News / Research Highlights / Ice-Ocean Modeling in the Arctic: A series of IARC Research Studies

Ice-Ocean Modeling in the Arctic: A series of IARC Research Studies

February 17, 2005

1. Dipole Anomaly and Arctic Oscillation in the Arctic

Dr. Jia Wang and his collaborators, Drs. Bingyi Wu and John Walsh, noticed a new atmospheric circulation structure called the dipole anomaly (DA). They are studying the relationship of DA to sea-ice movement in the Arctic. Data from the International Arctic Buoy Programme (IABP) (1979-98), as well as the National Centers for Environmental Prediction (NCEP) and the National Center for Atmospheric Research (NCAR) in Boulder, CO (1960-2002) is utilized. The DA occurs in the arctic winter atmosphere and the associated anomalous wind can drive sea ice out of the Arctic Basin, while moving cold air into the Barents and Nordic Seas and northern Europe. The two anomaly 'centers' in this study are located over the Canadian Archipelago and the northern Eurasia and Siberian marginal seas. Furthermore, the researchers use a Coupled Ice-Ocean Model (CIOM), which was developed at IARC, to confirm the arctic sea ice response to DA.

2. Ecosystem Modeling in the Bering Sea Middle Shelf

Dr. Wang and his colleagues, Drs. Clara Deal, Meibing Jin, and Nori Tanaka, are creating simulations of the ecosystem of the Bering Sea middle shelf and ice-algae populations off the coast of Barrow, Alaska. The study focuses on tidal and wind mixing, the vertical mixing of salt and heat in seawater. Tidal and wind mixing influences the success (i.e., timing and strength) of spring phytoplankton bloom in the southeastern Bering Sea middle shelf. They developed a one-dimensional model that combines physical and biological components with tidal current. The biological model uses nine components, including two types of phytoplankton and three types of zooplankton. Phytoplankton, tiny free-floating aquatic plants, such as single-celled algae, are found in plankton, a cluster of tiny plants and animals that float near the surface of the ocean, and are food to fish and other sea creatures. Zooplankton is plankton that is composed of microscopic animals. Three nutrients and detritus, the materials resulting from disintegration of rocks and organic particles, are also part of the model. Wind and tidal mixing appears to be an important part of the study for an accurate model of spring and summer phytoplankton bloom.

3. Simulations of Arctic Ocean Climate Using a Global Coupled Ice-Ocean Model

An IARC team of researchers is using the Earth Simulator supercomputer to create ice-ocean models of the Arctic Ocean. They successfully simulate, without model-to-data correction that most global climate models use, the Arctic Ocean's "Atlantic Layer," an intermediate warm (~0-2°C) water from the Atlantic Ocean that moves into the Arctic Ocean, using a 3-D combined model from Tokyo University and Los Alamos sea-ice models. When the mean value from the model was evaluated against observation data, they were encouragingly consistent, although there were some noticeable differences. New model simulations are being coupled to the atmosphere to reduce the uncertainty of the Arctic climate variability.

Left to right: Dr. John Walsh, Dr. Nori Tanaka, Dr. Sheng Zhang, Dr. Jia Wang, Dr.Clara Deal, Dr. Meibing Jin, Haoguo Hu (M.Sc.)

Photo Credits: sunset & sea ice from NABOS cruise, photographer unknown; diver under the ice, Rod Budd at NIWA; ice algae, Dough Allen; sea/ice landscape, T. Saito; Earth Simulator, ES gallery; researcher portraits by B. Travis, K. Hayes, and V. Zins.