Raw Temperature Data Research Articles

Seepage velocities derived from thermal records using wavelet analysis

Summary The main objective of this study was to determine if wavelet analysis can be used as a band-pass filter for non-stationary time series of temperature records. It was demonstrated that this new processing technique is efficient in calculating seepage velocities by using a virtual experiment and field data measured in the Mess Stream, Grand Duchy of Luxembourg, Europe. Temperature time series were measured continuously over a 2-year period in the streambed sediments. The seepage velocity was derived from the one-dimensional analytical solution of Stallman. However, the ubiquitous property of the temperature signal is that it is non-stationary, i.e. the frequency component of the signal becomes a function of time. Instead of applying traditional filtering techniques based on the Fourier transform, we introduce the continuous wavelet transform (CWT) as a band-pass filter to extract the daily component from raw temperature data. For the analysed time series, the estimated seepage velocities based on the amplitude ratio were always negative and within the range of −0.7 to −2.5 m d −1 , indicating gaining conditions prevailing in the Mess Stream. The uncertainty associated with the seepage velocities was calculated by the Monte Carlo analysis allowing several physical parameters of the model to vary over pre-defined intervals with normal distribution. Auxiliary hydraulic measurements in the stream and in the riverbank confirm the dominance of gaining stream conditions. However, the seepage rates based on the thermal records were much higher than the calculated Darcy velocities. This study demonstrates the applicability of continuous wavelet transform as an alternative method to Fourier transform for the analysis of non-stationary temperature time series.

Evaluation of maize variety suitability on lodging in target environments based on GIS

Lodging is one of the major problems in maize production which causes severe yield loss every year all over the world. In the present study, the lodging suitability of different maize varieties in target growing environments was investigated based on geographical information science. A total of 401 maize planting counties in northeast China and northern China were selected as study areas. The mean and standard deviation of environment accumulated temperature in vegetative stage of maize were calculated from raw temperature data obtained from 167 meteorology stations in these areas. The variety lodging resistance was determined based on the data of national regional variety trials for maize, and the environment lodging stress was measured using field survey data on lodging. Probability analysis based on the calculated values of environment accumulated temperature in vegetative stage of maize was utilized to determine whether a maize variety can be physically mature in a planting county, and lodging suitability of the variety was evaluated with geographical information science combining variety lodging resistance and local environment lodging stress together. A new maize variety NH1101 was taken as an example to illustrate the modeling and calculating procedures. The result shows that, from southwest to northeast of the study areas, the overall suitability trend changes from nonsuitable to suitable, then to not very suitable. And it is demonstrated that the lodging suitability is not only related to the variety resistance but also to the local environment stress.

Modelling the global constraints of temperature on transmission of Plasmodium falciparum and P. vivax

BackgroundTemperature is a key determinant of environmental suitability for transmission of human malaria, modulating endemicity in some regions and preventing transmission in others. The spatial modelling of malaria endemicity has become increasingly sophisticated and is now central to the global scale planning, implementation, and monitoring of disease control and regional efforts towards elimination, but existing efforts to model the constraints of temperature on the malaria landscape at these scales have been simplistic. Here, we define an analytical framework to model these constraints appropriately at fine spatial and temporal resolutions, providing a detailed dynamic description that can enhance large scale malaria cartography as a decision-support tool in public health.ResultsWe defined a dynamic biological model that incorporated the principal mechanisms of temperature dependency in the malaria transmission cycle and used it with fine spatial and temporal resolution temperature data to evaluate time-series of temperature suitability for transmission of Plasmodium falciparum and P. vivax throughout an average year, quantified using an index proportional to the basic reproductive number. Time-series were calculated for all 1 km resolution land pixels globally and were summarised to create high-resolution maps for each species delineating those regions where temperature precludes transmission throughout the year. Within suitable zones we mapped for each pixel the number of days in which transmission is possible and an integrated measure of the intensity of suitability across the year. The detailed evaluation of temporal suitability dynamics provided by the model is visualised in a series of accompanying animations.ConclusionsThese modelled products, made available freely in the public domain, can support the refined delineation of populations at risk; enhance endemicity mapping by offering a detailed, dynamic, and biologically driven alternative to the ubiquitous empirical incorporation of raw temperature data in geospatial models; and provide a rich spatial and temporal platform for future biological modelling studies.

Is New Zealand globally warming?

NIWA proposes a seven-station temperature series to assess a globally warming trend. The warming trend predicted by NIWA is a result of their arbitrary corrections of measured temperatures to account for change of site. These changes are always increasing the temperatures and they magnify the effect of the heat island build-up around urban areas. The individual analysis of the raw temperature data from different measuring stations clearly shows that there is no warming globally occurring, with warming being conversely very well localised in time and space.

A Critical Review of Global Surface Temperature Data Products

There are three main global temperature histories: the combined CRU-Hadley record (HADCRU), the NASA-GISS (GISTEMP) record, and the NOAA record. All three global averages depend on the same underlying land data archive, the Global Historical Climatology Network (GHCN). Because of this reliance on GHCN, its quality deficiencies will constrain the quality of all derived products. The number of weather stations providing data to GHCN plunged in 1990 and again in 2005. The sample size has fallen by over 75% from its peak in the early 1970s, and is now smaller than at any time since 1919. The collapse in sample size has increased the relative fraction of data coming from airports to about 50 percent (up from about 30 percent in the 1970s). It has also reduced the average latitude of source data and removed relatively more high-altitude monitoring sites. Oceanic data are based on sea surface temperature (SST) rather than marine air temperature (MAT). All three global products rely on SST series derived from the ICOADS archive. ICOADS observations were primarily obtained from ships that voluntarily monitored SST. Prior to the post-war era, coverage of the southern oceans and polar regions was very thin. Coverage has improved partly due to deployment of buoys, as well as use of satellites to support extrapolation. Ship-based readings changed over the 20th century from bucket-and-thermometer to engine-intake methods, leading to a warm bias as the new readings displaced the old. Until recently it was assumed that bucket methods disappeared after 1941, but this is now believed not to be the case, which may necessitate a major revision to the 20th century ocean record. There is evidence that SST trends overstate nearby MAT trends. The quality of data over land, namely the raw temperature data in GHCN, depends on the validity of adjustments for known problems due to urbanization and land-use change. The adequacy of these adjustments has been tested in three different ways, with two of the three finding evidence that they do not suffice to remove warming biases. The overall conclusion of this report is that there are serious quality problems in the surface temperature data sets that call into question whether the global temperature history, especially over land, can be considered both continuous and precise. Users should be aware of these limitations, especially in policy-sensitive applications.

Contribution of thermal expansion to present-day sea-level change revisited

We investigate the thermosteric (i.e., due to temperature only) sea-level change over the last 50 years using two global ocean temperature data sets recently published ( Levitus et al., 2000a [Levitus, S., Stephens, C.M., Antonov, J.I., Boyer, T.P., 2000a. Yearly and year-season upper ocean temperature anomaly fields, 1948–1998, pp. 23, U.S. Gov. Printing Office, Washington, DC] and Ishii et al., 2003 [Ishii, M., Kimoto, M., Kachi, M., 2003. Historical ocean subsurface temperature analysis with error estimates, Monthly Weather Rev., 131, 51–73]). These data sets which provide gridded temperatures, down to 3000 m and 500 m respectively, are based on interpolation schemes of raw historical profiles over 1950–1998. We find that the two data sets compare well over 1950–1990, both in terms of thermosteric sea-level trends and global mean. Some difference is noticed however beyond 1990, due to differences in the raw temperature data processing. Analyses based on ‘Empirical Orthogonal Function’ show that the interannual variability of the thermosteric sea level is dominated by the signatures of El Niño Southern Oscillation, Pacific Decadal Oscillation and influenced by North Atlantic Oscillation. As a result, regional thermosteric sea-level trends are not stationary on a century time scale and have a typical lifetime on the order of a decade. In terms of global mean, the rate of thermosteric sea-level change computed over 10-year windows displays high variability, with values reaching up to three times the 40-year (1950–1990) average at some periods. Even negative values are noticed at other periods. One important consequence is that the pattern of sea-level trends derived from Topex/Poseidon altimetry over 1993–2003, which is mainly caused by thermal expansion, is very likely a non-permanent feature. Thus past and future extrapolation based on this 10-year altimetry pattern should be considered with caution.

Fine resolution 3D temperature fields off Kerguelen from instrumented penguins

The use of diving animals as autonomous vectors of oceanographic instruments is rapidly increasing, because this approach yields cost-efficient new information and can be used in previously poorly sampled areas. However, methods for analyzing the collected data are still under development. In particular, difficulties may arise from the heterogeneous data distribution linked to animals’ behavior. Here we show how raw temperature data collected by penguin-borne loggers were transformed to a regular gridded dataset that provided new information on the local circulation off Kerguelen. A total of 16 king penguins ( Aptenodytes patagonicus) were equipped with satellite-positioning transmitters and with temperature–time–depth recorders (TTDRs) to record dive depth and sea temperature. The penguins’ foraging trips recorded during five summers ranged from 140 to 600 km from the colony and 11,000 dives >100 m were recorded. Temperature measurements recorded during diving were used to produce detailed 3D temperature fields of the area (0–200 m). The data treatment included dive location, determination of the vertical profile for each dive, averaging and gridding of those profiles onto 0.1°×0.1° cells, and optimal interpolation in both the horizontal and vertical using an objective analysis. Horizontal fields of temperature at the surface and 100 m are presented, as well as a vertical section along the main foraging direction of the penguins. Compared to conventional temperature databases (Levitus World Ocean Atlas and historical stations available in the area), the 3D temperature fields collected from penguins are extremely finely resolved, by one order finer. Although TTDRs were less accurate than conventional instruments, such a high spatial resolution of penguin-derived data provided unprecedented detailed information on the upper level circulation pattern east of Kerguelen, as well as the iron-enrichment mechanism leading to a high primary production over the Kerguelen Plateau.

Different Behavior of the Circadian Rhythms of Activity and Body Temperature During Resynchronization Following an Advance of the LD Cycle

Spontaneous activity and the body temperature of laboratory mice were recorded telemetrically using implantable transmitters. Following ten control days (L : D = 12 : 12; light from 07:00 to 19:00), the LD cycle was phase-advanced by shortening the light time by 8 h. Recordings were continued for a further 3 weeks. The raw temperature data were unmasked or ‘purified’ — that is, the temperature changes due to locomotor activity were removed, so revealing the endogenous component of the rhythm — using a regression method previously developed by us. The circadian rhythms of activity and measured body temperature resynchronized on average after 8 days. During resynchronization, both rhythms tended to show two components, one adjusting by a phase advance and the other by a phase delay. However, after purification of the body temperature rhythm, only the advancing component remained. These results indicate that the delaying component of the measured temperature rhythm was caused by masking due to activity, and that the endogenous component of this rhythm did not divide into two components during the resynchronization process. Also, the endogenous component of the circadian rhythm of body temperature and one component of the activity rhythm seemed to be controlled by the same oscillator. It remains uncertain how the other component of the activity rhythm is regulated.

A comparison of the suitabilities of rectal, gut, and insulated axilla temperatures for measurement of the circadian rhythm of core temperature in field studies

Eight healthy males were studied for a total of 13 subject-days to assess if gut (from an ingested pill) and axilla (from a thermally insulated skin probe) temperatures would act as a substitute for rectal temperature in field studies of the circadian rhythm of core temperature. Subjects slept and went about their activities, indoors and outdoors, normally. Regular recordings (at 6min intervals) were made of temperatures from the three sites. In addition, activity was measured (by a sensor on the nondominant wrist) so that the raw temperature data could be “purified,” that is, corrected for the direct effects of sleep and activity. Inspection of the raw data indicated that there was a close parallelism between rectal and gut temperatures, but that the parallelism between rectal and insulated axilla temperatures was less reliable. This parallelism was supported by initial calculations of the correlations between rectal and gut temperatures (high and positive) and between rectal and insulated axilla (lower, though still positive) temperatures. Calculation of the limits of agreement between the parameters of the cosine curves fitted to the raw data confirmed that the rectal and gut temperatures were far closer with regard to acrophase and amplitude than were rectal and insulated axilla temperatures (−0.31±0.89 vs. +0.75±6.03 h and +0.002±0.116 vs. +0.083±0.625°C, respectively). After purification of the temperature data, the limits of agreement for the cosine parameters acrophase and amplitude still indicated that there was a closer agreement between rectal and gut temperatures than between rectal and insulated axilla temperatures (−0.30±1.12 vs. +0.58±6.69 h, and +0.007±0.116 vs. +0.104±0.620°C, respectively). Part of the explanation of this difference was the unreliable relationships between temperature changes in insulated axilla temperature and bursts of activity and going to bed. It is concluded that, whereas gut temperature is a viable alternative to rectal temperature (from the viewpoints of both user acceptability and the reliability of data obtained), insulated axilla temperature, though acceptable to subjects, is unreliable from an experimental viewpoint.

Modeling the Effect of Spontaneous Activity on Core Temperature in Healthy Human Subjects

Nine healthy females were studied about the time of the spring equinox, while living in student accommodation and aware of the passage of solar time. After 7 control days, during which a conventional lifestyle was lived, subjects underwent a 24-h ‘constant routine’, followed by 17 ‘days’ on a 27-h ‘day’ (9 h sleep and 18 h wake). Throughout the experiment, regular recordings of (non-dominant) wrist activity (every 30 s) and rectal temperature (every 6 min) were made. Only the control and 27-h (experimental) ‘days’ have been analysed in the present report. From each subject, 24-h profiles of raw temperature (consisting of 240 points) were obtained: one (control days), by averaging the control days; the other (experimental days), by conflating 16 consecutive 27-h ‘days’. Activity data were first collected into 240 points by summing them over 6-min intervals; they were then converted into three data sets (each of 240 points) for control and, separately, for experimental days. These data sets were summed activities in the previous 18 min (A18), summed activity over the previous 18–30 min (A30), and summed activity over the previous 30–42 min (A42). The raw temperature data sets for control and experimental days were sepa-rately analysed by ANCOVA using two time-of-day factors: ‘hours’ (24 levels) and ‘six-minute-intervals’ (10 levels). The covariate was the three activity data sets; in order to make the analysis more versatile, a cubic polynomial model was used, with a linear, quadratic and cubic term for each of these activity data sets. Moreover, the effects of activity upon core temperature were separately assessed for four 6-h sections of the 24-h profile, centred on its low, rising, high and falling phases. The main results were as follows: 1. All three activity data sets made significant contributions to the model, but that by the A30 data set was the most powerful of the three. This supports the use of activity files covering the previous 30 min in other ‘purification’ methods. 2. Although the linear term was the one that was significant most frequently, quadratic and (negative) cubic terms were also present on several occasions. This result indicates that the effect of activity upon core temperature can be approximated by a linear function (as has been done in other ‘purification’ models), but that, with wider ranges of activity, a sigmoid curve would be more accurate, indicative of the process of thermoregulation. 3. During the experimental days, the effect of activity upon temperature was greater in the rising than the falling temperature phase, and greater in the low than in the high phase. These results are predicted from current understanding of the circadian rhythm of thermoregulation. 4. During control days, the effects of activity were more complex, probably due to the factors that were present at some, but not all, phases — factors such as sleep, meals, changes in posture, lighting, and so on. 5. The ANCOVA also enabled the temperature profiles, corrected for the effects of activity (and, therefore, to be considered as ‘purified’), to be displayed. We conclude that the use of ANCOVA to tackle the problem of ‘purifying’ raw temperature data is a promising one. So far, it has produced results that accord with those from other ‘purification’ methods and with predictions based on our current understanding of the circadian rhythm of thermoregulation.

Experimental instantaneous heat fluxes in the cylinder head and exhaust manifold of an air-cooled diesel engine

An experimental analysis is performed to study the instantaneous heat fluxes, during the engine cycle, in the combustion chamber walls of a direct injection (DI), air cooled, four stroke, Diesel engine located at the authors laboratory. For this purpose, a novel experimental installation has been developed, which separates the engine transient temperature signals into two parts, namely the ‘long’ and the ‘short’ term response ones, followed by their discrete processing in two independent data acquisition systems. Furthermore, a new pre-amplification unit for fast response thermocouples, appropriate heat flux sensors and an innovative, object oriented, control code for fast data acquisition have been designed and developed for the needs of the study. One dimensional heat conduction with Fourier analysis of the raw temperature data are implemented in order to calculate the instantaneous engine cylinder and exhaust pipe heat fluxes. Analysis of the experimental results reveal many interesting aspects of transient engine heat transfer. The effect of engine speed on cylinder head and exhaust manifold heat losses is presented. The simultaneous presentation of heat fluxes on the cylinder head and exhaust manifold, together with the engine indicator diagram, sheds light into the mechanisms governing the transient heat transfer. This is very important, since especially for air cooled Diesel engines, limited information seems to exist in the relevant literature.

Estimates of the Daily Phase and Amplitude of the Endogenous Component of the Circadian Rhythm of Core Temperature in Sedentary Humans Living Nychthemerally

Fifteen healthy female subjects were studied for eight days while living conventionally. Subjects were free to choose the ways they spent their time within a framework of regular times of retiring and rising; in practice, much of the waking time was spent in sedentary activities. Nine of the subjects were aware of the natural light-dark cycle, this approximating to a 12:12 L:D schedule at the time of year when the study took place. Before the study, subjects were assessed for their degree of "morningness" by questionnaire; throughout the study, they wore a rectal probe, and an activity meter on their non-dominant wrist. The timing (phase) and amplitude of the circadian rectal temperature rhythm were assessed on each day by cosinor analysis as well as by a me thod based on visual inspection of the data. These two parameters were also assessed after the temperature data for each day had been "purified" by a number of methods. From these results it was possible to investigate the effect of purification upon the amplitude of the circadian rhythm of temperature. Also, the day-by-day variability of phase, and the relationship between morningness and phase, were compared using these methods of phase estimation, and using cross-correlation between data sets from adjacent days; in all cases, raw and purified temperature data were used. There was a significantly greater amount of daily variation in phase using purified rather than raw data sets, and this difference was present with all methods of purification as well as with all methods for estimating phase. Purifi cation decreased the amplitude of the circadian temperature rhythm by about 30%. Finally, there was a significant correlation between the morningness score of the subjects and the phase of the circadian temperature rhythm, the phase becoming earlier with increasing morningness; when this relationship was re-examined using purified data, it became more marked. These results reflect the masking effects exerted upon raw temperature data by lifestyle. The extent to which the purification methods enable the endogenous component of a circadian rhythm – and, by implication, the output of the endogenous circadian oscillator – to be estimated in subjects living normally is addressed.

A COMPARISON OF SOME DIFFERENT METHODS FOR PURIFYING CORE TEMPERATURE DATA FROM HUMANS

Nine healthy females were studied about the time of the spring equinox while living in student accommodations and aware of the passage of solar time. After 7 control days, during which a conventional lifestyle was lived under a 24h “constant routine,” the subjects lived 17 × 27h “days” (9h sleep in the dark and 18h wake using domestic lighting, if required). Throughout the experiment, recordings of wrist activity and rectal (core) temperature were taken. The raw temperature data were assessed for phase and amplitude by cosinor analysis and another method, “crossover times,” which does not assume that the data set is sinusoidal. Two different purification methods were used in attempts to remove the masking effects of sleep and activity from the core temperature record and so to measure more closely the endogenous component of this rhythm; these two methods were “purification by categories” and “purification by intercepts.” The former method assumes that the endogenous component is a sinusoid, and that the masking effects can be estimated by putting activity into a number of bands or categories. The latter method assumes that a temperature that would correspond to complete inactivity can be estimated from measured temperatures by linear regression of these on activity and extrapolation to a temperature at zero activity. Three indices were calculated to assess the extent to which exogenous effects had been removed from the temperature data by these purification methods. These indices were the daily variation of phase about its median value; the ratio of this variation to the daily deviation of phase about midactivity; and the relationship between amplitude and the square of the deviation of phase from midactivity. In all cases, the index would decrease in size as the contribution of the exogenous component to a data set fell. The purification by categories approach was successful in proportion to the number of activity categories that was used, and as few as four categories produced a data set with significantly less masking than raw data. The method purification by intercepts was less successful unless the raw data had been “corrected” to reflect the direct effects of sleep that were independent of activity (a method to achieve this being produced). Use of this purification method with the corrected data then gave results that showed least exogenous influences. Both this method and the purification by categories method with 16 categories of activity gave evidence that the exogenous component no longer made a significant contribution to the purified data set. The results were not significantly influenced by assessing amplitude and phase of the circadian rhythm from crossover times rather than cosinor analysis. The relative merits of the different methods, as well as of other published methods, are compared briefly; it is concluded that several purification methods, of differing degrees of sophistication and ease of application to raw data, are of value in field studies and other circumstances in which constant routines are not possible or are ethically undesirable. It is also concluded that such methods are often somewhat limited insofar as they are based on pragmatic or biological, rather than mathematical, considerations, and so it is desirable to attempt to develop models based equally on mathematics and biology. (Chronobiology International, 17(4), 539–566, 2000)

Forced Desynchrony of Orcadian Rhythms of Body Temperature and Activity in Rats

The daily rhythm in body temperature is thought to be the result of the direct effects of activity and the effects of an endogenous circadian clock. Forced desynchrony (FD) is a tool used in human circadian rhythm research to disentangle endogenous and activity-related effects on daily rhythms. In the present study, we applied an FD protocol to rats. We subjected 8 rats for 5 days to a 20h forced activity cycle consisting of lOh of forced wakefulness and lOh for rest and sleep. The procedure aimed to introduce a lOh sleep/ lOh wake cycle, which period was different from the endogenous circadian (about 24h) rhythm. Of the variation in the raw body temperature data, 68–77% could be explained by a summation of estimated endogenous circadian cycle and forced activity cycle components of body temperature. Free-running circadian periods of body temperature during FD were similar to free-running periods measured in constant conditions. The applied forced activity cycle reduced clock-related circadian modulation of activity. This reduction of circadian modulation of activity did not affect body temperature. Also, the effects of the forced activity on body temperature were remarkably small.

Regression Analysis of Microwave Spectra for Temperature-Compensated and Density-Independent Determination of Wheat Moisture Content

Partial least-squares regression (PLSR) was used to generate wheat moisture content predictive models from eight-frequency microwave attenuation (A) and phase (P) spectra in the 10.36 to 18.0 GHz range, as obtained by a free-space technique with a 10.4 cm thick sample. Spectra (n = 379) were measured for a set of grain samples that had been treated to span the agriculturally practical ranges of moisture content (M) (10.6 to 19.2% g/g wet), temperature (K) (- 1 to 42 C), and bulk density (D) (0.72 to 0.88 g/mL). The sample property space formed by M, K, and D was used to prune redundant samples and select representative subsets for calibration (n = 279), cross-validation (n = 40 segments), and testing (n = 31). Twelve model types are reported and vary from attenuation or phase alone to the combination of attenuation, phase, temperature, and density (i.e., APKD). For optimization of each PLSR model, the raw spectral, temperature, and density data were preprocessed with variable ratios, mathematical transformations, and/or variable scaling. The lowest moisture prediction errors were for temperature and density-corrected models with variables AKD or APKD; these produced root-mean-square cross-validation and prediction errors (RMSECV and RMSEP) of 0.19 to 0.20% in moisture content units. The more practical unifrequency models, APK at 15.2 GHz, and AK at 18.0 GHz, yielded RMSECV values of 0.21% and 0.35%, respectively. Addition of temperature to dielectric data always substantially reduced the model error. However, the multiplicative effect of density is well corrected by using the ratio A/P, or partly corrected by using the features in the attenuation spectra. Data trends suggest that dual-frequency PK models might benefit from a wider frequency range, and unifrequency AK models might be better at frequencies higher than 18.0 GHz. The results presented make it possible to evaluate a wide variety of instrumental configurations that might be proposed to suit particular engineering criteria such as measurement accuracy, range of operating conditions, and hardware complexity.

Theory of transient experimental techniques for surface heat transfer

The paper describes the unified mathematical procedures of transient methods for measuring surface heat transfer rates. Three heat flux gauges are discussed: thin film, thick-wall gauges placed on semi-infinite substrates and thin-skin calorimeters. The aim of this paper is to present a method for a simple and accurate determination of the time-varying heat transfer coefficient (or heat flux) given an accurate temperature history of the body at a selected point beneath the surface. The interior temperature measurements are converted into local instantaneous heat transfer coefficients by solving the inverse heat conduction problem for the gauge. The effect of the inaccuracies in the measurement of the interior temperature was eliminated by cubic spline smoothing or digital filtering of the raw interior temperature data prior to using it in the inverse heat conduction analyses. General case closed form equations for instantaneous surface heat flux, or heat transfer coefficient, are developed.

Gridpoint Predictions of High Temperature from a Mesoscale Model

Mesoscale model gridpoint temperature data from simulations in the southwestern United States during the summer of 1990 are compared with both observations and statistical guidance from large-scale models over a 32-day period. Although the raw model temperature data at the lowest sigma level typically are much lower than observed, when the mean temperature bias is removed, the model values of high temperature compare favorably with both observations and operational statistical guidance products. A simple 7-day running mean bias calculation that could be used in an operational environment is tested and also found to produce good results. These comparisons suggest that the ability of mesoscale model gridpoint data to produce useful and accurate forecast products through the use of very simple bias corrections should be explored fully as mesoscale model data become routinely available.

Separating the endogenous and exogenous components of the circadian rhythm of body temperature during night work using some 'purification' models.

Ten nurses have been studied for a period of about ten days during which they had rest days and between two and seven successive night shifts. Rectal temperature and wrist movement were monitored throughout, and the nurses kept an activity log. The process of adjustment to night work was assessed by comparing shifts in body temperature with those in mid-sleep, using the mean of the values during rest days as a control in both cases. When raw temperature data were used, the measured shifts were significantly greater than when the temperature data were first modified or 'purified' by a series of methods that took into account the direct effects upon temperature of sleep and physical activity. The greater the 'purification' of the data--whether by using an activity profile derived from a wrist accelerometer or the subject's own log--the less rapid did adjustment to night work appear to be. We conclude that conventional measurements of the adjustment of the temperature rhythm to night work that make use of raw data over-estimate it due to masking effects. We suggest also that the purification methods that we have developed can be used in the field and enable estimates to be made of the size of masking effects caused by sleep and activity, as well as the shift of the endogenous component of the circadian rhythm.

Factors Affecting Capture of Corn Rootworm Beetles (Coleoptera: Chrysomelidae) at Traps Baited with Nonpheromonal Attractants

Adult western corn rootworm, Diabrotica virgifera virgifera LeConte, and northern corn rootworm, D. barberi Smith and Lawrence, were captured at white and yellow sticky traps and at traps made from plastic vials that contained a mixture of a toxicant and a feeding stimulant. Over 18 d, capture of western corn rootworm was up to 100 times greater at traps baited with estragole or p -methoxycinnamonitrile ( p -MCN) than at unbaited traps; baits of eugenol produced 3- to 50-fold increases in capture of northern corn rootworm. Addition of indole to baits containing estragole or p -MCN had little effect on capture at sticky traps but reduced numbers of both species caught in vials. Daily temperature-activity indices, based on bi-hourly temperatures and on actograph data from a previously published study, explained 26% (female) and 50% (male) of day-to-day variation in capture for western corn rootworm but only about 8% for northern corn rootworm. Lesser proportions of daily variation in capture were explained by raw temperature data and by measurements of wind, humidity, and numbers of beetles on plants. When traps were baited with 5, 50, or 500 mg of the attractants, catch of northern corn rootworm on sticky traps increased with the amount of eugenol, but catch of western corn rootworm in vials declined with increases in amount of attractant. Dose of attractant had relatively little effect on capture of western corn rootworm on sticky traps or northern corn rootworm in vials. Both species were captured primarily around midday, except that large numbers of northern corn rootworm (particularly males) were also captured on warm nights.

Approximate Geothermal Gradients in Niger Delta Sedimentary Basin

More than 1,000 well logs from the Niger delta sedimentary basin were examined for temperature-data quality. Most measurements were made within 4 to 8 hours of cessation of mud circulation. Such nonequilibrium temperatures were corrected to approximately true formation values by applying a numerical solution to a modified Lachenbruch-Brewer's equation. The subsurface temperature distributions based on both the raw and corrected temperature data, when presented as geothermal gradient maps, show that values are lowest over the center of the Niger delta, approximately 0.7 to 1.0°F/100 ft, and they increase to about 3°F/100 ft in the Cretaceous rocks on the north. The geothermal gradient map in the Niger delta could be used in the application of the hydrocarbon liquid-window concept for oil exploration. It reveals that theoretically there is a considerable thickness of potentially hydrocarbon-bearing interval in the delta region that is unexplored by current drilling programs.