existing between air and soil temperatures in Syria and Lebanon, by means fall ; 10 stations in the arid and semi-arid inland Syria; 6 stations in the. 5 stations. Evaluation of air–soil temperature relationships simulated by land A. David McGuire6, Eleanor J. Burke7, Xiaodong Chen21, Bertrand. isons between air and ground temperatures at periods appro- priate for climate the depth at which the ratio of the subsurface temperature perturba- tion to the . cate a value of 1×10−6 m2/s is a reasonable value (Clauser.
The borehole was cased with a zinc-coated steel tube 1. Thermal conductivity was measured on the only two available rock samples collected from two different depth sections, 1. Thermal diffusivity was estimated using typical density and specific heat values and fits into a typical range of 0. The diffusivity can be even lower due to a high specific heat of the pore water; e. The experiment started on 13 Novemberand is still running; data used in this report cover the period 13 November —1 August The arrangement of the monitoring experiment not to scale.
Monitoring results On long time scales, the land—atmosphere interface is in energy equilibrium, and temperatures measured in each medium reflect this energy balance.
The monitoring results of the ground—air temperature coupling may thus provide an important piece of knowledge to understand the complicated energy exchange mechanisms on this interface. Surface and near-surface ground temperatures in part smooth down the air temperature extremes.
The ground surface quality and properties e. The time-varying thermal properties of the surface rocks or seasonal vegetation changes surely do not make the solution of the problem easier. The problem was studied in detail by e. The year-long monitoring series obtained from the Sporilov observatory Czech Republic provided a small mean ground—air temperature offset of only 0.
Both records, confirming a substantial warming rate of more than 0. Regardless of this constancy, the difference reveals a typical annual course. Van Wanbeke compiled an extensive volume of information based on agriculture data summarizing the effect of the microvegetation cover on the surface ground temperature and reported that the surface was generally warmer than the air.
Judging the ground—air temperature offset observed in the MBCO in respect to the analogous values found elsewhere, this tendency was clearly confirmed: The noise level similarly decreases.
Noticeable annual temperature variations then gradually disappear in deeper series, the sign of periodicity vanishes and the time series appear as more or less random temperature fluctuations.
Time series of daily temperature averages at different depths in the borehole Malence. Although large number of studies has been done worldwide to investigate responses of various ecosystems to rising air temperatures, less is known about changes in subsurface temperatures, and potential impacts on various ecosystem functions and services. In this study, we used eight recent years of soil temperature data from different depths, cm depth increments in three stations in the state of Kuwait: Abdali, Sulaibya and wafra.
Analysis of variance ANOVA revealed statistically significant variations in soil temperatures with depth in all locations. Another interesting feature of our analysis was the highly linear relationship between air temperatures and soil temperatures up to 0. These findings shed an important light on whether or not ambient air temperature can be used as a reliable predictor of active root-zone Consequently, this paper contributes to the body of knowledge about the potential of soil temperatures being estimated from air temperature in Kuwait and can be applied to other countries in the Gulf region with similar soil and climatic conditions.
Keywords Air temperature; Desert; Regression; Soil; Subsurface layer Introduction Soil temperature has a number of agronomic, geo-environmental and geothermal applications. For example, soil temperature changes can alter the diversity and distribution of plant species leading to a change in biodiversity and plant production [ 12 ].
In arid deserts, like the Middle East region, the low moisture content severely limits microbial growth, abundance, diversity and growth of agricultural crops [ 3 ]. To make the situation even more troubling, the region, according to the most recent predictions, will be confronted with even more severe water shortages as temperature rises due to global warming [ 4 ].
What is uniquely interesting with soil temperature Ts is that whereas general public can easily relate to air temperature TaTs is not a commonly used environmental variable and understood concept. Furthermore, the Gulf region is located in low-elevation area close to sea level allowing humidity conditions to develop and, therefore, rising temperatures to accumulate at the earth surface [ 4 ].
One of the greatest challenges in projecting future impacts of climate changes on ecosystem functions is to understand how soil profile temperature tracks with ambient air temperature. Consequently, desert soil with little vegetation cover and low moisture content is subjected to large fluctuations in daily and annual temperatures. With global warming concerns, interest in soil profile temperature is growing because soil productive capacity, biodiversity and other essential ecosystem services heavily depend on soil temperature threshold [ 3 ].
Subsurface temperature variation not only affects living organisms, but also has a great potential to influence solute transport and leaching of salts and pollutant movement to groundwater aquifers [ 6 ].
Despite the aridity and hence greater vulnerability of the gulf region, only recently few climate change studies have been reported [ 47 - 9 ]. Most importantly, research on subsurface temperature measurements and monitoring at the root-zone effective depth is completely lacking. To the best of our knowledge, no study has so far been conducted to characterize soil profile temperature in Kuwait and the gulf region.
This is a major knowledge deficiency since most ecological and agricultural processes are affected by temperature differences in the soil profile. This is especially critical when there is a renewed urgency in enhancing food production from domestic farming to free, partially at least, the region from complete reliance on food import. The primary objectives of this study were to: Brief Overview of Study Areas and the Gulf Region The Arabian Gulf region is characterized by extremely arid and hot climate, and is prone to severe climatic changes.
Rainfall in the Gulf is not only scarce but also highly irregular. Rainfall and air temperature data during study period is shown in Figure 1; the year of being the driest year 34 mm followed by 39 mm. The wettest year recorded over the 8 years of this study was receiving a total of mm rain. Also, there was a sharp warming trend from to To ascertain long term behavior of atmospheric temperature, monthly average air temperatures averaged across all the three sites measured during study period and the long term normal 30 year averages were calculated and shown in Figure 2.
Warmer temperatures and not only dry but also less predictable rainfall portend to upset the delicate balance of desert soil ecology, which has sustained life for thousands of years. All these factors combined, average annual loss of potentially productive land due to desertification a key vulnerability indicator for ecological change is predicted to be among the highest in the world [ 10 ].
It has good drainage and airing characteristics but a very low water retention capacity. It is very poor in organic matter and the nutritional elements needed by plants.
As shown in Figure 3, these areas are located mainly in: Sulaibya area is described to be the most suitable land for crop production, where the soil is much better, as it is deep with a sandy texture, good drainage characteristics and relatively low salt [ 11 ].
Map of the State of Kuwait showing locations of the three study site. Moving forward, environmental conditions are not favorable for farming due to high temperature, water scarcity, and severity of land degradation.