scholarly journals A simple model to estimate air temperature and soil temperatures under vertisol

MAUSAM ◽  
2022 ◽  
Vol 45 (1) ◽  
pp. 69-74
Author(s):  
H. P. DAS ◽  
A. D. PUJARI ◽  
A. CHOWDHURY

Hnscd on a truncated s ine curve and exp onential fu nction models. diu rnal cha nges in airand soil temperat ures have I:....'en estima ted during day and night hours respect!....el..·. Each model uses o nlv fo urparameters. viz.. maximum a nd mini mum temperature at va rious levels. the lime ()f sunset and durat ion t;f da ylnight length. The models. when a pplied to experimental as well as independent dat a sets, were fo und to givereasonably accu rate estimates for a n>' lime of the day an d night except between I·B O1ST and sunset at the gro undsurface.

2004 ◽  
Vol 8 (4) ◽  
pp. 706-716 ◽  
Author(s):  
K. Rankinen ◽  
T. Karvonen ◽  
D. Butterfield

Abstract. Microbial processes in soil are moisture, nutrient and temperature dependent and, consequently, accurate calculation of soil temperature is important for modelling nitrogen processes. Microbial activity in soil occurs even at sub-zero temperatures so that, in northern latitudes, a method to calculate soil temperature under snow cover and in frozen soils is required. This paper describes a new and simple model to calculate daily values for soil temperature at various depths in both frozen and unfrozen soils. The model requires four parameters: average soil thermal conductivity, specific heat capacity of soil, specific heat capacity due to freezing and thawing and an empirical snow parameter. Precipitation, air temperature and snow depth (measured or calculated) are needed as input variables. The proposed model was applied to five sites in different parts of Finland representing different climates and soil types. Observed soil temperatures at depths of 20 and 50 cm (September 1981–August 1990) were used for model calibration. The calibrated model was then tested using observed soil temperatures from September 1990 to August 2001. R2-values of the calibration period varied between 0.87 and 0.96 at a depth of 20 cm and between 0.78 and 0.97 at 50 cm. R2-values of the testing period were between 0.87 and 0.94 at a depth of 20cm, and between 0.80 and 0.98 at 50cm. Thus, despite the simplifications made, the model was able to simulate soil temperature at these study sites. This simple model simulates soil temperature well in the uppermost soil layers where most of the nitrogen processes occur. The small number of parameters required means that the model is suitable for addition to catchment scale models. Keywords: soil temperature, snow model


2013 ◽  
Vol 10 (7) ◽  
pp. 4465-4479 ◽  
Author(s):  
K. L. Hanis ◽  
M. Tenuta ◽  
B. D. Amiro ◽  
T. N. Papakyriakou

Abstract. Ecosystem-scale methane (CH4) flux (FCH4) over a subarctic fen at Churchill, Manitoba, Canada was measured to understand the magnitude of emissions during spring and fall shoulder seasons, and the growing season in relation to physical and biological conditions. FCH4 was measured using eddy covariance with a closed-path analyser in four years (2008–2011). Cumulative measured annual FCH4 (shoulder plus growing seasons) ranged from 3.0 to 9.6 g CH4 m−2 yr−1 among the four study years, with a mean of 6.5 to 7.1 g CH4 m−2 yr−1 depending upon gap-filling method. Soil temperatures to depths of 50 cm and air temperature were highly correlated with FCH4, with near-surface soil temperature at 5 cm most correlated across spring, fall, and the shoulder and growing seasons. The response of FCH4 to soil temperature at the 5 cm depth and air temperature was more than double in spring to that of fall. Emission episodes were generally not observed during spring thaw. Growing season emissions also depended upon soil and air temperatures but the water table also exerted influence, with FCH4 highest when water was 2–13 cm below and lowest when it was at or above the mean peat surface.


2016 ◽  
Author(s):  
Jacques D Charlwood

Background: With the possible implications of global warming, the effect of temperature on the dynamics of malaria vectors in Africa has become a subject of increasing interest. Information from the field is, however, relatively sparse. We describe the effect of ambient temperature over a five-year period on the dynamics of An. funestus and An. gambiae s.l., collected from a single village in southern Mozambique where temperatures varied from a night-time minimum of 6oC in the cool season to a daytime maximum of 35oC in the hot season. Results: Mean daily air temperatures varied from 34o C to 20oC and soil temperatures varied from 26 o C to 12 o C. Diurnal variation was greatest in the cooler months of the year and were greater in air temperatures than soil temperatures. During the study 301, 705 female An. funestus were collected in 6043 light-trap collections, 161, 466 in 7397 exit collections and 16, 995 in 1315 resting collections. The equivalent numbers for An. gambiae s.l. are 72, 475 in light-traps, 33, 868 in exit collections and 5, 333 from indoor resting collections. Numbers of mosquito were greatest in the warmer months. Numbers of An. gambiae s.l. went through a one hundredfold change (from a mean of 0.14 mosquitoes a night to 14) whereas numbers of An. funestus merely doubled (from a mean of 20 to 40 a night). The highest environmental correlations and mosquito numbers were between mean air temperature (r2 = 0.52 for An. funestus and 0.77 for An. gambiae s.l.). Numbers of mosquito collected were not related to rainfall with lags of up to four weeks. Numbers of both gravid and unfed An. gambiae complex females in exit collections continued to increase at all temperatures recorded but gravid females of An. funestus decreased at temperatures above 28oC. Overall the numbers of gravid and unfed An. funestus collected in exit collections were not correlated (p = 0.07). For an unknown reason the number of An. gambiae s.l. fell below monitoring thresholds during the study. Conclusions: Mean air temperature was the most important environmental parameter affecting both vectors in this part of Mozambique. Numbers of An. gambiae s.l. increased at all temperatures recorded whilst An. funestus appeared to be adversely affected by temperatures of 28oC and above. These differences may influence the distribution of the vectors as the planet warms.


1993 ◽  
Vol 9 (3) ◽  
pp. 313-320 ◽  
Author(s):  
Antonio Carlos Miranda ◽  
Heloisa Sinátora Miranda ◽  
Inês de Fátima Oliveira Dias ◽  
Braulio Ferreira de Souza Dias

ABSTRACTAir and soil temperatures were measured during dry season heading fires in three different physiognomic forms of native vegetation common in Central Brazil: cerrado sensu stricto (dense scrub of shrubs and trees), campo cerrado (open scrub), and campo sujo (open grassland with scattered shrubs). The vegetation was protected from fire for 15 y in some areas, had been burned once every two years, and once each year in other areas. The temperatures were measured with type-k thermocouples and recorded at intervals of 22.5 sees. Air temperature measurements were taken at 1, 60 and 160 cm. Maximum air temperatures ranged from 85°C to 840°C, and the duration above 60°C varied from 20 to 270 seconds. In the soil, negligible temperature increases were recorded below 5 cm depth, whereas at 2 cm maximum soil temperatures varied from 29 to 38°C. Possible influences of fuel load and moisture on the recorded data and on the behaviour of fire in the cerrado ecosystems are discussed.


2008 ◽  
Vol 15 (3) ◽  
pp. 409-416 ◽  
Author(s):  
F. Anctil ◽  
A. Pratte ◽  
L. E. Parent ◽  
M. A. Bolinder

Abstract. The objective of this work was to compare time and frequency fluctuations of air and soil temperatures (2-, 5-, 10-, 20- and 50-cm below the soil surface) using the continuous wavelet transform, with a particular emphasis on the daily cycle. The analysis of wavelet power spectra and cross power spectra provided detailed non-stationary accounts with respect to frequencies (or periods) and to time of the structure of the data and also of the relationships that exist between time series. For this particular application to the temperature profile of a soil exposed to frost, both the air temperature and the 2-cm depth soil temperature time series exhibited a dominant power peak at 1-d periodicity, prominent from spring to autumn. This feature was gradually damped as it propagated deeper into the soil and was weak for the 20-cm depth. Influence of the incoming solar radiation was also revealed in the wavelet power spectra analysis by a weaker intensity of the 1-d peak. The principal divergence between air and soil temperatures, besides damping, occurred in winter from the latent heat release associated to the freezing of the soil water and the insulation effect of snowpack that cease the dependence of the soil temperature to the air temperature. Attenuation and phase-shifting of the 1-d periodicity could be quantified through scale-averaged power spectra and time-lag estimations. Air temperature variance was only partly transferred to the 2-cm soil temperature time series and much less so to the 20-cm soil depth.


1952 ◽  
Vol 5 (2) ◽  
pp. 303 ◽  
Author(s):  
ES West

Soil temperatures recorded at Griffith over an 8 year period at a depth ranging from 1 in. to 8 ft. have been examined and compared with air temperatures. The observed fluctuations m the soil temperatures fit closely the theoretical equation for the propagation of a simple harmonic temperature wave into the so11. The diffusivity of the sol1 has been deduced and compared with values found by other workers in other localities. The annual wave of the daily mean temperature at the surface of the soil has been deduced and compared with the annual wave of the dally mean air temperature and the differences in the means, amplitudes, and phase displacements have been discussed.


2019 ◽  
Vol 29 (3) ◽  
pp. 204-209
Author(s):  
Jade Dessent ◽  
Susan Lawler ◽  
Daryl Nielsen

AbstractFuture climate change predictions indicate that there will be an increase in ambient air temperature. Increases in ambient air temperature will result in a corresponding increase in soil temperature. The consequences of further increases in soil temperature will potentially be detrimental for the soil seed bank of plants in terms of length of dormancy and viability of seeds. This experiment investigated the effect of different exposure temperatures and duration of exposure on the germination of semi-aquatic plant species. Seeds of four species (Alternanthera denticulata, Juncus usitatus, Persicaria lapathifolia and Persicaria prostrata) were exposed to temperatures ranging from 25 to 100°C for durations between 1 and 14 days, before being germinated in an incubator for 6 weeks. Germination occurred in all four species after exposure to temperatures ranging from 25 to 60°C. These temperatures appeared to promote germination as the temperature and duration of exposure increased. However, in P. lapathifolia and P. prostrata, the number of seeds germinating declined when exposed to 70°C and there was no germination for temperatures exceeding this. In contrast, A. denticulata and J. usitatus only began to decline when exposed to 80°C, with no germination at higher temperatures. These results suggest that soil temperatures exceeding potential threshold temperatures of 70 and 80°C will result in a decline in the number of seeds germinating and may potentially see a change in species distributions. As such soil temperatures are already being experienced throughout Australia, some species may already be close to their thermal threshold.


2011 ◽  
Vol 2 (1) ◽  
pp. 161-210 ◽  
Author(s):  
D. Wisser ◽  
S. Marchenko ◽  
J. Talbot ◽  
C. Treat ◽  
S. Frolking

Abstract. Northern peatlands contain a large terrestrial carbon pool that plays an important role in the Earth's carbon cycle. A considerable fraction of this carbon pool is currently in permafrost and is biogeochemically relatively inert; this will change with increasing soil temperatures as a result of climate warming in the 21st century. We use a geospatially explicit representation of peat areas and peat depth from a recently-compiled database and a geothermal model to estimate northern North America soil temperature responses to predicted changes in air temperature. We find that, despite a widespread decline in the areas classified as permafrost, soil temperatures in peatlands respond more slowly to increases in air temperature owing to the insulating properties of peat. We estimate that an additional 670 km3 of peat soils in North America, containing ~33 Pg C, could be seasonally thawed by the end of the century, representing ~20% of the total peat volume in Alaska and Canada. Warming conditions result in a lengthening of the soil thaw period by ~40 days, averaged over the model domain. These changes have potentially important implications for the carbon balance of peat soils.


1928 ◽  
Vol 18 (1) ◽  
pp. 90-122 ◽  
Author(s):  
E. McKenzie Taylor

1. The soil temperatures in Egypt at a number of depths have been recorded by means of continuous recording thermometers. In general, the records show that the amplitude of the temperature wave at the surface of the soil is considerably greater than the air temperature wave. There is, however, a considerable damping of the wave with depth, no daily variation in temperature being observed at a depth of 100 cm.2. No definite relation between the air and soil temperatures could be traced. The maximum air temperature was recorded in May and the maximum soil temperature in July.3. The amplitude of the temperature wave decreases with increase in depth. The decrease in amplitude of the soil temperature wave is not regular owing to variations in the physical properties of the soil layers. Between any two depths, the ratio of the amplitudes of the temperature waves is constant throughout the year. The amplitude of the soil temperature wave bears no relation to the amplitude of the air temperature wave.4. The time of maximum temperature at the soil surface is constant throughout the year at 1 p.m. The times of maximum temperature at depths below the surface lag behind the time of surface maximum, but they are constant throughout the year. When plotted against depth, the times of maximum at the various soil depths lie on a straight line.


1986 ◽  
Vol 64 (11) ◽  
pp. 2517-2523 ◽  
Author(s):  
Katherine Hansen-Bristow

Significant differences in growing-season air and soil temperatures were found with increasing elevation in the upper montane and forest–alpine tundra ecotone. Temperature inversions in topographic depressions were frequent, especially during the growing season. Variability in bud flush timing with elevation was best accounted for by soil temperatures; however, air temperature recorded within a mat conifer also correlated well with bud flush timing. Significant differences in shoot elongation, needle length, and cuticular thickness were found with differences in climate and elevational changes.


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