Session: 06-08-01 Model Tests I

Paper Number: 101202

101202 - Use of Low-Cost Drifter Buoys by Students to Update Ocean Current Models 

Our work describes the use of low-cost drifter buoys by American high school students who work collaboratively with universities and governmental agencies around the world to provide observational data that can be compared to ocean current models. Currently students have deployed buoys in the East Mediterranean Sea and the Atlantic Gulf Stream.  Analysis has been completed on the drifter data from the Mediterranean. We provide a case example from one student who led the following study.

The team used an undrouged, researcher-developed drifter which provided its location through the global positioning system (GPS) and transmitted these data via the Iridium satellite link. The drifter was developed by East Carolina University, Old Dominion University, and the University of Maryland. Analysis of the data transmitted from the drifter required a geographical plotting of its location throughout its journey. To do this, we first imported the latitude and longitude coordinates of the drifter onto a Google Sheet cross-referenced with the date and time of the transmission. Then, we mapped the locations onto Google Maps. Next, to account for possible errors in the drifter’s GPS, we removed outliers and spikes (Poulain et al. 2004). For a data point to be labeled as an outlier, it had to fulfill three criteria: the forward or backward displacement was larger than 1 km, the forward or backward speed was greater than 50 cm/s, and the angle between consecutive velocity vectors was smaller than 45° (Poulain et al. 2004). The map with outliers removed is shown in Figure 2. Then, with information about the locations and size of gyres in the Mediterranean, we plotted the location of three primary eddies in the Eastern Mediterranean by longitude and latitude (Mauri et al. 2019). Finally, geopositioning these gyres on Google Maps, we overlaid the gyres onto the map of the drifter track (Mauri et al. 2019). Using both the geographical and temporal data that the drifter transmitted, we then plotted the drifter’s general path. The drifter floated in a direction that was opposite the gyres directional flow. However, to determine whether or not the track of this drifter is indicative of an intermittent current in the East Mediterranean or perhaps even a fault in our current models, we must exclude a factor that could potentially affect its path: the wind. Our drifter in the East Mediterranean differs from ones historically released in that it is undrouged. While upper-ocean currents control the velocity of drouged drifters, undrouged drifters have less purchase on the water and, therefore, can frequently be influenced by the winds (Kirwan et al. 1974). Even small gusts of wind could push the drifter from one current to another, radically altering its course (Kirwan et al. 1974). However, because most of the gyres and currents that surrounded the track of the drifter were cyclonic (that is, flowing counter to the route of the drifter), being pushed from current to current should not have so drastically altered the drifter’s course. In addition, most studies focused on the effect wind has on the velocity of the drifter and not on its direction. Even then, the wind speed had a minimal impact on the velocity of the drifter. For every increase in 10 m s-1 winds, undrouged drifters saw a rise in downwind leeway of 7 cm s-1 (Poulain et al. 2009). Because the surrounding currents all flowed in the same direction and because we can reasonably conclude that wind speed had little impact on the direction of the drifter, we can assume that wind had minimal effect on the drifter.

The implications of this work suggest viable oppportunities for engaging teenage students in authentic scientific research to address current models around the globe. Description of the program we use (i.e., Summer Ventures), support structures needed to sustain the students' work, dissemination and partner usage, and technical advising that leads to deeper understanding by the students will be addressed in the presentation. 

Presenting Author: Dan Dickerson East Carolina University

Presenting Author Biography: DANIEL DICKERSON, Ph.D., is the College of Education’s Associate Dean for Research and Innovation and Professor of Science Education in the Department of Mathematics, Science, and Instructional Technology Education at East Carolina University. His research focuses on the teaching and learning of earth and environmental science content, environmental education, and STEM instruction. He is a former high school earth science teacher who has served as PI, Co-PI, or Evaluator on NOAA, NSF, NIH, US Department of Education, IMLS, state, and foundation funded projects.

Authors:

Dan Dickerson East Carolina University
Evan Li East Carolina University - Summer Ventures
Nikhil Mehta East Carolina University - Summer Ventures
Joseph Dickerson East Carolina University
Petros Katsioloudis Old Dominion University
Shawn Moore East Carolina University