Oxford-RAL IASI Group Meetings

Meeting#06 (12May15)

Oxford: Anu Dudhia, Charlotte Birch, Elisa Carboni, Catherine Hayer, Lucy Ventress, Tony Vincent

RAL: Brian Kerridge, Diane Knappett, Richard Siddans

CH4 Retrievals (DK) [Prev] [Next]

Incorporate results of recent EUMETSAT study on IASI + MHS (microwave) retrievals: use study L2 products as a priori for IASI CH4, 3 test days. 3 cases, 1 Eumetsat T+q, 2: Eumetsat T,q + emiss, 3: Eumetsat T,q,emiss + cloud. Not yet clear which is best

IASI NRT web-site (CH) [Prev] [Next]

Web-site slowly progressing, last stages. Recent Calbuco (Chile) eruptions SO2 detected using linear retrieval. Sorting out netCDF standard names etc. Ash is not so good - lots of spurious features near the equator probably associated with cloud.

RFM Look-Up Tables (TV) [Prev] [Next]

IASI LUTs for 11 molecules used in RTTOV. Need special tests for volcanic SO2 atmospheres to avoid missing SO2 features.

T+H2O+O3 retrievals for Grim eruption. AVHRR image shows ash feature in the middle of scene. Look at IASI AVHRR cloud flag - spatially homogeneous ash doesn't get flagged. Tried retrieval on scene, ignoring ash.

Volcanic SO2 (EC) [Prev] [Next]

Large increase in SO2 from Bardarbunga drifted over Europe. Working on paperw with Anja Scmidt (ULeeds). Good agreement between IASI and UV instruments, and NAME model. IASI v3 band, in H2O region, limited to high altitude SO2, but can do better with v1 in window region. Using corrections for UV/IR weighting to improve agreement.

Report from MPhys student James Preston - linear retrievals. Annual averages of IASI linear retrievals shows clear volcanic emissions and pollution events.

Volcanic Ash (LV) [Prev] [Next]

comparing IASI and MODIS ash retrieval - very poor agreement in optical depth. IASI retrieves optical depths of 10 at most, while MODIS frequently much higher. Work part of SCOPE project. Suggest that comparing optical depth at 11um is better than using 10um since less dependent on composition assumption.