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SLTS
The measurement of sea level along polar coastlines presents great technical challenges for the Global Sea Level Observing System (GLOSS) of the WMO/IOC Joint Technical Commission for Oceanography and Marine Meteorology (JCOMM). The need for measurements in these data sparse regions has been clearly made in the scientific literature. For example, in oceanography, Arctic sea level data presently available suggest a common-mode of variability which provides insights in the quasi-resonant dynamics of the Arctic Ocean. Arctic sea level data are of particular interest within water balance studies concerning the freshening of the Arctic Ocean and its relationship to the Arctic Oscillation. Antarctic sea level changes have also been found to demonstrate considerable coherence related to the Southern Annular Mode and transports in the Antarctic Circumpolar Current. The need for measurements for climate studies by the Intergovernmental Panel on Climate Change has also been clearly made. Monitoring of levels in both high-latitude regions is necessary to understand more completely the spatial pattern of long term sea level change due to ocean warming and ice melt. Climate and sea level changes also affect the stability of ice shelves and fast ice and the glaciers behind them.This project will use existing and new Arctic sea level recorders (there are no sites currently operational in Greenland, for example) and will make enhancements to the existing network of gauges in Antarctica. Past and future tide gauge data sets will be used in combination with satellite altimeter and space gravity data where possible to understand further the regional ocean dynamics and climate change (EoI 580). Differences between Arctic and Antarctic in ocean dynamics and sea level response to climate change are particularly interesting. The new recorders will be high technology devices providing data at high frequency and real time, comprising the core of ongoing polar sea level monitoring networks. This will be an essential component of GLOSS and a major legacy of IPY (EoI 211). Benefits from enhanced polar networks can be anticipated in many ways not yet clear. However, sea level data are indispensable in many countries for practical applications such as flood warning, navigation, civil engineering and environmental monitoring, in addition to their scientific applications. Consequently, Arctic communities can be expected to benefit from investment in this collaborative sea level research. For example, the GREENSEAL project (EoI 761) will focus on developing the GLOSS network in Greenland which will benefit Arctic ocean circulation and sea ice flow studies, as well as providing essential practical data sets to local communities. The LEVANS project (EoI 304) will enhance corresponding data sets and understanding in Nordic Seas, while the Russian Arctic networks project (EoI 732) will see similar benefits to Russian science and coastal communities. The further understanding of ocean tides in polar regions is a particularly important component of sea level studies, being relevant to a range of geophysical (e.g. dissipation), physical oceanographic (mixing), glaciological (sea ice formation) and biological studies (EoI 590). High latitude bathymetry and sub-ice-shelf topography are needed in addition to tidal measurements from coastal and bottom tide gauges and (where possible) altimetry over ocean and ice-shelves. Summary provided by http://classic.ipy.org/development/eoi/proposal-details.php?id=13