Passive Microwave Sea Ice Data and Complications in the Development of a Sea Ice Climate Data Record

Over the past 30 years we have witnessed declining Arctic sea ice. Today it is recognized as one of the most dramatic indicators of climate change. The most comprehensive sea ice data are from a series of passive microwave sensors. They provide a continuous time-series of sea ice concentration and extent since October 1978. At the National Snow and Ice Data Center (NSIDC), passive microwave sea ice data sets have provided timely assessments of seasonal-scale variability as well as consistent long-term climate trends. However, there are still complicating issues that prevent our current data streams from being considered an authoritative sea ice climate data record (CDR). In this presentation we review NSIDC's current sea ice data holdings and how challenges, such as sensor changes and processing resources, impact the timeliness of sea ice data updates. Current challenges will certainly impact the development of an authoritative CDR, but other complicating issues are also explored. Several algorithms are being used to produce sea ice products, when an agreed-upon definitive algorithm is preferred for a consistent data record. In addition, comprehensive metadata and data quality information are lacking. Finally, thorough documentation of data provenance and processing steps should be made available for reproducibility and potential future reprocessing. As ice-free Arctic predictions continue to make headlines, it is becoming imperative that progress continues to be made toward the development of an accepted sea ice climate data record. NSIDC plans to take a leading role in these efforts.