13 research outputs found
Multi sensor validation and error characteristics of arctic satellite sea surface temperature observations
Get PDFVersion 2 of the EUMETSAT OSI SAF and ESA CCI sea-ice concentration climate data records
Get PDFWe 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
Fra Sputnik... - til moderne iskortlægning
No full textSiden opsendelsen af den første satellit i 1957 er der sket en rivende udvikling inden for anvendelsen af satellitdata. I Danmark har man for eksempel brugt data til meteorologiske analyser på DMI. I de seneste år har kortlægningen af havis-udbredelsen med satellit været et væsentligt bevis på, at vores klima er under forandring
Landcover classification of the Senegal River basin using characteristic parameters of vegetation and climatic elements
No full textNordpolen på skrump - dækket af "tynd" vinteris
No full textSiden man begyndte at kortlægge havisen i Polhavet med satellitdata, har Nordpolen både sommer og vinter været dækket af fl ere år gammel og 3-4 m tyk is – også kaldet polaris. Polarisen dækkede før i tiden næsten hele Polhavet med undtagelse af havet nord for Alaska, Bering Strædet og de Sibirske shelfområder. I løbet af februar 2008 hændte det så, at et usædvanligt stort område med is dannet denne vinter (vinteris) fra Bering Strædet og Sibirien for første gang, mens man har målt, nåede helt hen over Nordpolen. Vinteris bliver typisk ikke mere end 2 m tykt i løbet af en hel vinter i Polhavet
Use of remotely sensed precipitation and leaf area index in a distributed hydrological model
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Deriving Arctic 2m air temperatures over snow and ice from satellite surface temperature measurements
No full textSeeking an optimal algorithm for a new satellite-based Sea Ice Drift Climate Data Record : Motivations, plans and initial results from the ESA CCI Sea Ice project
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