Ship emissions measurement in the Arctic by plume intercepts of the Canadian Coast Guard icebreaker Amundsen from the Polar 6 aircraft platform

摘要

Decreasing sea ice and increasing marine navigability in northern latitudeshave changed Arctic ship traffic patterns in recent years and are predictedto increase annual ship traffic in the Arctic in the future. Development ofeffective regulations to manage environmental impacts of shipping requires anunderstanding of ship emissions and atmospheric processing in the Arcticenvironment. As part of the summer 2014 NETCARE (Network on Climate andAerosols) campaign, the plume dispersion and gas and particle emissionfactors of effluents originating from the Canadian Coast Guard icebreakerAmundsen operating near Resolute Bay, NU, Canada, were investigated. TheAmundsen burned distillate fuel with 1.5 wt % sulfur. Emissions werestudied via plume intercepts using the Polar 6 aircraft measurements, ananalytical plume dispersion model, and using the FLEXPART-WRF Lagrangianparticle dispersion model. The first plume intercept by the research aircraftwas carried out on 19 July 2014 during the operation of the Amundsen in theopen water. The second and third plume intercepts were carried out on 20 and21 July 2014 when the Amundsen had reached the ice edge and operated underice-breaking conditions. Typical of Arctic marine navigation, the engine loadwas low compared to cruising conditions for all of the plume intercepts. Themeasured species included mixing ratios of CO, NO, CO, SO,particle number concentration (CN), refractory black carbon (rBC), and cloudcondensation nuclei (CCN). The results were compared to similar experimentalstudies in mid-latitudes.Plume expansion rates () were calculated using the analytical modeland found to be   =  0.75 ± 0.81, 0.93 ± 0.37, and1.19 ± 0.39 for plumes 1, 2, and 3, respectively. These rates weresmaller than prior studies conducted at mid-latitudes, likely due to polarboundary layer dynamics, including reduced turbulent mixing compared to mid-latitudes. All emission factors were in agreement with prior observations atlow engine loads in mid-latitudes. Ice-breaking increased the NO emissionfactor from EF  =  43.1 ± 15.2 to 71.6 ± 9.68and 71.4 ± 4.14 g kg-diesel for plumes 1, 2, and 3, likely dueto changes in combustion temperatures. The CO emission factor wasEF  =  137 ± 120, 12.5 ± 3.70 and8.13 ± 1.34 g kg-diesel for plumes 1, 2, and 3. The rBCemission factor was EF  =  0.202 ± 0.052 and0.202 ± 0.125 g kg-diesel for plumes 1 and 2. The CN emissionfactor was reduced while ice-breaking fromEF  =  2.41 ± 0.47 to 0.45 ± 0.082 and0.507 ± 0.037  ×  10 kg-diesel for plumes 1, 2,and 3. At 0.6 % supersaturation, the CCN emission factor was comparable toobservations in mid-latitudes at low engine loads withEF  =  3.03 ± 0.933, 1.39 ± 0.319, and0.650 ± 0.136  ×  10 kg-diesel for plumes 1, 2,and 3.