CICCI is an open collaboration between several groups working in the Ny Ålesund region. The project is open to interested participants who have measurements to contribute to the goals of the research as outlined below.
The potential role of black carbon (BC) in climate change in the Arctic has gained considerable attention recently. In particular, numerous model-based studies have indicated there may be a link between observed rapid climate warming and black carbon that is transported from lower latitudes and deposited in the Arctic. However, in situ measurements of aerosol absorption, a proxy for BC, have revealed a decreasing trend over the past 30 years implying that the radiative forcing due to BC should also be decreasing. To resolve these seemingly opposed trends, the processes controlling black carbon transport, deposition and absorption-driven warming in Arctic must be well understood.
Several currently funded research efforts are focused on BC and its impacts on Arctic climate. The goal of this initiative is to coordinate these research activities so that they are conducted concurrently in the vicinity of Ny-Ålesund in spring of 2011 thereby maximizing research results. In some cases, alterations in presently proposed activities will be required. In others, the work will be carried out as planned, but with enhanced cooperation with concurrent activities. Limited investment in additional research activities as outlined below would contribute significantly to the overall result of the initiative. Funding for these activities will be sought by project partners from their national agencies.
The central goal of the initiative is to improve the understanding of processes controlling the distribution of black carbon (BC) in the Arctic atmosphere and deposition to snow and ice surfaces and the resulting climate impacts.
Specific questions include:
- What sources of BC contribute to snow and sea ice forcing in the Svalbard region?
- What are the processes that lead to BC deposition on snow and sea ice in the Spring time frame?
- How significant is the impact of BC deposition on snow albedo in relation to variability driven by physical processes?
- How well do existing satellite measurements characterize the aerosol structure of the atmosphere overlying the Svalbard region?
- Can variability in albedo driven by BC be observed from satellites?
Timeline of Activities:
A proposed time line of the major campaign activities is shown in the image below including the timelines of all activities operating as part of VAUUAV. Further activities under VAUUAV will continue intermittently in June and possibly July. The focus of activities will be different during the two VAUUAV campaign intensives. In the first period (early to mid April), activities will be focused on the collection of data from Holtedahlfonna and Kongsfjorden with occasional sea ice transects.
During the second period (mid April to mid May), activities will be focused on longer UAV flights covering sea ice, and including overflights of R/V Lance and inter-comparison flights with the POLAR-5. Ground activities associated with VAUUAV during this time will be in place primarily for ground truthing the UAV instruments. Throughout the entire CICCI activity period, observations of aerosols at Zeppelin Station (400 masl) and at the Gruvebadet station (40 masl) will be conducted; with profiles being collected by the miniaturized NOAA instrumentation either aboard the NOAA Manta UAS or attached to the AWIPEV tethered balloon. Additionally, the possibility to perform aerosol vertical profiles making use of an aerostatic ballon equipped with an OPC and a 5 stage sampler, supplied by Italian groups (UNIFI in cooperation with UNIMI Bicocca) will improve the data set and provide supplementary information mainly on the chemical composition variability in the ABL.
Coordinated Research Approach under CICCI:
To address the goals and objectives of the initiative we propose to integrate several airborne, station-based, and ground based activities. Individually, the projects alone do not have the capacity to address all the questions posed above, but collectively they can provide a robust suite of measurements that will be of significance to climate modelling and forecasting of Arctic variability.
Source regions of Arctic Aerosol
Through the POLARCAT measurements, existing analysis of historical lidar data from Koldeway, and long term observations at Zeppelin Station, we have gained considerable insight into the source regions of pollutants to the Ny Alesund region. Still, significant questions remain. In particular, no measurements have adequately characterized the source of the BC that is deposited to the surface and that may result in a regional climate impact. The POLAR-5 aircraft observations will provide a snapshot of the variability of BC across a transect of the Arctic, while measurements from the Zeppelin station will provide a long-term temporal history at a point location. The UAS operations will provide a regional perspective over a period of a month near Zeppelin, allowing for a more complete connection between the airborne ‘snapshot’ measurements and the station based long term observations. The use of FLEXPART transport modeling along with chemical tracers will aid in the determination of the sources of BC to the Ny Alesund region.
Deposition and Free-troposphere / Boundary Layer Fluxes
At Ny-Ålesund, and in the Arctic in general, the boundary layer is particularly stable. The Zeppelin observatory is intentionally placed at an elevation of 400 m.a.s.l. in order to measure the free troposphere air mass rather than a disturbed boundary layer. The aerosol measurements collected at the Gruvebadet site near sea level provide measurements of aerosol concentrations within the boundary layer.
The frequent flights with the NOAA UAS will allow profiling between the two air masses. This information is important in order to understand whether there is evidence of aerosol deposition, or if the two air masses are in fact discrete entities. Information from the Italian aerosotatic balloon, will additionally augment our profiling capability with chemical data not available on the UAS payloads, and will serve valuably in performing this analysis. Profiling of the boundary layer and lower free troposphere will take place both over land and over sea ice and open ocean (See Figure 1b), allowing us to evaluate the influence of orography on deposition processes.
Of significant interest will be evaluating these profile characteristics both on clear sky, fair weather days when dry deposition and settling would be anticipated to be larger than wet deposition, and on days with precipitation, when wet deposition and scavenging should be more significant. While the UAS will be challenged to fly in poor weather conditions, through the cooperation with AWIPEV and the Koldeway station personnel, we will also be able to conduct profiling using a tethered sonde. The NOAA-UAS aerosol payload will be able to be attached to the tethered sonde which can be used both locally near the Gruvebadet location, as well as remotely in the open fjord ice regions.
Cryospheric Impact on Energy Ny-Ålesund Budget
Concurrent with the NOAA UAS aerosol measurements, the VAUUAV project will be utilizing the CryoWing platform to collect spectral measurements of incoming irradiance and reflected radiance over sea ice, fjord, and glacial surfaces. These repeat flight track measurements will provide baseline variability reference for understanding the potential impact of the deposition of aerosols from polluted air masses. Additionally, ground teams working with the NILU Spectrogoniometer, the NOAA-GMD Mobile Observing System, and the two teams (one from NILU/NP and one from CNR-IIA) conducting ground based spectral reflectance measurements will provide highly detailed measurements of albedo, BRDF, and accurate characterization of the snow pack parameters that may impact the measurements.
Snow pack parameters that most strongly influence the albedo of the snow pack include grain size, snow water content, surface frost, and black carbon concentration. To parametrize these snow pack characteristics along our flight tracks, end point ground stations will be established, and snow samples for black carbon will be collected at each location. In addition to the snow samples, using the DUFISS instrument (see Platforms below) we will accurately obtain the optical grain size, while hand observations and photography will be used to measure the physical grain size. Stratigraphy will be noted using both micro snow pit observations and infra-red photography. Controlling for these physical parameters will allow for accurately assessing the impact of black carbon on the spectral reflectance of the snow surface, and the subsequent impact to the energy balance and climate.
The CICCI project brings together many international institutes, field campaigns, and activities. A major goal of the project is to expand collaboration and enhance the efforts through cooperation. Data, therefore, will be openly shared between participating groups. Complete scientific courtesy will be observed, and any use of data will be discussed directly with the responsible for generation and collection of the data, and co-authorship will be appropriately offered.