Oxford MIPAS meeting#102
18 September 06

Present

Oxford: Anu Dudhia, Joanne Walker, Claire Waymark

Envisat platform anomaly led to complete satellite shut down on 8Sep06 (more details on the Envisat Web-Site). Problem seems to have been fixed but MIPAS is using the opportunity for a decontamination. Due to switch back on today for MA followed by UA mode observations.

Current version of Mission Planning Document (2006 up to 12Nov) [XLS] [HTML].
New Web Page listing reduced-resolution measurement modes
Envisat Web-Site

August Monthly Report (AD) [Prev] [Next]

MIPAS monthly report for August is now available

[Summary].
Full report downloadable from http://earth.esa.int/pcs/envisat/mipas/reports/monthly/

L2 Data Anomalies [Prev] [Next]

CP Previously noted that 2002 data often missing near S.Pole, eg 25 Jul 02 - now recognised as an anomaly in the August report.

RR27 pT Retrieval (AD) [Prev] [Next]

Trying to find a set of microwindows for pT retrieval that work satisfactorily with the ORM.

IFAC report problems (high chi^2) incorporating new pT microwindows in region 750-770cm-1 (PT__0342,343 in previous list, 351,353 and 355 in latest list) - region of strong O3 emission?

Middle Atmosphere Mode (AD) [Prev] [Next]

Microwindow selection for MA mode observations (29 sweeps from 18-102km @ 3km steps). Intention is to use these to retrieve mesospheric data taken Jan 10-15 2005.

MW selection completed (pT, H2O, HNO3, O3, CH4, N2O, NO2 and CO) - now creating LUTs and irregular grids.

Aura Meeting (CW) [Prev] [Next]

EOS Aura Science & Validation Team Meeting 11-15 Sep 2006, Boulder, Colorado, USA

Presentations available from http://avdc.gsfc.nasa.gov/ST&WG/ST/ST_200609/index.html

MLS have corrected a problem with earlier data - new version (v2) now generally retrieves lower values.
HIRDLS think that they now retrieve good pT and O3, and reasonable HNO3, CFC-11 and CFC-12
TES concentrating on nadir-viewing measurements

Envisat Symposium 2007

To be held 23-27 April, Montreux. Website: http://www.envisat07.org/

Deadline for abstracts now extended to 1st October

Abstracts submitted from Oxford MIPAS group:

O3 Isotopes (CP)
Cloud properties (JH)
CO Retrievals (JW)
Stratospheric Trends (AD)
Joint MIPAS/TES O3 Retrievals (CW) ? - not yet submitted

ACPD Papers [Prev] [Next]

Papers selected from the ACPD website for discussion

" What does reflection from cloud sides tell us about vertical distribution of cloud droplet sizes? ", by Marshal et al (submitted 31.07.2006) - to be introduced by JH
" Annual variation and global distribution of strato-mesospheric carbon monoxide measured by ground-based Fourier Transform Infrared spectrometry", by Velazco et al. (submitted 28.07.2006) - introduced by JW - comments submitted to discussion
" Variability and trends in total and vertically resolved stratospheric ozone", by Brunner et al. (submitted 12.07.2006) - introduced by CW - discussion now closed
"Ground-based remote sensing of HDO/H2O ratio profiles: introduction and validation of an innovative retrieval approach" by M. Schneider et al. (submitted 27.06.2006) - introduced by CP - now discussion now closed

Summary of August Monthly Report (F. Niro, ESRIN)

The MIPAS instrument performs really well during the reporting month; in fact only 5 instrument anomalies were observed (IDU velocity error). As a result of this new operation stability the MIPAS Science Team in agreement with industry and ESA decided to increase the duty cycle of the instrument by slightly change the mission planning (see § 2.2.4). During August 2006 the instrument operated with a duty cycle of about 44%.
The instrument operated during August with the following planning (see § 2.2.1):

- UTLS-1 mode from 1st to 22nd August in support of AMMA campaign
- NOM measurements during 22 – 25 August and 30 Aug – 2 Sept.

We already pointed out that MIPAS performs really well during this month; in fact the instrument availability is equal to 98.25 % of the planned measurement time. The missing gaps due to PDS failure were about 9% of the planned time (see § 2.2.4).
The new MIPAS IPF 4.67 was activated at D-PAC on Monday 4th September for the OFL L1 processing of the reduced resolution data. This new processor was switched only to fix an operational issue which significantly affects processing performances on D-PAC cluster. Concerning L1 processing no impact on the scientific data is expected with this release with respect to previous IPF 4.65; on the contrary the L2 processing has been updated in order to fix two important anomalies (the NO2 high chi-square and the 4.61/4.62 discrepancy) (see § 2.4.1.1 for further details).
The long term monitoring of the ADC Min/Max counts during deep-space measurements is presented for the first time in this MR and will be kept up-to-date in the following report. The monitoring of ADC counts could give interesting insight into different topics related to instrument behavior such as instrument self-emission, forward/reverse effects, detector non-linearity and gain increase. The long term trend of the ADC max counts in channel A1 shows to be highly correlated with the seasonal variation of the instrument thermal condition (see § 2.3.2).
A new anomaly was reported on the L2 OFL data by C. Piccolo (OU); this problem was already reported on NRT products and was expected to be solved with the re-processing. The anomaly consists in the fact that during July 2002 several L2 profiles are missing in the Antarctic region, due to retrieval failure. The investigation of this problem is on-going (see § 2.5.3).
The monitoring of the instrument temperature shows a stable situation, the variation over the entire month being less than 2K (see § 2.3.1). The cooler perform really well, the spikes that were observed in the hottest part of the year (starting from May 2006) are now significantly reduced (see § 2.3.3.1).
The spectral correction factor shows a stable situation since the variations are of the order of 3 ppm over almost two years of operations, a decreasing trend can be observed along the mission, this is nominal and is due to the aging of the laser metrology (see § 2.4.2).
The gain weekly changes show a steady increase during the reporting month, the maximum of gain increase in the band A between two consecutive disseminated gains remains well below the acceptance criterion of 1% (see § 2.4.3.1).
The long term gain increase looks linear with time after the decontamination induced by the PLSOL of April. Nowadays the gain in the band A is about 19.5% higher (at its maximum) with respect to the first gain disseminated after the decontamination of June 2005 (see § 2.4.3.2).
The mispointing long term monitoring shows a steady situation; in fact during the last year the relative bias seems to be stable around a value of few mdeg. To be noted that the last disseminated LOS ADF was on March 2005 (see § 2.4.4).
The level 1 quality monitoring of the OFL products created at D-PAC is on going in parallel with the mission. The level 1b daily reports can be accessed at the following address:
http://earth.esa.int/pcs/envisat/mipas/reports/daily/Level_1_OFL/.
The long term monitoring of fringe count errors (FCE) for the RR mission was updated this month; this analysis shows that so far no correlation can be appreciated with respect to interferometer degradation.

Oxford MIPAS meeting#102 18 September 06

Oxford MIPAS meeting#102
18 September 06