scholarly journals Specifics of soil temperature under winter wheat canopy

2013 ◽  
Vol 43 (3) ◽  
pp. 209-223 ◽  
Author(s):  
Jana Krčmáŕová ◽  
Hana Stredová ◽  
Radovan Pokorný ◽  
Tomáš Stdŕeda
Keyword(s):  
Soil Moisture ◽  
Winter Wheat ◽  
Soil Temperature ◽  
Air Temperature ◽  
Surface Air Temperature ◽  
Soil Surface ◽  
Regression Equations ◽  
Experimental Plot ◽  
Near Surface ◽  
Soil Temperatures

Abstract 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 station ˇZabˇcice (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 (R2 = 0.93).

scholarly journals Specifics of soil temperature under winter oilseed rape canopy

2014 ◽  
Vol 44 (3) ◽  
pp. 205-218
Author(s):  
Jana Krčmářová ◽  
Tomáš Středa ◽  
Radovan Pokorný
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Oilseed Rape ◽  
Air Temperature ◽  
Surface Air Temperature ◽  
Regression Equations ◽  
Winter Oilseed Rape ◽  
Determination Coefficient ◽  
Soil Temperatures ◽  
Dwarf Variety

Abstract The aim of this study was to evaluate the course of soil temperature under the winter oilseed rape 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 pests and pathogens prediction, crop development, and yields models. The measurement of soil and near the ground air temperatures was performed at the experimental field Žabiče (South Moravia, the Czech Republic). The course of temperature was determined under or in the winter oilseed rape canopy during spring growth season in the course of four years (2010 - 2012 and 2014). In all years, the standard varieties (Petrol, Sherpa) were grown, in 2014 the semi-dwarf variety PX104 was added. Automatic soil sensors were positioned at three depths (0.05, 0.10 and 0.20 m) under soil surface, air temperature sensors in 0.05 m above soil surfaces. The course of soil temperature differs significantly between standard (Sherpa and Petrol) and semi-dwarf (PX104) varieties. Results of the cross correlation analysis showed, that the best interrelationships between air and soil temperature were achieved in 2 hours delay for the soil temperature in 0.05 m, 4 hour delay for 0.10 m and 7 hour delay for 0.20 m for standard varieties. For semi-dwarf variety, this delay reached 6 hour for the soil temperature in 0.05 m, 7 hour delay for 0.10 m and 11 hour for 0.20 m. After the time correction, the determination coefficient (R2) reached values from 0.67 to 0.95 for 0.05 m, 0.50 to 0.84 for 0.10 m in variety Sherpa during all experimental years. For variety PX104 this coefficient reached values from 0.51 to 0.72 in 0.05 m depth and from 0.39 to 0.67 in 0.10 m depth in the year 2014. The determination coefficient in the 0.20 m depth was lower for both varieties; its values were from 0.15 to 0.65 in variety Sherpa. In variety PX104 the values of R2 from 0.23 to 0.57 were determined. When using multiple regressions with quadratic spacing (modelling of 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 modelled soil temperatures in the depth of 0.05 m was -3.92 to 3.99°C. The regression equation paired with alternative agrometeorological instruments enables relatively accurate modelling of soil temperatures (R2 = 0.95).

scholarly journals Evaluation and Comparison of Noah and Pleim–Xiu Land Surface Models in MM5 Using GÖTE2001 Data: Spatial and Temporal Variations in Near-Surface Air Temperature

2007 ◽  
Vol 46 (10) ◽  
pp. 1587-1605 ◽  
Author(s):  
J-F. Miao ◽  
D. Chen ◽  
K. Borne
Keyword(s):  
Soil Moisture ◽  
Air Temperature ◽  
Land Surface ◽  
Model Performance ◽  
Surface Air Temperature ◽  
Near Surface ◽  
Surface Models ◽  
Urban Heat ◽  
Soil Moisture Initialization ◽  
Evident Difference

Abstract In this study, the performance of two advanced land surface models (LSMs; Noah LSM and Pleim–Xiu LSM) coupled with the fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5), version 3.7.2, in simulating the near-surface air temperature in the greater Göteborg area in Sweden is evaluated and compared using the GÖTE2001 field campaign data. Further, the effects of different planetary boundary layer schemes [Eta and Medium-Range Forecast (MRF) PBLs] for Noah LSM and soil moisture initialization approaches for Pleim–Xiu LSM are investigated. The investigation focuses on the evaluation and comparison of diurnal cycle intensity and maximum and minimum temperatures, as well as the urban heat island during the daytime and nighttime under the clear-sky and cloudy/rainy weather conditions for different experimental schemes. The results indicate that 1) there is an evident difference between Noah LSM and Pleim–Xiu LSM in simulating the near-surface air temperature, especially in the modeled urban heat island; 2) there is no evident difference in the model performance between the Eta PBL and MRF PBL coupled with the Noah LSM; and 3) soil moisture initialization is of crucial importance for model performance in the Pleim–Xiu LSM. In addition, owing to the recent release of MM5, version 3.7.3, some experiments done with version 3.7.2 were repeated to reveal the effects of the modifications in the Noah LSM and Pleim–Xiu LSM. The modification to longwave radiation parameterizations in Noah LSM significantly improves model performance while the adjustment of emissivity, one of the vegetation properties, affects Pleim–Xiu LSM performance to a larger extent. The study suggests that improvements both in Noah LSM physics and in Pleim–Xiu LSM initialization of soil moisture and parameterization of vegetation properties are important.

scholarly journals Seasonal dynamics of methane emissions from a subarctic fen in the Hudson Bay Lowlands

2013 ◽  
Vol 10 (7) ◽  
pp. 4465-4479 ◽  
Author(s):  
K. L. Hanis ◽  
M. Tenuta ◽  
B. D. Amiro ◽  
T. N. Papakyriakou
Keyword(s):  
Soil Temperature ◽  
Air Temperature ◽  
Growing Season ◽  
Near Surface ◽  
Growing Seasons ◽  
Air Temperatures ◽  
Soil Temperatures ◽  
Surface Soil Temperature ◽  
Filling Method ◽  
Highly Correlated

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.

The influence of rotation, tillage and row spacing on near-surface soil temperature for winter wheat in southern Alberta

2003 ◽  
Vol 83 (1) ◽  
pp. 89-98 ◽  
Author(s):  
F. J. Larney ◽  
T. Ren ◽  
S. M. McGinn ◽  
C. W. Lindwall ◽  
R. C. Izaurralde
Keyword(s):  
Winter Wheat ◽  
Soil Temperature ◽  
Management Practices ◽  
Spacing Effect ◽  
Triticum Aestivum L ◽  
Conventional Tillage ◽  
Row Spacing ◽  
Near Surface ◽  
Soil Temperatures ◽  
Surface Soil Temperature

Soil and crop management practices and their effects on surface residue levels can modify soil temperature. Our study investigated the effect of rotation, tillage and row spacing on near-surface (0.025 m) soil temperature under winter wheat (Triticum aestivum L.) in 1993-1994 and 1994-1995. The main treatment was winter wheat rotation: continuous winter wheat (WW); winter wheat-canola (Brassica campestris L.) (WC) or winter wheat-fallow (WF)] with tillage sub-treatments of conventional tillage (CT) vs. zero tillage (ZT) and row spacing treatments of uniform row (UR) vs. paired row (PR) spacing. From fall 1993 to spring 1994, ZT was cooler than CT by 1.2°C on the WC rotation, 1.1°C on WW and 0.4°C on the WF rotation. From fall 1994 to spring 1995, the magnitude of tillage differences was lower on all three rotations with ZT being cooler than CT by 0.1–0.9°C. The magnitude of the row spacing effect on soil temperature was less than that of the tillage effect. Extreme differences in soil temperature due to tillage were generally higher (1.0–4.9°C) on the WW and WC than the WF rotation (0.6–2.5°C) due to the presence of more crop residue. Results demonstrate that while ZT promotes overall cooler soils under winter wheat from fall to late spring, especially on continuously cropped (WW, WC) rotations, it also allows moderation of soil temperatures during extremely cold periods. Key words: Soil temperature, winter wheat, rotation, tillage, row spacing

Soil temperatures in Egypt

1928 ◽  
Vol 18 (1) ◽  
pp. 90-122 ◽  
Author(s):  
E. McKenzie Taylor
Keyword(s):  
Soil Temperature ◽  
Air Temperature ◽  
Soil Surface ◽  
Temperature Wave ◽  
Maximum Temperature ◽  
Straight Line ◽  
Temperature Waves ◽  
Soil Temperatures ◽  
The Times ◽  
Maximum Air Temperature

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.

Influence of snowmelt on soil moisture and on near surface air temperature during winter–spring transition season

2017 ◽  
Vol 51 (4) ◽  
pp. 1295-1309 ◽  
Author(s):  
Jaison Thomas Ambadan ◽  
Aaron A. Berg ◽  
William J. Merryfield ◽  
Woo-Sung Lee
Keyword(s):  
Soil Moisture ◽  
Air Temperature ◽  
Surface Air Temperature ◽  
Near Surface ◽  
Transition Season ◽  
Spring Transition

Impacts of Soil Heating Condition on Precipitation Simulations in the Weather Research and Forecasting Model

2009 ◽  
Vol 137 (7) ◽  
pp. 2263-2285 ◽  
Author(s):  
Xingang Fan
Keyword(s):  
Soil Temperature ◽  
Air Temperature ◽  
Land Surface ◽  
Lower Boundary ◽  
Land Surface Model ◽  
Surface Model ◽  
Heating Condition ◽  
Near Surface ◽  
Thermal Fields ◽  
Soil Temperatures

Soil temperature is a major variable in land surface models, representing soil energy status, storage, and transfer. It serves as an important factor indicating the underlying surface heating condition for weather and climate forecasts. This study utilizes the Weather Research and Forecasting (WRF) model to study the impacts of changes to the surface heating condition, derived from soil temperature observations, on regional weather simulations. Large cold biases are found in the 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis project (ERA-40) soil temperatures as compared to observations. At the same time, a warm bias is found in the lower boundary assumption adopted by the Noah land surface model. In six heavy rain cases studied herein, observed soil temperatures are used to initialize the land surface model and to provide a lower boundary condition at the bottom of the model soil layer. By analyzing the impacts from the incorporation of observed soil temperatures, the following major conclusions are drawn: 1) A consistent increase in the ground heat flux is found during the day, when the observed soil temperatures are used to correct the cold bias present in ERA-40. Soil temperature changes introduced at the initial time maintain positive values but gradually decrease in magnitude with time. Sensible and latent heat fluxes and the moisture flux experience an increase during the first 6 h. 2) An increase in soil temperature impacts the air temperature through surface exchange, and near-surface moisture through evaporation. During the first two days, an increase in air temperature is seen across the region from the surface up to about 800 hPa (∼1450 m). The maximum near-surface air temperature increase is found to be, averaged over all cases, 0.5 K on the first day and 0.3 K on the second day. 3) The strength of the low-level jet is affected by the changes described above and also by the consequent changes in horizontal gradients of pressure and thermal fields. Thus, the three-dimensional circulation is affected, in addition to changes seen in the humidity and thermal fields and the locations and intensities of precipitating systems. 4) Overall results indicate that the incorporation of observed soil temperatures introduces a persistent soil heating condition that is favorable to convective development and, consequently, improves the simulation of precipitation.

Quantifying Spatiotemporal Variations of Soil Moisture Control on Surface Energy Balance and Near-Surface Air Temperature

2017 ◽  
Vol 30 (18) ◽  
pp. 7105-7124 ◽  
Author(s):  
Clemens Schwingshackl ◽  
Martin Hirschi ◽  
Sonia I. Seneviratne
Keyword(s):  
Soil Moisture ◽  
Air Temperature ◽  
Full Range ◽  
Surface Air Temperature ◽  
Temporal Variations ◽  
Heat Fluxes ◽  
Moisture Regime ◽  
Transitional Regime ◽  
Evaporative Fraction ◽  
Near Surface

Abstract Soil moisture plays a crucial role for the energy partitioning at Earth’s surface. Changing fractions of latent and sensible heat fluxes caused by soil moisture variations can affect both near-surface air temperature and precipitation. In this study, a simple framework for the dependence of evaporative fraction (the ratio of latent heat flux over net radiation) on soil moisture is used to analyze spatial and temporal variations of land–atmosphere coupling and its effect on near-surface air temperature. Using three different data sources (two reanalysis datasets and one combination of different datasets), three key parameters for the relation between soil moisture and evaporative fraction are estimated: 1) the frequency of occurrence of different soil moisture regimes, 2) the sensitivity of evaporative fraction to soil moisture in the transitional soil moisture regime, and 3) the critical soil moisture value that separates soil moisture- and energy-limited evapotranspiration regimes. The results show that about 30%–60% (depending on the dataset) of the global land area is in the transitional regime during at least half of the year. Based on the identification of transitional regimes, the effect of changes in soil moisture on near-surface air temperature is analyzed. Typical soil moisture variations (standard deviation) can impact air temperature by up to 1.1–1.3 K, while changing soil moisture over its full range in the transitional regime can alter air temperature by up to 6–7 K. The results emphasize the role of soil moisture for atmosphere and climate and constitute a useful benchmark for the evaluation of the respective relationships in Earth system models.

ESTIMATION OF MANITOBA SOIL TEMPERATURES FROM ATMOSPHERIC METEOROLOGICAL MEASUREMENTS

1980 ◽  
Vol 60 (2) ◽  
pp. 299-309 ◽  
Author(s):  
A. REIMER ◽  
C. F. SHAYKEWICH
Keyword(s):  
Soil Temperature ◽  
Nuclear Research ◽  
Soil Surface ◽  
Damping Factor ◽  
Regression Equations ◽  
Estimation Equations ◽  
Surface Temperatures ◽  
Soil Temperatures ◽  
Explained Variance ◽  
The Difference

Soil-temperature studies were conducted under forage and zero tillage conditions at the Whiteshell Nuclear Research Establishment (WNRE), Pinawa, Manitoba, as part of the plant radiation ecology research program. The objective was to develop estimation equations for monthly mean and daily mean soil surface temperatures from atmospheric meteorological measurements. Subsoil temperatures were estimated from predicted soil surface temperatures by applying an appropriate damping factor. Monthly mean soil surface temperatures were estimated for summer and winter months from regression equations with meteorological predictors. Daily mean soil surface temperatures were predicted from regression equations with meteorological predictors combined with best-fit Fournier-series seasonal curves. Daily mean subsoil temperatures at 10 cm were estimated from predicted soil surface temperatures by applying an appropriate damping factor. The standard deviation of the difference between predicted and observed temperatures was generally less than 1 °C for daily and monthly estimates. A good estimate of the seasonal subsoil temperature at 10, 50, 100 and 200 cm was found from a periodic function with damping and phase paramaters. The explained variance was 95% or more. With appropriate assumptions regarding soil thermal properties and mean annual soil temperature, accurate results were obtained quickly and economically.

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