| This dataset contains Polar Mesospheric Clouds (PMCs) observed by the Spatial Heterodyne Imager for MEsospheric Radicals (SHIMMER) onboard the STPSat-1 satellite. The PMC (primarily a summertime phenomenon) data are derived from over a million limb images during its three-year mission, minus September through November for each year. Each file has a five-line header that includes: (1) Year and day of the year (DOY), (2) Total number of PMC detected on that day, (3) The number of PMC detected when using a phase function of the ice particles, (4) Hydroxyl (OH) radiances at 80 and 87 km, and (5) Labels of the output: Year, DOY, GMT, LAT, LON, LST, SSA, SZA, PMCRAW (1 for PMC detection and 0 for none), PMCMIE (detection above the applied threshold), BGRND (average Rayleigh scattered background signal in kR/nm), BRT (background corrected peak brightness in kR/nm), THRRAW (threshold used to identify a PMC), THRPHS (threshold used to detect PMC in kR/nm), PK (altitude of the peak emission in km), OH80 (OH solar resonance fluorescence radiance detected at 80 km in kR), OHE80 (uncertainty for the 80 km OH radiance in kR), OH87 (OH solar resonance fluorescence radiance detected at 87 km in kR), and OHE87 (uncertainty for the 87 km OH radiance in kR).
In addition to the PMC data, there are PMC maps and summary figures for each year of operations. The first figure for each year is map_YYYY.ps, where YYY represents the year. This shows the geographic location of each detected PMC, without regard to when it was detected. Also indicated on the maps are the total number of images tested for a PMC as well as the total number of PMC detected for each year. The second figure (summary_YYYY.ps) shows a time series of some important results of the analysis: the number of SHIMMER images tested, a time series of PMC detections for the year, a time series of thresholded PMC detections, and a time series of PMC altitudes defined as the altitude of peak brightness. |