Ground-based Measurements Part II Retrieving the Desired Information Comparison Between Instruments Satellite Validation Toward Model-Measurement Comparison Prepared by: Dr. Stella M L Melo University of Toronto 14/11/2018

AIRGLOW What it is? Proxy for MLT temperature, concentration and dynamics How we measure? Comparing T measurements using airglow with LIDAR T measurements. 14/11/2018

AIRGLOW What is it? - “Spontaneous luminescence that rises from discrete transitions of the constituents of the atmosphere” (A. García-Muñoz, in preparation); Has been used as proxy for atmospheric temperature, constituents and dynamics since back to the end of the 1950’s. Main source: atomic oxygen photodissociated at higher altitudes. 14/11/2018

AIRGLOW O + O + M  O2*+ M  250–1270 nm bands emission O2* + O  O(1S) + O2  557.7 nm emission Not including ionosphere… N + O  NO*  180–280 nm emission H + O3  OH*(v = 6-9) + O2  500–3000 nm bands emission (excess of energy 3.3 eV) 14/11/2018

O2 O2 O2(b-x) 0-1 band measured by Keck I/HIRES (50 min integration) Slanger and Copeland, 2003 14/11/2018

Airglow – Rocket measurements Rocket measurements – Alcantara (20S, 440W) 14/11/2018

OH Dyer et al., 1997 14/11/2018

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Mars: Airglow Modeling – OH* By A. García Muños 14/11/2018

Mars: Airglow Modeling – OH* Diurnal variation By A. García Muños 14/11/2018

MLT Temperature from airglow Atmospheric temperature is a basic parameter. Mesopause (85-100 km) Low temperature/low pressure Transition from turbulent to molecular diffusion Airglow can be used as proxy for MLT temperature - OH vibrational bands - well dispersed rotational lines - extending from 400nm to 4mm - intensity is relatively “easy” to measure Other planets! 14/11/2018

AIRGLOW Precision improve: rotational temperature Precision improve: - as the signal to noise ratio improves (DR/R decreases as the difference in rotational energy of the states (Fb-Fa) increases -> two lines that are farther apart in the spectrum will give a more precise measurement of the temperature 14/11/2018 Issues about LTE…

Airglow imager Iwagami et al., JASTP, 2002 14/11/2018

MLT Temperature from airglow Airglow (nadir) observations do not contain direct altitude information At the end of the 80’s - narrow-band sodium lidar begun to be used to remotely measure the altitude profile of the atmospheric temperature between 85-105 km Data-set show: bimodal character of the mesopause altitude the occurrence of the Temperature Inversion Layer above 85 km Lidar do not normally provide information about the horizontal structures 14/11/2018

Lidar T profile LIDAR – Light Detection and Range Normally Lidar technique is used to measure Rayleigh scattering from which air density distribution is obtained. By assuming hydrostatic and local thermodynamic equilibrium atmospheric temperature profiles can be calculated from the molecular backscatter profile. Measurements are reliable form 30km up to 80 km altitude Upper mesosphere: Na Lidar Na fluorescence cross-section is 14 orders higher than the Rayleigh-scattering cross-section at 589 nm Technique first proposed by Gibson et al., 1979 More on LIDAR? Carlo’s poster! 14/11/2018

Lidar T profile – Energy levels NaD2 lines - Doppler-broadened fluorescence spectra of NaD2 transition. 14/11/2018 She et al., Applied Optics, 1992

Lidar T profile 14/11/2018 Melo et al., 2001

Compare Lidar and OH* Temperature First proposed by von Zahn et al. (1987) - determine OH* altitude OH* layer at 86  4 km differences in temperature sometimes of up to 10 K influence of: clouds differences in field of view fast motions of the OH* layer due to gravity waves assumed OH* layer shape 14/11/2018

Lidar and OH* Temperature She and Lowe (1998) compared temperature measured with lidar (Fort Collins) and from OH airglow (FTS): Shape OH profile taken form WINDII measurements Generally, OH* rotational temperature can be used as a proxy of the atmospheric temperature at 87 ± 4 km 14/11/2018

Observations at Fort Collins (41N, 105W) November 2-3, 1997 Nocturnal average: Lidar ~ 30 K > OH* At 4.38 UT: Lidar 65 K > OH* 14/11/2018

Airglow Model Photochemical model O3+H  OH+O2 (3.3 eV) O + O2 + M  O3 + M OH(n) + O  H + O2 OH(n) + O2  OH(n-1) + O2 OH(n) + N2  OH(n-1) + N2 OH(n) OH(n-n) + hn (Based on Makhlouf et al. 1995) 14/11/2018

Comparing Model and Observations 14/11/2018

OH* Rotational Temperature - Observations OH* response to a gravity wave based on Swenson and Gardner (1998) Lz ~ 25 km 14/11/2018

Reed and Chandra (1975) parameterization GCC Summer School - 2004 Recovering Mesospheric Atomic Oxygen Density Profile from Airglow Measurements Reed and Chandra (1975) parameterization Upper mesosphere-lower thermosphere [O]z = [O]max * EXP (0.5 {1.0 + (Zmax - Z) / SH - EXP((Zmax - Z) / SH)}) 14/11/2018 Melo et al, 2001

Nightglow emissions - 80-110 km OI 5577 Green line O(1S 1D) O2 Atmospheric bands O2 (b1Sg+  X3Sg-) OH Meinel bands OH(X3Pn’  X3Pn” ) O+O+M O2*+M O2*+O O(1S ) + O2 O2*+O2 O2+O2 O(1S )+O2 O +O2 O + O + M O2*+M O2* + O2 O2(b1Sg+)+O2 O2* + O O2 + O2 O2(b1Sg+ )+M Prod. H + O3 OH* + O2 OH* + M Prod. O + O2 + M O3 + M 2 3 [O] [O] [M] 2 [O] [M] 2 IO2  [O] [M] IOH  IOI  14/11/2018

Recovering Mesospheric Atomic Oxygen Density Profile from Airglow Measurements O-parameters recovered from the technique (solid line) compared to the input (dashed lines). 14/11/2018

Recovering Mesospheric Atomic Oxygen Density Profile from Airglow Measurements Atomic oxygen density profiles (atoms/cm3) input (a) compared to retrieved (b) and the percentage difference (c). 14/11/2018

TOH TO2 14/11/2018

Measured by WINDII (symbols) and calculated (line) Hydroxyl Profile Measured by WINDII (symbols) and calculated (line) (13-06-93) 14/11/2018

Airglow Imaging Systems for Gravity Wave Observations in the Martian Atmosphere Stella M L Melo and K. Strong, University of Toronto R. P. Lowe and P. S. Argall University of Western Ontario A. Garcia Munoz, J. McConnell, I. C. McDade, York University T. Slanger and D. Huestis, SRI International, California, USA M. J. Taylor, Utah State University, USA K. Gilbert, London, Canada N. Rowlands, EMS Technologies Picture by Calvin J. Hamilton 14/11/2018

Mars Airglow REmote Sounding - MARES GCC Summer School - 2004 Mars Airglow REmote Sounding - MARES MARES-Ground is a zenith-sky imaging system for ground-based observation of wave activity in the Martian atmosphere through measurement of the contrast in images of selected airglow features. MARES-GWIM is a satellite-borne nadir-viewing imager which will produce static images of wave-induced radiance fluctuations in two vertically separated night airglow layers in the atmosphere. - GWIM has been developed for Earth’s atmosphere - MARES-GWIM will be an adaptation of GWIM for the Martian atmosphere. 14/11/2018