2 research outputs found
Version 2 of the EUMETSAT OSI SAF and ESA CCI sea-ice concentration climate data records
We introduce the OSI-450, the SICCI-25km and the SICCI-50km climate data
records of gridded global sea-ice concentration. These three records are
derived from passive microwave satellite data and offer three distinct
advantages compared to existing records: first, all three records provide
quantitative information on uncertainty and possibly applied filtering at
every grid point and every time step. Second, they are based on dynamic tie
points, which capture the time evolution of surface characteristics of the
ice cover and accommodate potential calibration differences between satellite
missions. Third, they are produced in the context of sustained services
offering committed extension, documentation, traceability, and user support.
The three records differ in the underlying satellite data (SMMR & SSM/I
& SSMIS or AMSR-E & AMSR2), in the imaging frequency channels (37 GHz
and either 6 or 19 GHz), in their horizontal resolution (25 or 50 km), and
in the time period they cover. We introduce the underlying algorithms and
provide an evaluation. We find that all three records compare well with
independent estimates of sea-ice concentration both in regions with very high
sea-ice concentration and in regions with very low sea-ice concentration. We
hence trust that these records will prove helpful for a better understanding
of the evolution of the Earth's sea-ice cover.</p
Advances in operational permafrost monitoring on Svalbard and in Norway
The cryosphere web portal maintained by the Norwegian Meteorological Institute (MET Norway), https://cryo.met.no , provides access to the latest operational data and the current state of sea ice, snow, and permafrost in Norway, the Arctic, and the Antarctic. We present the latest addition to this portal: the operational permafrost monitoring at MET Norway and methods for visualising real-time permafrost temperature data. The latest permafrost temperatures are compared to the climatology generated from the station’s data record, including median, confidence intervals, extremes, and trends. There are additional operational weather stations with extended measurement programs at these locations. The collocated monitoring offers daily updated data for studying and monitoring the current state, trends, and the effects of, e.g. extreme climate events on permafrost temperatures. Ground temperature rates obtained from the long-term records in the warmer permafrost found in Norway are typically 0.1 ^∘ C–0.2 ^∘ C per decade. In contrast, in the colder permafrost of the High Arctic on Svalbard, a warming of up to 0.7 ^∘ C per decade is apparent. The operational monitoring provides information faster than ever before, potentially assisting in the early detection of, e.g. record high active layer thickness and pronounced permafrost temperature increases. It may also become an important cornerstone of early warning systems for natural hazards associated with permafrost warming and degradation. Currently, data are submitted manually to the international Global Terrestrial Network for Permafrost and are scheduled for integration with World Meteorological Organisation (WMO) operational services through the WMO Global Cryosphere Watch