Atmospheric Measurements from Unmanned Aircraft during SODA - Deployment of miniFlux and Initial Data Analysis
Understanding the temperature structure of the upper ocean in the Arctic is very important for properly simulating the formation and melt of sea ice in climate and weather models. The presence (or absence) is important for a variety of activities, including shipping, energy exploration, and hunting by Native populations. Therefore, forecasting the presence of ice at shorter timescales is critically needed. Sea ice additionally has a controlling influence on climate by acting as a bright surface capable of reflecting sunlight back to space, thereby highlighting a need to accurately forecast it on decadal time scales. A significant source of errors in forecasts at all scales is the ability to predict to what extent mixing of the upper ocean occurs and how this mixing helps to eliminate gradients in temperature and salinity that might change the rate of ice formation or melt. An important item to understand is to what extent atmospheric winds, which we generally forecast relatively well, contribute to this upper-oceanic mixing through the transfer of energy between the atmosphere and ocean. This project will support the collection of key measurements necessary to help inform the improvement of weather and climate models to support prediction of sea ice at a variety of time scales.
In this study, an unmanned aircraft system will be deployed to provide measurements of atmospheric temperature, winds, and humidity. This information will be used together with information from surface buoys and ice imagery to understand atmosphere-ocean energy transfer during the fall freeze-up period. Specifically, this work will help to address questions related to the role of the presence of sea ice in energy transfer and how that role is simulated in numerical models, the extent to which mechanisms supporting transfer vary at small spatial scales and how those are handled in today's state of the art modeling tools, and the importance of vertical resolution of models in accurately capturing this energy transfer. Measurements will be compared to high-resolution models that couple the atmosphere, ice, and ocean together into single simulations. Flights will take place from northern Alaska in September and October of 2018 and will interface with a broader effort (the Stratified Ocean Dynamics of the Arctic, or SODA, project) to understand the upper ocean in this part of the world. Additionally, this work will interface with the ongoing Year of Polar Prediction, providing extra connections to the modeling communities who can benefit from these measurements.
This project will focus on measurements on the structure of the lower atmosphere, its spatial variability, and momentum exchange between the atmosphere and ocean using unmanned aircraft-based observations of the thermodynamic quantities, surface state, and winds as part of the Stratified Ocean Dynamics of the Arctic (SODA) project. During September and October of 2018, a team of two researchers will travel to Oliktok Point on the northern coast of Alaska. Researchers will add instrumentation to already scheduled unmanned aircraft flights operated by the University of Alaska’s, Alaska Center for Unmanned Aircraft Systems Integration (ACUASI) program.
Season Field Site
2018 Alaska - Oliktok Point
Under this effort, we integrated a relatively new sensor system onto a highly capable unmanned aircraft system (UAS) to obtain new perspectives on the Arctic atmosphere and underlying surface. Flights associated with this project were executed in October, as the sea ice is beginning to reform, and helped to capture information on atmospheric temperature, humidity, winds and turbulence, along with surface temperature in order to better understand how the ocean, ice and atmosphere interact. While the total number of flights for this campaign was limited due to poor weather conditions, we did complete a small number of flights, including one that extended over 4 hours and sampled the atmosphere over the Beaufort Sea. These data provide initial glimpses into the variability of atmospheric properties, into the transport of energy through the Earth system, and into the performance of atmospheric models in representing key processes. Additionally, these flights provide a critical first official field deployment for the miniFluxsensor system that was deployed. Along the way, the engineering team learned about the system performance in a harsh environment (it performed well), about considerations for the operation of specific system sensors in the Arctic, and about the procedures in place for system calibration, preparation and integration for a field deployment. Through this work, students and early career scientists and engineers were offered opportunities to be intimately involved with this field deployment, including the first official field deployment for an early career staff engineer. Results from this field campaign have been distributed through a variety of channels, including through public release of the data collected through the NSF Arctic Data Center, public presentations and seminars, and through the initial preparation of peer-reviewed publications and technical reports.