Oxford MIPAS meeting#125
04 Sep 07

Present

Oxford: Anu Dudhia, Jane Hurley, Joanne Walker, Claire Waymark
RAL: Alison Waterfall

30th Aug - 8th September: currently in a 10-day sequence based on the new 80% duty cycle: 4 days NOM, 1 day MA, 3 days NOM, 2 days off.

Next sequence will include side-viewing AE mode measurements over the N.Atlantic during NOM mode days (9-11th Sep).

Mission Planning Document for 2007 [XLS] [HTML].
Currently defined measurement modes
Envisat Web-Site

L1B Data (JH) [Prev] [Next]

L1B coverage maps updated to Aug 20th (or, will be shortly...)

[L1B Data Coverage]

Oxford L2 Processing (AD) [Prev] [Next]

Running MORSE to retrieve our own L2 data: pT, H2O, O3, HNO3, CH4, N2O, NO2, CFC-11, CFC-12, ClONO2, N2O5 and CO (LTE assumption).

[Oxford L2 Data Coverage]

Aim to process all available L1B data from 01 Jun 07 onwards, plus at least one day per month of earlier data (to determine trends).

Still having hardware problems with our cluster, but in the meantime started using desktop computers to process recent NOM mode data (from 26th Jul 07 onwards)
Currently latency: about 1 month behind real-time (2 weeks due to delay in L1B data availability)

NOy (JW) [Prev] [Next]

Odd-nitrogen molecules retrieved from MIPAS (NOy = NO2, HNO3, N2O5)

Converting ESA L2 and Oxford L2 (>2005) data to equivalent latitude to better follow evolution through polar winter conditions
Now sorted out use of ECMWF data for equivalent latitude/EPV: [Plot] of EPV @ 450K
Next: regrid existing MIPAS L2 data (p,lat) to (theta,equiv.lat) to map movement of odd nitrogen.

MIPAS/TES Retrievals (CW) [Prev] [Next]

Aim is to combine MIPAS limb measurements of stratospheric O3 with TES nadir-viewing measurements to obtain more information on tropospheric O3 profile (basically how TES was supposed to work before their problems with limb-views)

Sorted out H2O retrieval errors (plotting problem) but still have kink in temperature profile at 6km, which appears to be associated with the use of a particular microwindow at 1316-1319cm-1 (CH4/N2O bands).

CO non-LTE Retrieval (JW) [Prev] [Next]

MORSE has now been adapted to retrieve CO VMR and its vibrational temperature profile simultaneously.

Testing retrieval with an orbit of MIPAS full-resolution data

[Plot] showing 1 orbit of CO VMR retrieved (top panel), a priori (middle) and retrieval-a priori (bottom)
[Plot] of corresponding VT retrieval. NB: a priori assumption is that vibrational temperature=kinetic temperature

Retrieved VT looks reasonable but still some instabilities and unrealistic changes in CO between day and night (SZA plotted on bottom axes)

Cloud Top Height (JH) [Prev] [Next]

Comparing MIPAS cloud top height with the HIRDLS/Aura product

Difficult to find colocations so comparing gridded monthly data of average CTH for May 2006:

[MIPAS] monthly average
[HIRDLS] monthly average

Still a few questions over how to best perform this comparison: for example, the above plots only show average height of whenever cloud is detected but HIRDLS scans to lower altitudes than MIPAS so includes lower CTHs in each average.

RAL Work (AW) [Prev]

Trying to get 2D retrieval scheme working.

Works with simulated data - now trying out real data.

ACPD Papers [Prev] [Next]

Papers selected from the ACPD website for discussion

"Comparison between the first Odin-SMR, Aura MLS and CloudSat retrievals of cloud ice mass in the upper tropical troposphere": P.Eriksson et al. (published 14.08.2007, open until 09.10.2007); Introduced by JH.
"Growth rates of stratospheric HCFC-22": D.P.Moore & J.J.Remedios (published 23.07.2007, open until 17.09.2007); Comments being collected by AD.
"Short- and medium-term atmospheric effects of very large solar proton events": C.H.Jackman et al. (published 23.07.2007, open until 17.09.2007); Comments being collected by CW.
"Effects of total solar eclipse of 29 March 2006 on surface radiation": S. Kazadis et al. (published 29.06.2007, discussion now closed); Comments submitted by LMV.
"Observed poleward expansion of the Hadley circulation since 1979": Y. Hu & Q. Fu (published 02.07.2007, discussion now closed); Comments submitted by JW.

Other MIPAS-related papers in the Open Discussion phase, which may be adopted at a future meeting

"MIPAS measurements of upper tropospheric C2H6 and O3 during the Southern hemispheric biomass burning season in 2003": T.v.Clarmann et al. (published 15.08.2007, open until 10.10.2007)
"MIPAS: an instrument for atmospheric and climate research": H.Fischer et al. (published 25.06.2007, open until 11.09.2007)

Oxford MIPAS meeting#125 04 Sep 07

Oxford MIPAS meeting#125
04 Sep 07