TRACE GASES (HICRU)
| Clouds retrieved by HICRU | |
| 1. | INTRODUCTION |
| The detection of cloud parameters like cloud coverage, cloud top pressure or cloud optical thickness from satellite is an important issue: | |
| 1. for meteorology and the investigation of climate change and | |
| 2. for the analysis of tropospheric trace gases from space relevant to
environmental and climatological issues. | |
| Although the retrieval of different cloud parameters is useful
for trace gas retrievals, especially the accurate identification of completely
cloud free regions is crucial due to the shielding effect, which
causes an underestimation of the vertical column density of tropospheric trace gases
measured by satellite, because trace gases below a cloud cannot be seen by satellite. | |
| The Heidelberg Iterative Cloud Retrieval Utilities (HICRU) retrieve effective cloud
fraction - a combination of cloud coverage and cloud albedo - using spectra of two
instruments designed for trace gas retrievals from space: The Global Ozone Monitoring
Experiment (GOME) on the European Remote Sensing Satellite (ERS-2) and the SCanning
Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) on ENVISAT.
An algorithm for the retrieval of the cloud top height (MICRA) is in development. | |
| The images below are retrieved based on HICRU results. Composite images
of the earth in different wavelength ranges (PMD channel 3: 617-705 nm (red),
PMD channel 4: 805 - 900 (IR, used instead of green), PMD channel 2: 450 - 525
nm (blue)) show the earth without clouds (above) and including average cloud and
ice coverage from April 2004 (below). | |
 | |
 | |
| 2. | DOCUMENTATION OF THE HICRU ALGORITHM |
GOME: M. Grzegorski, M. Wenig, U. Platt, N. Fournier, P. Stammes, and T. Wagner. The heidelberg iterative cloud retrieval utilities (hicru) and its application to gome data. Atmosph. Chem. Phys., 6, 2006. pdf | |
| Description of the data format pdf | |
| SCIAMACHY: | |
| Algorithm Specification Document pdf
Product Specification Document pdf | |
| 3. | HICRU DOWNLOAD AREA |
Download HICRU data for GOME (version 1.1): data should be available here data can be obtained from /downloads/GOME | |
| Download HICRU data for SCIAMACHY (version 1.0). Data should be available here; data can be obtained from: /downloads/SCIA | |
| Releasenotes HICRU for GOME: pdf | |
| Releasenotes HICRU for SCIAMACHY: pdf |