ESMR Sea Ice Concentration dataset 1972-1977
The Electrically Scanning Microwave Radiometer (ESMR) on board the NIMBUS 5 satellite was a one channel 19.35 GHz horizontally polarized microwave radiometer operating from 11. Dec. 1972 to 16. May. 1977 (1617 days) with some interruptions. After a major data gap from 3. Jun. 1975 until 25. Aug. 1975 the instrument was only operated approximately every other day. The data have recently been made available online by NASA in the format which was used for the tape archive (TAP-files).
The experimental NIMBUS satellite programme was very successful and there is heritage from it in modern satellite programs and even though ESMR was a predecessor of modern multi-frequency radiometers there are still parts of modern processing methodologies which can be applied to the data to derive the sea ice extent globally. In fact both the dynamical tie-points and the atmospheric noise reduction of the brightness temperatures (Tb’s) can reduce the noise over both ice and open water consistently. These are also the reasons for reprocessing the data. The ESMR sea ice dataset extends the sea ice climate data record with an important period in the 1970s.