Automatic Loggers Research Articles

Mapping the potential distribution of frozen ground in Tucarroya (Monte Perdido Massif, the Pyrenees)

This paper shows the creation of a map of frozen ground potential for the Tucarroya valley in Ordesa National Park. To create this map, it was necessary to combine the identified landforms associated to the presence of frozen ground by fieldwork, ground temperature data continuously recorded during two years by automatic loggers, a Basal Temperature of Snow (BTS) survey, and predictor variables derived from a high resolution Digital Elevation Model (DEM). Four environments have been differentiated: unfrozen ground, seasonal frozen ground, possible permafrost and probable permafrost. The map confirms a very limited variety and extension of permafrost, above 2700 m a.s.l. on gentle and shadowed slopes. Seasonal frozen ground is the most common thermal regime, as it can be developed above 2500 m a.s.l. Snow-pack duration and thickness tightly control the duration of frozen ground and the freezing-thawing cycles. Frost activity and unfrozen ground is restricted from 2570 to 2750 m a.s.l.

Pacific climate reflected in Waipuna Cave drip water hydrochemistry

Abstract. Cave microclimate and geochemical monitoring is vitally important for correct interpretations of proxy time series from speleothems with regard to past climatic and environmental dynamics. We present results of a comprehensive cave-monitoring programme in Waipuna Cave in the North Island of New Zealand, a region that is strongly influenced by the Southern Westerlies and the El Niño–Southern Oscillation (ENSO). This study aims to characterise the response of the Waipuna Cave hydrological system to atmospheric circulation dynamics in the southwestern Pacific region in order to assure the quality of ongoing palaeo-environmental reconstructions from this cave. Drip water from 10 drip sites was collected at roughly monthly intervals for a period of ca. 3 years for isotopic (δ18O, δD, d-excess parameter, δ17O, and 17Oexcess) and elemental (Mg∕Ca and Sr∕Ca) analysis. The monitoring included spot measurements of drip rates and cave air CO2 concentration. Cave air temperature and drip rates were also continuously recorded by automatic loggers. These datasets were compared to surface air temperature, rainfall, and potential evaporation from nearby meteorological stations to test the degree of signal transfer and expression of surface environmental conditions in Waipuna Cave hydrochemistry. Based on the drip response dynamics to rainfall and other characteristics, we identified three types of discharge associated with hydrological routing in Waipuna Cave: (i) type 1 – diffuse flow, (ii) type 2 – fracture flow, and (iii) type 3 – combined flow. Drip water isotopes do not reflect seasonal variability but show higher values during severe drought. Drip water δ18O values are characterised by small variability and reflect the mean isotopic signature of precipitation, testifying to rapid and thorough homogenisation in the epikarst. Mg∕Ca and Sr∕Ca ratios in drip waters are predominantly controlled by prior calcite precipitation (PCP). Prior calcite precipitation is strongest during austral summer (December–February), reflecting drier conditions and a lack of effective infiltration, and is weakest during the wet austral winter (July–September). The Sr∕Ca ratio is particularly sensitive to ENSO conditions due to the interplay of congruent or incongruent host rock dissolution, which manifests itself in lower Sr∕Ca in above-average warmer and wetter (La Niña-like) conditions. Our microclimatic observations at Waipuna Cave provide a valuable baseline for the rigorous interpretation of speleothem proxy records aiming at reconstructing the past expression of Pacific climate modes.

Static Survey as Geological Engineering Method Verification of DSM Column Formation

The state-of-the-art methods for verifying the correctness of ground improvement performed using the DSM (Deep Soil Mixing) technology are largely focused on the selection of adequate factors impacting the achievement of a correct compressive strength fc [MPa] of the column core, which ensures the transfer of stress from the designed structures to the subsoil. In view of the operation of each of the columns, it is equally significant to ensure that their bases are located in load-bearing soil at the entire area of the improvement, without the need to perform many costly subsoil surveys. Based on the complementary soil investigation results and parameters obtained during deep soil mixing from an automatic logger installed on the drilling machine, a method of comparing the rotary drive pressure (working pressure) PKDK [bar] and the cone resistance qc [MPa] of the CPTU static probe (Cone Penetration Test Unit with Pore Pressure Measurement) was developed along with the method to interpret the results in the context of the correctness of the ground improvement on the construction site analyzed in this paper.

Recharge estimation from discrete water-table datasets in a coastal shallow aquifer in a humid subtropical climate

A time-series approach to the estimation of recharge rate in unconfined aquifers of highly variable water level is proposed. The approach, which is based on the water-table fluctuation method (WTF), utilizes discrete water-level measurements. Other similar techniques require continuous measurements, which makes them impossible to apply in cases where no data from automatic loggers are available. The procedure is deployed at the Ressacada Farm site, southern Brazil, on a coastal shallow aquifer located in a humid subtropical climate where diurnal water-level variations of up to 1 m can follow a precipitation event. The effect of tidal fluctuations on the groundwater levels is analyzed using a harmonic component builder, while a time-variable drainage term is evaluated through an independent analysis and included in the assessment. The estimated recharge values are compared with those obtained from the continuous measurements showing a good agreement with the approaches for discrete dataset intervals of up to 15 days. Subsequently, the estimated recharge rates are incorporated into a transient groundwater-flow model and the water levels are compared showing a good match. Henceforth, the approach extends the applicability of WTF to noncontinuous water-level datasets in groundwater recharge studies.

Experimental Tests of I Profile Made from UHPC Reinforced with Textile Glass Fibres

This abstract is summarizing production and subsequent experimental testing of 3D profile of the symmetrical I shape concrete from UHPC matrix and reinforced with textile glass fibres. Upper and bottom covering strips of this profile are at the outside fibres reinforced with textile glass reinforcement. Position of this reinforcement is fixed in the distance of about 3 mm from outside fibres and is connected with reinforcement of the profile stem located in its axis. Such prepared beams were tested with four-point flexure evenly loaded until fracture. Course of the measurement was continuously recorded by the automatic logger, where mostly increase of the force in relation to deflection in the middle of the span and change of position of supports were recorded. From the recorded data were prepared graphic outputs compared with the same experiments performed on I profile which is not reinforced, i.e. only UHPC matrix, and for comparison also on the profile made from UHPC matrix with use of metal wires. In the conclusion were compared achieved test results. Mainly suitability and loading capacity of individual beam types was compared. Within the experiment were performed supporting tests based on which were determined material characteristics of tested matrix and textile glass reinforcement. Tests were performed in the Klokner Institute within solution of the grant project GACŘ 13-12676S.

Reprint of: Salinity responses to inflow alterations in a 6500 ha Typha wetland

Salinity has affected the Colorado River for more than five decades: agriculture, mining and urban sprawl have exacerbated the problem, with the most severe impacts occurring in its southern basin and Mexico. However, moderate salinities (2.6gL−1 Total Dissolved Solids) and constant average flows (4m3s−1) from a U.S. agriculture drain, have allowed the establishment of a 6500ha cattail (Typha domingensis) dominated wetland in the mudflats of the upper Gulf of California in Mexico, called “Cienega de Santa Clara” (Cienega). This wetland could now be threatened due to the operation of the Yuma Desalting Plant (YDP). Operations will result in reduced flows and salinity increases in the canal that feeds the wetland. From 2006 to 2011 we monitored water quality conditions at the Cienega as part of a binational effort. Monthly monitoring of field parameters was made at the inflows and at 28 stations inside the wetland. In 2010, 4 automatic loggers were installed inside the wetland to take half an hour readings of temperature and salinity. At the center of the Cienega from 70 to 80% of salinity variations depended on salinity from the main inflow; this response was observed with both monthly data and daily data, indicating a rapid response from salinity inflows. The YDP demonstration run at 10% capacity caused a mean salinity increase from 3.0 to 3.3gL−1 TDS at the center of the wetland and from 3.8 to 5.2gL−1 TDS salinity increase at the periphery. During the YDP pilot run at one-third capacity, mean salinity increased from 3.2 to 4.3gL−1 TDS at the center of the wetland and from 4.3 to 8.3gL−1 TDS at the periphery. There was no evidence of upper Gulf of California tidal intrusion into the wetland. Salinity concentrations at the main inflow should not exceed 3.0gL−1 TDS in order to prevent a reduction in cattail growth inside the wetland. Nevertheless, our recommendation is to maintain salinities at 2.6±0.2gL−1 TDS at the main inflow, in order to preserve vigorous cattail stands. Operation of the YDP plant at 10%, one-third, two-thirds and full capacity without replacement water, will have negative effects on the vegetation. Future efforts should be oriented to compensate for possible salinity increases.

Salinity responses to inflow alterations in a 6500 ha Typha wetland

Salinity has affected the Colorado River for more than five decades: agriculture, mining and urban sprawl have exacerbated the problem, with the most severe impacts occurring in its southern basin and Mexico. However, moderate salinities (2.6gL−1 Total Dissolved Solids) and constant average flows (4m3s−1) from a U.S. agriculture drain, have allowed the establishment of a 6500ha cattail (Typha domingensis) dominated wetland in the mudflats of the upper Gulf of California in Mexico, called “Cienega de Santa Clara” (Cienega). This wetland could now be threatened due to the operation of the Yuma Desalting Plant (YDP). Operations will result in reduced flows and salinity increases in the canal that feeds the wetland. From 2006 to 2011 we monitored water quality conditions at the Cienega as part of a binational effort. Monthly monitoring of field parameters was made at the inflows and at 28 stations inside the wetland. In 2010, 4 automatic loggers were installed inside the wetland to take half an hour readings of temperature and salinity. At the center of the Cienega from 70 to 80% of salinity variations depended on salinity from the main inflow; this response was observed with both monthly data and daily data, indicating a rapid response from salinity inflows. The YDP demonstration run at 10% capacity caused a mean salinity increase from 3.0 to 3.3gL−1 TDS at the center of the wetland and from 3.8 to 5.2gL−1 TDS salinity increase at the periphery. During the YDP pilot run at one-third capacity, mean salinity increased from 3.2 to 4.3gL−1 TDS at the center of the wetland and from 4.3 to 8.3gL−1 TDS at the periphery. There was no evidence of upper Gulf of California tidal intrusion into the wetland. Salinity concentrations at the main inflow should not exceed 3.0gL−1 TDS in order to prevent a reduction in cattail growth inside the wetland. Nevertheless, our recommendation is to maintain salinities at 2.6±0.2gL−1 TDS at the main inflow, in order to preserve vigorous cattail stands. Operation of the YDP plant at 10%, one-third, two-thirds and full capacity without replacement water, will have negative effects on the vegetation. Future efforts should be oriented to compensate for possible salinity increases.

The Cow Ate My Fieldwork

![Figure][1] CREDIT: PETER HOEY/[WWW.PETERHOEY.COM][2] Life is easier today than when I studied stream temperature more than half a century ago. Unlike today, when scientists can collect data with automatic loggers, we had to be in the stream for every data point, night and day. Back then, during winter nights, a fire and an improvised shelter made life more comfortable. An alarm clock rang when it was time to read the thermometer. During summertime, we set up shelters in haystacks. I have good memories of those nights: shooting stars, nocturnal birds, and moonlight. However, I eventually realized that I had to choose between good data and pleasant memories. So I went high-tech: a mercury thermograph. The device was clumsy and heavy, but it could paint a week's temperatures on paper on a rotating drum. I had decided to investigate a weak trend in my haystack data with the new equipment. Four weeks of extraordinary high summer had confirmed an increasing trend. Now, at the last and most critical station, the thermograph had painted the temperatures of another high-summer week. How exciting it was to remove the paper from the drum and discover the trend that I had suspected—data destined for future textbooks! Eager to duplicate the findings, I changed the paper on the drum, leaving the saved graph safe under the weight of a stone. Busy and excited, I was not aware that I had company. No, it was not a farmer's young daughter, but a farmer's young and very inquisitive calf. In a split second, he snatched my paper graph from under the stone with his long tongue and ran. I pursued the fleeing beast, got a firm hold on its tail, lost my balance, and was drawn through water and dirt, only to watch the mischievous creature slowly and deliberately consume my data. Needless to say, this was the end of the high summer. And of my venture into fluvial temperature regimes. [1]: pending:yes [2]: http://WWW.PETERHOEY.COM

A Ten-year Period of Daily Sea Surface Temperature at a Coastal Station in Reunion Island, Indian Ocean (July 1993 – April 2004): Patterns of Variability and Biological Responses

Sea surface temperature (SST) was recorded hourly by an automatic data recorder in Reunion Island, at Pointe des Galets (21°55 S, 55°17 E) during 1993-2004. The data logger was installed on a beacon located at the port entrance exposed to the open sea. The SST measurements associated with auxiliary environmental data, such as wind stress, depict the main patterns of variability at various timescales for the marine climate of Reunion Island. The ’ten-year’ annual mean temperature is 25.7°C and the annual amplitude is 4.6°C. The highest monthly means are observed in February and March (28.0°C) and the lowest occur in September (23.4°C). The daily variation ranges from 0.25 to 0.74°C according to the season. In summer, the tropical cyclones are the major cause of short term variability, with sudden drops of SST than can exceed 2°C within a few hours. The annual cycle of SST is closely associated with that of wind stress, with a lagged response of about 2 months of SST to wind forcing. Throughout the ‘ten-year period’ covered by our dataset, the coldest years were 1993 and 2000, and the warmest were 2003 and 2004. A trend of increasing SST is suggested for the two major seasons, with a magnitude of 0.088°C/yr in summer and 0.052°C/yr in winter. Finally, the SST trend and variability depicted at our sampling site is shown to reflect the SST patterns of the whole south tropical Indian Ocean. Biological responses to SST variability are shown by coral bleaching events and the local tuna fishery. The major coral bleaching events recorded in Reunion in 1998, 2001, 2003 and 2004 occurred during episodes of intense and sustained anomalous high temperatures. The catch per unit effort (CPUE) of the local pelagic fishery was negatively correlated to SST anomalies with a decreasing trend of CPUE observed over the years, accompanied by an overall increase of SST. The SST observations made in Reunion Island, in a largely unsampled region of the Indian Ocean, show their relevance at a larger regional scale and their usefulness in monitoring changes of some biological components of the marine ecosystem. These examples highlight the need to maintain networks of automatic loggers worldwide at coastal stations.

Simulation and measurement procedures for effective isolated wind and hybrid system development in south Patagonia

This paper presents results of experience with simulation and measurement systems applied to local wind and hybrid (wind-diesel) isolated systems in south Patagonia, especially in Santa Cruz and Chubut provinces (Argentina) and the XII Region of Magallanes in Chile. Wind resource evaluation with a network of automatic loggers is discussed. Performance measurements include an integrated power curve evaluation system for small wind turbines. Some of the power, energy (early so-called SISMED systems) and commercial wind measurement systems have been operating in the region since 1999 or earlier, and their data provides important insight regarding best practices for sizing criteria in local wind and climate regimes. The data collected has been of value for validating simulations using NREL's free HOMER software. The more recent Small Wind Turbine – Power Curve Evaluation System (SWT-PCES) addresses the special requirements involved in power curve measurement for small wind turbines, and has been deployed for very low-power isolated systems in Chubut province (Argentina). Data and operational aspects from systems installed are shown and discussed.

Canadian Arctic Permafrost Observatories: Detecting contemporary climate change through inversion of subsurface temperature time series

We describe long‐term permafrost temperature and climate change observatories established in the northeastern Canadian High Arctic (77°–82.5°N). Two sites have deep temperature logs (165 and 800 m), and thermistor cables and automatic loggers have been installed in the upper ∼65 m. The third site has multiple temperature logs at three 61‐m boreholes with thermistor cables frozen into the permafrost. A fourth deep site (750 m) is included for regional completeness. Geothermal spectrum inversion is used to determine ground surface temperature histories. The Little Ice Age is resolved from the mid‐1700s to mid‐1800s with surface temperatures ∼ 1 K below the long‐term mean; a subsequent recovery yields late 20th century surface temperatures ∼3 K higher. These results correlate with similar reconstructions reported for Greenland ice cap holes GRIP and Dye‐3 to the southeast. The Canadian and Greenland surface temperatures show a weak, inverse correlation with the North Atlantic Oscillation, suggesting recent climate change as a common causal source. Simultaneous inversions of multiple logs over 22 years at the 61‐m holes resolve two to three major cycles in ground surface temperature variation over the latter half of the 20th century. Here permafrost ground temperatures increase 0.3°–0.5°C/decade, compared to 0.6°C/decade for air temperatures; annual total snow increases 22 cm/decade and may insulate permafrost from the larger transient trends in air temperatures. Finally, atmospheric temperature inversions prevalent in Arctic winters may contribute to anomalously high ground surface temperatures observed at two locations.

Surface soil water dynamics in pastures in northern New South Wales. 2. Surface runoff

Surface runoff can represent a significant part of the hydrological balance of grazed pastures on the north-west slopes of New South Wales, and is influenced by a range of rainfall characteristic, soil property, and pasture conditions. Runoff plots were established on grazed pastures at 3 sites as part of the Sustainable Grazing Systems National Experiment (SGS NE). Pastures were either native (redgrass, wallaby grass and wire grass) or sown species (phalaris, subterranean clover and lucerne) and a range of grazing management treatments were imposed to manipulate pasture herbage mass, litter mass and ground cover. Rainfall and runoff events were recorded using automatic data loggers between January 1998 and September 2001. Stored soil water in the surface layer (0–22.5 cm) was monitored continuously using electrical resistance sensors and automatic loggers. Pasture herbage mass, litter mass and ground cover were estimated regularly to provide information useful in interpreting runoff generation processes.Total runoff ranged from 6.6 mm at Manilla (0.3% of rainfall) to 185 mm at Nundle (5.7% of rainfall) for different grazing treatments, with the largest runoff event being recorded at Nundle (46.7 mm). Combined site linear regression analyses showed that soil depth, rainfall depth and rainfall duration explained up to 30.3% of the variation in runoff depth. For individual sites, these same variables were also important, accounting for 13.3–33.6% of the variation in runoff depth. Continuous monitoring of stored soil water in relation to these runoff events indicated that the majority of these events were generated by saturation excess, with major events in winter contributing substantially to regional flooding. Long-term simulation modelling (1957–2001) using the SGS Pasture Model indicated that most runoff events were generated in summer, which concurred with the number of flood events recorded at Gunnedah, NSW, downstream of the SGS sites. However, floods also occurred frequently in winter, but the simulations generated few runoff events at that time of the year. These results have important implications for sustainability of grazed pastures and long-term simulation modelling of the hydrological balance of such systems, since runoff generation processes are likely to vary both spatially and temporally for different rainfall events.

Hindrances to upstream migration of atlantic salmon (Salmo salar) in a northern Swedish river caused by a hydroelectric power‐station

AbstractMany Baltic salmon rivers have lost their natural juvenile production due to human activities blocking or reducing access to their spawning grounds, e.g. damming, power generation, partial hinders, etc. One such hindrance is a hydroelectric complex located in the lower reaches of River Umeälven in northern Sweden. Water from the forbay created by the dam Norrfors is directed to the Stornorrfors power‐station. At times, 100% of the river water is directed to the power‐station. Water from the power‐station then flows via a tunnel and outlet channel to the river. From the point of the tunnel's discharge into the river, the old river bed acts as a bypass channel directing migrating adult fish to a fish ladder located at the base of the dam.In this study, the effect that an additional turbine, that was installed at the power‐station in 1986, had on fish passage run‐time was examined. Changes in run‐time were compared for two periods 1974–1985 and 1986–1995. In 1997, 55 wild and 25 hatchery salmon were captured in the Umeälven estuary, radio tagged with uniquely coded tags, and tracked upstream. Both manual and automatic loggers were used to locate fish daily. The main findings show that only 26% of the wild salmon and none of the hatchery salmon found the fish ladder. It is suggested that the salmon followed the main water discharge from the power‐station outlet and are thus directed away from the entrance to the bypass channel leading to the fish ladder. Salmon respond by moving upstream or downstream depending on the current flow regimes. The bypass channel consists of partial hinders that may explain why it takes on average 52 days for the salmon to migrate 32 km from the estuary to the fish ladder. Adding a fourth turbine at the power‐station did not appear to have changed the timing of the migration or the seasonal distribution of the migrating wild salmon through the fish ladder. There was no significant effect of the fourth turbine on the duration of the middle 50% of the run in any weight‐class for wild salmon. Daily turbine discharges or ambient water temperature and daily counts of wild salmon at the fish ladder were not related. Copyright © 2001 John Wiley & Sons, Ltd.

Instrumentation at Berkeley nuclear power station

From the shut-down power of about 10 watts upwards neutron flux instrumentation is used for reactor power measurement and to operate safety trips. At high powers, control and protection is based on temperature measurements (fuel element, channel gas, graphite etc.). Selected fuel element temperatures can shut down the reactor, others being recorded by multi-point recorders and automatic loggers. The shut-down initiating devices shut down the reactor only if at least two out of the three give a trip signal. The system of faulty fuel element detection employs an automatic logger which computes averages, giving discrimination between random and significant rises in CO2 gas activity. Equipment is also provided, for the detection of leaks between steam and CO2 circuits; in addition radiation activity in and around the station is monitored. Gas and steam flows are measured and the data transmitted by a pneumatic system. The display equipment for the major instrumentation is centralized in or near the station control room.

Closure to “Discussions of ‘Information Center With Automatic Logger and Scanner—Neches Power Station, Gulf States Utilities Company’” (1957, Trans. ASME, 79, p. 1661)

Closure to “Discussions of ‘Information Center With Automatic Logger and Scanner—Neches Power Station, Gulf States Utilities Company’” (1957, Trans. ASME, 79, p. 1661)

Information Center With Automatic Logger and Scanner—Neches Power Station, Gulf States Utilities Company

Abstract Neches Power Station of the Gulf States Utilities Company in Beaumont, Texas, has six relatively small turbine-boiler units. After installing an information system (which includes alarms, scanners, and a logger), sufficient personnel were released to man new large modern units. The installation is expected to pay for itself in three years and to increase over-all plant economy. Hourly unit efficiencies are computed and recorded.