Cloud pressure retrieval using the O₂‐O₂ absorption band at 477 nm

We present an operational method for cloud pressure retrieval from the Earth's reflectance spectrum in the visible, using the O 2 ‐O 2 absorption band at 477 nm. The algorithm is simple and robust. Apart from cloud pressure, an effective cloud fraction is also retrieved. Using simulations and Global Ozone Monitoring Instrument (GOME) data the accuracy of the O 2 ‐O 2 retrieval method is estimated. The Ozone Monitoring Instrument (OMI), to be space‐borne on board the EOS‐AURA platform in 2004, will use this algorithm to produce an official cloud product. The cloud product will be used to support the cloud correction of several of the OMI trace gas retrievals.