The new satellite instrument, IASI (Infrared Atmospheric Sounding Interferometer), is a moderate resolution (0.25 cm-1) Fourier Transform spectrometer launched in 2002 on the European METOP satellite. This instrument offers more spectral channels at a considerably higher spectral resolution than HIRS (High Resolution Infrared Sounder) - the instrument which it replaced as the operational infra-red sounder. IASI delivers vertical profiles of temperature and humidity data with a resolution of 1km compared with approximately 4km from HIRS. Translating the improvement in the spectral resolution of the instrument into improvements in the accuracy and height resolution of the temperature, humidity and ozone profiles is dependent on a detailed knowledge of the spectroscopy of the atmosphere in this spectral region. The aim of the Validation of IASI (Infrared Atmospheric Sounding Interferometer) Radiative Transfer Experiments and Modelling (VIRTEM) project was to make the improvements to the spectroscopy necessary to make full use of the increased spectral resolution of IASI. The primary objectives of the VIRTEM project were: *To generate a detailed set of atmospheric observations of radiances and supporting in-situ data. *To analyse and validate the current spectroscopy using state of the art line-by-line radiation models. *To generate an improved spectroscopic database. VIRTEM was an EU project to validate the instrumentation and retrieval methods to be used on IASI. Data in this dataset collection include both aircraft based and lab based spectroscopic measurements.

This dataset contains output from the Met Office operational unified model (UM) in support of the Joint Airborne IASI Validation Experiment (JAIVEX). The Infrared Atmospheric Sounding Interferometer (IASI) instrument was launched on the METOP satellite in October 2006 (delayed from April 2006). The European Organisation for the Exploitation of Meteorological Satellites (Eumetsat) provided funds for the Facility for Airborne Atmospheric Measurement (FAAM) aircraft BAe146 to be involved in validation of IASI radiative transfer and some level 2 products. Flights were flown over oceans to coincide with METOP satellite overpasses. Further low level flights were flown over specific land calibration sites to characterise land surface emissivity. This dataset does not contain data collected by IASI on the Metop satellite.

This dataset contains global monthly averaged effective sulphur dioxide (SO2) column amounts derived from the Infrared Atmospheric Sounding Interferometer (IASI) instrument on the METOP-A satellite. The data have been produced by the University of Oxford as part of the NERC Centre for the Observation and Modelling of Earthquakes, Volcanoes and Tectonics (COMET). This dataset has been produced using the Walker et al. (2011, 2012) linear retrieval developed for the Infrared Atmospheric Sounding Interferometer, which is able to detect sulphur dioxide (SO2) gas. This dataset contains monthly averages of this retrieval output from June 2007 to December 2014 across the globe, within which it is possible to identify the period and the location of when we have an anomaly of SO2 in atmosphere. This includes volcanic eruptions alongside non-eruptive volcanic degassing, and human pollution sources. Within the dataset are the average effective SO2 column amounts in Dobson Units (DU) for 0.125º by 0.125º gridboxes across the globe. Also included for each grid box are the standard deviation, and the number of pixel boxes contributing to the mean. The results from this dataset are discussed in Taylor et al. (2018) 'Exploring the utility of IASI for monitoring volcanic SO2 emissions' in review at JGR: Atmospheres.

This dataset contains global retrieval of sulphur dioxide (SO2) column amounts and altitudes derived from the Infrared Atmospheric Sounding Interferometer (IASI) instrument on the METOP-A satellite. The data have been produced by the University of Oxford as part of the NERC Centre for the Observation and Modelling of Earthquakes, Volcanoes and Tectonics (COMET). This dataset has been produced using the Carboni et al. (2012,2016) retrieval algorithm for the Infrared Atmospheric Sounding Interferometer which retrieve column amount and altitude (together with a comprehensive error budget for every pixel) using simultaneously all the IASI channels between 1000–1200 and 1300–1410 cm−1. It has a global coverage and includes the six-month-long Holuhraun eruption, from September 2014 to February 2015, together with other events during the same periods such as: volcanic activity on the Kamchatka peninsula, Etna and Capo verde eruptions, anthropogenic SO2 emissions from China. The data presents the results of the retrieval for every IASI 'plume' pixels (e.g. that result positive to the IASI SO2 detection) including: column amount (in Dobson Unit - DU), altitude (in millibar and successively converted in km using meteorological profile), surface temperature. It also includes quality control parameters and quality flags: for generic use we recommend using data with flag = 1. Quality control parameters available are: degree of freedom, cost function, convergence. These quality control paramenters are also summarized in two 'stricted' and 'relaxed' quality control flags. This dataset also includes location of all IASI pixels in the same orbit (non plume pixel) to allow regridding and comparison with other instruments and models.

This Infrared Atmospheric Sounding Interferometer (IASI) methane dataset contains height-resolved and column-averaged volume mixing ratios of atmospheric methane (CH4) retrieved from the IASI instrument on the MetOp-B satellite. It also includes column-averaged water vapour (H2O), a scale factor for the HDO (water vapour isotopologue) volume mixing ratio profile, surface temperature, effective cloud fraction, effective cloud-top pressure and scale factors for two systematic residual spectra which are jointly retrieved from the spectral range 1232.25-1290.00 cm-1. This dataset was produced by Version 2.0 of the Rutherford Appleton Laboratory's (RAL's) IASI optimal estimation scheme to retrieve methane, which takes as input temperature and water vapour profiles and surface spectral emissivity pre-retrieved by RAL's Infrared and Microwave Scheme applied to IASI, MHS and AMSU-A on MetOp-B. The dataset additionally contains selected a priori values and uncertainties adopted in the optimal estimation scheme and retrieval output diagnostics such as the retrieval cost and the averaging kernels. Development of the Version 2.0 scheme and its application to MetOp-A (2007-2017, http://dx.doi.org/10.5285/f717a8ea622f495397f4e76f777349d1) was funded by the National Centre for Earth Observation (NCEO) under the UK Natural Environment Research Council (NERC) with additional funding from EUMETSAT. Adaptation to MetOp-B and production of the IASI MetOp-B methane dataset 01/2018-03/2021 were funded by NCEO and ESA Contract No. 4000129987/20/I-DT Methane+. Data were produced by the United Kingdom Research and Innovation (UKRI) Science and Technology Facilities Council (STFC) Remote Sensing Group (RSG) at the Rutherford Appleton Laboratory (RAL).

This dataset contains level 1C data products from the Infrared Atmospheric Sounding Interferometer (IASI) instrument onboard the Eumetsat EPS Metop-C satellite. IASI was designed to measure the infrared spectrum emitted by the earth. IASI provides infrared soundings of the temperature profiles in the troposphere and lower stratosphere, moisture profiles in the troposphere, as well as some of the chemical components playing a key role in the climate monitoring, global change and atmospheric chemistry. the IASI L1c product contains infra-red radiance spectra at the 0.5cm-1 resolution, covering the range between 645.0 cm-1 and 2760 cm-1. Please note an erratum has been raised in relation to 2017 data please see the Ten-Year Assessment of IASI Radiance and Temperature in the documentation section. This data set contains the original processed data.. in the following directories based on processing algorithm. Please see information under the process tab for further information. This data has been provided by EUMETSAT to CEDA to support access to active scientists from the following institutions only - The Science and Technology Facilities Council (STFC) - The National Centre for Earth Observation (NCEO) - The National Centre for Atmospheric Science (NCAS) If you are from one of these institutions, please apply for access below and follow the instructions. If you are not from one of these institutions, please go to the documentation section for the relevant link to the EUMETSAT EO portal where you can obtain the data directly.

The Rutherford Appleton Laboratory (RAL) Infrared Microwave Sounder (IMS) data set contains vertical profiles of temperature, water vapour, and ozone as well as surface spectral emissivity spanning infrared and microwave, surface temperature, cloud fraction and height. Data are retrieved from co-located measurements by the Infrared Atmospheric Sounding Interferometer (IASI), the Microwave Humidity Sounder (MHS) and the Advanced Microwave Sounding Unit (AMSU) on board the Eumetsat Metop satellites. Development of the IMS scheme and data production were funded by the UK’s National Centre for Earth Observation (NCEO) under the Natural Environment Research Council (NERC), with additional funding from EUMETSAT contract EUM/CO/13/4600001252/THH. Data were produced by the Remote Sensing Group (RSG) at the Rutherford Appleton Laboratory (RAL). This first public release consists of a full processing of the Metop A mission from 2007 to the end of 2016, using version 2.1 of the algorithm. IMS data are produced with the horizontal sampling of IASI, ~25 x 25 km

This dataset contains level 1C data products from the Infrared Atmospheric Sounding Interferometer (IASI) instrument onboard the Eumetsat EPS Metop-A satellite. IASI was designed to measure the infrared spectrum emitted by the earth. IASI provides infrared soundings of the temperature profiles in the troposphere and lower stratosphere, moisture profiles in the troposphere, as well as some of the chemical components playing a key role in the climate monitoring, global change and atmospheric chemistry. The IASI L1c product contains infra-red radiance spectra at the 0.5cm-1 resolution, covering the range between 645.0 cm-1 and 2760 cm-1 This data set contains both the original processed data and reprocessed archive. In the following directories based on processing algorithm. Please see information under the process tab for further information. Please note an erratum has been raised in relation to 2017 data please see the Ten-Year Assessment of IASI Radiance and Temperature in the documentation section. This data has been provided by EUMETSAT to CEDA to support access to active scientists from the following institutions only - The Science and Technology Facilities Council (STFC) - The National Centre for Earth Observation (NCEO) - The National Centre for Atmospheric Science (NCAS) If you are from one of these institutions, please apply for access below and follow the instructions. If you are not from one of these institutions, please go to the documentation section for the relevant link to the EUMETSAT EO portal where you can obtain the data directly.

This Infrared Atmospheric Sounding Interferometer (IASI) methane dataset contains height-resolved and column-averaged volume mixing ratios of atmospheric methane (CH4). It also includes column-averaged water vapour (H2O), a scale factor for the HDO (water vapour isotopologue) volume mixing ratio profile, surface temperature, effective cloud fraction, effective cloud-top pressure and scale factors for two systematic residual spectra which are jointly retrieved from the spectral range 1232.25-1290.00 cm-1 by the Rutherford Appleton Laboratory (RAL) IASI optimal estimation methane retrieval scheme. The dataset additionally contains selected a priori values and uncertainties adopted in the optimal estimation scheme and retrieval output diagnostics such as the retrieval cost and the averaging kernels. This work was funded by the National Centre for Earth Observation (NCEO) under the UK Natural Environment Research Council (NERC) with additional funding from EUMETSAT. Data were produced by the United Kingdom Research and Innnovation (UKRI) Science and Technology Facilities Council (STFC) Remote Sensing Group (RSG) at the Rutherford Appleton Laboratory (RAL). This is version 2.0 of the dataset.

This dataset contains level 1C data products from the Infrared Atmospheric Sounding Interferometer (IASI) instrument onboard the Eumetsat EPS Metop-B satellite. IASI was designed to measure the infrared spectrum emitted by the earth. IASI provides infrared soundings of the temperature profiles in the troposphere and lower stratosphere, moisture profiles in the troposphere, as well as some of the chemical components playing a key role in the climate monitoring, global change and atmospheric chemistry. The IASI L1c product contains infra-red radiance spectra at the 0.5cm-1 resolution, covering the range between 645.0 cm-1 and 2760 cm-1 This data set contains both the original processed data and reprocessed archive in the following directories based on processing algorithm. Please see information under the process tab for further information. Please note an erratum has been raised in relation to 2017 data please see the Ten-Year Assessment of IASI Radiance and Temperature in the documentation section. This data has been provided by EUMETSAT to CEDA to support access to active scientists from the following institutions only. - The Science and Technology Facilities Council (STFC) - The National Centre for Earth Observation (NCEO) - The National Centre for Atmospheric Science (NCAS) If you are from one of these institutions, please apply for access below and follow the instructions. If you are not from one of these institutions, please go to the documentation section for the relevant link to the EUMETSAT EO portal where you can obtain the data directly.