HR: 0800h
AN: C11B-0459    [Abstracts]
TI: 20th Century Russian ice variability: results from a new digital dataset
AU: * Mahoney, A R
EM: Andrew.Mahoney@nsidc.org
AF: National Snow and Ice Data Center, University of Colorado at Boulder, UCB 449, Boulder, CO 80309, United States
AU: Barry, R G
EM: rbarry@nsidc.org
AF: National Snow and Ice Data Center, University of Colorado at Boulder, UCB 449, Boulder, CO 80309, United States
AU: Fetterer, F
EM: fetterer@nsidc.org
AF: National Snow and Ice Data Center, University of Colorado at Boulder, UCB 449, Boulder, CO 80309, United States
AB: As the Arctic sea ice pack retreats to record-breaking minimum extents, it is increasingly important to be able to set these changes in a longer-term context. Here, we present a recently digitized set of sea ice charts provided by the Arctic and Antarctic Research Institute (AARI), St Petersburg, Russia. The earliest chart dates back to July 1933 making the AARI ice charts perhaps the longest-lived systematic sea ice record in existance. Converting the ice charts to equal area scaleable Earth (EASE) grid format, we compare the sea ice concentrations reported in the AARI ice charts with those from two other datasets: the National Ice Center (NIC) gridded sea ice charts; and the Hadley Centre Global Sea Ice and Sea Surface Temperature (HadISST) dataset. Where the data overlap spatially and temporally, we are able to identify long term and seasonal differences between the datasets. By identifying the underlying causes of these differences, we present the basis for assimilating the concentration data with the view of creating an optimal hybrid sea ice data set for the Arctic. We also present an analysis of sea ice and air temperature variability in the Russian Arctic, derived from the AARI ice charts and meteorological station data, respectively. These results reveal three distinct periods of variability: a period of warm winters and decreasing summer and fall sea ice extent (period A), followed by a cool period of stable or slightly increasing extent (period B) before a period of year-round warm temperatures and ice loss (period C). In magnitude and seasonality, the warming and ice loss during period C are more significant that those during period A. However, the Russian Arctic ice pack did not fully recover during period B, suggesting that the early 20th Century warming during period A may have preconditioned the Arctic for greater change in recent decades. At the end of period B, there is a rapid expansion of both first year and multi year ice extent, which may also have been a catalyst for the subsequent rapid changes in recent years.
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1621 Cryospheric change (0776)
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 4540 Ice mechanics and air/sea/ice exchange processes (0700, 0750, 0752, 0754)
SC: Cryosphere [C]
MN: 2007 Fall Meeting