Air temperature controls diel oscillation of the CO2 concentration in a desert soil

Mapping Intimacies ◽

10.5194/egusphere-egu21-434 ◽

2021 ◽

Author(s):

Marie Spohn ◽

Stefan Holzheu

Keyword(s):

Soil Temperature ◽

Air Temperature ◽

Thermal Convection ◽

Soil Depth ◽

Co2 Concentration ◽

Desert Soil ◽

Precipitation Event ◽

Physical Factors ◽

The North ◽

Measuring Period

The factors that control the soil CO2 concentration are not yet well understood. Therefore, the objective of this study was to explore what factors control the soil CO2 concentration and its dynamic in a desert soil. For this purpose, CO2 concentration and temperature were measured in six soil depths (ranging from 15 to 185 cm) in a deeply weathered, coarse-textured desert soil in the North of Chile at high frequency (every 60 minutes) together with precipitation and air temperature for one year. The mean CO2 concentration calculated across the whole measuring period increased linearly with soil depth from 463 ppm in 15 cm to 1542 ppm in 185 cm soil depth. We observed a diel oscillation of the CO2 concentration that decreased with soil depth and a hysteretic relationship between the topsoil CO2 concentration and both air and soil temperature. A small precipitation event increased the CO2 concentrations in 15, 30, and 50 cm soil depths for several days but did not alter the amplitude of the diel oscillation of the CO2 concentration. The diel oscillation was very likely caused by strong differences between the soil and the air temperature at night, in particular in summer, causing transport of topsoil air to the atmosphere by thermal convection. Our results have important implications as they show that the soil CO2 concentration can be controlled by air temperature through thermal convection, rather than by soil temperature, and that the hysteretic relationship between soil CO2 concentration and temperature can be caused by physical factors alone.&#160;

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Temperature controls diel oscillation of the CO2 concentration in a desert soil

Biogeochemistry ◽

10.1007/s10533-021-00845-0 ◽

2021 ◽

Vol 156 (2) ◽

pp. 279-292

Author(s):

Marie Spohn ◽

Stefan Holzheu

Keyword(s):

Air Temperature ◽

Soil Depth ◽

Co2 Concentration ◽

Darcy Number ◽

Early Morning ◽

Desert Soil ◽

Precipitation Event ◽

Large Temperature ◽

The North ◽

Measuring Period

AbstractThe diel dynamic of the CO2 concentration in soils in relation to temperature is not yet fully understood. Air temperature might control the soil CO2 concentration due to thermal convective venting at sites experiencing large temperature differences between the atmosphere and the soil. Therefore, the objective of this study was to determine the soil CO2 concentration and its temporal dynamic in a deep desert soil in relationship to soil and air temperature based on high frequency measurements. For this purpose, CO2 concentration and temperature were measured in six soil depths (ranging from 15 to 185 cm) in a coarse-textured desert soil in the North of Chile every 60 min together with precipitation and air temperature for one year. The mean CO2 concentration calculated across the whole measuring period increased linearly with soil depth from 463 ppm in 15 cm to 1542 ppm in 185 cm depth. We observed a strong diel oscillation of the CO2 concentration that decreased with soil depth and a hysteretic relationship between the topsoil CO2 concentration and both air and soil temperature. The Rayleigh-Darcy number calculated for different times indicates that thermal convective venting of the soil occurred during the night and in the early morning. A small precipitation event (4 mm) increased the CO2 concentrations in 15, 30, and 50 cm depths for several days but did not alter the amplitude of the diel oscillation of the CO2 concentration. The diel oscillation of the CO2 concentration and the hysteretic relationship between soil CO2 concentration and air temperature were likely caused by thermal convection, leading to transport of CO2-rich air from the soil to the atmosphere at night. In conclusion, our results indicate that the soil CO2 concentration can be largely controlled by convection caused by temperature differences, and not only by diffusion. The results have important implications as they provide further evidence that thermal convective venting contributes to gas exchange at sites experiencing large temperature differences between the atmosphere and the soil, which is relevant for soil chemical reactions.

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Non-stationary temporal characterization of the temperature profile of a soil exposed to frost in south-eastern Canada

Nonlinear Processes in Geophysics ◽

10.5194/npg-15-409-2008 ◽

2008 ◽

Vol 15 (3) ◽

pp. 409-416 ◽

Cited By ~ 10

Author(s):

F. Anctil ◽

A. Pratte ◽

L. E. Parent ◽

M. A. Bolinder

Keyword(s):

Time Series ◽

Soil Temperature ◽

Temperature Profile ◽

Air Temperature ◽

Soil Depth ◽

Time Lag ◽

Power Spectra ◽

Temperature Time Series ◽

Soil Temperatures ◽

Temperature Time

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.

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Root growth dependence on soil temperature for Opuntia ficus-indica : influences of air temperature and a doubled CO2 concentration

Functional Ecology ◽

10.1046/j.1365-2435.1998.00276.x ◽

1998 ◽

Vol 12 (6) ◽

pp. 959-964 ◽

Cited By ~ 19

Author(s):

P. M. Drennan ◽

P. S. Nobel

Keyword(s):

Root Growth ◽

Soil Temperature ◽

Air Temperature ◽

Co2 Concentration ◽

Opuntia Ficus Indica ◽

Doubled Co2 Concentration

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Recognition of Changes in Air and Soil Temperatures at a Station Typical of China’s Subtropical Monsoon Region (1961–2018)

Advances in Meteorology ◽

10.1155/2019/6927045 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Ming-jin Zhan ◽

Lingjun Xia ◽

Longfei Zhan ◽

Yuanhao Wang

Keyword(s):

Climate Change ◽

Soil Temperature ◽

Air Temperature ◽

Soil Depth ◽

Terrestrial Ecosystems ◽

Soil Temperatures ◽

Different Depths ◽

Change Impact ◽

The Mean ◽

Autumn And Winter

Trends in soil temperature are important but rarely reported indicators of climate change. Based on daily air and soil temperatures (depth: 0, 20, 80, and 320 cm) recorded at the Nanchang Weather Station (1961–2018), this study investigated the variation trend, abrupt changes, and years of anomalous annual and seasonal mean air and soil temperatures. The differences and relationships between annual air and soil temperatures were also analyzed. The results showed close correlations between air temperature and soil temperature at different depths. Annual and seasonal mean air and soil temperatures mainly displayed significant trends of increase over the past 58 years, although the rise of the mean air temperature and the mean soil temperature was asymmetric. The rates of increase in air temperature and soil temperature (depth: 0, 20, and 80 cm) were most obvious in spring; the most significant increase in soil temperature at the depth of 320 cm was in summer. Mean soil temperature displayed a decreasing trend with increasing soil depth in both spring and summer. Air temperature was lower than the soil temperature at depths of 0 and 20 cm but higher than the soil temperature at depths of 80 and 320 cm in spring and summer. Mean ground temperature had a rising trend with increasing soil depth in autumn and winter. Air temperature was lower than the soil temperature at all depths in autumn and winter. Years with anomalously low air temperature and soil temperature at depths of 0, 20, 80, and 320 cm were relatively consistent in winter. Years with anomalous air and soil temperatures (depths: 0, 20, and 80 cm) were generally consistent; however, the relationship between air temperature and soil temperature at 320 cm depth was less consistent. The findings provide a basis for understanding and assessing climate change impact on terrestrial ecosystems.

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A weighted coefficient model for estimation of Australian daily soil temperature at depths of 5cm to 100cm based on air temperature and rainfall

Soil Research ◽

10.1071/sr10151 ◽

2011 ◽

Vol 49 (4) ◽

pp. 305 ◽

Cited By ~ 10

Author(s):

Brian Horton ◽

Ross Corkrey

Keyword(s):

Soil Temperature ◽

Air Temperature ◽

Cross Validation ◽

Soil Depth ◽

Mean Square ◽

Air Temperatures ◽

Proposed Model ◽

Soil Temperatures ◽

Weather Stations ◽

Fold Cross Validation

Soil temperatures are related to air temperature and rainfall on the current day and preceding days, and this can be expressed in a non-linear relationship to provide a weighted value for the effect of air temperature or rainfall based on days lag and soil depth. The weighted minimum and maximum air temperatures and weighted rainfall can then be combined with latitude and a seasonal function to estimate soil temperature at any depth in the range 5–100 cm. The model had a root mean square deviation of 1.21–1.85°C for minimum, average, and maximum soil temperature for all weather stations in Australia (mainland and Tasmania), except for maximum soil temperature at 5 and 10 cm, where the model was less precise (3.39° and 2.52°, respectively). Data for this analysis were obtained from 32–40 Bureau of Meteorology weather stations throughout Australia and the proposed model was validated using 5-fold cross-validation.

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Soil Temperature in the Peanut Pod Zone with Subsurface Drip Irrigation

Peanut Science ◽

10.3146/pnut.29.2.0007 ◽

2002 ◽

Vol 29 (2) ◽

pp. 115-122 ◽

Cited By ~ 5

Author(s):

R. B. Sorensen ◽

F. S. Wright

Keyword(s):

Soil Temperature ◽

Air Temperature ◽

Drip Irrigation ◽

Soil Depth ◽

Soil Surface ◽

Subsurface Drip Irrigation ◽

Average Maximum ◽

Soil Temperatures ◽

Subsurface Drip ◽

Maximum Air Temperature

Abstract Maintaining soil temperatures at specified levels (below 29 C) in peanut (Arachis hypogaea L.) is vital to crop growth, development, and pod yield. Subsurface drip irrigation (SDI) systems are not designed to wet the soil surface. Possible lack of moisture in the pod zone could result in elevated soil temperatures that could be detrimental to the peanut crop. The objective of this study was to document the response of pod zone soil temperature when irrigated with a SDI system. Thermocouple sensors were inserted at 5-cm soil depth in the crop row and at specified distances from the crop row in SDI and nonirrigated (NI) treatments. Maximum hourly and daily soil temperature data were measured at three locations, one in Virginia and two in Georgia. The maximum daily soil temperature decreased as plant canopy increased. During the first 50 d after planting (DAP), the average maximum soil temperature was 1 to 2 C cooler for both the SDI and NI treatments than the average maximum air temperature. From 50 DAP to harvest, the average maximum soil temperatures for SDI and NI treatments were 6 C cooler than the average maximum air temperature. During pod filling and maturation, the average maximum soil temperature was about 5 C cooler (27 C) for SDI treatments than the maximum air temperature and 2 C cooler than the recommended 29 C. Soil temperature in the NI treatments did exceed 29 C during periods of drought but decreased to values similar to SDI treatments immediately following a rainfall event. Overall, SDI can maintain maximum soil temperatures below critical values (29 C) during peanut fruit initiation to crop harvest.

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The Storage of Antecedent Precipitation and Air Temperature Signals in Soil Temperature over China

Journal of Hydrometeorology ◽

10.1175/jhm-d-21-0126.1 ◽

2022 ◽

Keyword(s):

Soil Temperature ◽

Air Temperature ◽

Soil Depth ◽

Global Climate ◽

Weather Forecast ◽

Temperature And Precipitation ◽

Antecedent Precipitation ◽

Key Variables ◽

Atmospheric Changes ◽

Monthly Variations

Abstract Soil temperature (ST) is one of the key variables in land-atmosphere interactions. The response of ST to atmospheric changes and subsequent influence of ST on atmosphere can be recognized as the processes of signals propagation. Understanding the storing and releasing of atmosphere signals in ST favors the improvement of climate prediction and weather forecast. However the current understanding of the lagging response of ST to atmospheric changes is very insufficient. The analysis based on observation shows that both the storage of air temperature signals in deep ST even after four months and the storage of precipitation signals in shallow ST after one month are widespread phenomena in China. Air temperature signals at 2m can propagate to the soil depths of 160 cm and 320 cm after 1 month and 2 months, respectively. The storage of antecedent air temperature and precipitation signals in ST is slightly weaker and stronger during April to September, respectively, which is related to more precipitation during growing season. The precipitation signals in ST rapidly weaken after 2 months. Moreover, the effects of accumulated precipitation and air temperature on the signal storage in ST have significant monthly variations and vary linearly with soil depth and latitude. The storage of antecedent air temperature or precipitation signals in ST exhibits an obvious decadal variation with a period of more than 50 years, and it may be resulted from the modulation of the global climate patterns which largely affect local air temperature and precipitation.

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Seasonal Changes in Soil and Air Temperature at Three Locations in Puerto Rico, 1963-67

The Journal of Agriculture of the University of Puerto Rico ◽

10.46429/jaupr.v56i3.10837 ◽

1969 ◽

Vol 56 (3) ◽

pp. 307-317 ◽

Cited By ~ 1

Author(s):

M. A. Lugo-López ◽

Modesto Capiel

Keyword(s):

Soil Moisture ◽

Soil Temperature ◽

Air Temperature ◽

Soil Cover ◽

Bare Soil ◽

Soil Conditions ◽

Adequate Explanation ◽

The North ◽

Air Temperatures ◽

Soil Temperatures

Soil temperature data at Río Piedras in the north, Lajas in the southwest, and Fortuna in the south, are given in this paper for the 5-year period 1963- 67. Seasonal variations in soil and air temperatures follow distinct patterns somewhat, depending on the nature of the soil cover and rainfall. Mean maximum and minimum temperatures at the 2-inch depth, respectively, are: Río Piedras, 96.2° F. and 79.6° F.; Lajas, 102.1° F. and 69.0° F.; and Fortuna, 93.2° F. and 79.1° F. The corresponding soil temperatures at the 8-inch depth, respectively, are: Río Piedras, 80.5° F. and 77.4° F.; Lajas, 83.4° F. and 77.8° F.; and Fortuna, 85.7° F. and 82.7° F. The differences and trends of soil temperature at 2-inch and 8-inch depths can find adequate explanation when soil moisture and soil cover are considered. However, the differences between maximum and minimum soil temperatures at 8 inches of depth are roughly one fifth of the corresponding ones at the 2-inch depth. The maximum and minimum air temperature at Lajas, Fortuna and Río Piedras are much more similar to each other than the corresponding soil temperature, especially at the 2-inch depth. This is mainly because air temperature is rather measured on a macro and integrating scale while soil temperature measurements exhibit localized effects of soil cover and soil moisture. It was found that highly significant 2-inch soil-air temperature relationships are evident under bare soil conditions. The same relationships were not significant under sod cover at Fortuna.

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