SUMMER TEMPERATURES OF CRYOSOLIC SOILS IN THE NORTH-CENTRAL KEEWATIN, N.W.T.

1980 ◽  
Vol 60 (2) ◽  
pp. 311-327 ◽  
Author(s):  
CHARLES TARNOCAI
Keyword(s):  
Soil Temperature ◽  
Slope Position ◽  
North Central ◽  
Soil Material ◽  
The North ◽  
Soil Temperatures ◽  
Summer Temperatures ◽  
The Mean

Soil temperatures were measured at six depths within 1 m of the surface on 10 Cryosolic soils in the north-central Keewatin area during the summer of 1976. The mean soil temperatures during the study period varied between 1.7 °C and 8.2 °C at a depth of 20 cm and −0.2 °C and 6.0 °C at a depth of 50 cm. The maximum and minimum soil temperatures at a depth of 20 cm ranged from 4.4 °C to 13.9 °C and from −0.6°C to 3.9 °C, respectively, while those at a depth of 50 cm ranged from −0.2 °C to 6.7 °C and from −1.1 °C to 2.2 °C, respectively. During the study period a freeze-back of 30 cm or more occurred from the permafrost on several sites. Soil temperatures were markedly higher where the soil material and vegetation were disturbed. The effects of drainage, soil materials, aspect, slope position, vegetation and peat cover on the soil temperature are discussed.

Soil temperature regime in a forested Appalachian watershed

1986 ◽  
Vol 16 (3) ◽  
pp. 624-629 ◽  
Author(s):  
S. J. Tajchman ◽  
C. M. Minton
Keyword(s):  
Surface Temperature ◽  
Soil Temperature ◽  
Soil Layer ◽  
The North ◽  
Soil Temperature Regime ◽  
Temperature Ranges ◽  
The Mean ◽  
The Difference ◽  
Topographic Positions ◽  
Lower Slope

Daily and seasonal variations in soil temperature at various topographic positions in a forested catchment are compared. The experimental sites were designed as ridgetop, north-facing lower slope, south-facing lower slope, and southwest-facing slope. On sunny days during the growing season, the surface temperature had the greatest amplitude (7.8 °C) at the south-facing upper slope and the smallest amplitude (4.0 °C) at the north-facing slope; the remaining sites were intermediate. The maximum surface temperature was observed in the afternoon at all sites. With increasing depth, daily soil temperature ranges diminished and, below 10 cm depth, they were less than 1 °C. Under overcast conditions, daily soil temperature fluctations lessened. For individual months, the mean temperatures of the 2–30 cm soil layer generally varied among all sites by less than 1 °C and never the difference exceeded 1.8 °C. The surface temperature variations and their differences among sites appear to be the most distinguished feature of the soil thermal regime and they seem to be aspect related.

scholarly journals Spatial and temporal variations of rainy days and mean daily rainfall intensity in northern Nigeria.

MAUSAM ◽  
2021 ◽  
Vol 44 (1) ◽  
pp. 85-92
Author(s):  
E. O. OLADIPO ◽  
S. SALAHU
Keyword(s):  
Rainfall Intensity ◽  
Daily Rainfall ◽  
Temporal Variations ◽  
Spatial And Temporal Variations ◽  
Northern Nigeria ◽  
Rainfall Trend ◽  
North Central ◽  
The North ◽  
The Mean ◽  
Rainy Days

The spatial and temporal variations of rainy Gays arid daily rainfall intensity for northern Nigeria for using 54 years data are analysed, The extent and nature of non-random changes, such as trend and fluctuations are Investigated. In general, both, the rainy day frequency and mean daily rainfall intensity decreases northwards except for localized orographic effect in the north central Part of the region. There is statistical evidence or decreasing trend in the, number of rainy days over the period of study, but the trend analysis showed no significance or the mean daily rainfall intensity. This suggests that the recent decreasing rainfall trend In the region particularly In the Sahellan zone, In the result of decrease In the frequency of rainy days and not due to any significant change In the rainfall intensity.  

scholarly journals Study of Seasonal Surface Refractivity over North-Central Nigeria

2021 ◽  
pp. 5-13
Author(s):  
Muhammad Ladan ◽  
Oyedum David ◽  
Jibrin Yabagi ◽  
Ndanusa Babakacha ◽  
Mohammed Kimpa ◽  
...  
Keyword(s):  
High Frequency ◽  
Meteorological Data ◽  
Central Zone ◽  
Ground Level ◽  
Weather Conditions ◽  
Very High Frequency ◽  
International Telecommunication Union ◽  
North Central ◽  
The North ◽  
The Mean

Tropospheric radio wave signals experience loss due to multipath effect, scattering and other forms of attenuation through the atmospheric medium, primarily due to variations in weather conditions with time. The knowledge of surface refractivity profile is important for optimal planning of Very High Frequency/Ultra High Frequency (VHF/UHF) terrestrial radio links in a region. The study of surface refractivity (Ns) over the North-Central Nigeria was carried out using meteorological data from seven locations in North-Central zone of Nigeria. The seasonal variations of Ns were also derived using the monthly summaries of surface data obtained from Nigerian Meteorological Agency (NIMET) over seven stations of Abuja, Lafia, Lokoja, Makurdi, Jos, Minna and Ilorin between 2005 and 2010.The results indicated that the monthly averages of radio refractivity during the rainy season months (April to October) are greater than the Ns values during the dry season months (November to March) for all the locations throughout the years of the study. The computed of mean monthly Ns over all the seven stations in the first 1 km above the ground level is 348 N-units, which gives mean refractivity gradient (dN/dh) of -49 N/k, these shows that the region is characterised by low scale super-refraction. The mean k-factor over the entire region in the first 1 km above the ground level is 1.4; the mean Field Strength Variability (FSV) in first 1 km of height in the region was calculated to be 14 dB. The mean Radio Horizon distance within 1 km height for a transmitter height of 100 m over the stations is 42 km. The results provide useful information needed by radio engineers to set up new terrestrial radio propagation links or to improve on the existing ones especially at VHF, UHF in the North-Central region of Nigeria, as recommended by International Telecommunication Union Recommendations (ITU-R P.453, 2013), which observed the need for local reference data on refractivity and refractivity gradients all over the world.

Effects of drainage on substrate temperature and phenology of some trees and shrubs in an Alberta peatland

1987 ◽  
Vol 17 (2) ◽  
pp. 97-104 ◽  
Author(s):  
V. J. Lieffers ◽  
R. L. Rothwell
Keyword(s):  
Water Table ◽  
Black Spruce ◽  
North Central ◽  
Air Temperatures ◽  
Dwarf Birch ◽  
Summer Temperatures ◽  
The Mean ◽  
Study Sites ◽  
Individual Trees ◽  
Trees And Shrubs

A 50-ha portion of an intermediate fen in north central Alberta was drained in 1984. Study sites were established in the drained area and in an adjacent undrained area. In each site, seasonal water table depth and substrate and air temperatures were monitored. The drainage lowered the water table from 20 to 50 cm compared with the adjacent undrained site. Substrate of the drained area warmed above 0 °C slightly later than the undrained area but maximum summer temperatures were higher in the drained site. Temperatures in 1985 at the 10-cm depth of the drained site peaked in early August at 15–16 °C, 3–4 °C higher than the undrained site. Forty-five black spruce (Piceamariana (Mill.) B.S.P.), 45 tamarack (Larixlaricina (Du Roi) K. Koch), and 25 dwarf birch (Betulapumila L.) were tagged and examined twice weekly. For tamarack and dwarf birch, flowering and bud flush were significantly earlier by 2–6 days in the drained site. For black spruce, flowering was earlier in the drained site; bud flush, however, was earlier in the undrained site in 1985 but there were no differences between sites in 1986. For both black spruce and tamarack, the mean date at which individual trees reached 50% of total leader elongation was earlier in the drained site in both 1984 and 1985.

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

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
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.

RELIEF AND MICROCLIMATE AS RELATED TO SOIL PROPERTIES

1978 ◽  
Vol 58 (3) ◽  
pp. 421-438 ◽  
Author(s):  
T. M. MACYK ◽  
J. D. LINDSAY ◽  
S. PAWLUK
Keyword(s):  
Redox Potential ◽  
Soil Temperature ◽  
Soil Properties ◽  
Exchange Capacity ◽  
Moisture Regime ◽  
X Ray Diffraction ◽  
The South ◽  
The North ◽  
Soil Moisture Regime ◽  
Soil Temperatures

This study was undertaken to determine the influence of relief and microclimate on soil properties. Seven sites were chosen at different positions on the north- and south-facing slopes of a moderately rolling till knob. Physical, chemical and mineralogical analyses were conducted to characterize the soils at each of the sites. The vegetation of the area was described and soil temperatures and moisture were monitored at four depths. Redox potential and pH were measured to detect seasonal variations. Data for oxalate and dithionite-extractable iron and aluminum, cation exchange capacity, and X-ray diffraction showed only minor differences among the seven pedons along the slope faces. Soil temperature was higher on the south-facing slope than on the north-facing slope and air temperature was usually higher than soil temperature at the 10-cm depth. Soil moisture regime varied with position in the landscape. The soil on the north-facing slope was generally more moist than the soil on the south-facing slope. Redox potential varied seasonally and appeared to be related to the moisture content of the soil.

Soil Temperature Effects on Free Carbohydrate Concentrations in Peanut (Arachis hypogaea L.) Seed1

1990 ◽  
Vol 17 (1) ◽  
pp. 31-35 ◽  
Author(s):  
J. L. McMeans ◽  
T. H. Sanders ◽  
B. W. Wood ◽  
P. D. Blankenship
Keyword(s):  
Soil Temperature ◽  
Temperature Treatment ◽  
Acid Interaction ◽  
Roasted Peanut ◽  
Peanut Seed ◽  
Arachis Hypogaea L ◽  
Soil Temperatures ◽  
Amino Acid Interaction ◽  
The Mean ◽  
Free Carbohydrates

Abstract Research has indicated that variation in the mean soil temperature of only a few degrees results in quality differences of peanut seed. The importance of the carbohydrate-amino acid interaction in the development of roasted peanut flavor and color is well documented. The objective of this study was to determine the influence of controlled field soil temperatures on free carbohydrates in commercially sized peanut seed. Florunner peanuts were grown in 5.48 × 12.19 m plots. Soil temperatures were modified from 28 days after planting to produce mean temperatures warmer (28.8 C) and cooler (21.7 C) than ambient (24.5 C) at the 5.0 cm depth in 1982 and 28.2, 22.5, and 25.8 C, respectively, in 1983. Carbohydrates were determined by gas chromatography. Sucrose concentrations decreased significantly as accumulated heat units and seed size increased. In general, fructose, glucose, and raffinose concentrations followed the same trends. The carbohydrate differences found in sized seed were similar to those found among maturity stages from each soil temperature treatment. The data indicate that seed carbohydrate concentrations decrease with higher soil temperature.

The effects of early season soil temperatures on emergence of summer crops on the north-western plains of NSW

1971 ◽  
Vol 11 (48) ◽  
pp. 39 ◽  
Author(s):  
TE Launders
Keyword(s):  
Soil Temperature ◽  
Pearl Millet ◽  
Early Season ◽  
Related Data ◽  
The North ◽  
Temperature Requirement ◽  
Soil Temperatures ◽  
Emergence Percentage ◽  
Rate Of Emergence ◽  
Lower Temperature

The influence of early season soil temperatures on the extent and rate of emergence of five summer crops was examined using four sowings at weekly intervals between late September and late October. The crops were maize, grain sorghum, pearl millet, and two forage sorghums. Increasing soil temperature reduced the interval between sowing and first emergence, and gave variable results for the interval between first and final emergence. Percentage emergence of maize was high at all sowings, whereas that of all three sorghums was low at sowings with soil temperatures at 4 inches of below 65�F, but did not differ significantly between sowings at temperatures above 65�F. Emergence of pearl millet improved with each later sowing, but differences were not significant. Rate of emergence was accelerated by rising soil temperatures in the four days after first emergence, but subsequent effects after four days were generally minimal. Maize appeared to have a lower temperature requirement for emergence than grain and forage sorghums, which, in turn, showed a lower temperature requirement than pearl millet. From the results and other related data, it seems that maize can be sown with reasonable safety when four inch depth soil temperatures are 59� to 64�F (expected in late September), sorghums (both grain and forage) when this temperature is 65� to 69�F (expected in early- to mid-October), and pearl millet when it is 68� to 72�F (expected in early- to mid-November). The results support the concept of soil temperature being the best criterion to determine a safe time for early season sowing of summer crops.

scholarly journals Validation of Noah-Simulated Soil Temperature in the North American Land Data Assimilation System Phase 2

2013 ◽  
Vol 52 (2) ◽  
pp. 455-471 ◽  
Author(s):  
Youlong Xia ◽  
Michael Ek ◽  
Justin Sheffield ◽  
Ben Livneh ◽  
Maoyi Huang ◽  
...  
Keyword(s):  
Soil Temperature ◽  
Time Scales ◽  
Land Surface ◽  
Phase 2 ◽  
Soil Layers ◽  
The North ◽  
Weather And Climate ◽  
Soil Temperatures ◽  
Land Data Assimilation

AbstractSoil temperature can exhibit considerable memory from weather and climate signals and is among the most important initial conditions in numerical weather and climate models. Consequently, a more accurate long-term land surface soil temperature dataset is needed to improve weather and climate simulation and prediction, and is also important for the simulation of agricultural crop yield and ecological processes. The North American Land Data Assimilation phase 2 (NLDAS-2) has generated 31 years (1979–2009) of simulated hourly soil temperature data with a spatial resolution of ⅛°. This dataset has not been comprehensively evaluated to date. Thus, the purpose of this paper is to assess Noah-simulated soil temperature for different soil depths and time scales. The authors used long-term (1979–2001) observed monthly mean soil temperatures from 137 cooperative stations over the United States to evaluate simulated soil temperature for three soil layers (0–10, 10–40, and 40–100 cm) for annual and monthly time scales. Short-term (1997–99) observed soil temperatures from 72 Oklahoma Mesonet stations were used to validate simulated soil temperatures for three soil layers and for daily and hourly time scales. The results showed that the Noah land surface model generally matches observed soil temperature well for different soil layers and time scales. At greater depths, the simulation skill (anomaly correlation) decreased for all time scales. The monthly mean diurnal cycle difference between simulated and observed soil temperature revealed large midnight biases in the cold season that are due to small downward longwave radiation and issues related to model parameters.

Temperature of upland and peatland soils in a north central Minnesota forest

1998 ◽  
Vol 78 (3) ◽  
pp. 493-509 ◽  
Author(s):  
Dale S. Nichols
Keyword(s):  
Soil Temperature ◽  
Air Temperature ◽  
Black Spruce ◽  
Biological Activities ◽  
Cold Weather ◽  
Peat Soils ◽  
North Central ◽  
Air Temperatures ◽  
Soil Temperatures ◽  
Aspen Forest

Soil temperature strongly influences physical, chemical, and biological activities in soil. However, soil temperature data for forest landscapes are scarce. For 6 yr, weekly soil temperatures were measured at two upland and four peatland sites in north central Minnesota. One upland site supported mature aspen forest, the other supported short grass. One peatland site was forested with black spruce, one supported tall willow and alder brush, and two had open vegetation — sedges and low shrubs. Mean annual air temperature averaged 3.6 °C. Mean annual soil temperatures at 10- to 200-cm depths ranged from 5.5 to 7.6 °C among the six sites. Soils with open vegetation, whether mineral or peat, averaged about 1 °C warmer annually and from 2 to 3 °C warmer during summer than the forested soils. The tall brush peatland was cooler than all other sites due to strong groundwater inputs. The mineral soils warmed more quickly in the spring, achieved higher temperatures in the summer, and cooled more quickly in the fall than the peat soils; however, the greatest temperature differences between mineral and peat soils occurred at or below 50 cm. In the upper 20 cm, vegetation and groundwater had greater effects on temperature than did soil type (mineral or peat). Summer soil temperatures were higher, relative to air temperature, during periods of greater precipitation. This effect was minimal at upland sites but substantial in the peatlands. In spite of the persistent sub-freezing air temperatures typical of Minnesota winters, significant frost developed in the soils only in those years when severe cold weather arrived before an insulating cover of snow had accumulated. Key words: Soil temperature, vegetation effects, forest soils, groundwater, peatlands

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