130 likes | 259 Views
Comparison of MIRS Sea Ice Concentration and Snow Water Equivalent Retrievals with AMSR-E Daily Products. C. Grassotti, C. Kongoli, and S.-A. Boukabara. MIRS-AMSR Products Comparison. Initial preliminary comparison with AMSR-E Level 3 Daily Products (SIC and SWE) on 20 October 2008
E N D
Comparison of MIRS Sea Ice Concentration and Snow Water Equivalent Retrievals with AMSR-E Daily Products C. Grassotti, C. Kongoli, and S.-A. Boukabara
MIRS-AMSR Products Comparison • Initial preliminary comparison with AMSR-E Level 3 Daily Products (SIC and SWE) on 20 October 2008 • AMSR-E SIC: p.s. projection, 12.5 km resolution • 2 algorithms: NASA Team2, and Bootstrap • 3 products: Daily, Ascending, Descending • AMSR-E SWE: Polar EASE projection, 25 km resolution • Data remapped to common grid for intercomparison
Sea Ice Concentration: MetopA vs. AMSR AMSR MIRS Negative differences north of Siberia and Alaska (new or fy ice?) MIRS - AMSR
Sea Ice Concentration: N18 vs. AMSR AMSR MIRS Negative differences north of Siberia and Alaska (new or fy ice?) MIRS - AMSR
Sea Ice Concentration: F16 vs. AMSR AMSR MIRS Negative differences more extensive MIRS - AMSR
AMSR SIC: NASA Team 2 vs. Bootstrap Daily Ascending NASA Team 2 much greater along ice edge Descending
AMSR SIC: NASA Team 2 vs. Bootstrap Daily Ascending NASA Team 2 higher at ice edge, lower over thicker icepack Descending
Snow Water Equivalent: MetopA vs. AMSR AMSR MIRS Snow covered areas agree approximately Little apparent bias, but large differences locally MIRS - AMSR
Snow Water Equivalent: N18 vs. AMSR AMSR MIRS Snow covered areas agree aproximately Little apparent bias, but large differences locally MIRS - AMSR
Snow Water Equivalent: F16 vs. AMSR AMSR MIRS Snow covered areas less than AMSR Large positive differences where both detect snow cover MIRS - AMSR
Summary • MIRS N18 and MetopA SIC and SWE retrievals in relatively good agreement with AMSR, and with each other (TBD: dependence on AMSR validation product, e.g. NASA Team 2 vs. Bootrap, seasonal dependence, etc.) • AMSR: NASA Team 2 higher SIC vs. Bootstrap near ice edge • MIRS F16 retrievals significant underestimation of SIC in NH • MIRS F16 SWE retrievals problematic: undetected AMSR snow-covered areas and overestimation in areas where both agree • F16 issues: Emissivity catalogs different for F16 vs. Metop and NOAA (scanning and polarization differences). Suggests use of spectral gradients rather than absolute magnitudes? Resolution a high priority. • AMSR products not absolute validation, but good first step toward independent assessment