Articles | Volume 15, issue 6
https://doi.org/10.5194/amt-15-1755-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/amt-15-1755-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
23 Mar 2022
Research article |
| 23 Mar 2022
| 23 Mar 2022
Emissivity retrievals with FORUM's end-to-end simulator: challenges and recommendations
ESA – ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, the Netherlands
Hilke Oetjen
ESA – ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, the Netherlands
Helen Brindley
Space and Atmospheric Physics Group, Department of Physics, Imperial College London SW7 2AZ, United Kingdom
William Cossich
Dipartimento di Fisica e Astronomia, Università di Bologna, Viale Berti Pichat 6/2, 40126 Bologna, Italy
Dulce Lajas
ESA – ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, the Netherlands
Tiziano Maestri
Dipartimento di Fisica e Astronomia, Università di Bologna, Viale Berti Pichat 6/2, 40126 Bologna, Italy
Davide Magurno
Dipartimento di Fisica e Astronomia, Università di Bologna, Viale Berti Pichat 6/2, 40126 Bologna, Italy
Piera Raspollini
IFAC – CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy
Luca Sgheri
IAC – CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy
Laura Warwick
Space and Atmospheric Physics Group, Department of Physics, Imperial College London SW7 2AZ, United Kingdom
Related authors
Maya Ben-Yami, Lana Blaschke, Sebastian Bathiany, and Niklas Boers
EGUsphere, https://doi.org/10.5194/egusphere-2024-1106, https://doi.org/10.5194/egusphere-2024-1106, 2024
Preprint archived
Short summary
Short summary
Recent work has used observations to find statistical signs that the Atlantic Meridional Overturning Circulation (AMOC) may be approaching a collapse. We find that in complex climate models in which the AMOC does not collapse before 2100, the statistical signs that are present in the observations are not found in the 1850–2014 equivalent model time series. This indicates that the observed statistical signs are not prone to false positives.
Luca Sgheri, Claudio Belotti, Maya Ben-Yami, Giovanni Bianchini, Bernardo Carnicero Dominguez, Ugo Cortesi, William Cossich, Samuele Del Bianco, Gianluca Di Natale, Tomás Guardabrazo, Dulce Lajas, Tiziano Maestri, Davide Magurno, Hilke Oetjen, Piera Raspollini, and Cristina Sgattoni
Atmos. Meas. Tech., 15, 573–604, https://doi.org/10.5194/amt-15-573-2022, https://doi.org/10.5194/amt-15-573-2022, 2022
Short summary
Short summary
The FORUM instrument will look at the Earth's atmosphere from a satellite, covering a spectral range responsible for about 95 % of the radiation lost by our planet. FORUM helps to measure the imbalance between incoming and outgoing radiation that is responsible for the increasing average temperatures on Earth. The end-to-end simulator is a chain of codes that simulates the FORUM measurement process. The goal of the project is to study how the instrument reacts to different retrieval conditions.
Gianluca Di Natale, Helen Brindley, Laura Warwick, Sanjeevani Panditharatne, Ping Yang, Robert Oscar David, Tim Carlsen, Sorin Nicolae Vâjâiac, Alex Vlad, Sorin Ghemulet, Richard Bantges, Andreas Foth, Martin Flügge, Reidar Lyngra, Hilke Oetjen, Dirk Schuettemeyer, Luca Palchetti, and Jonathan Murray
EGUsphere, https://doi.org/10.5194/egusphere-2025-3547, https://doi.org/10.5194/egusphere-2025-3547, 2025
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
Short summary
Cirrus clouds play a vital role in regulating the energy balance of our planet. Unfortunately, these are still not completely understood representing the major source of error in the predictive performance of climate models. We show that a good consinstency between in situ measurements of cirrus cloud microphysics and remote sensing observations from ground base is achievable by simulating the emitted spectrum with the current parameterization of cirrus optical properties.
Federico Donat, Tiziano Maestri, Elisa Fabbri, Michele Martinazzo, Giovanni Bianchini, Massimo Del Guasta, Gianluca Di Natale, Luca Palchetti, Guido Masiello, Carmine Serio, and Giuliano Liuzzi
EGUsphere, https://doi.org/10.5194/egusphere-2025-2793, https://doi.org/10.5194/egusphere-2025-2793, 2025
This preprint is open for discussion and under review for Atmospheric Measurement Techniques (AMT).
Short summary
Short summary
The cloud occurrence over the Antarctic Plateau is characterized using ground-based interferometric data from 2012 to 2020. The results show a yearly pattern, and a six-month cycle linked to atmospheric oscillations. The cloud radiative forcing at far infrared doubles during cloud occurrence oscillation peaks. Infrared Atmospheric Sounding Interferometer (IASI) Level 2 products are compared to ground data, showing an improved agreement in cloud identification from year 2020.
Sanjeevani Panditharatne, Helen Brindley, Caroline Cox, Rui Song, Richard Siddans, Richard Bantges, Jonathan Murray, Stuart Fox, and Cathryn Fox
EGUsphere, https://doi.org/10.5194/egusphere-2025-647, https://doi.org/10.5194/egusphere-2025-647, 2025
Short summary
Short summary
Upwelling radiation with wavelengths between 15 and 100 microns is theorised to be highly sensitive to the properties of ice clouds, particularly the shape of the ice crystals. We exploit this sensitivity and perform the first retrieval of ice cloud properties using these wavelengths from an observation taken on an aircraft and evaluate it against measurements of the cloud’s properties.
Cecilia Tirelli, Simone Ceccherini, Samuele Del Bianco, Bernd Funke, Michael Höpfner, Ugo Cortesi, and Piera Raspollini
EGUsphere, https://doi.org/10.5194/egusphere-2025-1283, https://doi.org/10.5194/egusphere-2025-1283, 2025
Short summary
Short summary
The Complete Data Fusion is an a posteriori method to combine remote sensing products from independent observations of the same air mass. In this study, we extended the algorithm’s applicability to two-dimensional products, testing it with simulated ozone datasets from nadir and limb measurements. We demonstrated that the exploitation of the tomographic capabilities of future atmospheric sensors maximizes the information extracted from complementary datasets.
Sanjeevani Panditharatne, Helen Brindley, Caroline Cox, Richard Siddans, Jonathan Murray, Laura Warwick, and Stuart Fox
Atmos. Meas. Tech., 18, 717–735, https://doi.org/10.5194/amt-18-717-2025, https://doi.org/10.5194/amt-18-717-2025, 2025
Short summary
Short summary
Observations from the upcoming European Space Agency’s Far-Infrared Outgoing Radiation Understanding and Monitoring (FORUM) satellite are theorised to be highly sensitive to distributions of water vapour within Earth’s atmosphere. We exploit this sensitivity and extend the Infrared Microwave Sounding retrieval scheme for use on observations from FORUM. This scheme is evaluated on both simulated and observed measurements and shows good agreement with references of the atmospheric state.
Jacqueline E. Russell, Richard J. Bantges, Helen E. Brindley, and Alejandro Bodas-Salcedo
Earth Syst. Sci. Data, 16, 4243–4266, https://doi.org/10.5194/essd-16-4243-2024, https://doi.org/10.5194/essd-16-4243-2024, 2024
Short summary
Short summary
We present a dataset of top-of-atmosphere diurnally resolved reflected solar and emitted thermal energy for Earth system model evaluation. The multi-year, monthly hourly dataset, derived from observations made by the Geostationary Earth Radiation Budget instrument, covers the range 60° N–60° S, 60° E–60° W at 1° resolution. Comparison with two versions of the Hadley Centre Global Environmental Model highlight how the data can be used to assess updates to key model parameterizations.
Laura Warwick, Jonathan E. Murray, and Helen Brindley
Atmos. Meas. Tech., 17, 4777–4787, https://doi.org/10.5194/amt-17-4777-2024, https://doi.org/10.5194/amt-17-4777-2024, 2024
Short summary
Short summary
We describe a method for measuring the emissivity of natural surfaces using data from the new Far-INfrarEd Spectrometer for Surface Emissivity (FINESSE) instrument. We demonstrate our method by making measurements of the emissivity of water. We then compare our results to the emissivity predicted using a model and find good agreement. The observations from FINESSE are novel because they allow us to determine surface emissivity at longer wavelengths than have been routinely measured before.
Jonathan E. Murray, Laura Warwick, Helen Brindley, Alan Last, Patrick Quigley, Andy Rochester, Alexander Dewar, and Daniel Cummins
Atmos. Meas. Tech., 17, 4757–4775, https://doi.org/10.5194/amt-17-4757-2024, https://doi.org/10.5194/amt-17-4757-2024, 2024
Short summary
Short summary
The Far INfrarEd Spectrometer for Surface Emissivity, FINESSE, is designed to measure the ability of natural surfaces to emit infrared radiation. FINESSE combines a commercial instrument with custom-built optics to view a surface from different angles with complementary views of the sky. Its choice of internal components means it can cover a wide range of wavelengths, extending into the far-infrared. We characterize FINESSE’s uncertainty budget and provide examples of its measurement capability.
Karen De Los Ríos, Paulina Ordoñez, Gabriele P. Stiller, Piera Raspollini, Marco Gai, Kaley A. Walker, Cristina Peña-Ortiz, and Luis Acosta
Atmos. Meas. Tech., 17, 3401–3418, https://doi.org/10.5194/amt-17-3401-2024, https://doi.org/10.5194/amt-17-3401-2024, 2024
Short summary
Short summary
This study examines newer versions of H2O and HDO retrievals from Envisat/MIPAS and SCISAT/ACE-FTS. Results reveal a better agreement in stratospheric H2O profiles than in HDO profiles. The H2O tape recorder signal is consistent across databases, but δD tape recorder composites show differences that impact the interpretation of water vapour transport. These findings enhance the need for intercomparisons to refine our insights.
Maya Ben-Yami, Lana Blaschke, Sebastian Bathiany, and Niklas Boers
EGUsphere, https://doi.org/10.5194/egusphere-2024-1106, https://doi.org/10.5194/egusphere-2024-1106, 2024
Preprint archived
Short summary
Short summary
Recent work has used observations to find statistical signs that the Atlantic Meridional Overturning Circulation (AMOC) may be approaching a collapse. We find that in complex climate models in which the AMOC does not collapse before 2100, the statistical signs that are present in the observations are not found in the 1850–2014 equivalent model time series. This indicates that the observed statistical signs are not prone to false positives.
Brian Kahn, Cameron Bertossa, Xiuhong Chen, Brian Drouin, Erin Hokanson, Xianglei Huang, Tristan L'Ecuyer, Kyle Mattingly, Aronne Merrelli, Tim Michaels, Nate Miller, Federico Donat, Tiziano Maestri, and Michele Martinazzo
EGUsphere, https://doi.org/10.5194/egusphere-2023-2463, https://doi.org/10.5194/egusphere-2023-2463, 2023
Preprint archived
Short summary
Short summary
A cloud detection mask algorithm is developed for the upcoming Polar Radiant Energy in the Far Infrared Experiment (PREFIRE) satellite mission to be launched by NASA in May 2024. The cloud mask is compared to "truth" and is capable of detecting over 90 % of all clouds globally tested with simulated data, and about 87 % of all clouds in the Arctic region.
Michael Kiefer, Dale F. Hurst, Gabriele P. Stiller, Stefan Lossow, Holger Vömel, John Anderson, Faiza Azam, Jean-Loup Bertaux, Laurent Blanot, Klaus Bramstedt, John P. Burrows, Robert Damadeo, Bianca Maria Dinelli, Patrick Eriksson, Maya García-Comas, John C. Gille, Mark Hervig, Yasuko Kasai, Farahnaz Khosrawi, Donal Murtagh, Gerald E. Nedoluha, Stefan Noël, Piera Raspollini, William G. Read, Karen H. Rosenlof, Alexei Rozanov, Christopher E. Sioris, Takafumi Sugita, Thomas von Clarmann, Kaley A. Walker, and Katja Weigel
Atmos. Meas. Tech., 16, 4589–4642, https://doi.org/10.5194/amt-16-4589-2023, https://doi.org/10.5194/amt-16-4589-2023, 2023
Short summary
Short summary
We quantify biases and drifts (and their uncertainties) between the stratospheric water vapor measurement records of 15 satellite-based instruments (SATs, with 31 different retrievals) and balloon-borne frost point hygrometers (FPs) launched at 27 globally distributed stations. These comparisons of measurements during the period 2000–2016 are made using robust, consistent statistical methods. With some exceptions, the biases and drifts determined for most SAT–FP pairs are < 10 % and < 1 % yr−1.
Stefano Della Fera, Federico Fabiano, Piera Raspollini, Marco Ridolfi, Ugo Cortesi, Flavio Barbara, and Jost von Hardenberg
Geosci. Model Dev., 16, 1379–1394, https://doi.org/10.5194/gmd-16-1379-2023, https://doi.org/10.5194/gmd-16-1379-2023, 2023
Short summary
Short summary
The long-term comparison between observed and simulated outgoing longwave radiances represents a strict test to evaluate climate model performance. In this work, 9 years of synthetic spectrally resolved radiances, simulated online on the basis of the atmospheric fields predicted by the EC-Earth global climate model (v3.3.3) in clear-sky conditions, are compared to IASI spectral radiance climatology in order to detect model biases in temperature and humidity at different atmospheric levels.
Gianluca Di Natale, David D. Turner, Giovanni Bianchini, Massimo Del Guasta, Luca Palchetti, Alessandro Bracci, Luca Baldini, Tiziano Maestri, William Cossich, Michele Martinazzo, and Luca Facheris
Atmos. Meas. Tech., 15, 7235–7258, https://doi.org/10.5194/amt-15-7235-2022, https://doi.org/10.5194/amt-15-7235-2022, 2022
Short summary
Short summary
In this paper, we describe a new approach to test the consistency of the precipitating ice cloud optical and microphysical properties in Antarctica, Dome C, retrieved from hyperspectral measurements in the far-infrared, with the reflectivity detected by a co-located micro rain radar operating at 24 GHz. The retrieved ice crystal sizes were found in accordance with the direct measurements of an optical imager, also installed at Dome C, which can collect the falling ice particles.
Gerald Wetzel, Michael Höpfner, Hermann Oelhaf, Felix Friedl-Vallon, Anne Kleinert, Guido Maucher, Miriam Sinnhuber, Janna Abalichin, Angelika Dehn, and Piera Raspollini
Atmos. Meas. Tech., 15, 6669–6704, https://doi.org/10.5194/amt-15-6669-2022, https://doi.org/10.5194/amt-15-6669-2022, 2022
Short summary
Short summary
Satellite measurements of stratospheric trace gases are essential for monitoring distributions and trends of these species on a global scale. Here, we compare the final MIPAS ESA Level 2 version 8 data (temperature and trace gases) with measurements obtained with the balloon version of MIPAS in terms of data agreement of both sensors, including combined errors. For most gases, we find a 5 % to 20 % agreement of the retrieved vertical profiles of both MIPAS instruments in the lower stratosphere.
William G. Read, Gabriele Stiller, Stefan Lossow, Michael Kiefer, Farahnaz Khosrawi, Dale Hurst, Holger Vömel, Karen Rosenlof, Bianca M. Dinelli, Piera Raspollini, Gerald E. Nedoluha, John C. Gille, Yasuko Kasai, Patrick Eriksson, Christopher E. Sioris, Kaley A. Walker, Katja Weigel, John P. Burrows, and Alexei Rozanov
Atmos. Meas. Tech., 15, 3377–3400, https://doi.org/10.5194/amt-15-3377-2022, https://doi.org/10.5194/amt-15-3377-2022, 2022
Short summary
Short summary
This paper attempts to provide an assessment of the accuracy of 21 satellite-based instruments that remotely measure atmospheric humidity in the upper troposphere of the Earth's atmosphere. The instruments made their measurements from 1984 to the present time; however, most of these instruments began operations after 2000, and only a few are still operational. The objective of this study is to quantify the accuracy of each satellite humidity data set.
Piera Raspollini, Enrico Arnone, Flavio Barbara, Massimo Bianchini, Bruno Carli, Simone Ceccherini, Martyn P. Chipperfield, Angelika Dehn, Stefano Della Fera, Bianca Maria Dinelli, Anu Dudhia, Jean-Marie Flaud, Marco Gai, Michael Kiefer, Manuel López-Puertas, David P. Moore, Alessandro Piro, John J. Remedios, Marco Ridolfi, Harjinder Sembhi, Luca Sgheri, and Nicola Zoppetti
Atmos. Meas. Tech., 15, 1871–1901, https://doi.org/10.5194/amt-15-1871-2022, https://doi.org/10.5194/amt-15-1871-2022, 2022
Short summary
Short summary
The MIPAS instrument onboard the ENVISAT satellite provided 10 years of measurements of the atmospheric emission al limb that allow for the retrieval of latitude- and altitude-resolved atmospheric composition. We describe the improvements implemented in the retrieval algorithm used for the full mission reanalysis, which allows for the generation of the global distributions of 21 atmospheric constituents plus temperature with increased accuracy with respect to previously generated data.
Luca Sgheri, Claudio Belotti, Maya Ben-Yami, Giovanni Bianchini, Bernardo Carnicero Dominguez, Ugo Cortesi, William Cossich, Samuele Del Bianco, Gianluca Di Natale, Tomás Guardabrazo, Dulce Lajas, Tiziano Maestri, Davide Magurno, Hilke Oetjen, Piera Raspollini, and Cristina Sgattoni
Atmos. Meas. Tech., 15, 573–604, https://doi.org/10.5194/amt-15-573-2022, https://doi.org/10.5194/amt-15-573-2022, 2022
Short summary
Short summary
The FORUM instrument will look at the Earth's atmosphere from a satellite, covering a spectral range responsible for about 95 % of the radiation lost by our planet. FORUM helps to measure the imbalance between incoming and outgoing radiation that is responsible for the increasing average temperatures on Earth. The end-to-end simulator is a chain of codes that simulates the FORUM measurement process. The goal of the project is to study how the instrument reacts to different retrieval conditions.
Bianca Maria Dinelli, Piera Raspollini, Marco Gai, Luca Sgheri, Marco Ridolfi, Simone Ceccherini, Flavio Barbara, Nicola Zoppetti, Elisa Castelli, Enzo Papandrea, Paolo Pettinari, Angelika Dehn, Anu Dudhia, Michael Kiefer, Alessandro Piro, Jean-Marie Flaud, Manuel López-Puertas, David Moore, John Remedios, and Massimo Bianchini
Atmos. Meas. Tech., 14, 7975–7998, https://doi.org/10.5194/amt-14-7975-2021, https://doi.org/10.5194/amt-14-7975-2021, 2021
Short summary
Short summary
The level-2 v8 database from the measurements of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), aboard the European Space Agency Envisat satellite, containing atmospheric fields of pressure, temperature, and volume mixing ratio of 21 trace gases, is described in this paper. The database covers all the measurements acquired by MIPAS (from July 2002 to April 2012). The number of species included makes it of particular importance for the studies of stratospheric chemistry.
Paolo Pettinari, Flavio Barbara, Simone Ceccherini, Bianca Maria Dinelli, Marco Gai, Piera Raspollini, Luca Sgheri, Massimo Valeri, Gerald Wetzel, Nicola Zoppetti, and Marco Ridolfi
Atmos. Meas. Tech., 14, 7959–7974, https://doi.org/10.5194/amt-14-7959-2021, https://doi.org/10.5194/amt-14-7959-2021, 2021
Short summary
Short summary
Phosgene (COCl2) is a toxic gas whose presence is a consequence of human activity. Besides its direct injection in the troposphere, stratospheric COCl2 is produced from the decomposition of CCl4, an anthropogenic gas regulated by the Montreal Protocol. As a consequence, COCl2 negative trends characterize the lower and part of the middle stratosphere. However, we find positive trends in the upper troposphere, demonstrating the non-negligible role of other Cl-containing species not yet regulated.
William Cossich, Tiziano Maestri, Davide Magurno, Michele Martinazzo, Gianluca Di Natale, Luca Palchetti, Giovanni Bianchini, and Massimo Del Guasta
Atmos. Chem. Phys., 21, 13811–13833, https://doi.org/10.5194/acp-21-13811-2021, https://doi.org/10.5194/acp-21-13811-2021, 2021
Short summary
Short summary
The presence of clouds over Concordia, in the Antarctic Plateau, is investigated. Results are obtained by applying a machine learning algorithm to measurements of the infrared radiation emitted by the atmosphere toward the surface. The clear-sky, ice cloud, and mixed-phase cloud occurrence at different timescales is studied. A comparison with satellite measurements highlights the ability of the algorithm to identify multiple cloud conditions and study their variability at different timescales.
Luca Palchetti, Marco Barucci, Claudio Belotti, Giovanni Bianchini, Bertrand Cluzet, Francesco D'Amato, Samuele Del Bianco, Gianluca Di Natale, Marco Gai, Dina Khordakova, Alessio Montori, Hilke Oetjen, Markus Rettinger, Christian Rolf, Dirk Schuettemeyer, Ralf Sussmann, Silvia Viciani, Hannes Vogelmann, and Frank Gunther Wienhold
Earth Syst. Sci. Data, 13, 4303–4312, https://doi.org/10.5194/essd-13-4303-2021, https://doi.org/10.5194/essd-13-4303-2021, 2021
Short summary
Short summary
The FIRMOS far-infrared (IR) prototype, developed for the preparation of the ESA FORUM mission, was deployed for the first time at Mt. Zugspitze at 3000 m altitude to measure the far-IR spectrum of atmospheric emissions. The measurements, including co-located radiometers, lidars, radio soundings, weather, and surface properties, provide a unique dataset to study radiative properties of water vapour, cirrus clouds, and snow emissivity over the IR emissions, including the under-explored far-IR.
Richard J. Bantges, Helen E. Brindley, Jonathan E. Murray, Alan E. Last, Jacqueline E. Russell, Cathryn Fox, Stuart Fox, Chawn Harlow, Sebastian J. O'Shea, Keith N. Bower, Bryan A. Baum, Ping Yang, Hilke Oetjen, and Juliet C. Pickering
Atmos. Chem. Phys., 20, 12889–12903, https://doi.org/10.5194/acp-20-12889-2020, https://doi.org/10.5194/acp-20-12889-2020, 2020
Short summary
Short summary
Understanding how ice clouds influence the Earth's energy balance remains a key challenge for predicting the future climate. These clouds are ubiquitous and are composed of ice crystals that have complex shapes that are incredibly difficult to model. This work exploits new measurements of the Earth's emitted thermal energy made from instruments flown on board an aircraft to test how well the latest ice cloud models can represent these clouds. Results indicate further developments are required.
Cited articles
Baldridge, A., Hook, S., Grove, C., and Rivera, G.: The ASTER spectral library version 2.0, Remote Sens. Environ., 113, 711–715, https://doi.org/10.1016/j.rse.2008.11.007, 2009. a
Bellisario, C., Brindley, H. E., Murray, J. E., Last, A., Pickering, J., Harlow, R. C., Fox, S., Fox, C., Newman, S. M., Smith, M., Anderson, D., Huang, X., and Chen, X.: Retrievals of the Far Infrared Surface Emissivity Over the Greenland Plateau Using the Tropospheric Airborne Fourier Transform Spectrometer (TAFTS), J. Geophys. Res.-Atmos., 122, 12152–12166, https://doi.org/10.1002/2017JD027328, 2017. a, b, c
Ben-Yami, M.: FORUM end-to-end simulator emissivity retrievals, Zenodo [data set], https://doi.org/10.5281/zenodo.5960223, 2022a. a
Ben-Yami, M.: mayaby/FORUM_emissivity: FORUM_emissivity (Version v1), Zenodo [code], https://doi.org/10.5281/zenodo.6205876, 2022b. a
Borbas, E. E., Hulley, G., Feltz, M., Knuteson, R., and Hook, S.: The Combined ASTER MODIS Emissivity over Land (CAMEL) Part 1: Methodology and High Spectral Resolution Application, Remote Sens., 10, 643, https://doi.org/10.3390/rs10040643, 2018. a
Capelle, V., Chédin, A., Péquignot, E., Schlüssel, P., Newman, S. M., and Scott, N. A.: Infrared Continental Surface Emissivity
Spectra and Skin Temperature Retrieved from IASI Observations over the
Tropics, J. Appl. Meteorol. Clim., 51, 1164–1179,
https://doi.org/10.1175/JAMC-D-11-0145.1, 2012. a
Clough, S., Shephard, M., Mlawer, E., Delamere, J., Iacono, M., Cady-Pereira, K., Boukabara, S., and Brown, P.: Atmospheric radiative transfer modeling: a summary of the AER codes, J. Quant. Spectrosc. Ra., 91, 233–244, https://doi.org/10.1016/j.jqsrt.2004.05.058, 2005. a
Dinelli, B. M., Castelli, E., Carli, B., Del Bianco, S., Gai, M., Santurri, L., Moyna, B. P., Oldfield, M., Siddans, R., Gerber, D., Reburn, W. J., Kerridge, B. J., and Keim, C.: Technical Note: Measurement of the tropical UTLS composition in presence of clouds using millimetre-wave heterodyne spectroscopy, Atmos. Chem. Phys., 9, 1191–1207, https://doi.org/10.5194/acp-9-1191-2009, 2009. a, b
Feldman, D. R., Collins, W. D., Pincus, R., Huang, X., and Chen, X.: Far-infrared surface emissivity and climate, P. Natl. Acad. Sci. USA, 111, 16297–16302, https://doi.org/10.1073/pnas.1413640111, 2014. a, b
Feltz, M., Borbas, E., Knuteson, R., Hulley, G., and Hook, S.: The Combined
ASTER MODIS Emissivity over Land (CAMEL) Part 2: Uncertainty and Validation, Remote Sens., 10, 664, https://doi.org/10.3390/rs10050664, 2018. a
Harries, J., Carli, B., Rizzi, R., Serio, C., Mlynczak, M., Palchetti, L.,
Maestri, T., Brindley, H., and Masiello, G.: The Far-infrared Earth, Rev. Geophys., 46, RG4004, https://doi.org/10.1029/2007RG000233, 2008. a
Hersbach, H., Bell, B., Berrisford, P., Hirahara, S., Horányi, A., Muñoz-Sabater, J., Nicolas, J., Peubey, C., Radu, R., Schepers, D., Simmons, A., Soci, C., Abdalla, S., Abellan, X., Balsamo, G., Bechtold, P., Biavati, G., Bidlot, J., Bonavita, M., Chiara, G., Dahlgren, P., Dee, D., Diamantakis, M., Dragani, R., Flemming, J., Forbes, R., Fuentes, M., Geer, A., Haimberger, L., Healy, S., Hogan, R. J., Hólm, E., Janisková,
M., Keeley, S., Laloyaux, P., Lopez, P., Lupu, C., Radnoti, G., Rosnay, P.,
Rozum, I., Vamborg, F., Villaume, S., and Thépaut, J.-N.: The ERA5
global reanalysis, Q. J. Roy. Meteor. Soc., 146, 1999–2049, https://doi.org/10.1002/qj.3803, 2020. a
Huang, X., Chen, X., Flanner, M., Yang, P., Feldman, D., and Kuo,
C.: Improved Representation of Surface Spectral Emissivity in a Global
Climate Model and Its Impact on Simulated Climate, J. Climate, 31,
3711–3727, https://doi.org/10.1175/JCLI-D-17-0125.1, 2018. a, b, c
Knuteson, R., Best, F., DeSlover, D., Osborne, B., Revercomb, H., and Smith,
W.: Infrared land surface remote sensing using high spectral resolution
aircraft observations, Adv. Space Res., 33, 1114–1119,
https://doi.org/10.1016/S0273-1177(03)00752-X, 2004. a
Kuo, C., Feldman, D. R., Huang, X., Flanner, M., Yang, P., and Chen, X.:
Time-Dependent Cryospheric Longwave Surface Emissivity Feedback in the
Community Earth System Model, J. Geophys. Res.-Atmos., 123, 789–813, https://doi.org/10.1002/2017JD027595, 2018. a, b
L’Ecuyer, T. S., Drouin, B. J., Anheuser, J., Grames, M., Henderson, D. S., Huang, X., Kahn, B. H., Kay, J. E., Lim, B. H., Mateling, M., Merrelli, A., Miller, N. B., Padmanabhan, S., Peterson, C., Schlegel, N.-J., White, M. L.,
and Xie, Y.: The Polar Radiant Energy in the Far Infrared Experiment: A New
Perspective on Polar Longwave Energy Exchanges, B. Am. Meteorol. Soc., 102, E1431–E1449, https://doi.org/10.1175/BAMS-D-20-0155.1, 2021. a
Li, Z.-L., Wu, H., Wang, N., Qiu, S., Sobrino, J. A., Wan, Z.,
Tang, B.-H., and Yan, G.: Land surface emissivity retrieval from
satellite data, Int. J. Remote Sens., 34, 3084–3127,
https://doi.org/10.1080/01431161.2012.716540, 2013. a, b
Loveless, M., Borbas, E., Knuteson, R., Cawse-Nicholson, K., Hulley, G., and
Hook, S.: Climatology of the Combined ASTER MODIS Emissivity over Land
(CAMEL) Version 2, Remote Sens., 13, 111, https://doi.org/10.3390/rs13010111, 2020. a
Masiello, G. and Serio, C.: Simultaneous physical retrieval of surface
emissivity spectrum and atmospheric parameters from infrared atmospheric
sounder interferometer spectral radiances, Appl. Opt., 52, 2428–2446,
https://doi.org/10.1364/AO.52.002428, 2013. a
Murray, J. E., Brindley, H. E., Fox, S., Bellisario, C., Pickering, J. C., Fox, C., Harlow, C., Smith, M., Anderson, D., Huang, X., Chen, X., Last, A., and Bantges, R.: Retrievals of High-Latitude Surface Emissivity Across the Infrared From High-Altitude Aircraft Flights,
J. Geophys. Res.-Atmos., 125, e33672, https://doi.org/10.1029/2020JD033672, 2020. a, b, c, d
Palchetti, L., Di Natale, G., and Bianchini, G.: Remote sensing of
cirrus cloud microphysical properties using spectral measurements over the
full range of their thermal emission, J. Geophys. Res.-Atmos., 121, 10804–10819, https://doi.org/10.1002/2016JD025162, 2016. a
Palchetti, L., Brindley, H., Bantges, R., Buehler, S. A., Camy-Peyret, C., Carli, B., Cortesi, U., Bianco, S. D., Natale, G. D., Dinelli, B. M., Feldman, D., Huang, X. L., C.-Labonnote, L., Libois, Q., Maestri, T., Mlynczak, M. G., Murray, J. E., Oetjen, H., Ridolfi, M., Riese, M., Russell,
J., Saunders, R., and Serio, C.: FORUM: Unique Far-Infrared Satellite
Observations to Better Understand How Earth Radiates Energy to Space,
B. Am. Meteorol. Soc., 101, E2030–E2046, https://doi.org/10.1175/BAMS-D-19-0322.1, 2020. a, b
Palchetti, L., Barucci, M., Belotti, C., Bianchini, G., Cluzet, B., D'Amato, F., Del Bianco, S., Di Natale, G., Gai, M., Khordakova, D., Montori, A., Oetjen, H., Rettinger, M., Rolf, C., Schuettemeyer, D., Sussmann, R., Viciani, S., Vogelmann, H., and Wienhold, F. G.: Observations of the downwelling far-infrared atmospheric emission at the Zugspitze observatory, Earth Syst. Sci. Data, 13, 4303–4312, https://doi.org/10.5194/essd-13-4303-2021, 2021. a
Ridolfi, M. and Sgheri, L.: Iterative approach to self-adapting and
altitude-dependent regularization for atmospheric profile retrievals, Opt.
Express, 19, 26696–26709, https://doi.org/10.1364/OE.19.026696, 2011. a
Ridolfi, M., Del Bianco, S., Di Roma, A., Castelli, E., Belotti, C., Dandini, P., Di Natale, G., Dinelli, B. M., C.-Labonnote, L., and Palchetti, L.: FORUM
Earth Explorer 9: Characteristics of Level 2 Products and Synergies with
IASI-NG, Remote Sens., 12, 1496, https://doi.org/10.3390/rs12091496, 2020. a, b, c
Rodgers, C. D.: Retrieval of Atmospheric Temperature and Composition From Remote Measurements of Thermal Radiation, Rev. Geophys. Space GE, 14, 609–624, https://doi.org/10.1029/RG014i004p00609, 1976. a
Rodgers, C. D.: Inverse Methods for Atmospheric Sounding, World Scientific,
https://doi.org/10.1142/3171, 2000. a, b, c, d
Sgheri, L., Raspollini, P., and Ridolfi, M.: Auto-adaptive Tikhonov
regularization of water vapor profiles: application to FORUM measurements,
Appl. Anal., 99, 1–11, https://doi.org/10.1080/00036811.2020.1751825, 2020. a, b
Sgheri, L., Belotti, C., Ben-Yami, M., Bianchini, G., Carnicero Dominguez, B., Cortesi, U., Cossich, W., Del Bianco, S., Di Natale, G., Guardabrazo, T., Lajas, D., Maestri, T., Magurno, D., Oetjen, H., Raspollini, P., and Sgattoni, C.: The FORUM end-to-end simulator project: architecture and results, Atmos. Meas. Tech., 15, 573–604, https://doi.org/10.5194/amt-15-573-2022, 2022. a, b, c, d, e, f, g, h, i, j, k, l
Susskind, J., Blaisdell, J. M., and Iredell, L.: Improved methodology for surface and atmospheric soundings, error estimates, and quality control procedures: the atmospheric infrared sounder science team version-6 retrieval
algorithm, J. Appl. Remote Sens., 8, 1–34,
https://doi.org/10.1117/1.JRS.8.084994, 2014. a
Transtrum, M. K., Machta, B. B., and Sethna, J. P.: Geometry of nonlinear least squares with applications to sloppy models and optimization, Phys. Rev. E, 83, 036701, https://doi.org/10.1103/PhysRevE.83.036701, 2011. a
von Clarmann, T., Degenstein, D. A., Livesey, N. J., Bender, S., Braverman, A., Butz, A., Compernolle, S., Damadeo, R., Dueck, S., Eriksson, P., Funke, B., Johnson, M. C., Kasai, Y., Keppens, A., Kleinert, A., Kramarova, N. A., Laeng, A., Langerock, B., Payne, V. H., Rozanov, A., Sato, T. O., Schneider, M., Sheese, P., Sofieva, V., Stiller, G. P., von Savigny, C., and Zawada, D.: Overview: Estimating and reporting uncertainties in remotely sensed atmospheric composition and temperature, Atmos. Meas. Tech., 13, 4393–4436, https://doi.org/10.5194/amt-13-4393-2020, 2020. a, b
Wan, Z.: New refinements and validation of the collection-6 MODIS land-surface temperature/emissivity product, Remote Sens. Environ., 140, 36–45, https://doi.org/10.1016/j.rse.2013.08.027, 2014. a
Wang, K., Wan, Z., Wang, P., Sparrow, M., Liu, J., Zhou, X., and Haginoya, S.: Estimation of surface long wave radiation and broadband emissivity using
Moderate Resolution Imaging Spectroradiometer (MODIS) land surface
temperature/emissivity products, J. Geophys. Res.-Atmos., 110, D11109, https://doi.org/10.1029/2004JD005566, 2005. a
Short summary
Spectral emissivity is a key property of the Earth's surface. Few measurements exist in the far-infrared, despite recent work showing that its contribution is important for accurate modelling of global climate. In preparation for ESA’s EE9 FORUM mission (launch in 2026), this study takes the first steps towards the development of an operational emissivity retrieval for FORUM by investigating the sensitivity of the emissivity product to different physical and operational parameters.
Spectral emissivity is a key property of the Earth's surface. Few measurements exist in the...
