Detlev Helmig Vertical profiling with tethered balloons

Project summary

The OASIS (Ocean-Atmosphere-Sea Ice-Snowpack Interactions in Polar Region) 2009 experiment at Barrow, Alaska, to be conducted in late winter/spring 2009, will investigate connections between surface fluxes, atmospheric chemistry and boundary layer dynamics.  A particular emphasis will be to elucidate the radical chemistry that leads to the ozone and mercury depletion events that have been observed in this coastal arctic environment.  Furthermore, this research ties into the question of how atmospheric chemical processing is connected to ecological impacts, and how climate change will feedback on these interactions.  Previous research has convincingly shown the high dependency of surface layer trace gas concentrations on boundary layer dynamics, as highly stable conditions that develop over snow and ice can lead towards the buildup of trace gas concentrations and unique chemical cycling.  OASIS will entail a multitude of new surface exchange and atmospheric measurements in an international collaborative effort between scientists from universities and the National Center for Atmospheric Research (NCAR).  Atmospheric experiments planned to date will be surface-based and lack the capability to probe the vertical dependency of reactants and chemical processes.  This proposal presents an important extension of these capabilities by providing the platform for vertical chemical profiling using the University of Colorado tethered balloon system. 

Intellectual merit of this project

Two kinds of balloon profiling experiments are proposed.  A smaller size balloon will be deployed for measuring meteorological data and ozone profiles 2-3 times per day between the surface and ~600 m altitude.   A second experiment, using a larger balloon, will raise three sampling lines to heights of ~120, 80, and 40 m.  Air pulled from these inlets will be analyzed for trace gases with monitors located in instrument shelters on the ground.  Measurements from the stationary balloon inlets will include nitrogen oxides (NOx), as well as nonmethane hydrocarbons (NMHC), and peroxyacyl nitrates (e.g. PAN), yielding the first high resolution, simultaneous, and continuous NOx, NMHC and PAN vertical profiles from a polar research site.  The balloon meteorological data will reveal the boundary layer mixing conditions; this information will allow evaluation and further interpretation of surface measurements.  The tethered balloon data will be of extremely high value for input and validation of chemical modeling to be done in the context of OASIS. 

Broader impacts

Data and findings from this work will be readily shared among all OASIS scientists for broader dissemination of the findings from this research.  Analytical developments within this project will be beneficial for other future atmospheric research applications.  This experiment will bring together scientists, including students, from the University of Colorado and NCAR, as well as from other OASIS-participating research institutions.  One CU graduate student will be supported from this grant and participate in the field work, offering this student a unique polar research experience.   In our previous balloon research we have found that balloon operations attract a lot of public attention; these experiments are particularly fascinating for school children.  In light of this, we will invite students and teachers from Barrow schools for a visit to the balloon site and will give them a tour of the balloon experiment and its scientific purpose, to provide these students with a rare and exciting opportunity to experience a science experiment in their front yard.