A5033226466- Marine and coastal ecosystems
- Water Quality and Pollution Assessment
- Aquatic Ecosystems and Phytoplankton Dynamics
- Water Quality Monitoring and Analysis
- Remote Sensing in Agriculture
- Water Quality Monitoring Technologies
- Atmospheric and Environmental Gas Dynamics
- Remote-Sensing Image Classification
- Land Use and Ecosystem Services
- Remote Sensing and LiDAR Applications
- Mercury impact and mitigation studies
- Isotope Analysis in Ecology
- Soil and Water Nutrient Dynamics
- Fish Ecology and Management Studies
- Remote Sensing and Land Use
- Marine and fisheries research
- Water Quality and Resources Studies
- Marine Bivalve and Aquaculture Studies
- Aquatic and Environmental Studies
- Water Resources and Management
- Water Treatment and Disinfection
University of Minnesota
2013-2023
Minnesota Department of Natural Resources
2012-2023
University of Minnesota System
2021
Atmospheric correction over inland and coastal waters is one of the major remaining challenges in aquatic remote sensing, often hindering quantitative retrieval biogeochemical variables analysis their spatial temporal variability within environments. The Correction Intercomparison Exercise (ACIX-Aqua), a joint NASA – ESA activity, was initiated to enable thorough evaluation eight state-of-the-art atmospheric (AC) processors available for Landsat-8 Sentinel-2 data processing. Over 1000...
Constructing multi-source satellite-derived water quality (WQ) products in inland and nearshore coastal waters from the past, present, future missions is a long-standing challenge. Despite inherent differences sensors' spectral capability, spatial sampling, radiometric performance, research efforts focused on formulating, implementing, validating universal WQ algorithms continue to evolve. This extends recently developed machine-learning (ML) model, i.e., Mixture Density Networks (MDNs)...
Abstract The development of algorithms for remote sensing water quality (RSWQ) requires a large amount in situ data to account the bio-geo-optical diversity inland and coastal waters. GLObal Reflectance community dataset Imaging optical Aquatic environments (GLORIA) includes 7,572 curated hyperspectral reflectance measurements at 1 nm intervals within 350 900 wavelength range. In addition, least one co-located measurement chlorophyll , total suspended solids, absorption by dissolved...
This study evaluates currently available imagery from Landsat, MERIS, MODIS, and AWiFS sensors for their usefulness in regional‐scale measurements of lake water clarity chlorophyll comprehensive management scientific studies (e.g., modeling). Images these systems were collected nearly concurrently processed using methods similar to those developed previously regional assessments Landsat imagery. We tested both atmospherically corrected uncorrected products; the products performed as well or...
Abstract Secchi depth (SD), a primary metric to assess trophic state, is controlled in many lakes by algal densities, measured as chlorophyll‐ (chl‐ ) concentration. Two other optically related water quality variables also directly affect SD : non‐algal suspended solids ( SS NA and colored dissolved organic matter CDOM , expressed the absorption coefficient at 440 nm, ). Using database of ~1,460 samples from ~625 inland lake basins Minnesota two Upper Midwest states, Wisconsin Michigan, we...
Absorption of solar radiation by colored dissolved organic matter (CDOM) in surface waters results the formation photochemically produced reactive intermediates (PPRIs) that react with pollutants water. Knowing steady-state concentrations PPRIs ([PPRI]ss) is critical to predicting persistence sunlit waters. CDOM levels (a440) can be measured remotely for lakes over large areas using satellite imagery. Laboratory measurements [PPRI]ss and apparent quantum yields (Φ) three (3DOM*, 1O2, •OH)...
As global surface temperatures continue to rise as a result of anthropogenic climate change, effects in temperate lakes are likely be more pronounced than other ecosystems. Decreases snow and ice cover extent duration extended periods summer stratification have been observed lake systems throughout the Anthropocene. However, changing on lacustrine communities remain largely uninvestigated. We examined underwater light associated primary productivity patterns under snow-covered clear-lake 6...
Abstract A large 20‐year database on water clarity for all M innesota lakes ≥8 ha was analyzed statistically spatial distributions, temporal trends, and relationships with in‐lake watershed factors that potentially affect lake clarity. The includes Landsat‐based estimates expressed in terms of Secchi depth ( SD Landsat ), an integrative measure quality, more than 10,500 time periods centered around 1985, 1990, 1995, 2000, 2005. Minnesota is lower (more turbid) the south southwest clearer...
The dominant wavelength and hue angle can be used to quantify the color of lake water. Understanding water is important because relates quality its related public perceptions. In this paper, we compared accuracy levels two methods in calculating values using simulated satellite data calculated from situ reflectance hyperspectra for 325 lakes rivers Minnesota Wisconsin. developed by van der Woerd Wernand 2015 Wang et al. were applied sensor Sentinel-2, Sentinel-3, Landsat 8 satellites. Both...
Abstract Despite increasing interest in winter limnology, few studies have examined under-ice zooplankton communities and the factors shaping them different types of temperate lakes. To better understand drivers community structure summer, we sampled 13 lakes across a large trophic status gradient for crustacean abundance, taxonomic functional composition C/N stable isotopes. Average densities were one-third summer study Proportionally, cladocerans more abundant than winter, with opposite...
Colored dissolved organic matter (CDOM), a major component of the carbon (DOC) pool in many lakes, is an important controlling factor lake ecosystem functioning. Absorption coefficients at 440 nm (a440, m-1), common measure CDOM, exhibited strong associations with iron (Fediss) and DOC 280 lakes Upper Great Lakes States (UGLS: Minnesota, Wisconsin, Michigan), as has been found Scandinavia elsewhere. Linear regressions between three variables on UGLS data typically yielded R2 values 0.6-0.9,...
Olmanson LG, Bauer ME. 2017. Land cover classification of the Lake Woods/Rainy River Basin by object-based image analysis Landsat and lidar data. Reserv Manage. 33:335–346.The recent availability data throughout Minnesota, USA has opened up many opportunities for improved land mapping. To integrate spectral spatial information from imagery point cloud topographic metrics, we utilized (OBIA) with random forest classification. By classifying objects instead pixels, were able to use...