ALTEX Arctic Cruise
October 7 - November 7, 2001
Tromso, Norway to the Arctic Circle
Cruise History & Purpose


Exploring the Arctic with Robots

The Monterey Bay Aquarium Research Institute (MBARI) together with Fuel Cell Technologies (FCT), Scientific Solutions, Incorporated (SSI), the NOAA Pacific Marine Environmental Laboratory (PMEL), and the Massachusetts Institute of Technology (MIT) are developing an Autonomous Underwater Vehicle for Arctic research with unprecedented endurance and the capability to relay data through the ice to satellites. Our goal is to greatly increase access to the Arctic Ocean by creating and demonstrating a safe and economical platform capable of basin-scale surveys. We will provide a means of monitoring changes taking place in the Arctic Ocean and investigate their impact on global warming. The vehicle will also be capable of seafloor surveys throughout the Arctic basin. We call the vehicle the ALTEX AUV, for the Atlantic Layer Tracking Experiment that motivated its development.

The Arctic Ocean poses unique challenges for oceanography because it is, for the most part, covered with sea ice. This makes the Arctic very difficult to observe because the most widely used observational techniques today are either ship or satellite based. Much of our understanding of the Arctic Ocean comes from the use of nuclear submarines as research platforms. These submarines are active U.S. Naval vessels, and access to them has been provided via a highly successful multi-agency agreement called the SCICEX (Scientific Ice Expeditions) program. There are, however, some limitations to the use of such a platform for oceanography:

  • The unclassified depth rating of the SSN 637 submarines available to the scientific community is 300 meters; this does not allow characterization of the entire water column
  • Nuclear submarines are expensive to maintain and operate.
  • Measurements near bottom can be carried out only in a relatively small portion of the Arctic basin, limited by the submarine’s depth rating at the lower extreme, and by dangers of operating under ice at the shallow extreme.
  • The ice-capable Sturgeon-class submarines are likely to be unavailable soon, potentially ending the SCICEX program.

AUVs have been employed for Arctic science since the 1970s, however operations are typically limited to excursions from ice holes on the order of kilometers. Perhaps the longest under-ice run has been achieved in the deployment of a fiber optic cable from Ellesmere Island to an ice camp 175 km offshore by a very large AUV. All of these operations were shallow, never exceeding depths of a few hundred meters. In contrast, for AUVs to address the large-scale climate issues of the Arctic basin, ranges on the order of a 1,000 km and depths of 1,500 meters must be achieved, thus providing the goals for our efforts.

While the developmental effort is presently focused on Arctic Ocean hydrography, this advanced vehicle can be used for a range of oceanographic applications, including seafloor mapping. Furthermore, in many ocean regions, the range and navigation capabilities provided by this vehicle would allow shore-based operations. The 4500 meter depth rating of the core vehicle allows the system to be used for deep-sea vent studies, studies of the sea floor spreading, exploration of the Antarctic ice shelf, and coupled observation/modeling systems in coastal and continental shelf environments.


Arctic Hydrography and Global Climate

Recent SCICEX cruises have returned evidence that the Arctic is in the midst of a significant change involving both the atmosphere and the ocean. This is indicated by the increased coverage of the warmer Atlantic water that has been observed in recent years. Data collected all indicate that the area occupied by the warmer, eastern water types is nearly 20 percent greater than previously observed. These observed differences represent a fundamental change in the Arctic; it is of utmost importance that these changes in the Arctic Ocean be studied in detail.

Temperature and salinity changes observed between 1991, 1994, and 1996 are consistent with a warming of the Fram Strait Atlantic inflow. Observations in the next years may be particularly significant in view of the changes observed in the Atlantic Oscillation (AO), which has had a persistent positive phase through the 1990s. Data from the spring of 1999 show a major reversal to the phase of the AO with a major increase in sea level pressure. A 16 millibar plus anomaly in the sea level pressure was observed over the Kara Sea in March of 1999. These observations point to the urgent need to conduct experiments to study the changes taking place in the Arctic.

There is an inherent difficulty in distinguishing between anthropogenic climate change and natural variability. Climate models are nearly unanimous in predicting amplified polar response to greenhouse warming although models tend to show warming in winter while recent data show warming (ice reduction) in spring and summer. The connection between lower atmospheric pressure in the Arctic and the incursion of warm Atlantic water into the Makarov Basin may indicate an important link in how the climate system manifests polar amplification. Overcoming the challenges inherent in observing the Atlantic water incursion into the Arctic basin is the fundamental driver for our AUV development.

The Altantic Layer Tracking EXperiment (ALTEX) is designed to help determine the fate of the Atlantic water advected into the Arctic basin by exploiting the new AUV capabilities. The need is to understand heat exchange between the Arctic basin and other ocean basins. More specifically, the transport of heat and salt is needed to understand the role of the Atlantic water in the Arctic ocean on the global climate. In many respect this program is the logical follow-on to the Surface Heat Budget of the Arctic Ocean (SHEBA) program, which examined heat flux between the Arctic ocean and atmosphere.

Findings of the changes taking place in the Arctic have generated great interest because of their broad implications and their relation to changes at lower latitudes. Examining the evolution of the variations over time will tell us about the global interaction of Arctic climatic events. This warrants a multifaceted approach of measurements, observation, data analysis, and modeling. The need is to make repeated hydrographic measurements over the entire Arctic basin.


ALTEX AUV

Primary contacts for the ALTEX project

James G. Bellingham
Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, CA 95039-0628, USA
Dr. Bellingham led the MIT Sea Grant AUV Laboratory from its founding in 1989 until 2000.

William Kirkwood
Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, CA 95039-0628, USA

James Overland
Pacific Marine Environmental Laboratory, 7600 Sand Point Way NE, Seattle, WA 98115, USA

Peter Stein
Scientific Solutions Inc., 18 Clinton Drive Hollis, NH 03049-6576, USA

John Stannard
Fuel Cell Technologies Ltd., 20 Binnington Ct., Kingston, ON K7M8S3, Canada

 

Click on the links to the left to find out more about this exciting cruise!