Abstract
Wind-driven turbidity plumes frequently occur in the western arm of Lake Superior and may represent a significant cross-shelf transport mechanism for sediment, nutrient, and biota. Here, we characterize a plume that formed in late April 2016 using observations from in situ sensors and remote sensing imagery, and estimate the volume of cross-shelf transport using both the observations and an idealized analytical model of plume formation. The steady-state, barotropic model is used to determine a relationship between the intensity and duration of a wind event and the volume of water transported from nearshore to offshore during the event. The model transport is the result of nearshore flow in the direction of the wind and a pressure-gradient-driven counter flow in the deeper offshore waters, consistent with observations. The volume of offshore transport associated with the 2016 plume is estimated by both methods to have been on the order of 1010 m3. Analysis of similar events from 2008 to 2016 shows a strong relationship between specific wind impulse and plume volume. Differences in the intensity and duration of individual events as well as ice cover, which prevents plume formation, lead to interannual variability of offshore transport ranging over an order of magnitude and illustrates how wind-driven processes may contribute to interannual variability of ecosystem functioning.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1309-1322 |
| Number of pages | 14 |
| Journal | Limnology and Oceanography |
| Volume | 64 |
| Issue number | 3 |
| DOIs | |
| State | Published - May 2019 |
Bibliographical note
Funding Information:We thank the captain and crew of the R/V Blue Heron for deployment and recovery of observational platforms utilized in this study. We are thankful for the comments and suggestions made by two anonymous reviewers which improved the quality and clarity of the manuscript. This research was performed while PM held an NRC Research Associateship award at the U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, Duluth, MN. The glider was purchased under NSF OCE grant 0406543. The autonomous profiler was purchased under NSF MRI-1126453. Additional sensors and operating costs were supported by the U.S. IOOS Office for the development and operation of the Great Lakes Observing System (GLOS) and administered through a cooperative agreement with the Cooperative Institute for Limnology and Ecosystem Research. MODIS band 1 reflectance data and images obtained from https://lpdaac.usgs.gov/ maintained by the NASA EOSDIS Land Processes Distributed Active Archive Center (LP DAAC), USGS/Earth Resources Observation and Science (EROS) Center, Sioux Falls, South Dakota. MODIS Sea surface temperature image obtained from https://oceancolor.gsfc.nasa.gov/ maintained by the NASA Goddard Space Flight Center, Ocean Ecology Laboratory, Ocean Biology Processing Group. Moderate-resolution Imaging Spectroradiometer (MODIS) Terra Level 2 SST Data; NASA OB.DAAC, Greenbelt, MD, USA. MODIS true color image obtained from http://ge.ssec.wisc.edu/modis-today/maintained by Space Science & Engineering Center; University of Wisconsin–Madison.
Funding Information:
We thank the captain and crew of the R/V Blue Heron for deployment and recovery of observational platforms utilized in this study. We are thankful for the comments and suggestions made by two anonymous reviewers which improved the quality and clarity of the manuscript. This research was performed while PM held an NRC Research Associateship award at the U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, Duluth, MN. The glider was purchased under NSF OCE grant 0406543. The autonomous profiler was purchased under NSF MRI-1126453. Additional sensors and operating costs were supported by the U.S. IOOS Office for the development and operation of the Great Lakes Observing System (GLOS) and administered through a cooperative agreement with the Cooperative Institute for Limnology and Ecosystem Research. MODIS band 1 reflectance data and images obtained from https://lpdaac.usgs.gov/ maintained by the NASA EOSDIS Land Processes Distributed Active Archive Center (LP DAAC), USGS/Earth Resources Observation and Science (EROS) Center, Sioux Falls, South Dakota. MODIS Sea surface temperature image obtained from https:// oceancolor.gsfc.nasa.gov/ maintained by the NASA Goddard Space Flight Center, Ocean Ecology Laboratory, Ocean Biology Processing Group. Moderate-resolution Imaging Spectroradiometer (MODIS) Terra Level 2 SST Data; NASA OB.DAAC, Greenbelt, MD, USA. MODIS true color image obtained from http://ge.ssec.wisc.edu/modis-today/ maintained by Space Science & Engineering Center; University of Wisconsin–Madison.
Publisher Copyright:
© 2019 Association for the Sciences of Limnology and Oceanography