Flow Analysis Techniques for Spatial and Temporal Measurement of Nutrients in Aquatic Systems

2006 ◽  
Vol 3 (1) ◽  
pp. 3 ◽  
Author(s):  
Sarah Gray ◽  
Grady Hanrahan ◽  
Ian McKelvie ◽  
Alan Tappin ◽  
Florence Tse ◽  
...  
Keyword(s):  
Flow Injection ◽  
Measurement Techniques ◽  
Flow Analysis ◽  
Economic Consequences ◽  
Aquatic Systems ◽  
Spatial And Temporal Variability ◽  
Powerful Approach ◽  
Temporal Measurement

Environmental Context.Eutrophication is a growing problem globally, and it has significant ecological and socio-economic consequences. Understanding the causes of eutrophication requires a knowledge of nutrient biogeochemistry in aquatic systems. Owing to the high spatial and temporal variability of nutrients in these systems, there is a need for autonomous in situ measurement techniques with rapid response and the ability to collect long-term data. Flow injection analysis is one technique that meets these demands. Abstract.Flow analysis offers a versatile and powerful approach to monitoring of the aquatic environment. The present review highlights the drivers for determining macro- and micro-nutrients in marine and fresh waters, and outlines the instrumental requirements for in situ instrumentation. The principles of flow analysis, specifically flow injection and derivative techniques, and the chemical bases for macro- and micro-nutrient detection are discussed, and key examples of suitable approaches are considered. The successful deployment of flow analysis nutrient monitoring systems for spatial and temporal measurements is illustrated by specific examples relating to surface transects, depth profiles and temporal deployments. Finally, the challenges and imperatives of research in this area are outlined.

scholarly journals Accomplishments of the MUSICA project to provide accurate, long-term, global and high-resolution observations of tropospheric {H<sub>2</sub>O,<i>δ</i>D} pairs – a review

2016 ◽  
Vol 9 (7) ◽  
pp. 2845-2875 ◽  
Author(s):  
Matthias Schneider ◽  
Andreas Wiegele ◽  
Sabine Barthlott ◽  
Yenny González ◽  
Emanuel Christner ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Measurement Techniques ◽  
Remote Sensing Data ◽  
Global Scale ◽  
Horizontal Resolution ◽  
Atmospheric Composition ◽  
Remote Sensing Techniques ◽  
Middle Infrared

Abstract. In the lower/middle troposphere, {H2O,δD} pairs are good proxies for moisture pathways; however, their observation, in particular when using remote sensing techniques, is challenging. The project MUSICA (MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water) addresses this challenge by integrating the remote sensing with in situ measurement techniques. The aim is to retrieve calibrated tropospheric {H2O,δD} pairs from the middle infrared spectra measured from ground by FTIR (Fourier transform infrared) spectrometers of the NDACC (Network for the Detection of Atmospheric Composition Change) and the thermal nadir spectra measured by IASI (Infrared Atmospheric Sounding Interferometer) aboard the MetOp satellites. In this paper, we present the final MUSICA products, and discuss the characteristics and potential of the NDACC/FTIR and MetOp/IASI {H2O,δD} data pairs. First, we briefly resume the particularities of an {H2O,δD} pair retrieval. Second, we show that the remote sensing data of the final product version are absolutely calibrated with respect to H2O and δD in situ profile references measured in the subtropics, between 0 and 7 km. Third, we reveal that the {H2O,δD} pair distributions obtained from the different remote sensors are consistent and allow distinct lower/middle tropospheric moisture pathways to be identified in agreement with multi-year in situ references. Fourth, we document the possibilities of the NDACC/FTIR instruments for climatological studies (due to long-term monitoring) and of the MetOp/IASI sensors for observing diurnal signals on a quasi-global scale and with high horizontal resolution. Fifth, we discuss the risk of misinterpreting {H2O,δD} pair distributions due to incomplete processing of the remote sensing products.

scholarly journals Observations of seasonal and diurnal glacier velocities at Mount Rainier, Washington, using terrestrial radar interferometry

2015 ◽  
Vol 9 (6) ◽  
pp. 2219-2235 ◽  
Author(s):  
K. E. Allstadt ◽  
D. E. Shean ◽  
A. Campbell ◽  
M. Fahnestock ◽  
S. D. Malone
Keyword(s):  
Radar Interferometry ◽  
Surface Velocity ◽  
Spatial And Temporal Variability ◽  
Diurnal Variability ◽  
Alpine Glacier ◽  
Mount Rainier ◽  
Glacier Dynamics ◽  
Central Regions

Abstract. We present surface velocity maps derived from repeat terrestrial radar interferometry (TRI) measurements and use these time series to examine seasonal and diurnal dynamics of alpine glaciers at Mount Rainier, Washington. We show that the Nisqually and Emmons glaciers have small slope-parallel velocities near the summit (< 0.2 m day−1), high velocities over their upper and central regions (1.0–1.5 m day−1), and stagnant debris-covered regions near the terminus (< 0.05 m day−1). Velocity uncertainties are as low as &amp;pm;0.02–0.08 m day−1. We document a large seasonal velocity decrease of 0.2–0.7 m day−1 (−25 to −50 %) from July to November for most of the Nisqually Glacier, excluding the icefall, suggesting significant seasonal subglacial water storage under most of the glacier. We did not detect diurnal variability above the noise level. Simple 2-D ice flow modeling using TRI velocities suggests that sliding accounts for 91 and 99 % of the July velocity field for the Emmons and Nisqually glaciers with possible ranges of 60–97 and 93–99.5 %, respectively, when considering model uncertainty. We validate our observations against recent in situ velocity measurements and examine the long-term evolution of Nisqually Glacier dynamics through comparisons with historical velocity data. This study shows that repeat TRI measurements with > 10 km range can be used to investigate spatial and temporal variability of alpine glacier dynamics over large areas, including hazardous and inaccessible areas.

scholarly journals Evaluation of new laser spectrometer techniques for in-situ carbon monoxide measurements

2012 ◽  
Vol 5 (10) ◽  
pp. 2555-2567 ◽  
Author(s):  
C. Zellweger ◽  
M. Steinbacher ◽  
B. Buchmann
Keyword(s):  
Carbon Monoxide ◽  
Measurement Techniques ◽  
Field Measurements ◽  
Current Data ◽  
Atmospheric Composition ◽  
Environmental Research ◽  
Spectroscopic Techniques ◽  
New Techniques

Abstract. Long-term time series of the atmospheric composition are essential for environmental research and thus require compatible, multi-decadal monitoring activities. The current data quality objectives of the World Meteorological Organization (WMO) for carbon monoxide (CO) in the atmosphere are very challenging to meet with the measurement techniques that have been used until recently. During the past few years, new spectroscopic techniques came to market with promising properties for trace gas analytics. The current study compares three instruments that have recently become commercially available (since 2011) with the best currently available technique (Vacuum UV Fluorescence) and provides a link to previous comparison studies. The instruments were investigated for their performance regarding repeatability, reproducibility, drift, temperature dependence, water vapour interference and linearity. Finally, all instruments were examined during a short measurement campaign to assess their applicability for long-term field measurements. It could be shown that the new techniques perform considerably better compared to previous techniques, although some issues, such as temperature influence and cross sensitivities, need further attention.

scholarly journals IMMU-37. DIRECT REPROGRAMMING OF GLIOBLASTOMA TO ANTIGEN PRESENTING-LIKE CELLS BY MASTER REGULATORS PREDICTED FROM AN ARTIFICIAL INTELLIGENCE PLATFORM

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii112-ii113
Author(s):  
Dan Jin ◽  
Mathew Sebastian ◽  
Son Le ◽  
Dongjiang Chen ◽  
Nagheme Thomas ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Morphological Changes ◽  
Antigen Presenting Cells ◽  
Term Survival ◽  
Powerful Approach ◽  
Antigen Presenting ◽  
Fate Determinants ◽  
Capacity Characteristic

Abstract Glioblastoma (GBM) is the most common and lethal malignant brain cancer in adults. Immunotherapy has emerged as a potentially powerful approach to achieve long-term survival in patients with GBM. Antigen presenting cells (APCs) play a central role in priming cancer-specific immune responses due to their ability to sample and present tumor neoantigens to the immune system. We hypothesis that antigen presenting cells could be induced by transdifferentiated from GBM in-situ so that these locally created APC will find themselves pre-planted in the tumor microenvironment (TME) with full access to tumor neoantigens. Top ten ranked candidate fate determinants for the GBM-DC transdifferentiation were predicted by NETZEN, an integrated deep-learning and gene network-based ranking artificial intelligence (AI) platform for precision medicine. We successfully transdifferentiated the murine GBM cell line GL261 into CD45+ immune cells accompanying morphological changes to less adhering cells by a combination of four factors (PU.1, IRF8, BATF3, ID2). Of these induced CD45 positive cells, a significant fraction also expresses high levels of the myeloid marker CD11b and antigen presenting molecules MHCII and MHCI by flow cytometry, suggesting these induced CD45+ cells are myeloid lineage APCs (iAPC).These iAPC exhibit phagocytic property, tested by incubating pHrodo Red bioparticles conjugated with Zymosan, an antigen found on the surface of fungi. More importantly, these induced iAPC appear to have lost their proliferative capacity characteristic of the parental GBM cells. Total live cell numbers were significantly reduced in 4F-induced culture compared to the EV control. In conclusion, we successfully transdifferentiated mouse GBM cells into APC-like cells based on NETZEN prediction and our work can potentially provide a novel therapeutic approach for developing an in-situ APC vaccine immunotherapy for GBM, and for other cancers.

scholarly journals Observations of seasonal and diurnal glacier velocities at Mount Rainier, Washington using terrestrial radar interferometry

2015 ◽  
Vol 9 (4) ◽  
pp. 4067-4116
Author(s):  
K. E. Allstadt ◽  
D. E. Shean ◽  
A. Campbell ◽  
M. Fahnestock ◽  
S. D. Malone
Keyword(s):  
Radar Interferometry ◽  
Spatial And Temporal Variability ◽  
Ice Flow ◽  
Diurnal Variability ◽  
Alpine Glacier ◽  
Mount Rainier ◽  
Glacier Dynamics ◽  
Central Regions

Abstract. We present spatially continuous velocity maps using repeat terrestrial radar interferometry (TRI) measurements to examine seasonal and diurnal dynamics of alpine glaciers at Mount Rainier, Washington. We show that the Nisqually and Emmons glaciers have small slope-parallel velocities near the summit (< 0.2 m day−1), high velocities over their upper and central regions (1.0–1.5 m day−1), and stagnant debris-covered regions near the terminus (< 0.05 m day−1). Velocity uncertainties are as low as ±0.02–0.08 m day−1. We document a large seasonal velocity decrease of 0.2–0.7 m day−1 (−25 to −50 %) from July to November for most of the Nisqually glacier, excluding the icefall, suggesting significant seasonal subglacial water storage under most of the glacier. We did not detect diurnal variability above the noise level. Preliminary 2-D ice flow modeling using TRI velocities suggests that sliding accounts for roughly 91 and 99 % of the July velocity field for the Emmons and Nisqually glaciers, respectively. We validate our observations against recent in situ velocity measurements and examine the long-term evolution of Nisqually glacier dynamics through comparisons with historical velocity data. This study shows that repeat TRI measurements with > 10 km range can be used to investigate spatial and temporal variability of alpine glacier dynamics over large areas, including hazardous and inaccessible areas.

scholarly journals Evaluation of three new laser spectrometer techniques for in-situ carbon monoxide measurements

2012 ◽  
Vol 5 (4) ◽  
pp. 4735-4769 ◽  
Author(s):  
C. Zellweger ◽  
M. Steinbacher ◽  
B. Buchmann
Keyword(s):  
Carbon Monoxide ◽  
Measurement Techniques ◽  
Field Measurements ◽  
Current Data ◽  
Atmospheric Composition ◽  
Environmental Research ◽  
Spectroscopic Techniques ◽  
New Techniques

Abstract. Long-term time series of the atmospheric composition are essential for environmental research and thus require compatible, multi-decadal monitoring activities. However, the current data quality objectives of the World Meteorological Organization (WMO) for carbon monoxide (CO) in the atmosphere are very challenging to meet with the measurement techniques that have been used until recently. During the past few years, new spectroscopic techniques came on the market with promising properties for trace gas analytics. The current study compares three instruments that are recently commercially available (since 2011) with the up to now best available technique (vacuum UV fluorescence) and provides a link to previous comparison studies. The instruments were investigated for their performance regarding repeatability, reproducibility, drift, temperature dependence, water vapour interference and linearity. Finally, all instruments were examined during a short measurement campaign to assess their applicability for long-term field measurements. It could be shown that the new techniques provide a considerably better performance compared to previous techniques, although some issues such as temperature influence and cross sensitivities need further attention.

scholarly journals A framework for accurate, long-term, global and high resolution observations of tropospheric H<sub>2</sub>O-δD pairs – a MUSICA review

2016 ◽  
Author(s):  
M. Schneider ◽  
A. Wiegele ◽  
S. Barthlott ◽  
Y. González ◽  
E. Christner ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Measurement Techniques ◽  
Remote Sensing Data ◽  
Global Scale ◽  
Horizontal Resolution ◽  
Atmospheric Composition ◽  
Sensing Data ◽  
Middle Infrared

Abstract. Abstract. In the lower/middle troposphere H2O-δD pairs are good proxies for moisture pathways, however their observation is challenging. The project MUSICA (MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water) addresses this challenge by integrating remote sensing with in-situ measurement techniques. The aim is to retrieve accurate tropospheric H2O-δD pairs from the middle infrared spectra measured from ground by the FTIR (Fourier Transform InfraRed) spectrometers of the NDACC (Network for the Detection of Atmospheric Composition Change) and the thermal nadir spectra measured by IASI (Infrared Atmospheric Sounding Interferometer) aboard the MetOp satellites. In this paper we review the MUSICA framework, present the final MUSICA products, and outline the NDACC/FTIR’s and METOP/IASI’s potential for observing accurate and consistent H2O-δD data pairs. First, we briefly resume the particularities of an H2O-δD pair retrieval. Second, we show that the remote sensing data of the final product version are absolutely calibrated with respect to H2O and δD in-situ profile references measured in the subtropics, between 0 and 7 km. Third, we empirically demonstrate that the calibrated remote sensing H2O-δD pairs can identify different lower/middle tropospheric moisture pathways and advert to the risk of misinterpretations caused by an incorrect processing of such remote sensing data. Fourth, we reveal that the different sensors (NDACC/FTIR instruments, MetOp/IASI-A, and MetOp/IASI-B) provide consistent H2O-δD pairs for very distinct atmospheric clear sky conditions. Fifth, we document the unique possibilities of the NDACC/FTIR instruments for providing long-term records (important for climatological studies) and of the MetOp/IASI sensors for observing diurnal signals on quasi global scale and with high horizontal resolution.

scholarly journals Global soil moisture data derived through machine learning trained with in-situ measurements

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Sungmin O. ◽  
Rene Orth
Keyword(s):  
Machine Learning ◽  
Soil Moisture ◽  
Large Scale ◽  
Short Term Memory ◽  
Temporal Dynamics ◽  
Soil Moisture Data ◽  
Wide Range ◽  
Global Soil

AbstractWhile soil moisture information is essential for a wide range of hydrologic and climate applications, spatially-continuous soil moisture data is only available from satellite observations or model simulations. Here we present a global, long-term dataset of soil moisture derived through machine learning trained with in-situ measurements, SoMo.ml. We train a Long Short-Term Memory (LSTM) model to extrapolate daily soil moisture dynamics in space and in time, based on in-situ data collected from more than 1,000 stations across the globe. SoMo.ml provides multi-layer soil moisture data (0–10 cm, 10–30 cm, and 30–50 cm) at 0.25° spatial and daily temporal resolution over the period 2000–2019. The performance of the resulting dataset is evaluated through cross validation and inter-comparison with existing soil moisture datasets. SoMo.ml performs especially well in terms of temporal dynamics, making it particularly useful for applications requiring time-varying soil moisture, such as anomaly detection and memory analyses. SoMo.ml complements the existing suite of modelled and satellite-based datasets given its distinct derivation, to support large-scale hydrological, meteorological, and ecological analyses.

scholarly journals A Study of UVER in Santiago, Chile Based on Long-Term In Situ Measurements (Five Years) and Empirical Modelling

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 368
Author(s):  
Lisdelys González-Rodríguez ◽  
Amauri Pereira de Oliveira ◽  
Lien Rodríguez-López ◽  
Jorge Rosas ◽  
David Contreras ◽  
...  
Keyword(s):  
Urban Areas ◽  
Solar Spectrum ◽  
Sun Exposure ◽  
Great Accuracy ◽  
In Situ Measurements ◽  
Uv Index ◽  
Empirical Modelling ◽  
The People

Ultraviolet radiation is a highly energetic component of the solar spectrum that needs to be monitored because is harmful to life on Earth, especially in areas where the ozone layer has been depleted, like Chile. This work is the first to address the long-term (five-year) behaviour of ultraviolet erythemal radiation (UVER) in Santiago, Chile (33.5° S, 70.7° W, 500 m) using in situ measurements and empirical modelling. Observations indicate that to alert the people on the risks of UVER overexposure, it is necessary to use, in addition to the currently available UV index (UVI), three more erythema indices: standard erythemal doses (SEDs), minimum erythemal doses (MEDs), and sun exposure time (tery). The combination of UVI, SEDs, MEDs, and tery shows that in Santiago, individuals with skin types III and IV are exposed to harmfully high UVER doses for 46% of the time that UVI indicates is safe. Empirical models predicted hourly and daily values UVER in Santiago with great accuracy and can be applied to other Chilean urban areas with similar climate. This research inspires future advances in reconstructing large datasets to analyse the UVER in Central Chile, its trends, and its changes.

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