MODIS-ST Description


MODIS, Terra and Aqua

Local Observation Time and Length of Data Record

10:30 AM and 10:30 PM ; 2001–2009,
1:30 AM and 1:30 PM ; 2003–2009

Spatial Resolution

1 km (detection, COD, CRE, CWP, phase retrieval), 5 km (CP, CT, CEM retrieval)

Cloud Detection

multi-spectral IR/NIR/VIS (16 channels)+ time-space variances

Retrieval Methodology

CP, CEM → CT, cloud phase (water/ice), COD, CRE, CWP

MODIS Science Team uses spectral testing to determine cloud amount, "CO2 slicing" to determine cloud pressure and emissivity and a Look-Up Table approach using solar reflectance channels to retrieve cloud optical depth and effective particle radius.

Ancillary Input

  • NCEP GDAS profiles
  • 16 day spectral surface albedo climatology
  • radiative transfer+particle model
  • mixed particle habits for ice
  • References

  • Ackerman, S. A., K. I. Strabala, W. P. Menzel, R. A. Frey, C. C. Moeller, and L. E. Gumley, 1998: Discriminating Clear-sky from Clouds with MODIS. J. Geophys. Res., 103, D24, 32,141.
  • Frey, R. A., S. A. Ackerman, Y. Liu, K. I. Strabala, H. Zhang, J. Key and X. Wang, 2008: Cloud Detection with MODIS, Part I: Recent Improvements in the MODIS Cloud Mask, J. Atmos. Oceanic Tech., 25, 1057-1072.
  • Menzel, W. P., R. A. Frey, H. Zhang, D. P. Wylie, C. C. Moeller, R. E. Holz, B. Maddux, B. A. Baum, K. I. Strabala, and L. E. Gumley, 2008: MODIS Global Cloud-Top Pressure and Amount Estimation: Algorithm Description and Results. J. Appl. Meteor. Climatol., 47, 1175-1198.
  • Platnick, S., M. D. King, S. A. Ackerman, W. P. Menzel, B. A. Baum, J. C. Riedi, and R. A. Frey, 2003: The MODIS cloud products: Algorithms and examples from TERRA. IEEE Trans. Geosci. Remote Sens., 41, 459-473.