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Abstract Aquatic scientists require robust, accurate information about nutrient concentrations and indicators of algal biomass in unsampled lakes in order to understand and predict the effects of global climate and land‐use change. Historically, lake and landscape characteristics have been used as predictor variables in regression models to generate nutrient predictions, but often with significant uncertainty. An alternative approach to improve predictions is to leverage the observed relationship between water clarity and nutrients, which is possible because water clarity is more commonly measured than lake nutrients. We used a joint‐nutrient model that conditioned predictions of total phosphorus, nitrogen, and chlorophyll aon observed water clarity. Our results demonstrated substantial reductions (8–27%; median = 23%) in prediction error when conditioning on water clarity. These models will provide new opportunities for predicting nutrient concentrations of unsampled lakes across broad spatial scales with reduced uncertainty.
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Observations of radiatively driven convection in a deep lake
Abstract Observations of radiatively driven convection in deep, ice‐free Lake Superior from a set of moorings and an autonomous glider are used to characterize the spatial and temporal scales of the phenomenon. The moored observations show that instability builds at the surface on scales of hours, water near the bottom of the lake begins warming roughly 6 h after sunup, and the water column homogenizes a few hours after sundown. Glider observations suggest the existence of distinct convective chimneys, which carry warmed water to depth with horizontal scales on the order of tens of meters. Patches of photoquenched phytoplankton coincide with patches of anomalously warm water, providing a secondary tracer of water recently in the euphotic zone, and provide insight into the vertical development of convective chimneys. An analysis of the abundance of convective chimneys is used to estimate the lateral scale of convective cells, which appears to be on the order of 50 m.
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- Award ID(s):
- 1829895
- PAR ID:
- 10460410
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Limnology and Oceanography
- Volume:
- 64
- Issue:
- 5
- ISSN:
- 0024-3590
- Page Range / eLocation ID:
- p. 2152-2160
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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