Transcript Document 7919057

GCC Summer School - 2004
Ground-based Measurements
Part II
•
Measurements
•
Retrieving the Desired Information
•
Comparison Between Instruments
•
Satellite Validation
•
Toward Model-Measurement Comparison
Prepared by: Dr. Stella M L Melo
University of Toronto
2016-05-27
GCC Summer School - 2004
AIRGLOW




2016-05-27
What it is?
Proxy for MLT temperature,
concentration and dynamics
How we measure?
Comparing T measurements using
airglow with LIDAR T
measurements.
2
GCC Summer School - 2004
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.
2016-05-27
3
GCC Summer School - 2004
AIRGLOW


O + O + M  O2*+ M  250–1270 nm bands
emission
O2* + O  O(1S) + O2  557.7 nm emission



2016-05-27
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)
4
GCC Summer School - 2004
O2
O2
Slanger and Copeland, 2003
2016-05-27
O2(b-x) 0-1 band measured
by Keck I/HIRES (50 min
integration)
5
GCC Summer School - 2004
Airglow – Rocket measurements
-3
-1
Taxa de emissão volumétrica (fótons.cm .s )
0
50
100
150
200
120
115
Altura (km)
110
OI 557,7 nm
105
100
95
90
O2A(0-0)
85
80
0
1000
2000
3000
4000
-3
5000
-1
Taxa de emissão volumétrica (fótons.cm .s )
Rocket measurements – Alcantara (20S, 440W)
2016-05-27
6
GCC Summer School - 2004
OH
2016-05-27
Dyer et al., 1997
7
GCC Summer School - 2004
2016-05-27
8
GCC Summer School - 2004
Mars: Airglow Modeling – OH*
By A. García Muños
2016-05-27
9
GCC Summer School - 2004
Mars: Airglow Modeling – OH*
Diurnal variation
By A. García Muños
2016-05-27
10
GCC Summer School - 2004
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!
2016-05-27
11
GCC Summer School - 2004
AIRGLOW
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
2016-05-27
Issues about LTE…
12
GCC Summer School - 2004
Airglow imager
Iwagami et al.,
JASTP, 2002
2016-05-27
13
GCC Summer School - 2004
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
2016-05-27
14
GCC Summer School - 2004
Lidar T profile
LIDAR – Light Detection and Range
o Normally Lidar technique is used to measure Rayleigh
scattering from which air density distribution is obtained.
o By assuming hydrostatic and local thermodynamic
equilibrium atmospheric temperature profiles can be
calculated from the molecular backscatter profile.
o Measurements are reliable form 30km up to 80 km altitude
o 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!
2016-05-27
15
GCC Summer School - 2004
Lidar T profile
(a)– Energy levels NaD2 lines
(b)- Doppler-broadened fluorescence spectra of NaD2
transition.
2016-05-27
She et al., Applied Optics, 1992
16
GCC Summer School - 2004
Lidar T profile
Temperature
Fort Collins 2-3 Nov. 1997
Altitude (km)
110
Lidar 4.38 UT
MSIS
100
90
80
150
200
250
300
Temperature (K)
2016-05-27
Melo et al., 2001
17
GCC Summer School - 2004
Compare Lidar and OH* Temperature

First proposed by von Zahn et al. (1987) determine OH* altitude



2016-05-27
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
18
GCC Summer School - 2004
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
2016-05-27
19
GCC Summer School - 2004
Observations at Fort Collins (41N, 105W)
November 2-3, 1997
3:12 UT
110
10:38 UT
105
105
Altitude (km)
100
Altitude (km)
100
95
90
85
95
80
120
240
360
90
480
600
720
840
960 1080 1200
Temperature (K)
4.38 UT
290
85
80
170
190
210
230
250
270
290
Temperature (K)
Nocturnal average: Lidar ~ 30 K > OH*
At 4.38 UT: Lidar 65 K > OH*
2016-05-27
Temperature (K)
9.63 UT
280
Lidar
270
MTM (OH*)
260
250
240
230
220
210
200
1
2
3
4
5
6
7
8
UT Time (hrs)
9
10
11
12
13
20
GCC Summer School - 2004
Airglow Model

Photochemical model
O3+H  OH+O2 (3.3 eV)
O + O 2 + 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)
2016-05-27
21
GCC Summer School - 2004
Comparing Model and Observations
OH(6-2) Band
105
Altitude (km)
100
95
90
85
80
0
2000
4000
6000
8000
10000
-3
-1
Volume Emission Rate (photons.cm .s )
2016-05-27
22
GCC Summer School - 2004
OH* Rotational Temperature Observations
OH* response to a gravity wave based on Swenson and
Gardner (1998) Lz ~ 25 km
3:12 UT
10:38 UT
105
Altitude (km)
100
95
90
85
80
120
240
360
480
600
720
840
960 1080 1200
Temperature (K)
2016-05-27
23
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)})
DAVIS Jul 02,2000 (20N, 165W)
115
13:24
Altitude (km)
110
14:28
Climatology 23S
105
100
95
90
85
80
0.E+00
2.E+11
4.E+11
6.E+11
8.E+11
[O] (cm-3)
2016-05-27
Melo et al, 2001
24
GCC Summer School - 2004
Nightglow emissions - 80-110 km
OI 5577 Green line
O(1S 1D)
O+O+M
O2*+M
O2*+O
O(1S ) + O2
O2*+O2
O(1S )+O2
IOI 
O+O+M
O2*+M
O2* + O2
O2(b1Sg+)+O2
O2+O2
O2 * + O
O2 + O2
O +O2
O2(b1Sg+
[O]
[O]
2016-05-27
O2 Atmospheric bands
O2 (b1Sg+  X3Sg-)
3
2
)+M
Prod.
2
IO2  [O] [M]
[M]
OH Meinel bands
OH(X3Pn’  X3Pn” )
H + O3
OH* + O2
OH* + M
Prod.
O + O2 + M
O3 + M
IOH 
[O] [M]
[O] [M]
2
GCC Summer School - 2004
Recovering Mesospheric Atomic Oxygen Density Profile
from Airglow Measurements
O-parameters recovered from the technique (solid line) compared to the input (dashed lines).
2016-05-27
26
GCC Summer School - 2004
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).
2016-05-27
27
GCC Summer School - 2004
Ground-Based measurements
0
23 S 930613
104
160
140
100
120
98
100
96
240
80
94
Rotational Temperature (k)
Peak Altitude (km)
102
92
Peak Density (cm-3)
6.0e+11
90
5.5e+11
5.0e+11
4.5e+11
4.0e+11
220
TOH
TOH(9-4)
400
O2A(0-1)
200
350
300
180
250
TO2
160
150
-6 -5 -4 -3 -2 -1
0
1
2
3
4
5
6
100
700
Local TIme
Integrated Intensity (R)
8
7
6
sH
200
TO2(0-1)
140
9
3.5e+11
5
4
3
2
OI557.7 nm
60
OH(9-4)
600
500
400
300
1
-6
-5
-4
-3
-2
-1
0
1
2
Local Time
2016-05-27
3
4
5
6
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
Local TIme
28
GCC Summer School - 2004
Hydroxyl Profile
Measured by WINDII (symbols) and calculated (line)
(13-06-93)
105
100
Altitude (km)
Day 930613
Local Time 19.80
Day 930613
Local Time19.6
95
90
85
80
75
0.0
0.2
0.4
0.6
0.8
1.0
1.2
0.0
0.2
0.4
0.6
0.8
1.0
1.2
Normalized volume emission rate
2016-05-27
29
GCC Summer School - 2004
Airglow Imaging Systems for Gravity
Wave Observations in the Martian
Atmosphere
Picture by Calvin J. Hamilton
2016-05-27
• 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
30
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.
2016-05-27
31