Oxford-RAL IASI Group Meetings

Meeting#20 (15Dec16 @ Oxf)

Oxford: Elisa Carboni, Anu Dudhia, Robert Hargreaves, Isabelle Taylor

RAL: Brian Kerridge, Diane Knappett, Richard Siddans, Joanne Walker

CH4 (DK) [Prev] [Next]

CH4 retrievals using different Met Data inputs: ECMWF, EUMETSAT PWLR3 L2 and RAL retrieved T,q. Best improvement from retrieving emissivity rather than using Wisconsin data.

SO2 (EC) [Prev] [Next]

2014/15 Bardabunga total emission plots v time, compared with local Iceland measurements. Estimate total SO2 emission 4Tg (could be too low due to missing data from cloudy scenes), cf local estimate 10Tg.

Time series of Etna emissions from iterative retrieval, assuming ECMWF T,q and Wisconsin emissivity. Question whether emissivity/topography matters for this case. May2012 sudden change, possible change in L1C data. Seems to be an annual cycle in the SO2, presumably due to incorrectly modelled H2O.

NH3 (RH) [Prev] [Next]

Alternative method using SVD of ensemble of RTTOV profiles plus varying surface temperatures to reconstruct observed spectrum. Try to estimate Jacobian from difference between a pair of channels, but seems more sensitive to cloud contamination.

Ash (IT) [Prev] [Next]

CO2-slicing for ash altitude. Simulated ash clouds for different altitudes/optical depths. Compared results with CALIPSO for Eyja eruption. Problem reading ECMWF data.

IMS Retrievals (JW) [Prev] [Next]

Performing 10 year run, adapted for varying greenhouse gases and RTTOV coefficients. Still problems with output file size if AKs included.

MORSE (AD) [Prev] [Next]

Written IDL reader for IASI L1C .nat data

• read_l1c.html

Next step is to produce preprocessor for MORSE.

Desert Emissivity (BJK) [Prev] [Next]

Why are there problems with emissivity over the desert?