scholarly journals The Cottonwood Lake study area, a long-term wetland ecosystem monitoring site

Fact Sheet ◽  
2012 ◽  
Author(s):  
David M. Mushet ◽  
Ned H. Euliss
Keyword(s):  
Monitoring Site ◽  
Wetland Ecosystem ◽  
Ecosystem Monitoring

scholarly journals The Forest Ecosystem Monitoring Cooperative Long-Term Monitoring Update – 2018

2020 ◽  
Author(s):  
Mathias Nevins ◽  
Alexandra Kosiba ◽  
John Truong ◽  
Rebecca Stern ◽  
Jennifer Pontius
Keyword(s):  
Forest Ecosystem ◽  
Ecosystem Monitoring ◽  
Long Term Monitoring ◽  
Term Monitoring

Environmental drivers of a decline in a coastal zooplankton community

2021 ◽  
Author(s):  
Seòna R Wells ◽  
Eileen Bresnan ◽  
Kathryn Cook ◽  
Dafne Eerkes-Medrano ◽  
Margarita Machairopoulou ◽  
...  
Keyword(s):  
Zooplankton Community ◽  
Water Masses ◽  
Environmental Drivers ◽  
High Temporal Resolution ◽  
Monitoring Site ◽  
Zooplankton Abundance ◽  
Offshore Water ◽  
Additive Mixed Models ◽  
Zooplankton Communities

Abstract Major changes in North Atlantic zooplankton communities in recent decades have been linked to climate change but the roles of environmental drivers are often complex. High temporal resolution data is required to disentangle the natural seasonal drivers from additional sources of variability in highly heterogeneous marine systems. Here, physical and plankton abundance data spanning 2003–2017 from a weekly long-term monitoring site on the west coast of Scotland were used to investigate the cause of an increasing decline to approximately -80± 5% in annual average total zooplankton abundance from 2011 to 2017. Generalized additive mixed models (GAMMs), with an autoregressive correlation structure, were used to examine seasonal and inter-annual trends in zooplankton abundance and their relationship with environmental variables. Substantial declines were detected across all dominant taxa, with ∼ 30–70% of the declines in abundance explained by a concurrent negative trend in salinity, alongside the seasonal cycle, with the additional significance of food availability found for some taxa. Temperature was found to drive seasonal variation but not the long-term trends in the zooplankton community. The reduction in salinity had the largest effect on several important taxa. Salinity changes could partly be explained by locally higher freshwater run-off driven by precipitation as well as potential links to changes in offshore water masses. The results highlight that changes in salinity, caused by either freshwater input (expected from climate predictions) or fresher offshore water masses, may adversely impact coastal zooplankton communities and the predators that depend on them.

scholarly journals Aerosol optical depth retrievals in central Amazonia from a multi-filter rotating shadow-band radiometer calibrated on-site

2019 ◽  
Vol 12 (2) ◽  
pp. 921-934
Author(s):  
Nilton E. Rosário ◽  
Thamara Sauini ◽  
Theotonio Pauliquevis ◽  
Henrique M. J. Barbosa ◽  
Marcia A. Yamasoe ◽  
...  
Keyword(s):  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Spectral Response ◽  
Monitoring Site ◽  
Direct Normal Irradiance ◽  
Central Amazonia ◽  
Long Term Monitoring ◽  
Term Monitoring ◽  
Band Radiometer

Abstract. Extraterrestrial spectral response calibration of a multi-filter rotating shadow band radiometer (MFRSR) under pristine Amazonian Forest atmosphere conditions was performed using the Langley plot method. The MFRSR is installed in central Amazonia as part of a long-term monitoring site, which was used in the context of the GoAmazon2014/5 experiment. It has been operating continuously since 2011 without regular extraterrestrial calibration, preventing its application to accurate monitoring of aerosol particles. Once calibrated, the MFRSR measurements were applied to retrieve aerosol particle columnar optical properties, specifically aerosol optical depth (AODλ) and Ångström exponent (AE), which were evaluated against retrievals from a collocated Cimel Sun photometer belonging to the AErosol RObotic NETwork (AERONET). Results obtained revealed that pristine Amazonian conditions are able to provide MFRSR extraterrestrial spectral response with relative uncertainty lower than 1.0 % in visible channels. The worst estimate (air mass =1) for absolute uncertainty in AODλ retrieval varied from ≈0.02 to ≈0.03, depending on the assumption regarding uncertainty for MFRSR direct normal irradiance measured at the surface. The obtained root mean square error (RMSE ≈0.025) from the evaluation of MFRSR retrievals against AERONET AODλ was, in general, lower than estimated MFRSR AODλ uncertainty, and close to the uncertainty of AERONET field Sun photometers (≈0.02).

scholarly journals Isotopic evidence of increasing water abundance and lake hydrological change in Old Crow Flats, Yukon, Canada

2021 ◽  
Vol 16 (12) ◽  
pp. 124024
Author(s):  
Lauren A MacDonald ◽  
Kevin W Turner ◽  
Ian McDonald ◽  
Mitchell L Kay ◽  
Roland I Hall ◽  
...  
Keyword(s):  
Isotope Composition ◽  
Monitoring Program ◽  
Additive Models ◽  
Water Levels ◽  
Wildlife Habitat ◽  
Ecosystem Monitoring ◽  
International Polar Year ◽  
Monitoring Programs ◽  
Old Crow Flats

Abstract Lake-rich northern permafrost landscapes are sensitive to changing climate conditions, but ability to track real-time and potentially multiple hydrological responses (e.g. lake expansion, drawdown, drainage) is challenging due to absence of long-term, sustainable monitoring programs in these remote locations. Old Crow Flats (OCF), Yukon, is a Ramsar Wetland of International Importance where concerns about low water levels and their consequences for wildlife habitat and traditional ways of life prompted multidisciplinary studies during the International Polar Year (2007–2008) and led to the establishment of an aquatic ecosystem monitoring program. Here, we report water isotope data from 14 representative thermokarst lakes in OCF, the foundation of the monitoring program, and time-series of derived metrics including the isotope composition of input waters and evaporation-to-inflow ratios for a 13 year period (2007–2019). Although the lakes spanned multiple hydrological categories (i.e. rainfall-, snowmelt- and evaporation-dominated) based on initial surveys, well-defined trends from application of generalized additive models and meteorological records reveal that lakes have become increasingly influenced by rainfall, and potentially waters from thawing permafrost. These sources of input have led to more positive lake water balances. Given the documented role of rainfall in causing thermokarst lake drainage events in OCF and elsewhere, we anticipate increased vulnerability of lateral water export from OCF. This study demonstrates the value of long-term isotope-based monitoring programs for identifying hydrological consequences of climate change in lake-rich permafrost landscapes.

scholarly journals Aerosol Optical Depth retrievals in Central Amazonia from a Multi-Filter Rotating Shadow-band Radiometer on-site calibrated

2018 ◽  
Author(s):  
Nilton E. Rosário ◽  
Thamara Sauini ◽  
Theotonio Pauliquevis ◽  
Henrique M. J. Barbosa ◽  
Marcia A. Yamasoe ◽  
...  
Keyword(s):  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Spectral Response ◽  
Monitoring Site ◽  
Direct Normal Irradiance ◽  
Central Amazonia ◽  
Mean Square Errors ◽  
Term Monitoring ◽  
Band Radiometer

Abstract. Extraterrestrial spectral response calibration of a Multi-Filter Rotating Shadow band Radiometer (MFRSR) under Amazonian Forest atmosphere pristine conditions using the Langley plot method was performed and evaluated. The MFRSR is installed in central Amazonia as part of a long-term monitoring site, which was used in the context of the GoAmazon2014/5 Experiment. It has been operating continuously since 2011 without regular extraterrestrial calibration, preventing its application to accurate monitoring of aerosol particles. Once calibrated, the MFRSR measurements were applied to retrieve aerosols particles columnar optical properties, specifically Aerosol Optical Depth (AODλ) and Ångström Exponent (AE), which were evaluated against retrievals from a collocated CIMEL sunphotometer belonging to the AErosol RObotic NETwork (AERONET). Results obtained revealed that Amazonian pristine conditions are able to provide MFRSR extraterrestrial spectral response with relative uncertainty lower than 1.0 % at visible channels. The worst estimate (air mass = 1) for absolute uncertainty in AODλ retrieval varied from ~ 0.02 to ~ 0.03, depending on the assumption regarding uncertainty for MFRSR direct-normal irradiance measured at the surface. Obtained Root Mean Square Errors (RMSE ~ 0.025) from the evaluation of MFRSR retrievals against AERONET AODλ were, in general, lower than estimate MFRSR AODλ uncertainties, and close to AERONET field sunphotometers (~ 0.02).

Mercury background monitoring in the Lake Baikal region

2021 ◽  
Author(s):  
Fidel Pankratov ◽  
Alexander Mahura ◽  
Valentin Popov ◽  
Vladimir Masloboev
Keyword(s):  
Northern Hemisphere ◽  
Lake Baikal ◽  
Baikal Region ◽  
Background Level ◽  
Average Concentration ◽  
Monitoring Site ◽  
Average Value ◽  
Lake Baikal Region ◽  
Mercury Analyzer

<p>During 2013-2015 the gaseous elemental mercury (thereafter, mercury) measurements were carried out at two weather monitoring stations/sites (Listvyanka – from 25 July until 19 November 2013 and Tankhoj – from 27 July 2014 until 11 January 2015). The mercury analyzer Lumex RA-915AM was used for measurements. Although in the Northern Hemisphere the minimal average mercury concentration is about 1.5 ng m<sup>-3</sup>, the obtained results indicated that in the southern part of the Lake Baikal the lowest average concentration was about 1.18 ng m<sup>-3</sup>. Thus, the natural reserve territory of the Lake Baikal can be used as the main region to the background level of especially clean areas for monitoring heavy metals and persistent organic pollutants.</p><p>For the Listvyanka measurements, the mercury analyzer was installed at 20 m distance from a shore of the lake. During July-November 2013, the average concentration value was about 1.41±0.37 ng m<sup>-3</sup> (with max - 4.81, min - 0.16). For the July-August period, the maximum variance distribution was estimates as 0.62 ng m<sup>-3</sup>. For the August-November period, the variance did not exceed the value of 0.38 ng m<sup>-3</sup>. Mercury from the atmosphere is deposited on the underlying surface, and with increasing intensity of total solar radiation the re-emission of mercury occurred resulting in increased concentrations of mercury at Listvyanka. A rather low mercury values were recorded during October-November 2013. Analysis of atmospheric transport during summer showed, that main sources of pollution are situated to the west of the lake, and it is a relatively larger area in the southwestern sector, and therefore, it is complex to identify exact locations of such pollution sources.</p><p>For the Tankhoj site, in July 2014 the mercury analyzer was installed at about 100 m distance from a shore of the lake. It was for the first time, when the mercury monitoring was conducted for such long-term period of time in the Lake Baikal region. Note, that short-term measurements of mercury do not provide full understanding of the background level mercury and are insufficient to study dynamics. Analysis of obtained time-series showed that summer is characterized by a high variability of mercury (max - 2.86, min - 0.27, with an average 1.19±0.27 ng m<sup>-3</sup>). In particular, in July an average value of 1.18 ng m<sup>-3</sup> (max - 2.68, min - 0.43) was obtained, which corresponds to concentrations observed in the Northern Hemisphere. In August the average value of 1.22 ng m<sup>-3</sup> (max - 2.86, min - 0.27) was obtained.</p><p>Moreover, obtained results showed that location of the Tankhoj monitoring site can be used for long-term background monitoring of mercury.</p>

scholarly journals Increasing Weekend Effect in Ground-Level O3 in Metropolitan Areas of Mexico during 1988–2016

2018 ◽  
Vol 10 (9) ◽  
pp. 3330 ◽  
Author(s):  
Iván Hernández-Paniagua ◽  
Rodrigo Lopez-Farias ◽  
José Piña-Mondragón ◽  
Juan Pichardo-Corpus ◽  
Olivia Delgadillo-Ruiz ◽  
...  
Keyword(s):  
Total Population ◽  
Metropolitan Areas ◽  
Ground Level ◽  
Weekend Effect ◽  
Monitoring Site ◽  
Lower Growth ◽  
Urban Core ◽  
Long Term Trends ◽  
Increasing Trends

Here, we present an assessment of long-term trends in the O3 weekend effect (WE) occurrences and spread within the Mexico City (MCMA), Guadalajara (GMA), and Monterrey (MMA) metropolitan areas, which are the three largest metropolitan areas (MAs) of Mexico and concentrate around 33% of the total population in the country. Daytime averages and peak differences in O3 concentrations from weekdays to weekends were used as a proxy of WE occurrence. All MAs exhibited the occurrence of WE in all years at least in one monitoring site. Substantial differences in O3 daytime averages and peaks from weekdays to weekends have decreased over time in all MAs, and since 1998 and 2013 for the MCMA and GMA, respectively, higher O3 levels during weekends are typical during most of the year. The largest variations in the O3 WE were observed at downwind and urban core sites of the MCMA and GMA. Significant increasing trends (p < 0.05) in the O3 WE magnitude were observed for Sundays at all sites within the MCMA, with trends in annual averages ranging between 0.33 and 1.29 ppb O3 yr−1. Within the GMA, for Sundays, fewer sites exhibited increasing trends in the WE occurrence and at lower growth rates (0.32 and 0.48 ppb yr−1, p < 0.1) than within the MCMA, while within the MMA no apparent trends were observed in marked contrast with the MCMA and GMA. Our findings suggest that policies implemented have been successful in controlling weekday ground-level O3 within the MCMA and GMA, but further actions must be introduced to control the increases in the O3 WE magnitude and spread.

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