scholarly journals Long-Term Global Irradiance Calibration of Multifilter UV Radiometers

2019 ◽  
Vol 36 (12) ◽  
pp. 2415-2427
Author(s):  
A. A. Piedehierro ◽  
M. L. Cancillo ◽  
J. M. Vilaplana ◽  
A. Serrano

AbstractMultifilter instruments such as the Norwegian Institute for Air Research (NILU)-UV Irradiance Meter (NILU-UV) are suitable for long-term monitoring of UV radiation, as long as their irradiance scale is maintained. The sensitivity of these instruments varies with time; thus, periodic standard absolute calibrations are required. However, standard calibrations may be insufficient to characterize the short-term variations of channels sensitivity. Therefore, results from standard calibrations have to be combined with the information derived from frequent relative calibrations, leading to a stable irradiance scale. This paper focuses on the long-term application of three calibration methods, hereinafter referred to as CC, CC2, and CC2(ϕ), as applied to the NILU-UV 119 multifilter radiometer. Here a generalization is proposed, consisting of using empirical functions in order to guarantee the accurate calibration of multifilter instruments over long time periods. These function-based methods need to be updated regularly to account for changes on instrument sensitivity. The changes in sensitivity of the NILU-UV 119 were found to be channel dependent. The detected drifts range from 23% to 42% for a 4-yr period of study. Time series of calibrated irradiance are obtained by applying the proposed methods. Results suggest that calibration methods using empirical functions perform better than classic calibration approaches that use constant calibration factors. When methods CC2 and CC2(ϕ) are applied, calibrated irradiances agree with the measurements of reference within ±5% for channel 305 and within ±3% for channels 312, 320, and 340.

2003 ◽  
Vol 37 (2) ◽  
pp. 13-22 ◽  
Author(s):  
Sean Wiggins

Advancements in low-power and high-data capacity computer technology during the past decade have been adapted to autonomously record acoustic data from vocalizing whales over long time periods. Acoustic monitoring of whales has advantages over traditional visual surveys including greater detection ranges, continuous long-term monitoring in remote locations and in various weather conditions, and lower cost. An autonomous acoustic recording package (ARP) is described that uses a tethered hydrophone above a seafloor-mounted instrument frame. ARPs have been deployed to record baleen whale sounds in the Bering Sea, off the coast of southern California, near the West Antarctic Peninsula, and near Hawaii. ARP data have provided new information on the seasonal presence, abundance, call character, and patterns of vocalizing whales. Current development is underway for a broader-band, higher-data capacity system capable of recording odontocete whales, dolphins, and porpoises for long time periods.


2021 ◽  
Author(s):  
Andreas Heinemeyer ◽  
Anthony Jones ◽  
Tom Holmes ◽  
Abby Mycroft ◽  
Will Burn ◽  
...  

<p>Large parts of the rather cold and wet UK uplands are dominated by peatlands, specifically blanket bogs. During most of the Holocene, those peatlands have locked away carbon for many thousands of years due to water logged conditions leading to low decomposition rates and long-term accumulation of soil organic matter as peat. Importantly, this peat accumulation not just increases carbon but also water storage and provides many other associated and vital ecosystem services to societies across the UK, such as drinking water.</p><p>However, since around 1850, much of the UK uplands have been under grousemoor management to encourage red grouse populations as part of shooting estates, including controversial drainage, heather burning, and more recently, alternative cutting. Due to the rather weak and often conflicting evidence base around impacts of such management more research is needed to unravel climate and management impacts on ecosystem functions and associated ecosystem services. Much of the controversial evidence base is based on short-term monitoring of only a few years (potentially misinterpreting short-term disturbance effects as long-term impacts), single site studies (not capturing edaphic and climatic variability) and space-for-time studies, often with different treatments located at different sites (and thus limited in their ability or even unable to disentangle confounding variables such as site environmental conditions/history from actual management impacts).</p><p>We present long-term data from a previously government-funded, and currently multi-funded and to 10 years extended, peatland management project investigating ecosystem functions from plot-to-catchment scales on three grousemoor sites across Northern England. The <strong>Peatland-ES-UK</strong> project is part of the Ecological Continuity Trust’s long-term monitoring network and is based on a Before-After Control-Impact design approach. Each of three replicated field sites consist of two paired 10 ha catchments under previous burn rotation management and part of current peatland restoration work. After one year of pre-treatment monitoring, catchments were allocated either a continuation of burning or an alternative mowing post-treatment catchment management rotation (the latter containing several 5x5 m sub-treatment monitoring plots including no management). Monitoring includes assessing hydrology, water budgets, carbon cycling, greenhouse gas emissions, peat properties, vegetation composition and key biodiversity.</p><p>We shall provide new and sometimes surprising and even challenging insights into blanket bog ecosystem functioning in an ecosystem services and habitat status context, highlighting the importance of long-term monitoring, experimental design, spatio-temporal changes and remaining uncertainties. Specifically, we shall present findings about water storage (water tables and stream flow), long-term carbon accumulation rates (peat cores), recent carbon budgets (flux chambers) and net greenhouse gas emissions (including methane). We also present some peatland model predictions around various land use impacts on past, present and future carbon storage potential. Finally, we call for a joint funding commitment across research, policy and land user organisations to ensure the continuation of such joined-up ‘real-world’ experimental and long-term monitoring work, as part of a national applied research platform network, as it provides the “gold standard” to inform evidence-based policy directly related to practitioner needs.</p>


2017 ◽  
Vol 13 (S336) ◽  
pp. 279-280 ◽  
Author(s):  
Busaba H. Kramer ◽  
Karl M. Menten ◽  
Alex Kraus

AbstractWe present the results from an ongoing long-term monitoring of the 22 GHz H2O maser in W49N with the 100-m Effelsberg radio telescope from February 2014 to September 2017. The unique Effelsbergs spectral line observation capability provides a broad velocity range coverage from −500 to +500 km s−1 with a spectral resolution better than 0.1 km/s. Following the strong major outburst in W49N in late 2013, we have started a long-term monitoring programme at Effelsberg. The major outburst feature (up to 80,000 Jy at VLSR − 98 km s−1) faded away by June 2014. However, we found that the site is still active with several high velocity outbursts (both blue and redshifted). Some features appear at extremely high velocities (up to ±280 km s−1) and show rapid flux variations within a 1-2 month period. This sub-year scale variability implies that the water masers could be excited by episodic shock propagation caused by a high-velocity protostellar jet.


2021 ◽  
Vol 9 ◽  
Author(s):  
Evgenii Vorobeichik ◽  
Alexey Nesterkov ◽  
Elena Golovanova ◽  
Dina Nesterkova ◽  
Alexander Ermakov ◽  
...  

Since the late 1980s, long-term monitoring of terrestrial ecosystems in metal-contaminated areas has been carried out in the Central Urals. As a part of these monitoring programmes, the data on soil macroinvertebrates in undisturbed areas as reference sites continues to be gathered. These data help study the local biodiversity and long-term dynamics of soil macroinvertebrate abundance in non-polluted areas. The dataset (available from the GBIF network at https://www.gbif.org/dataset/bf5bc7f6-71a3-4abd-8abc-861ee3cbf84a) includes information from a long-term monitoring programme for two taxa of Annelids, Lumbricidae and Enchytraeidae, which dwell in the topsoil of spruce-fir, birch, pine and floodplain forests in the Central Urals. The dataset includes information on the earthworm community structure (list of species, species abundance, number of egg cocoons, cocoon exuvia, juveniles and adults) and enchytraeid abundance. The dataset consists of 553 sampling events (= samples, corresponding to upper and lower layers of the soil monoliths) and 12739 occurrences (earthworms, mainly identified to species and earthworm cocoons and enchytraeids, identified to family) collected during 1990–1991, 2004, 2014–2016 and 2018–2020. In total, 3305 individuals of earthworms were collected, representing ten (out of twelve) species and all eight genera recorded for the fauna of the Central Urals. In addition, 7292 earthworm egg cocoons and cocoon exuvia and 6926 individuals of enchytraeids were accumulated. The presence-absence data on each of the ten earthworm species, egg cocoons, cocoon exuvia and enchytraeids are provided for each sampling event. All data were collected in undisturbed non-polluted areas and are used as a local reference for ecotoxicological monitoring. The dataset provides valuable information for estimating the composition and abundance of earthworm communities in different habitats over a long time and contributes to the study of soil fauna biodiversity in the Urals.


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