studied, based on 3 hourly observations.. pattern of penetration of .thermal wave within the soil has been examined and time of occurrence of maximum/minimum temperatures discussed for various depths. Temperature ranges in different layers have been theoretically computed and compared with those based on actual observations. Heat balance at various depths has also been presented and discussed.

scholarly journals A Numerical Model to Estimate the Soil Thermal Conductivity Using Field Experimental Data

2019 ◽  
Vol 9 (22) ◽  
pp. 4799 ◽  
Author(s):  
Leugim Corteze Romio ◽  
Débora Regina Roberti ◽  
Lidiane Buligon ◽  
Tamires Zimmer ◽  
Gervásio Annes Degrazia
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Heat Flux ◽  
Numerical Model ◽  
Soil Temperature ◽  
Field Experiments ◽  
Soil Heat Flux ◽  
Soil Thermal Conductivity ◽  
Empirical Parameter ◽  
Soil Temperature Gradient

Soil thermal conductivity is an important parameter for understanding soil heat transfer. It is difficult to measure in situ with available instruments. This work aims to propose a numerical model to estimate the thermal conductivity from the experimental measurements of soil heat flux and soil temperature. The new numerical model is based on the Fourier Law adding a constant empirical parameter to minimize the uncertainties contained in the data from field experiments. Numerically, the soil thermal conductivity is obtained by experimental linear data fitting by the Least Squares Method (LSM). This method avoids numerical indetermination when the soil temperature gradient or soil heat flux is very close to zero. The new model is tested against the different numerical methodology to estimate the soil heat flux and validated with field experimental data. The results indicate that the proposed model represents the experimental data satisfactorily. In addition, we show the influence of the different methodologies on evaluating the dependence of the thermal conductivity on the soil water content.

scholarly journals Heat storage in forest biomass improves energy balance closure

2010 ◽  
Vol 7 (1) ◽  
pp. 301-313 ◽  
Author(s):  
A. Lindroth ◽  
M. Mölder ◽  
F. Lagergren
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Latent Heat ◽  
Heat Storage ◽  
Soil Heat Flux ◽  
Energy Balance Closure ◽  
Sensible Heat ◽  
Net Radiation ◽  
Tree Biomass ◽  
Stable Conditions

Abstract. Temperature measurements in trunks and branches in a mature ca. 100 years-old mixed pine and spruce forest in central Sweden were used to estimate the heat storage in the tree biomass. The estimated heat flux in the sample trees and data on biomass distributions were used to scale up to stand level biomass heat fluxes. The rate of change of sensible and latent heat storage in the air layer below the level of the flux measurements was estimated from air temperature and humidity profile measurements and soil heat flux was estimated from heat flux plates and soil temperature measurements. The fluxes of sensible and latent heat from the forest were measured with an eddy covariance system in a tower. The analysis was made for a two-month period in summer of 1995. The tree biomass heat flux was the largest of the estimated storage components and varied between 40 and −35 W m−2 on summer days with nice weather. Averaged over two months the diurnal maximum of total heat storage was 45 W m−2 and the minimum was −35 W m−2. The soil heat flux and the sensible heat storage in air were out of phase with the biomass flux and they reached maximum values that were about 75% of the maximum of the tree biomass heat storage. The energy balance closure improved significantly when the total heat storage was added to the turbulent fluxes. The slope of a regression line with sum of fluxes and storage as independent and net radiation as dependent variable, increased from 0.86 to 0.95 for half-hourly data and the scatter was also reduced. The most significant finding was, however, that during nights with strongly stable conditions when the sensible heat flux dropped to nearly zero, the total storage matched the net radiation very well. Another interesting result was that the mean energy imbalance started to increase when the Richardson number became more negative than ca. −0.1. In fact, the largest energy deficit occurred at maximum instability. Our conclusion is that eddy covariance measurements can function well during stable conditions but that the functioning under strong instabilities might be a so far unforeseen problem.

scholarly journals Fluxo de calor no solo modelado a partir de dados de temperatura em dois níveis de profundidade em uma floresta tropical na Amazônia Ocidental

2018 ◽  
Vol 40 ◽  
pp. 138
Author(s):  
Antônio Vinicius do Prado Rodrigues ◽  
Nelma Tavares Dias Soares ◽  
Renata Gonçalves Aguiar ◽  
Alberto Dresch Webler ◽  
Bruno Soares de Castro
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Soil Temperature ◽  
Tropical Forest ◽  
Large Scale ◽  
Energy Exchange ◽  
Global Climate ◽  
Soil Heat Flux ◽  
Measured Data ◽  
Biological Reserve

The global climate is dependent of ecological balance of forests, especially tropical. The heat flux in the soil is an important factor in studies of energy balance representing the main form of energy exchange between soil and atmosphere. The aim of the present work was to estimate soil heat flux using soil temperature measurements at two depth levels in a tropical forest in the Western Amazon, in order to obtain coherent data for both the use of the values and for the filling of failures in database. Had been used data on temperature and soil heat flux collected in a micrometeorological tower belonging to the towers network of the Large Scale Biosphere-Atmosphere Program in the Amazon, located in the Jaru Biological Reserve. The estimated data presented 94% agreement with the measured data, the two have similar behaviors that allow the use in filling of failures in a demonstrative way. However, there is a delay in the estimated values of the heat flux in the soil in relation to the measured one, which interferes in the result of the model, provoking more studies to improve it.

scholarly journals Promotion of surface energy closure by monitoring tree biomass heat storage

2016 ◽  
Author(s):  
Minghan Yu ◽  
Guodong Ding ◽  
Guanglei Gao ◽  
Yuanyuan Zhao ◽  
Ke Sai ◽  
...  
Keyword(s):  
Heat Flux ◽  
Surface Energy ◽  
Forest Ecosystems ◽  
Heat Storage ◽  
Significant Proportion ◽  
Soil Heat Flux ◽  
Energy Budgets ◽  
Time Lags ◽  
Tree Biomass ◽  
Latent Heat Storage

Biomass heat storage is important for promoting energy closure in forest ecosystems; however, this issue is often ignored in surface energy budgets. To determine an accurate approach to calculate biomass heat storage, we monitored the stem temperature of Pinus sylvestris in different heights, depths and orientations. At the same time, air sensible and latent heat storage and soil heat storage are also monitored together with biomass heat storage to study the heat storage share in surface energy budgets. The results showed that (1) temperature in different heights, depths and orientations in stem showed obviously differences dynamics, and time lags are existed between different measuring points inside stem. (2) Tree biomass heat flux varied around 12 W m−2. Soil heat flux and air heat storage were around 20 W m−2 and 8 W m−2 separately, but out of phase with biomass heat flux. (3) Total heat storage in soil, biomass, and air was 60 W m −2 , accounting for ~10% of net radiation, which is a significant proportion of the total energy flux. This study will help improve biomass heat storage models and contribute to fundamental knowledge regarding energy balance closure in forest ecosystems.

scholarly journals Heat storage in forest biomass significantly improves energy balance closure particularly during stable conditions

2009 ◽  
Vol 6 (4) ◽  
pp. 8531-8567
Author(s):  
A. Lindroth ◽  
M. Mölder ◽  
F. Lagergren
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Latent Heat ◽  
Heat Storage ◽  
Soil Heat Flux ◽  
Energy Balance Closure ◽  
Sensible Heat ◽  
Net Radiation ◽  
Tree Biomass ◽  
Stable Conditions

Abstract. Temperature measurements in trunks and branches in a mature ca. 100 years-old mixed pine and spruce forest in central Sweden were used to estimate the heat storage in the tree biomass. The estimated heat flux in the sample trees and data on biomass distributions were used to scale up to stand level biomass heat fluxes. The rate of change of sensible and latent heat storage in the air layer below the level of the flux measurements was estimated from air temperature and humidity profile measurements and soil heat flux was estimated from heat flux plates and soil temperature measurements. The fluxes of sensible and latent heat from the forest were measured with an eddy covariance system in a tower. The analysis was made for a two-month period in summer of 1995. The tree biomass heat flux was the largest of the estimated storage components and varied between 40 and −35 W m−2 on summer days with nice weather. Averaged over two months the diurnal maximum of total heat storage was 45 W m−2 and the minimum was −35 W m−2. The soil heat flux and the sensible heat storage in air were out of phase with the biomass flux and they reached maximum values that were about 75% of the maximum of the tree biomass heat storage. The energy balance closure improved significantly when the total heat storage was added to the turbulent fluxes. The slope of a regression line with sum of fluxes and storage as independent and net radiation as dependent variable, increased from 0.86 to 0.95 for half-hourly data and the scatter was also reduced. The most significant finding was, however, that during nights with strongly stable conditions when the sensible heat flux dropped to nearly zero, the total storage matched the net radiation nearly perfectly. Another interesting result was that the mean energy imbalance started to increase when the Richardson number became more negative than ca. −0.1. In fact, the largest energy deficit occurred at maximum instability. Our conclusion is that eddy covariance measurements can function well during stable conditions but that the functioning under strong instabilities might be a so far unforeseen problem.

scholarly journals Promotion of surface energy closure by monitoring tree biomass heat storage

2016 ◽  
Author(s):  
Minghan Yu ◽  
Guodong Ding ◽  
Guanglei Gao ◽  
Yuanyuan Zhao ◽  
Ke Sai ◽  
...  
Keyword(s):  
Heat Flux ◽  
Surface Energy ◽  
Forest Ecosystems ◽  
Heat Storage ◽  
Significant Proportion ◽  
Soil Heat Flux ◽  
Energy Budgets ◽  
Time Lags ◽  
Tree Biomass ◽  
Latent Heat Storage

Biomass heat storage is important for promoting energy closure in forest ecosystems; however, this issue is often ignored in surface energy budgets. To determine an accurate approach to calculate biomass heat storage, we monitored the stem temperature of Pinus sylvestris in different heights, depths and orientations. At the same time, air sensible and latent heat storage and soil heat storage are also monitored together with biomass heat storage to study the heat storage share in surface energy budgets. The results showed that (1) temperature in different heights, depths and orientations in stem showed obviously differences dynamics, and time lags are existed between different measuring points inside stem. (2) Tree biomass heat flux varied around 12 W m−2. Soil heat flux and air heat storage were around 20 W m−2 and 8 W m−2 separately, but out of phase with biomass heat flux. (3) Total heat storage in soil, biomass, and air was 60 W m −2 , accounting for ~10% of net radiation, which is a significant proportion of the total energy flux. This study will help improve biomass heat storage models and contribute to fundamental knowledge regarding energy balance closure in forest ecosystems.

scholarly journals Ramdas layer and thermal wave during winter period

MAUSAM ◽  
2022 ◽  
Vol 52 (4) ◽  
pp. 697-702
Author(s):  
S. ABRAHAM THAMBI RAJA ◽  
G. RENUKA ◽  
K. RETNAKUMARI
Keyword(s):  
Mathematical Model ◽  
Heat Flux ◽  
Energy Balance ◽  
Thermal Wave ◽  
Soil Surface ◽  
Soil Heat Flux ◽  
Rate Of Change ◽  
Winter Period ◽  
Maximum Height ◽  
Lower Height

Earlier works on Ramdas Layer were about its certainty, its existence, energy balance on the layer and a matching mathematical model. We, first identified it in Thiruvananthapuram, Kerala, for eight days during a fortnight study on soil heat flux. A lifted minimum in temperature could have implications in agriculture and horticulture and so with a view to finding out a range of height through which Ramdas layer occurs, Ramdas-max, Ramdas-min are identified. On 24 January 1994, Ramdas layer occurred at a maximum height of 0.8m from the surface and the day is labeled as Ramdas-max. On 1 February 1994, it occurred at a lower height of 0.4m from the surface and the day is labeled as Ramdas-min.   The thermal wave at the ground and at 0.05m depth, the range of thermal wave, its relationship with Ramdas layer, the temperature profile, the rate of change of heat in that layer with that at the surface and the subsoil heat flux at the sub-soil surface stratum(surface-0.05m) during R~mdas-max and Ramdas-min are duly compared and discussed.

scholarly journals Análise Comparativa do Fluxo de Calor no Solo em Profundidade e na Superfície (Brazil Comparative Analysis of Soil Heat Flux in Depth and Surface)

2013 ◽  
Vol 6 (4) ◽  
pp. 665
Author(s):  
Willames Albuquerque Soares
Keyword(s):  
Heat Flux ◽  
Comparative Analysis ◽  
Thermal Diffusivity ◽  
Heat Flow ◽  
Soil Temperature ◽  
Soil Surface ◽  
Soil Heat Flux ◽  
Clear Sky ◽  
Harmonic Method ◽  
Sky Conditions

O objetivo deste estudo é comparar os resultados do fluxo de calor no solo, na superfície e em profundidade, encontrados por sensores de fluxo de calor no solo e pelo método harmônico, em cultivo de mamoneira. No dia sem chuvas, a pouca quantidade de água no solo diminuiu a sua difusividade térmica, provocando um maior acúmulo de energia no solo, e, consequentemente, a elevação na temperatura nas camadas mais próximas à superfície. As principais diferenças entre os valores medidos e estimados aconteceram nos horários de maior insolação, principalmente nos dias em que o céu estava encoberto por nuvens. A presença da vegetação cobrindo o solo influenciou diretamente nos valores medidos e modelados. As estimativas tanto em profundidade como para a superfície do solo se mostraram bastante satisfatórias, tanto em dias de céu claro como para dias de céu encoberto.     A B S T R A C T The aim of this study was to compare the results of soil heat flow, in the surface and depth, found by sensors soil heat flux and by harmonic method, in castor  crop . On days without rainfall, the small amounts of water in the soil decreased its thermal diffusivity, causing a higher energy accumulation in the soil and consequently an increase at a temperature on the layers nearest the surface. The main differences between the measured and estimated values occurred at times of intense sunlight, especially on days when the sky was obscured by clouds. The presence of vegetation covering the soil directly influenced the values measured and modeled. Estimates both in depth and to the soil surface proved very satisfactory, both in clear sky conditions as for overcast days.   Key-Words: Harmonic Method, Soil temperature, soil heat flux plates.

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