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1.
Thermochron iButtons incorporate the latest in digital technology, making them smaller, less expensive, durable and potentially more reliable than many other temperature logging devices. The objective of this study was to test the accuracy of an inexpensive air temperature measurement system, composed of a Thermochron iButton and radiation shield. Sixty‐one iButtons were subjected to a sequence of two water baths (0 °C and 24·9 °C) to assess the absolute accuracy of the sensors. Five solar radiation shields were tested in a greenhouse setting to evaluate the reduction in radiative heating. Significant differences (p < 0·05) were detected between instruments subsequent to both water‐bath treatment analyses. The accuracy of the sensors was well within the manufacturer's stated specification of ±1·0 °C with a collective temperature variance of ±0·21 °C. Temperature responses generated by the Thermochron iButtons in different radiation shields were consistent, but varied significantly (p < 0·05) from 28 to 44 °C based on diurnal temperature ranges. Results indicate that the Thermochron iButton is an accurate, inexpensive alternative to more expensive temperature data‐logging systems, and is well suited for obtaining quality spatially distributed data for hydrologic and water quality investigations. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
2.
River temperature models play an increasingly important role in the management of fisheries and aquatic resources. Among river temperature models, forecasting models remain relatively unused compared to water temperature simulation models. However, water temperature forecasting is extremely important for in-season management of fisheries, especially when short-term forecasts (a few days) are required. In this study, forecast and simulation models were applied to the Little Southwest Miramichi River (New Brunswick, Canada), where water temperatures can regularly exceed 25–29°C during summer, necessitating associated fisheries closures. Second- and third-order autoregressive models (AR2, AR3) were calibrated and validated using air temperature as the exogenous variable to predict minimum, mean and maximum daily water temperatures. These models were then used to predict river temperatures in forecast mode (1-, 2- and 3-day forecasts using real-time data) and in simulation mode (using only air temperature as input). The results showed that the models performed better when used to forecast rather than simulate water temperatures. The AR3 model slightly outperformed the AR2 in the forecasting mode, with root mean square errors (RMSE) generally between 0.87°C and 1.58°C. However, in the simulation mode, the AR2 slightly outperformed the AR3 model (1.25°C < RMSE < 1.90°C). One-day forecast models performed the best (RMSE ~ 1°C) and model performance decreased as time lag increased (RMSE close to 1.5°C after 3 days). The study showed that marked improvement in the modelling can be accomplished using forecasting models compared to water temperature simulations, especially for short-term forecasts.
EDITOR M.C. Acreman ASSOCIATE EDITOR S. Huang 相似文献
3.
A physics‐based model is provided for predicting the impact of climate change on stream temperature and, in turn, on Formosan landlocked salmon (Oncorhynchus masou formosanus) habitat. Because upstream watersheds on Taiwan Island are surrounded with high and steep mountains, the influence of mountain shading on solar radiation and longwave radiation is taken into account by using a digital elevation model. Projections using CGCM2 and HADCM3 models and CCCM and GISS models provided information on future climatic conditions. The results indicate that annual average stream temperatures may rise by 0·5 °C (HADCM3 short term) to 2·9 °C (CGCM2 long term) due to climate change. The simulation results also indicate that the average suitable habitat for the Formosan landlocked salmon may decline by 333 m (HADCM3 short term) to 1633 m (CGCM2 long term) and 166 m (HADCM3 short term) to 1833 m (CGCM2 long term) depending on which thermal criterion (17 °C and 18 °C respectively) is applied. The results of this study draw attention to the tasks of Formosan landlocked salmon conservation agencies, not only with regard to restoration plans of the local environment, but also to the mitigation strategies to global climate change that are necessary and require further research. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
4.
Continuous temperature measurements at 11 stream sites in small lowland streams of North Zealand, Denmark over a year showed much higher summer temperatures and lower winter temperatures along the course of the stream with artificial lakes than in the stream without lakes. The influence of lakes was even more prominent in the comparisons of colder lake inlets and warmer outlets and led to the decline of cold‐water and oxygen‐demanding brown trout. Seasonal and daily temperature variations were, as anticipated, dampened by forest cover, groundwater input, input from sewage plants and high downstream discharges. Seasonal variations in daily water temperature could be predicted with high accuracy at all sites by a linear air‐water regression model (r2: 0·903–0·947). The predictions improved in all instances (r2: 0·927–0·964) by a non‐linear logistic regression according to which water temperatures do not fall below freezing and they increase less steeply than air temperatures at high temperatures because of enhanced heat loss from the stream by evaporation and back radiation. The predictions improved slightly (r2: 0·933–0·969) by a multiple regression model which, in addition to air temperature as the main predictor, included solar radiation at un‐shaded sites, relative humidity, precipitation and discharge. Application of the non‐linear logistic model for a warming scenario of 4–5 °C higher air temperatures in Denmark in 2070‐2100 yielded predictions of temperatures rising 1·6–3·0 °C during winter and summer and 4·4–6·0 °C during spring in un‐shaded streams with low groundwater input. Groundwater‐fed springs are expected to follow the increase of mean air temperatures for the region. Great caution should be exercised in these temperature projections because global and regional climate scenarios remain open to discussion. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
5.
《水文科学杂志》2013,58(3)
Abstract Abstract Routine estimates of daily incoming solar radiation from the GOES-8 satellite were compared to locally measured values in Florida. Longwave radiation estimates corrected using GOES-derived cloud amount and cloud top temperature products improved net radiation estimates as compared to a clear sky longwave approach. The Penman-Monteith, Turc, Hargreaves and Makkink models were applied using GOES-derived estimates of solar radiation and net radiation to predict daily evapotranspiration and were compared to evapotranspiration measured with an eddy-correlation system in an emergent wetland experimental site in north-central Florida under unstressed conditions. While the Penman-Monteith model provided the best estimates of evapotranspiration (R 2 = 0.92), the empirical Makkink method demonstrated nearly comparable agreement (R 2 = 0.90) using only the GOES solar radiation and measured temperature. The results show that it is possible to generate spatially distributed daily potential evapotranspiration estimates using GOES-derived solar radiation and net radiation with limited additional surface measurements. 相似文献
6.
E. Mair G. Leitinger S. Della Chiesa G. Niedrist U. Tappeiner G. Bertoldi 《水文科学杂志》2013,58(11):2050-2060
ABSTRACTMeasuring winter solid and liquid precipitation with high temporal resolution in remote or higher elevation regions is a challenging task because of undercatch and power supply issues. However, the number of micro-meteorological stations and ultrasonic height sensors in mountain regions is steadily increasing. To gain more benefit from such stations, a new simple approach for EStimating SOlid and LIquid Precipitation (ESOLIP) is presented. The method consists of three main steps: (1) definition of precipitation events using micro-meteorological data, (2) quantification of solid and liquid precipitation using wet-bulb temperature and filtered snow height and (3) calculation of fresh snow density. ESOLIP performance was validated using data from a heated rain gauge, snow pillow and daily manual observations both for single precipitation events and over three winter seasons. Results proved ESOLIP as an effective approach for precipitation quantification, where snow height observations and basic meteorological measurements (air temperature, solar radiation, wind speed, relative humidity), but no reliable rain gauges are available. 相似文献
7.
This investigation is a follow-up of a paper in which we showed that both major magnetic components of the solar dynamo, viz. the toroidal and the poloidal ones, are correlated with average terrestrial surface temperatures. Here, we quantify, improve and specify that result and search for their causes.We studied seven recent temperature files. They were smoothed in order to eliminate the Schwabe-type (11 years) variations. While the total temperature gradient over the period of investigation (1610–1970) is 0.087 °C/century; a gradient of 0.077 °C/century is correlated with the equatorial (toroidal) magnetic field component. Half of it is explained by the increase of the Total Solar Irradiance over the period of investigation, while the other half is due to feedback by evaporated water vapour. A yet unexplained gradient of ?0.040 °C/century is correlated with the polar (poloidal) magnetic field. The residual temperature increase over that period, not correlated with solar variability, is 0.051 °C/century. It is ascribed to climatologic forcings and internal modes of variation.We used these results to study present terrestrial surface warming. By subtracting the above-mentioned components from the observed temperatures we found a residual excess of 0.31° in 1999, this being the triangularly weighted residual over the period 1990–2008.We show that solar forcing of the ground temperature associated with significant feedback is a regularly occurring feature, by describing some well observed events during the Holocene. 相似文献
8.
Pia Zacharias 《Surveys in Geophysics》2014,35(4):897-912
With the advent of space-based total solar irradiance (TSI) observations about 35 years ago, researchers’ understanding of solar variability and its causes has greatly improved. Controversies regarding the cross-calibration of the data from various TSI instruments have resulted in many different TSI composite time series. These composites agree well with each other on timescales ranging from days to years, but due to the limited stability of the instruments contributing to the composites, their quality is not yet sufficient to unambiguously detect possible changes between subsequent cycle minima. In this paper, the construction of the three most prominent TSI composite time series and the underlying TSI models is addressed. The difficulties associated with the cross-calibration of the data are considered, and the viewpoints of the different groups involved in the development of the composites are discussed. 相似文献
9.
Distributed modeling of monthly air temperatures over the rugged terrain of the Yellow River Basin 总被引：1，自引：0，他引：1
Our analyses of the monthly mean air temperature of meteorological stations show that altitude, global solar radiation and
surface effective radiation have a significant impact on air temperature. We set up a physically-based empirical model for
monthly air temperature simulation. Combined the proposed model with the distributed modeling results of global solar radiation
and routine meteorological observation data, we also developed a method for the distributed simulation of monthly air temperatures
over rugged terrain. Spatial distribution maps are generated at a resolution of 1 km×1 km for the monthly mean, the monthly
mean maximum and the monthly mean minimum air temperatures for the Yellow River Basin. Analysis shows that the simulation
results reflect to a considerable extent the macro and local distribution characteristics of air temperature. Cross-validation
shows that the proposed model displays good stability with mean absolute bias errors of 0.19°C–0.35°C. Tests carried out on
local meteorological station data and case year data show that the model has good spatial and temporal simulation capacity.
The proposed model solely uses routine meteorological data and can be applied easily to other regions.
Supported by China Meteorological Administration key Project on New Technique Diffusion (Grant No. CMATG2006Z10) and Jiangsu
Key Laboratory of Meteorological Disasters (Grant No. KLME050102) 相似文献
10.
AbstractRiver water temperature regimes are expected to change along with climate over the next decades. This work focuses on three important salmon rivers of eastern Canada, two of which warm up most summers to temperatures higher than the Atlantic salmon lethal limit (>28°C). Water temperature was monitored at 53 sites on the three basins during 2–18 summers, with about half of these sites either known or potential thermal refugia for salmon. Site-specific statistical models predicting water temperature, based on 10 different climate scenarios, were developed in order to assess how many of these sites will remain cool enough to serve as refugia in the future (2046–2065). The results indicate that, while 19 of the 23 identified refugia will persist, important increases in the occurrence and duration of temperature events in excess of 24°C and 28°C, respectively, in the mainstems of the rivers, will lead to higher demands for thermal refugia in the salmonid populations.
Editor Z.W. Kundzewicz; Associate editor T. Okruszko 相似文献
11.
P. S. Minyuk T. V. Subbotnikova A. A. Plyashkevich 《Izvestiya Physics of the Solid Earth》2011,47(9):762-774
Magnetic susceptibility (MS) of natural specimens of hematite and goethite is studied under continuous heating with various
additives: with carbon (sugar), nitrogen (carbamide), and elemental sulfur. It is found that heating of hematite with carbon
above 450°C results in the formation of single-domain magnetite, while the magnetic susceptibility rises by a factor of 165.
The increase in magnetic susceptibility on heating of hematite with nitrogen above 540°C reflects the generation of a single-domain
maghemite with the Curie point of about 650°C, which is stable to heating. After the first heating, the magnetic susceptibility
increases by 415 times. The subsequent cycle of thermal treatment results in the transition of maghemite to hematite, a decrease
of MS, and an increase of coercivity. Heating with sulfur produces a stable single-domain magnetite at a temperature above
the Curie point, which is manifested in the cooling curves. Here, the MS increases by a factor of 400. The heating curves
for goethite exhibit a sharp drop in susceptibility to a temperature of 350–360°C, which reflects the transition of hematite
to goethite. Heating of hematite with carbon produces stable maghemite at above 530°C, and with sulphur and nitrogen, it produces
magnetite. When heated with pyrite, hematite reduces to magnetite under the action of sulfur released from pyrite. 相似文献
12.
V. I. Skomorovsky V. D. Trifonov G. P. Mashinch Yu. S. Zaiganova V. G. Fainshtein G. I. Kushtal’ S. A. Chuprakov 《Geomagnetism and Aeronomy》2011,51(8):1063-1077
A new telescope has been created to investigate the solar corona during eclipses. One lens simultaneously forms three corona
images occurring as coronal radiation passes through three polarizers with transmission directions rotated 0°, 60°, and 120°
relative to the selected direction; in addition, one image is formed without the polarizer. The telescope was used for solar
corona observation during the eclipse of August 1, 2008. We obtained the distributions of polarization brightness, K corona
brightness, degree of K corona polarization, and total degree of polarization as well as polarization directions depending
on the latitude and radius in the sky plane. Radial distributions of the electron density depending on latitude were calculated.
The coronal plasma temperature was determined for different corona structures under the assumption of hydrostatic equilibrium. 相似文献
13.
The effects of variability in climate and watershed (groundwater withdrawal and land use) on dry‐weather streamflows were investigated using SWAT (Soil and Water Assessment Tool). The equation to predict the total runoff (TR) using climate data was derived from simulation results for 30 years by multiple regression analysis. These may be used to estimate effects of various climate variations (precipitation during the dry period, precipitation during the previous wet period, solar radiation, and maximum temperature). For example, if daily average maximum temperature increases by 3 °C, TR during the dry period will decrease by 27·9%. Similarly, groundwater withdrawals strongly affect streamflow during the dry period. However, land use changes (increasing urbanization) within the forested watershed do not appear to significantly affect TR during the dry period. Finally, a combined equation was derived that describes the relationships between the TR during the dry period and the climate, groundwater withdrawal and urban area proportion in a small monsoon watershed. This equation will be effective to predict the water availability during the dry periods in the future since it is closely related to changes of temperature, precipitation, solar radiation, urban area ratio, and groundwater withdrawal quantity. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
14.
Hemispherical photographs of forest canopies can be used to develop sophisticated models that predict incident below canopy shortwave radiation on the surface of interest (i.e. soil and water). Hemispherical photographs were collected on eight dates over the course of a growing season to estimate leaf area index and to quantify solar radiation incident on the surface of two stream reaches based on output from Gap Light Analyser and Hemisfer software. Stream reaches were shaded by a mixed‐deciduous Ozark border forested riparian canopy. Hemispherical photo model results were compared to observed solar radiation sensed at climate stations adjacent to each stream reach for the entire 2010 water year. Modeled stream‐incident shortwave radiation was validated with above‐stream pyranometers for the month of September. On average, the best hemispherical photo models underestimated daily averages of solar radiation by approximately 14% and 12% for E–W and N–S flowing stream reaches, respectively (44.7 W/m2 measured vs 38.4 W/m2 modeled E–W, 46.8 W/m2 vs. 41.1 W/m2N–S). The best hemispherical photo models overestimated solar radiation relative to in–Stream pyranometers placed in the center of each stream reach by approximately 7% and 17% for E–W and N–S stream reaches respectively (31.3 W/m2 measured vs 33.5 W/m2 modeled E–W, 31.5 W/m2 vs. 37.1 W/m2N–S). The model provides a geographically transferable means for quantifying changes in the solar radiation regime at a stream surface due to changes in canopy density through a growing season, thus providing a relatively simple method for estimating surface and water heating in canopy altered environments (e.g. forest harvest). Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
15.
16.
Artificial diagenesis of the intra-crystalline proteins isolated from Patella vulgata was induced by isothermal heating at 140 °C, 110 °C and 80 °C. Protein breakdown was quantified for multiple amino acids, measuring the extent of peptide bond hydrolysis, amino acid racemisation and decomposition. The patterns of diagenesis are complex; therefore the kinetic parameters of the main reactions were estimated by two different methods: 1) a well-established approach based on fitting mathematical expressions to the experimental data, e.g. first-order rate equations for hydrolysis and power-transformed first-order rate equations for racemisation; and 2) an alternative model-free approach, which was developed by estimating a “scaling” factor for the independent variable (time) which produces the best alignment of the experimental data. This method allows the calculation of the relative reaction rates for the different temperatures of isothermal heating.High-temperature data were compared with the extent of degradation detected in sub-fossil Patella specimens of known age, and we evaluated the ability of kinetic experiments to mimic diagenesis at burial temperature. The results highlighted a difference between patterns of degradation at low and high temperature and therefore we recommend caution for the extrapolation of protein breakdown rates to low burial temperatures for geochronological purposes when relying solely on kinetic data. 相似文献
17.
T. Y. Lee J. C. Huang L. Y. Liao C. S. Tzeng C. H. Yang P. K. Kalita C. P. Tung 《水文研究》2012,26(24):3635-3644
Reducing or stabilizing the stream temperature of ChiChiaWan Creek is a crucial work for Formosan Landlocked Salmon because ChiChiaWan Creek is the only one habitat for this endangered species. Planting trees in the riparian zone would be one of the alternatives. The purpose of this study was to evaluate the effects of several planting strategies on daily maximum stream temperature along the river. The results showed the effective vegetative shading angles should be more than 50° along ChiChiaWan Creek to reduce the direct solar radiation heating effectively. Upstream planting with 70° vegetative shading angle could be the most effective way among all the scenarios. However, this planting strategy could not improve the worst situations in summer because of the large solar elevation angles. The upstream planting in ChiChiaWan Creek was strongly recommended because the canopies could be easier to extend to totally cover the narrow width of river producing the most effective shades. Practicing the upstream planting with 90° vegetative shading angle can increase more than 1 km long suitable habitats for the endangered Salmon in summer. Alternatively, the west‐side planting scenario was the second effective way for temperature reduction. Our result provided a useful suggestion for the authorities in charge of saving the Formosan Landlocked Salmon, particularly under the stress of global warming. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
18.
The electrical conductivity of a single crystal of San Carlos olivine (Fo92, 0.16 wt.% Fe2O3) has been measured as a function of temperature and oxygen fugacity (fO2). After heating to 1338°C at fO2 = 10?12 atm., the conductivity at 950°C was 10?5 (ohm-m)?1, almost 3 orders of magnitude less than that measured in air. This decrease is due to the reduction of Fe3+ to Fe2+. Further heating to 1500°C at fO2 = 10?14 atm., decreased the electrical conductivity at 950°C to 10?6 (ohm-m)?1. When recovered at room temperature, the speciment had Fo96 composition and contained small, opaque blebs distributed throughout the crystal. Derivations of temperature profiles for the earth's mantle from conductivity-depth models must take account of the important role played by iron oxidation state in the electrical conductivity of olivine. 相似文献
19.
Erythemal ultraviolet (UVER; 280–400 nm) and total shortwave (SW; 305–2800 nm) solar irradiances were recorded from 2000 to 2009 in Valladolid, Spain. UVER and SW values under cloudless conditions are simulated by radiative transfer (TUV 4.6) and empirical models. These model estimations are tested with experimental measurements showing a great agreement (root mean square error around 7%). The aerosol effect on UVER irradiance is determined through a model study. UVER radiation and total ozone column (TOC) temporal evolutions show a negative relationship. TOC accounts for 80% of UVER variance and its radiation amplification factor is 1.1 at zenith of 65°. Cloud effects on solar radiation are shown and quantified by the cloud modification factor. Moreover the enhancement effect cases are analysed. SW radiation proves more sensitive to clouds than UVER. Clouds are seen to attenuate and enhance solar radiation by up to 93% and 22% in the UVER range, respectively. 相似文献
20.
Huhou Li 《中国科学D辑(英文版)》1998,41(4):437-441
The implantation of artificial quartz with nickel ion has succeeded in using a heavy ion accelerator. The quartz with nickel
ion is called ”nickel quartz“. The sensitivity of their thermoluminescence (TL) response to the beta radiation was decreased
with the increasing of irradiating and heating times. Two TL characteristics have appeared: the sensitivity of TL response
at lower temperature (ll0°C) peaks of the nickel quartz to beta radiation is higher than that of the pure quartz, this results
from the Ni+1 ion entering the quartz lattice; and a new peak appearing at 445°C may be related with both Ni+1 and Ni+3. 相似文献