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Evaluation and Global-Scale Observation of Nitrous Oxide from IASI on Metop-A

Chalinel, Rémi; Attié, Jean-Luc; Ricaud, Philippe; Vidot, Jérôme; Kangah, Yannick; Hauglustaine, Didier; Thompson, Rona Louise

Nitrous oxide (N2O) is a greenhouse gas difficult to estimate by satellite because of its weak spectral signature in the infra-red band and its low variability in the troposphere. Nevertheless, this study presents the evaluation of new tropospheric N2O observations from the Infrared Atmospheric Sounder Interferometer (IASI) on Metop-A using the Toulouse N2O Retrieval Version 2.0 tool. This tool is based on the Radiative Transfer for Tiros Operational Vertical sounder (RTTOV) model version 12.3 coupled to the Levenberg-Marquardt optimal estimation method enabling the simultaneous retrieval of methane, water vapour, temperature profiles together with surface temperature and emissivity within the 1240–1350 cm−1 window. In this study, we focused on the upper troposphere (300 hPa) where the sensitivity of IASI is significant. The IASI N2O data has been evaluated using aircraft N2O observations from the High-performance Instrumented Airborne Platform for Environmental Research Pole-to-Pole Observations (HIPPO) campaigns in 2009, 2010, and 2011 and from the National Oceanic and Atmospheric Administration’s (NOAA) Global Greenhouse Gas Reference Network (GGGRN) in 2011. In addition, we evaluated the IASI N2O using ground-based N2O measurements from 9 stations belonging to the Network for the Detection of Atmospheric Composition Change (NDACC). We found a total random error of ∼2 ppbv (0.6%) for one single retrieval at 300 hPa. Under favorable conditions, this error is also found in the vertical level pressure range 300–500 hPa. It decreases rapidly to ∼0.4 ppbv (0.1%) when we average on a 1° × 1° box. In addition, independent observations allows the estimation of bias with the IASI TN2OR v2.0 N2O. The bias between IASI and aircraft N2O data at 300 hPa is ∼1.0 ppbv (∼0.3%). We found an estimated random error of ∼2.3 ppbv (∼0.75%). This study also shows relatively high correlations between IASI data and aircraft in situ profiles but more varying correlations over the year 2011 depending on the location between IASI and NDACC remote sensing data. Finally, we present daily, monthly, and seasonal IASI N2O horizontal distributions in the upper troposphere as well as cross sections for different seasons that exhibit maxima in the Tropical band especially over Africa and South America.

MDPI

2022

Evaluation and inter-comparison of open road line source (ORLS) models currently being used in the Nordic countries. Powerpoint presentation. NILU F

Berger, J.; Walker, S.E.; Denby, B.; Berkowicz, R.; Løfstrøm, P.; Ketzel, M.; Kukkonen, J.

2007

Evaluation and inter-comparison of open road line source models currently being used in the nordic countries: a NORPAC project.

Berger, J.; Berkowicz, R.; Walker, S.E.; Denby, B.; Løfstrøm, P.; Ketzel, M.; Kukkonen, J.

2007

Evaluation and inter-comparison of open road line source models currently being used in the nordic countries: a NORPAC project. NILU PP

Berger, J.; Walker, S.E.; Denby, B.; Løfstrøm, P.; Ketzel, M.; Berkowicz, R.

2007

Evaluation and inter-comparison of open road line source models currently in use in the Nordic countries.

Berger, J.; Walker, S.-E.; Denby, B.; Berkowicz, R.; Løfstrøm, P.; Ketzel, M.; Härkönen, J.; Nikmo, J.; Karppinen, A.

2010

Evaluation and inter-comparison of open road line source models currently in use in the Nordic countries.

Berger, J.; Walker, S.E.; Denby, B.; Berkowicz, R.; Løfstrøm, P.; Ketzel, M.; Härkonen, J.; Nikmo, J.; Karppinen, A.

2008

Evaluation and optimization of ICOS atmosphere station data as part of the labeling process

Yver-Kwok, Camille; Philippon, Camille; Bergamaschi, Peter; Biermann, Tobias; Calzolari, Francescopiero; Chen, Huilin; Conil, Sébastien; Cristofanelli, Paolo; Delmotte, Marc; Hatakka, Juha; Heliasz, Michal; Hermansen, Ove; Kominkova, Katerina; Kubistin, Dagmar; Kumps, Nicolas; Laurent, Olivier; Laurila, Tuomas; Lehner, Irene; Levula, Janne; Lindauer, Matthias; Lopez, Morgan; Mammarella, Ivan; Manca, Giovanni; Marklund, Per; Metzger, Jean-Marc; Mölder, Meelis; Platt, Stephen Matthew; Ramonet, Michel; Rivier, Leonard; Scheeren, Bert; Sha, Mahesh Kumar; Smith, Paul; Steinbacher, Martin; Vitkova, Gabriela; Wyss, Simon

The Integrated Carbon Observation System (ICOS) is a pan-European research infrastructure which provides harmonized and high-precision scientific data on the carbon cycle and the greenhouse gas budget. All stations have to undergo a rigorous assessment before being labeled, i.e., receiving approval to join the network. In this paper, we present the labeling process for the ICOS atmosphere network through the 23 stations that were labeled between November 2017 and November 2019. We describe the labeling steps, as well as the quality controls, used to verify that the ICOS data (CO2, CH4, CO and meteorological measurements) attain the expected quality level defined within ICOS. To ensure the quality of the greenhouse gas data, three to four calibration gases and two target gases are measured: one target two to three times a day, the other gases twice a month. The data are verified on a weekly basis, and tests on the station sampling lines are performed twice a year. From these high-quality data, we conclude that regular calibrations of the CO2, CH4 and CO analyzers used here (twice a month) are important in particular for carbon monoxide (CO) due to the analyzer's variability and that reducing the number of calibration injections (from four to three) in a calibration sequence is possible, saving gas and extending the calibration gas lifespan. We also show that currently, the on-site water vapor correction test does not deliver quantitative results possibly due to environmental factors. Thus the use of a drying system is strongly recommended. Finally, the mandatory regular intake line tests are shown to be useful in detecting artifacts and leaks, as shown here via three different examples at the stations.

2021

Evaluation of a city-scale forecast system for air quality in Hamburg

Karl, Matthias; Ramacher, Martin O. P.; Hamer, Paul David; Athanasopoulou, E.; Speyer, O.; Matthias, Volker

2020

Evaluation of aerosol processes between roadside and neighbourhood scale.

Karl, M.; Kukkonen, J.; Pirjola, L.; Keuken, M.P.

2015

Evaluation of AirQUIS platform. NILU TR

Bøhler, T.; Thanh, T.N.; Krognes, T.; Ødegård, R.

2007

Evaluation of AOD uncertainties in three 17-year ATSR-2/AATSR retrievals.

Stebel, K.; Povey, A.; Heckel, A.; Kinne, S.; Kolmonen, P.; de Leeuw, G.; North, P.; Sogacheva, L.; Thomas, G.; Popp, T.

2016

Evaluation of climate model aerosol trends with ground-based observations over the last 2 decades – an AeroCom and CMIP6 analysis

Mortier, Augustin; Gliss, Jonas; Schulz, Michael; Aas, Wenche; Andrews, Elisabeth; Bian, Huisheng; Chin, Mian; Ginoux, Paul; Hand, Jenny; Holben, Brent; Zhang, Hua; Kipling, Zak; Kirkevåg, Alf; Laj, Paolo; Lurton, Thibault; Myhre, Gunnar; Neubauer, David; Oliviè, Dirk Jan Leo; Salzen, Knut von; Skeie, Ragnhild Bieltvedt; Takemura, Toshihiko; Tilmes, Simone

This study presents a multiparameter analysis of aerosol trends over the last 2 decades at regional and global scales. Regional time series have been computed for a set of nine optical, chemical-composition and mass aerosol properties by using the observations from several ground-based networks. From these regional time series the aerosol trends have been derived for the different regions of the world. Most of the properties related to aerosol loading exhibit negative trends, both at the surface and in the total atmospheric column. Significant decreases in aerosol optical depth (AOD) are found in Europe, North America, South America, North Africa and Asia, ranging from −1.2 % yr−1 to −3.1 % yr−1. An error and representativity analysis of the spatially and temporally limited observational data has been performed using model data subsets in order to investigate how much the observed trends represent the actual trends happening in the regions over the full study period from 2000 to 2014. This analysis reveals that significant uncertainty is associated with some of the regional trends due to time and space sampling deficiencies. The set of observed regional trends has then been used for the evaluation of 10 models (6 AeroCom phase III models and 4 CMIP6 models) and the CAMS reanalysis dataset and of their skills in reproducing the aerosol trends. Model performance is found to vary depending on the parameters and the regions of the world. The models tend to capture trends in AOD, the column Ångström exponent, sulfate and particulate matter well (except in North Africa), but they show larger discrepancies for coarse-mode AOD. The rather good agreement of the trends, across different aerosol parameters between models and observations, when co-locating them in time and space, implies that global model trends, including those in poorly monitored regions, are likely correct. The models can help to provide a global picture of the aerosol trends by filling the gaps in regions not covered by observations. The calculation of aerosol trends at a global scale reveals a different picture from that depicted by solely relying on ground-based observations. Using a model with complete diagnostics (NorESM2), we find a global increase in AOD of about 0.2 % yr−1 between 2000 and 2014, primarily caused by an increase in the loads of organic aerosols, sulfate and black carbon.

2020

Evaluation of Copernicus MACC-II ensemble products in the ETC/ACM spatial air quality mapping. ETC/ACM Technical Paper, 2013/9

Horalek, J.; Tarrasón, L.; de Smet, P.; Malherbe, L.; Schneider, P.; Ung, A.; Corbet, L.; Denby, B.

2014

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