KNORR CRUISE SYNOPSIS
|Voyage - Leg:||KN 193-01,02|
|Voyage Dates:||19 Mar -12 Apr & 13-24 Apr, 2008|
|Chief Scientist(s):||Tim Bates (Bates)|
|Cruise Objective:||A springtime study of aerosol properties and atmospheric chemistry over the ice-free region of the Arctic. This project is part of the International Polar Year activity POLARCAT (http://www.polarcat.no/polarcat)|
International Chemistry Experiment in the Arctic LOwer Troposphere
As part of POLARCAT, NOAA will undertake a research cruise in an ice-free region of the Arctic during March and April of 2008. The study area will include the Greenland, Norwegian, and Barents Seas. Scientific issues to be addressed include springtime sources and transport of pollutants to the Arctic, evolution of aerosols and gases into and within the Arctic, and climate impacts of haze and ozone in the Arctic.
|Science Activities:||Surface seawater and atmospheric sampling, continuous sampling - no stations|
|Departure Port:||Woods Hole, MA|
|Agent:||Master R/V Ship Name|
Attn: Scientist's Name
266 Woods Hole Rd.
Woods Hole, MA 02543
Contact: John Dyke
Phone: (508) 289-3770
Fax: (508) 457-2185
|Arrival Port:||Tromso, Norway (12-13 Apr), Reykjavik, Iceland (24 Apr)|
|Agent:||Tromso, Norway Agent, TBD|
All packages that have the value of 100 EUR or more should be sent (with transit report) to the following address:
Master R/V Ship Name
Attn: Scientist's Name
c/o TVG-Zimsen ehf
Contact: Mr. Gunnlaugsson
All other packages can be sent directly to:
Master R/V Ship Name
Attn: Scientist's Name
c/o EIMSKIP Port Agency Services
Contact: Berry Timmermans
Phone: 354 525 7273
Fax: 354 525 7279
Cell: 354 825 7273
||Vans mounted on bow, main deck and 01 deck - 10 vans|
Weather ballons deployed from Aft Hanger (17Dec-JD)
Liquid Nitrogen generator mounted in forward Hanger - may need tracks removed (05 Feb-JD)
Sensors to be mounted on the bow Met tower, equipment in bosun's locker (05 Feb-JD)
Two level tower(16ft tall) to hold sensors for daily access, to be mounted on 02 Deck, bow, starboard side(05Feb-JD)
Sensors will also be mounted on the forward side of the foremast with lines run to bow vans.(05Feb-JD)
Large amount of gas bottles to be loaded ~180-200, gas bottle racks to be obtained and used for loading and securing (05Feb-JD)
||Night Work Anticipated|
Drew Hamilton and Derek Coffman have been trained in hazardous material response.
All materials will be offloaded with our scientific laboratory vans when the ship returns to the continental US.
Initial plan is to depart Woods Hole and head south into Long Island Sound sampling air pollution then head north through the Cape Cod Canal off of Boston and then Portland before heading into International waters. Possibility of 2 scientists departing vessel by ship's small boat off of Boston or Portland. (05Feb-JD)
In the late 1950s, pilots flying over the Canadian and Alaskan Artic observed a haze of unknown origin that significantly decreased visibility. This “Arctic Haze” is a phenomenon that recurs every winter and spring and is now understood to be due to long range transport of anthropogenic aerosols primarily from Europe and Western Asia. The haze is composed of a varying mixture of sulfate, nitrate, particulate organic matter (POM), dust, and black carbon. Long-term measurements at ground sites within the Arctic (Barrow and Alert), reveal a decreasing trend in concentrations of aerosol black carbon during March and April throughout the 1990s. Since the beginning of the 21st century, however, concentrations have increased not only during the Arctic Haze months but also during the summer. Aerosol light scattering follows a similar trend with levels decreasing through the 1990s and increasing since 2000. In addition, concentrations of nitrate have increased at Alert from the early 1980s to present. In contrast, levels of sulfate have decreased from the 1990s to present. The lack of long term measurements of POM in the Arctic makes it difficult to assess trends in POM. Reasons for the changing trends, especially the decoupling of sulfate from nitrate and black carbon, are uncertain as are the impacts on the climate of the region.
Just as anthropogenic aerosol is transported to the Arctic during the spring, so are gas phase compounds that impact the oxidative capacity of the atmosphere and Arctic climate. The peak in average surface level arctic ozone concentrations occurs coincidentally with the artic haze during springtime due to the presence of reactive nitrogen and other ozone precursors. There are uncertainties surrounding the partitioning of reactive nitrogen as it is transported into the Arctic and the mechanism for the conversion and cycling between NOx (=NO + NO2) and NOy (= the sum of all reactive nitrogen). The uncertainty in reactive nitrogen chemistry leads to uncertainty in the rate of photochemical ozone production in relation to processes such as long range transport and stratosphere-troposphere exchange during the arctic spring ozone maximum. For example, photochemical HOx production, a key component of ozone photochemistry, has a potentially large but still uncertain contribution from long wavelength photolysis of HOx and NOx reservoir compounds at the high solar zenith angles that occur during the spring in the Arctic. Furthermore, the production and photochemical cycling of halogen species has a profound effect on the local O3 in the lower arctic troposphere, leading to intense ozone destruction events (ODEs). There are considerable uncertainties in this chemistry, including the processes that are responsible for its initiation, the magnitude and extent of halogen radical processing in this environment, the interplay between chlorine and bromine, and the broader implications of this chemistry, especially with respect to hydrocarbon processing.
Changes in surface air temperature and ice extent over the past decade suggest that anthropogenically-induced climate change is occurring in the Arctic. However, the impact of short lived pollutants such as aerosols and tropospheric ozone versus long lived greenhouse gases on Arctic climate is, as of yet, unknown. A better understanding of the climatic effects of the short lived pollutants is required to guide mitigation strategies and, in particular, to determine to what extent reducing concentrations of aerosols and tropospheric ozone in the source regions will reduce the rate of warming in the Arctic.
NOAA will undertake a research cruise in the eastern Arctic in March and April of 2008 to address scientific questions related to the sources, transport, and climatic impacts of anthropogenic aerosol and gas phase species. This experiment, which will be part of POLARCAT (an IPY activity), will take place in the Greenland, Norwegian, and Barents Seas. One unique aspect of the project is the focus on the ice free region of the Arctic at a time when the fraction of Arctic ice coverage is decreasing. In addition, measurements made of aerosol and gas phase species associated with ship emissions will serve as a “baseline” before the possibility of an increase in ship traffic as a result of the decrease in ice coverage is realized along the Northern Sea Route and Northwest Passage. Specific scientific questions to be addressed are listed below.
Q1. Springtime sources and transport of pollutants to the Arctic
Measurements of aerosol properties coupled with chemical transport models are required to understand the apparently changing trends in certain components of Arctic Haze. Measurements of aerosol composition will be made and these data will be used in conjunction with chemical transport models to determine:
• What is the composition of the aerosol during March and April over the ice-free regions of the Arctic?
• What are the sources of the aerosol to this region during March and April?
How significant is local production of aerosols (e.g., oceanic emissions of particles and trace gases, emissions from ships, local point sources in the Arctic)? What are the dominant oxidation pathways in the production of aerosols from these sources?
How significant is the North Atlantic as a marine boundary layer transport pathway for mid-latitude pollutants into this region of the Arctic?
How significant is the exchange of aerosols between the MBL and free troposphere?
Q2. Evolution of aerosols and gases into and within the Arctic
The impact of aerosols on climate is determined by the size and composition of the particles which, in turn, is affected by processing during transport and the spring progression. Measurements will be made to determine:
• How do aerosol precursor gases and the chemical, physical, optical and cloud nucleating properties of the aerosol evolve along the North Atlantic transport route?
• How do aerosol precursor gases and the chemical, physical, optical and cloud nucleating properties of the aerosol evolve as the spring progresses?
Previous aircraft and surface measurements in the Arctic have provided evidence for reactive nitrogen transport into the Arctic during spring. Although most of the measured NOy is in the form of PAN, modeling studies suggest that N2O5 hydrolysis is responsible for much of the conversion of NOx to NOy during transport. Measurements will be made to determine:
• What is the partitioning of reactive nitrogen in the springtime Arctic?
• What is the rate of N2O5 hydrolysis in the Arctic, and how does it impact NOy?
• What are the lifetimes of and loss processes for NO3 in the Arctic?
The lower tropospheric ozone maximum that occurs in the Arctic spring has contributions from long range transport, stratosphere-troposphere exchange, and in-situ production. Modeling of aircraft data from 2000 showed an unexpectedly large contribution from the latter. Additional uncertainties surrounding the Arctic springtime ozone budget include the importance of HOx in the photochemical production of ozone and ozone depletion events linked to halogen activation in the Arctic spring. Measurements will be made to determine:
• What are the in-situ ozone production rates during the spring in the Arctic?
• What is the role of HOx chemistry at high solar zenith angles?
• Are ozone depletion events due to halogen activation significant in the ice-free regions of the Arctic?
• What mechanism activates halogens to initiate arctic ozone depletion events?
• What is the role of reactive nitrogen uptake by sea salt?
Q3. Climate Impacts of aerosols and ozone in the Arctic
The contribution of aerosols to anthropogenically-induced climate change in the Arctic is uncertain yet may be significant through direct interaction with solar and longwave radiation, aerosol – cloud interactions, and feedback processes. Measurements will be made to determine:
• What is the impact of anthropogenic aerosol on the clear-sky radiation balance of the ice-free regions of the Arctic during March and April?
• How do anthropogenic aerosols affect the radiative properties of clouds in this region?
What are the cloud nucleating properties of the aerosol?
What is the impact of anthropogenic aerosol on cloud drop effective radius and reflectivity?
What is the impact of anthropogenic aerosol on longwave downwelling radiation, atmospheric heating rates, and surface warming?
During the winter and early spring, tropospheric ozone is sufficiently long-lived to be transported from lower latitude source regions to the Arctic. Since ozone absorbs both infrared and shortwave radiation, it can induce large warming over highly reflective surfaces which may, in turn, contribute to snow/ice melting.
• Given the observed surface concentrations and vertical profiles of tropospheric ozone, what is the radiative impact in the springtime western Arctic?
• How does radiative forcing by tropospheric ozone vary as a function of ozone production and depletion in the ice-free western Arctic?
|SSSG Tech:||sssg @knorr.whoi.edu|
|US Customs Form||Yes||For all items|
|Diplomatic Clearance||Yes||Canada(T), Denmark(T), Greenland(T), Russian Federation(T), France(T), Iceland(T), Norway(T)|
|Isotope Use Approval||No|