1. Shirley, J. H., Newman, C., Mischna, M. & Richardson, M. Replication of the historic record of Martian global dust storm occurrence in an atmospheric general circulation model. Icarus 317, 197–208 (2019).

2. Montabone, L. et al. Eight-year climatology of dust optical depth on Mars. Icarus 251, 65–95 (2015).

3. Haberle, R. M., Clancy, R. T., Forget, F., Smith, M. D. & Zurek, R. W. The Atmosphere and Climate of Mars (Cambridge Univ. Press, Cambridge, 2017).

4. Daerden, F. et al. Mars atmospheric chemistry simulations with the GEM-Mars general circulation model. Icarus https://doi.org/10.1016/j.icarus.2019.02.030 (in the press).

5. Fedorova, A. et al. Water vapor in the middle atmosphere of Mars during the 2007 global dust storm. Icarus 300, 440–457 (2018).

6. Heavens, N. G. et al. Hydrogen escape from Mars enhanced by deep convection in dust storms. Nat. Astron. 2, 126–132 (2018).

7. Smith, M., Daerden, F., Neary, L. & Khayat, A. The climatology of carbon monoxide and interannual variation of water vapor on Mars as observed by CRISM and modeled by the GEM-Mars general circulation model. Icarus 301, 117–131 (2018).

8. Trokhimovskiy, A. et al. Mars’ water vapor mapping by the SPICAM IR spectrometer: five Martian years of observations. Icarus 251, 50–64 (2015).

9. Sanchez-Lavega, A. et al. The 2018 Martian global dust storm over the south pole studied with VMC onboard Mars Express. AGU Fall Meeting 2018, abstr. P43K-3885 (2018).

10. Schofield, J., Kleinbohl, A., Kass, D. M. & McCleese, D. The Mars Climate Sounder – six Martian years of global atmospheric observations. In 42nd COSPAR Scientific Meeting abstr. B4.1-0002-18 (2018).

11. Smith, M. D. THEMIS observations of Mars planet-encircling dust storm 2018a. In AGU Fall Meeting 2018 abstr. P43J-3865 (2018).

12. Vasavada, A. Contributions of the Curiosity rover to the understanding of the Martian atmosphere. In 42nd COSPAR Scientific Meeting abstr. C3.1-0008-18 (2018).

13. Guzewich, S., Talaat, E., Toigo, A., Waugh, D. W. & McConnochie, T. High-altitude dust layers on Mars: observations with the thermal emission spectrometer. J. Geophys. Res. Planets 118, 1177–1194 (2013).

14. Heavens, N. G. et al. Seasonal and diurnal variability of detached dust layers in the tropical Martian atmosphere. J. Geophys. Res. Planets 119, 1748–1774 (2014).

15. Määttänen, A. et al. A complete climatology of the aerosol vertical distribution on Mars from MEx/SPICAM UV solar occultations. Icarus 223, 892–941 (2013).

16. Wang, C. et al. Parameterization of rocket dust storms on Mars in the LMD Martian GCM: modeling details and validation. J. Geophys. Res. 123, 982–1000 (2018).

17. Rafkin, S. The potential importance of non-local, deep transport on the energetics, momentum, chemistry, and aerosol distributions in the atmospheres of Earth, Mars, and Titan. Planet. Space Sci. 60, 147–154 (2012).

18. Spiga, A., Faure, J., Madeleine, J. B., Määttänen, A. & Forget, F. Rocket dust storms and detached dust layers in the Martian atmosphere. J. Geophys. Res. 118, 746–767 (2013).

19. Daerden, F. et al. A solar escalator on Mars: self-lifting of dust layers by radiative heating. Geophys. Res. Lett. 42, 7319–7326 (2015).

20. Clancy, R. T. et al. Extension of atmospheric dust loading to high altitudes during the 2001 Mars dust storm: MGS TES limb observations. Icarus 207, 98–109 (2010).

21. Sefton-Nash, E. et al. Climatology and first-order composition estimates of mesospheric clouds from Mars Climate Sounder limb spectra. Icarus 222, 342–356 (2013).

22. McCleese, D. J. et al. Structure and dynamics of the Martian lower and middle atmosphere as observed by the Mars Climate Sounder: seasonal variations in zonal mean temperature, dust, and water ice aerosols. J. Geophys. Res. 115, E12016 (2010).

23. Chaffin, M. S., Deighan, J., Schneider, N. M. & Stewart, A. I. F. Elevated atmospheric escape of atomic hydrogen from Mars induced by high-altitude water. Nat. Geosci. 10, 174–178 (2017).

24. Forget, F. et al. Improved general circulation models of the Martian atmosphere from the surface to above 80 km. J. Geophys. Res. 104, 24155–24175 (1999).

25. Neary, L. & Daerden, F. The GEM-Mars general circulation model for Mars: description and evaluation. Icarus 300, 458–476 (2018).

26. Steele, L. et al. The seasonal cycle of water vapour on Mars from assimilation of Thermal Emission Spectrometer data. Icarus 237, 97–115 (2014).

27. Lewis, S. R. et al. The solsticial pause on Mars: 1. A planetary wave reanalysis. Icarus 264, 456–464 (2016).

28. Lammer, H. et al. Outgassing history and escape of the martian atmosphere and water inventory. Space Sci. Rev. 174, 113–154 (2013).

29. Encrenaz, T. et al. New measurements of D/H on Mars using EXES aboard SOFIA. Astron. Astrophys. 612, A112 (2018).

30. Aoki, S. et al. Seasonal variation of the HDO/H 2 O ratio in the atmosphere of Mars at the middle of northern spring and beginning of northern summer. Icarus 260, 7–22 (2015).

31. Villanueva, G. et al. Strong water isotopic anomalies in the martian atmosphere: probing current and ancient reservoirs. Science 348, 218–221 (2015).

32. Webster, C. R. et al. Isotope ratios of H, C and O in CO 2 and H 2 O of the martian atmosphere. Science 341, 260–263 (2013).

33. Montmessin, F., Fouchet, T. & Forget, F. Modeling the annual cycle of HDO in the Martian atmosphere. J. Geophys. Res. 110, E03006 (2005).

34. Vandaele, A. C. et al. NOMAD, an integrated suite of three spectrometers for the ExoMars Trace Gas mission: technical description, science objectives and expected performance. Space Sci. Rev. 214, 80 (2018).

35. Neefs, E. et al. NOMAD spectrometer on the ExoMars trace gas orbiter mission: part 1—design, manufacturing and testing of the infrared channels. Appl. Opt. 54, 8494–8520 (2015).

36. Patel, M. R. et al. The NOMAD spectrometer on the ExoMars Trace Gas Orbiter mission: part 2—design, manufacturing and testing of the ultraviolet and visible channel. Appl. Opt. 56, 2771–2782 (2017).

37. Svedhem, H. et al. The ExoMars Trace Gas Orbiter. Space Sci. Rev. (in the press).

38. Nevejans, D. et al. Compact high-resolution spaceborne echelle grating spectrometer with acousto-optical tunable filter based on order sorting for the infrared domain from 2.2 to 4.3 μm. Appl. Opt. 45, 5191–5206 (2006).

39. Titov, D. V. et al. Venus Express: scientific goals, instrumentation and scenario of the mission. Cosm. Res. 44, 334–348 (2006).

40. Korablev, O. et al. The Atmospheric Chemistry Suite (ACS) of three spectrometers for the ExoMars 2016 Trace Gas Orbiter. Space Sci. Rev. 214, 7 (2018).

41. Korablev, O. et al. SPICAM IR acousto-optic spectrometer experiment on Mars Express. J. Geophys. Res. 111, E09S03 (2006).

42. Formisano, V. et al. The Planetary Fourier Spectrometer (PFS) onboard the European Mars Express mission. Planet. Space Sci. 53, 963–974 (2005).

43. Trompet, L. et al. Improved algorithm for the transmittance estimation of spectra obtained with SOIR/Venus Express. Appl. Opt. 55, 9275–9281 (2016).

44. Lemoine, F. G. et al. An improved solution of the gravity field of Mars (GMM-2B) from Mars Global Surveyor. J. Geophys. Res. 106, 23359-23376 (2001).

45. Millour, E. et al. The Mars Climate Database (MCD version 5.2). European Planetary Science Congress 2015, abstr. EPSC2015-43810 (2015).

46. Villanueva, G., Smith, M., Protopasa, S., Faggi, S. & Mandell, A. M. Planetary Spectrum Generator: an accurate online radiative transfer suite for atmospheres, comets, small bodies and exoplanets. J. Quant. Spectrosc. Radiat. Transf. 217, 86–104 (2018).

47. Devi, V. M. et al. Line parameters for CO 2 - and self-broadening in the v 3 band of HD16O. J. Quant. Spectrosc. Radiat. Transf. 203, 158–174 (2017).

48. Devi, V. M. et al. Line parameters for CO 2 - and self-broadening in the v 1 band of HD16O. J. Quant. Spectrosc. Radiat. Transf. 203, 133–157 (2017).

49. Gordon, I. E. et al. The HITRAN2016 molecular spectroscopic database. J. Quant. Spectrosc. Radiat. Transf. 203, 3–69 (2017).

50. Liuzzi, G. et al. Methane on Mars: new insights into the sensitivity of CH 4 with the NOMAD/ExoMars spectrometer through its first in-flight calibration. Icarus 321, 671–690 (2019).

51. Rodgers, C. D. Inverse Methods for Atmospheric Sounding: Theory and Practice (World Scientific, Singapore, 2000).

52. Maltagliati, L. et al. Annual survey of water vapor vertical distribution and water–aerosol coupling in the martian atmosphere observed by SPICAM/MEx solar occultations. Icarus 223, 942–962 (2013).

53. Levenberg, K. A method for the solution of certain non-linear problems in least squares. Q. J. Appl. Math. 2, 164–168 (1944).

54. Marquardt, D. An algorithm for least-squares estimation of nonlinear parameters. J. Soc. Ind. Appl. Math. 11, 431–441 (1963).

55. Fedorova, A. et al. Solar infrared occultation observations by SPICAM experiment on Mars-Express: simultaneous measurements of the vertical distributions of H 2 O, CO 2 and aerosol. Icarus 200, 96–117 (2009).

56. Warren, S. G. & Brandt, R. E. Optical constants of ice from the ultraviolet to the microwave: a revised compilation. J. Geophys. Res. 113, D14220 (2008).

57. Wolff, M. J. et al. Wavelength dependence of dust aerosol single scattering albedo as observed by CRISM. J. Geophys. Res. 114, E00D04 (2009).

58. Fedorova, A. et al. Evidence for a bimodal size distribution for the suspended aerosol particles on Mars. Icarus 231, 239–260 (2014).