Long-term validation of MIPAS ESA operational products using MIPAS-B measurements: L1v7/L2v8 T, H 2 O, and O 3

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1 Long-term validation of MIPAS ESA operational products using MIPAS-B measurements: Lv/L2v T, O, and Gerald Wetzel, Michael Höpfner, and Hermann Oelhaf CCN #: Report to Lv/L2v DDS validation T+ O (instead of Lv/L2v DDS T+ O) KIT,, Karlsruhe, Germany (gerald.wetzel@kit.edu) Contents Introduction Experimental details and data analysis Intercomparison method Validation results Summary and outlook KIT The Research University in the Helmholtz Association

2 NESR [nw/(cm 2 sr cm - )] MIPAS-B experimental details MIPAS-B (Michelson Interferometer for Passive Atmospheric Sounding - Balloon version) Cryogenic limb emission FTIR spectrometer (- C, liquid nitrogen). Spectral coverage: - µm (four channels), unapodized spectral resolution: 0.0 cm - (OPD max =. cm); apodized NESR (single spectrum) - nw/(cm 2 sr cm - ). Averaging of ~ 2 to spectra per elevation scan improves signal to noise ratio (big advantage of balloon observations compared to satellite measurements). INS/GPS-based pointing system plus star camera for absolute reference with an after all knowledge of z min better than 0 m ( σ). Profiles (limb mode) from UT up to float altitude; vertical resolution:. - 3 km, horizontal resolution: > 0 km along track and < km cross track MIPAS-B NESR (/ Sep. ) high-resolution single calibrated spectrum, apodized The MIPAS-B gondola Channel Channel 2 Channel 3 Channel Friedl-Vallon et al., Appl. Opt. 3, 33-3, Wavenumber [cm - ] 2.0. Gerald Wetzel et al., QWG # 3, KIT, - July

3 MIPAS-B data analysis Radiative transfer: Calculated with KOPRA (Karlsruhe Optimized and Precise Radiative transfer Algorithm) line-by-line and layer-by-layer model. Spectroscopic parameters originate from HITRAN 2 and a MIPAS dedicated spectroscopic database 3. Retrieval calculations: Least squares fitting procedure KOPRA_FIT using a Tikhonov- Phillips regularization approach which was constrained with respect to a first derivative a priori profile x a of the target species; state parameters x i for iteration i+: x T T i xi [ K i S y Ki R] [ Ki S y ( ymeas y( xi )) R( xi xa where: y meas measured radiance vector; y(x i ) calculated radiance (forward) vector; K Jacobian matrix ( y(x i )/ x i ); inverse noise measurement covariance matrix; R regularization matrix; T R L L operator. S y 0 where: regularization parameter; and L first order finite differences Error estimation: Includes random noise as well as the mutual influence (covariance) of the fitted parameters, temperature errors, pointing inaccuracies, errors of non-simultaneously fitted interfering gases, and spectroscopic data errors ( σ). 0 )] Stiller et al., J. Quant. Spectrosc. Radiat. Transfer, 2, 2-20, Rothman et al., J. Quant. Spectrosc. Radiat. Transfer,, 33-2, 0. 3 Raspollini et al., Atmos. Meas. Tech.,, 2-, 3. Höpfner et al., Geophys. Res. Lett., 2(), 2, Gerald Wetzel et al., QWG # 3, KIT, - July

4 MIPAS-B spectral windows Overview of MIPAS-B spectral windows used for the analysis of ESA atmospheric target parameters together with typical precision errors, total errors, and altitude resolution. Target parameter Spectral range (cm - ) Precision error Total error Alt. resolution Temperature O K 0..0 K 2 3 km 2 % % 3 km 0. % % 2 3 km HN % % 2 km CH & N 2 O.. 3 % % 2 km NO % 2 % 2 3 km N 2 O % % 2 km ClONO % % 2 3 km CFC % % 3 km CFC % % 3 km HCFC % 2 % 3 km CCl % % 3 km CF % % 3 km COF % 2 % 3 km HCN % 2 % 3 km.0. Gerald Wetzel et al., QWG # 3, KIT, - July

5 MIPAS-B validation flights Overview of MIPAS balloon flights used for intercomparison with MIPAS-E (FR and OR time period). Distances and times between closest trace gas profile pairs observed by MIPAS-E and the validation instrument refer to an altitude of km (Kiruna) and km (Aire sur l Adour and Teresina). Location Date Distance (km) Time difference (min) Mar 03 (FR period) / / 03 Jul 03 (FR period) Trajectories only Kiruna (Sweden, N) Aire sur l Adour (France, N) Teresina (Brazil, S) Mar 0 (OR period) / 2 / 2 Jan (OR period) / 2 / 3 Mar (OR period) Trajectories only 2 Sep 02 (FR period) 2 / / / 2 /3 / / Jun 0 (OR period) / / / 33 / / 2 / 2 0 Jun 0 (OR period) / 2 / 00 / / / /0 2-day forw./backw. trajectories (FU Berlin trajectory model, ECMWF. x. analyses) were calculated at different altitudes of each MIPAS-B observation to search for matches ( h, 00 km) with the satellite sensor. Diurnal variations of photochemically reactive species (mainly NO 2 and N 2 O ) were corrected taking into account differences in the SZA between the measurements of both sensors using a -D model 2 constrained with MIPAS-B measured NO y. Naujokat and Grunow, Proc. th Esa Symp. Rocket Balloon Progr. Res.,, 2-, Bracher et al., Atmos. Chem. Phys.,, 33-0, Gerald Wetzel et al., QWG # 3, KIT, - July

6 Intercomparison method Differences between measured quantities of MIPAS-E and MIPAS-B are expressed in absolute units and relative differences. Mean differences Δx mean and Δx mean,rel for N profile pairs of compared observations are given as: x mean N N n ( x x E, n B, n ; and where x E and x B are VMR values of MIPAS-E and MIPAS-B at one altitude level. Combined errors σ comb of both instruments are defined as: where σ E and σ B are the precision, systematic or total errors of MIPAS-E and the validation instrument MIPAS-B, respectively. Precision errors characterize the reproducibility of a measurement and correspond, in general, to random noise errors. Systematic errors (MIPAS-E) of the ESA processor have been assessed in corresponding studies,2. A bias between both instruments is considered significant if the SEM is smaller than the bias itself. The comparison between the VMR difference and the combined systematic error (for statistical comparisons) or total error (for single comparisons) is appropriate to identify unexplained biases in the MIPAS-E data when they exceed these combined error limits. Dudhia et al., Appl. Opt.,, 3-33, Raspollini et al., Atmos. Meas. Tech.,, 2, 3. ) x mean mean, rel N N x n x B, n 0% comb 2 E 2 B.0. Gerald Wetzel et al., QWG # 3, KIT, - July

7 Temperature (v) MIPAS-E MIPAS-B Arctic Midlat. Tropics ESA ML2PP V (Arctic) day traject. (# coll., adiab. corr.) 0 Mean diff.: 0. ± 0.0K ESA ML2PP V (Midlat.) day traject. (# coll., adiab. corr.) 0 Mean diff.: -.3 ± 0.2 0K ESA ML2PP V (Tropics) day traject. (# coll., adiab. corr.) 0 Mean diff.: 2. ± 0. 0K FR mode OR mode all old ESA ML2PP V (FR mode) 2-day traject. (# coll., adiab. corr.) 0 Mean diff.: -0. ± 0.2 0K ESA ML2PP V (OR mode) day traject. (# coll., adiab. corr.) 0 Mean diff.:. ± 0.0K ESA ML2PP V 2-day traject. (# coll., adiab. corr.) 0 Mean diff.: 0. ± 0.3 0K Difference within ± 2 K in the stratosphere (larger deviations below tropopause, esp. in the tropics) Gerald Wetzel et al., QWG # 3, KIT, - July

8 Temperature (Lv/L2v) MIPAS-E MIPAS-B Arctic Midlat. Tropics MIPAS-E - MIPAS-B (Arctic) ESA ML2PP Lv/L2v day traject. (# coll., adiab. corr.) 0 Mean diff.: 0.2 ± 0.3 0K MIPAS-E - MIPAS-B (Midlat.) ESA ML2PP Lv/L2v day traject. (# coll., adiab. corr.) 0 Mean diff.: -.2 ± 0.2 0K MIPAS-E - MIPAS-B (Tropics) ESA ML2PP Lv/L2v day traject. (# coll., adiab. corr.) 0 Mean diff.: 2. ± 0. 0K FR mode OR mode all new MIPAS-E - MIPAS-B (FR mode) ESA ML2PP Lv/L2v 2-day traject. (# coll., adiab. corr.) 0 Mean diff.: -0. ± 0.2 0K MIPAS-E - MIPAS-B (OR mode) ESA ML2PP Lv/L2v day traject. (# coll., adiab. corr.) 0 Mean diff.:. ± 0.0K ESA ML2PP Lv/L2v 2-day traject. (# coll., adiab. corr.) 0 Mean diff.: 0.2 ± 0.2 0K Slightly better agreement compared to previous v data (mean diff. only 0.2 K) Gerald Wetzel et al., QWG # 3, KIT, - July

9 0 O (v) MIPAS-E MIPAS-B & 0 * (MIPAS-E MIPAS-B) / MIPAS-B ESA ML2PP V (Arctic) Mean diff.: ± 3.0 ppmv 0. ±.3 % tot. mean comb. err Arctic Midlat. Tropics O VMR Difference (ppmv) ESA ML2PP V (Midlat.) Mean diff.: 2.3 0±.2 ppmv 0. ± 3. % tot. mean comb. err O VMR Difference (ppmv) ESA ML2PP V (Tropics) Mean diff.:. 0± 0. ppmv 0 2. ±.0 % tot. mean comb. err O VMR Difference (ppmv) ESA ML2PP V (FR mode) Mean diff.: ± 2.3 ppmv 0.3 ± 3. % tot. mean comb. err FR mode OR mode all old O VMR Difference (ppmv) ESA ML2PP V (OR mode) Mean diff.: 0.3 0± 0. ppmv 0. ± 3. % tot. mean comb. err O VMR Difference (ppmv) ESA ML2PP V Mean diff.: ± 2.3 ppmv 0.0 ± 3. % tot. mean comb. err O VMR Difference (ppmv) Positive MIPAS-E bias (~ %) within comb. sys. errors (above hygropause); pronounced pos. bias in FR period..0. Gerald Wetzel et al., QWG # 3, KIT, - July

10 0 O (Lv/L2v) MIPAS-E MIPAS-B & 0 * (MIPAS-E MIPAS-B) / MIPAS-B Arctic Midlat. Tropics MIPAS-E - MIPAS-B (Arctic) ESA ML2PP Lv/L2v Mean diff.: -. 0 ±. ppmv 0. ± 3. % tot. mean comb. err O VMR Difference (ppmv) 0 MIPAS-E - MIPAS-B (Midlat.) ESA ML2PP Lv/L2v Mean diff.:. 0±. ppmv 0.2 ± 3. % tot. mean comb. err O VMR Difference (ppmv) 0 MIPAS-E - MIPAS-B (Tropics) ESA ML2PP Lv/L2v Mean diff.: 2. 0± 0. ppmv 0. ±.2 % tot. mean comb. err O VMR Difference (ppmv) FR mode OR mode all new MIPAS-E - MIPAS-B (FR mode) ESA ML2PP Lv/L2v Mean diff.: -. 0 ±. ppmv 0.3 ± 3. % tot. mean comb. err O VMR Difference (ppmv) 0 MIPAS-E - MIPAS-B (OR mode) ESA ML2PP Lv/L2v Mean diff.: 0. 0± 0. ppmv 0. ±. % tot. mean comb. err O VMR Difference (ppmv) ESA ML2PP Lv/L2v Mean diff.: -. 0 ±. ppmv 0 2. ± 3. % tot. mean comb. err O VMR Difference (ppmv) Slightly reduced positive MIPAS-E bias in FR period compared to v data, but increased bias in OR period..0. Gerald Wetzel et al., QWG # 3, KIT, - July

11 (v) MIPAS-E MIPAS-B & 0 * (MIPAS-E MIPAS-B) / MIPAS-B Arctic Midlat. Tropics MIPAS-E - MIPAS-B (all) 2 ESA ML2PP V (Arctic) 2 2 Mean diff.: 0. ± 0.02 ppmv. ±. % VMR Difference (ppmv) MIPAS-E - MIPAS-B (all) MIPAS-E - MIPAS-B (all) ESA ML2PP V (Midlat.) ESA ML2PP V (Tropics) Mean diff.: 0. ± 0.0 ppmv Mean diff.: 0. ± 0.0 ppmv 3.0 ± 2. %. ±. % VMR Difference (ppmv) FR mode OR mode all old MIPAS-E - MIPAS-B (all) ESA ML2PP V (FR mode) Mean diff.: 0.3 ± 0.03 ppmv. ±. % VMR Difference (ppmv) MIPAS-E - MIPAS-B (all) 2 ESA ML2PP V (OR mode) 2 2 Mean diff.: 0. ± 0.02 ppmv. ±. % VMR Difference (ppmv) VMR Difference (ppmv) MIPAS-E - MIPAS-B (all) ESA ML2PP V 2 2 Mean diff.: 0. ± 0.03 ppmv ±.2 % VMR Difference (ppmv) Difference between both instruments within ± %..0. Gerald Wetzel et al., QWG # 3, KIT, - July

12 (Lv/L2v) MIPAS-E MIPAS-B & 0 * (MIPAS-E MIPAS-B) / MIPAS-B Arctic Midlat. Tropics MIPAS-E - MIPAS-B (Arctic) ESA ML2PP Lv/L2v 0 Mean diff.: 0.0 ± 0.03 ppmv. ± 3. % VMR Difference (ppmv) MIPAS-E - MIPAS-B (Midlat.) MIPAS-E - MIPAS-B (Tropics) ESA ML2PP Lv/L2v 0 ESA ML2PP Lv/L2v 2 Mean diff.: 0. ± 0.0 ppmv Mean diff.: 0.2 ± 0. ppmv 3. ± 2.2 %.0 ±. % VMR Difference (ppmv) FR mode OR mode all new MIPAS-E - MIPAS-B (FR mode) ESA ML2PP Lv/L2v Mean diff.: 0.2 ± 0.03 ppmv 3. ±. % VMR Difference (ppmv) MIPAS-E - MIPAS-B (OR mode) 20 ESA ML2PP Lv/L2v 2 3 Mean diff.: 0. ± 0.0 ppmv. ±.3 % VMR Difference (ppmv) VMR Difference (ppmv) MIPAS-E - MIPAS-B (all) 2 ESA ML2PP Lv/L2v 2 Mean diff.: 0. ± 0.03 ppmv. ±. % VMR Difference (ppmv) Positive MIPAS-E bias (~ %) in the tropics above 2 km (less pronounced in v data, different MWs?) Gerald Wetzel et al., QWG # 3, KIT, - July

13 (MIPAS-B flight Teresina, June 0) MIPAS-B flight Teresina, June 0 Tropical standard atmosphere RS, Teresina (. S, 2. W)-000-0:33 UTC RS, Teresina (. S, 2. W)-000-0: UTC RS, Teresina 33 (. S, 2. W)-003-: UTC RS, Teresina (. S, 2. W)-003-: UTC, AK smoothed RS, Teresina (. S, 2. W)-00-:2 UTC MIPAS-B Seq. 0 (. S,. W, 0:3 UTC) EMAC Seq. 0 MIPAS-B Seq. 02 (2. S,.2 W, 0: UTC) EMAC Seq. 02 MIPAS-B 3 Seq. 0 (. S,.2 W, : UTC) EMAC Seq. 0 MIPAS-B Seq. 2 (.3 S, 3. W, 2:2 UTC) EMAC Seq. 2 MIPAS-E 2-day trajectory match (Lv/L2v) MIPAS-E (. S,.3 W)-00-0:0 UTC (Lv/L2v) MIPAS-E (. S, 2. W)-00-0:0 UTC (Lv/L2v) MIPAS-E (. S,. W)-00-0:0 UTC (Lv/L2v) (ppmv) Quite large variability of profiles. Clear bias between both MIPAS sensors Gerald Wetzel et al., QWG # 3, KIT, - July

14 Summary and outlook MIPAS (ESA ML2PP Lv/L2v & v) vs. MIPAS-B Summary of MIPAS-ENVISAT validation results (trajectory comparison to eight MIPAS-B flights). Atmospheric parameter differences refer to MIPAS-ENVISAT minus the balloon instrument. Parameter Comments (Lv/L2v data) Changes from v to Lv/L2v Tendency Temp. Difference within ±2 K between and 3 km Slightly better agreement O Positive bias (about %) between and 3 km (within combined systematic errors) Slightly reduced positive bias in FR- and increased bias in OR period Difference within ±% for all altitudes between and 3 km Enhanced positive bias in the tropics above 2 km Next steps: Delivery of Lv/L2v DDS by IFAC (date in CCN # proposal, p. 2: May ) Validation of MIPAS Lv/L2v DDS (Oct. ) & FM (Jan. ) for T, O,, HN, NO 2, CH, N 2 O, ClONO 2, N 2 O, CFC-, CFC-2 (GL) HCN, CCl, COF 2, HCFC-, CF (GL 2) C 2, HCOOH, CFC-3, COCl 2, CH 3 Cl (GL 3) systematic MIPAS errors available for all species (except HCOOH) on Uni Oxford webpage. Validation reports on corresponding data sets (Lv/L2v, Lv/L2v)..0. Gerald Wetzel et al., QWG # 3, KIT, - July