Observing System

ATMOSPHERE

NASA Atmosphere Observing System(AOS)
Daniel J. Cecil1, NASA MSFCAOS Deputy Project Scientist – Suborbital
Daniel.J.Cecil@nasa.gov

SHAPE FILL
WITH IMAGE

Scott Braun2, John Yorks2, Tyler Thorsen3
1 NASA Marshall Space Flight Center
2 NASA Goddard Space Flight Center
3 NASA Langley Research Center12/6/2023

ESA-JAXA Pre-Launch EarthCARE
Science and Validation Workshop
November 2023
1

AOS Addresses Aerosol, Cloud, Convection,and Precipitation Processes• AOS-Storm (Inclined orbit, 2029)
o JAXA PMM Radar (Ku-band, Doppler)Pre-decisional
AOS-Sky [US led)Doppler Radar

AOS-Storm [US led)

o CNES C2OMODO tandem radiometers (89-325 GHZ)
o ALICAT backscatter lidar (532, 1064 nm)• AOS-Sky (Sun-synchronous orbit, 2031)
o Backscatter lidar (details TBD – Italian partnership?)o Doppler radar (details TBD)
o Passive microwave radiometer (89-700 GHz)o Polarimeter (350-1570 nm)
o CSA Thin Ice Cloud Imaging Radiometer (4-73 mm)
o CSA aerosol and moisture limb imagers• AOS Suborbitalo Post-launch field programso Surface-based networks, supersites
International partnerships are very important to AOS, botho Leverage existing capabilities, more international partners in the satellite constellation and in suborbital activities.

2AOS Suborbital
Low Clouds: Microphysics, precipitation
initiation

Convection/High Clouds: Microphysics
and dynamics, anvil cirrus lifecycle.

Aircraft and payloads depicted arenotional… instruments to be prioritized/ deconflicted for each campaign.
Need a high altitude (over-storm)
remote sensor…

Aerosol-Cloud-Radiation Interactions: …mid/high altitude
Vertically resolved aerosol-cloud-radiationinteraction processes and lifecycle.

aircraft to provideboth remote sensing
and in situ (aerosol,cloud, precip)

Large airborne campaigns addressing all science themes• Link airborne campaigns with well-instrumented
surface sites• Partner with other programs / nations where practical
Campaigns after launch to enable cal-val…low/mid altitude
aircraft to provide
both remote sensing
and in situ (aerosol,cloud, precip)

Aircraft, surface sites, and networks from partners will be especially helpful.
3

AOS and EarthCARE• AOS and EarthCARE approach cloud andaerosol profiling using similar instrumenttypes, but different frequencies and otherdetails

Pre-decisional
AOS-Sky [US led)
Doppler Radar

AOS-Storm [US led)

o Many people / institutions aligned with both missions• Some commonality in the cal-val needs• Surface-based measurements, field
campaigns, validation approaches used byeach will be of interest to the other
o Validation best-practices talk Wednesday afternoon
o I’m here to discuss collaborations, match names tofaces, etc.

Graphic reflects initial architecture concept directed at KDPA. Additional direction was provided to study architecture4changes, which are still on-going.

JAXA PMM Radar Capabilities
JAXA Wide Swath Ku Doppler Radar

Baseline Requirements
Doppler obs.

Dense sampling obs.
x3

Model “Truth”

Height (km)Normal scan obs.
・x49
・・

Simulated Ku Doppler Velocity
Nadirdirectionof flight
Courtesy of Pavlos Kollias

NLT March 2029 launch
430 km orbit, 55° inclination

Vertical sampling, resolution:
250, 500 m for Doppler, dense
125, 250 m for normal scan
Horizontal Resolution: 5 km
Observation range (altitude):
Doppler 17 km
Dense 20 km
Normal 18-20 km
Swath: 250 kmSensitivity (min dBZ):
Doppler 7.3 dBZ
Dense 7.3 dBZ
Normal 15 dBZ
Doppler uncertainty: 2 m/s @ 16 dBZ
Unambiguous Doppler range: ±30 m/s
5March 2029 launch
C2OMODO Radiometer Capabilities NLT
430 km orbit, 55° inclination

C2OMODO: Convective Core Observations
through MicrOwave Derivatives in thetrOpics (Brogniez et al. 2022)

CNES Radiometer Scan Pattern
Near Nadir

CNES Microwave Radiometers (89, 183, 325 GHz)89 GHz89 GHz
10 km FOV 1 channel
183.31 GHz 5 km FOV 6 channels
325.15 GHz 3 km FOV 3 channels

Nyquist sampling
Nyquist sampling
Continuous sampling

183 GHz

325 GHzTime-differenced radiometer measurements(~1-2-minutes) contain information onconvective vertical motions

6

ALICAT Lidar Capabilities
CATS Backscatter Lidar Example• NLT March 2029 launch• 430 km orbit, 55° inclination

ALICAT: Atmospheric Lidar for
Cloud and Aerosol Transport
Low pulse energy, high pulse
repetition frequency

Frequencies: 532, 1064 nm
Provides total attenuatedbackscatter and depolarization
at both frequencies
Heritage: Cloud Physics Lidar,
Cloud-Aerosol Transport
System (CATS)
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AOS-Sky Lidar• NET December 2031 launch• 450 km orbit, sun-sync-13:30 LTAN

532 nm, 1064 Backscatter Lidar*• Target requirement of daytime SNR
equivalent to CALIPSO night SNR• NASA HQ has initiated study ofpartnership with Italian Space Agency(ASI)• ASI lidar:• 355 nm Raman (extinction)• 532, 1064 nm backscatter

Clouds• Requires formation flying of AOS-Sky
and ASI lidar

Dust
Smoke
Clouds• NET December 2031 launch• 450 km orbit, sun-sync-13:30 LTAN

AOS-Sky Radar
Baseline Requirements
Quantity
Radarreflectivity,
cloudprofiling

Resolution @ altitude
Horiz.: 2.0 km
Vert.: 300 m @ 0.5 – 1.0 km
300 m @ 1.0 - 2.5 km
500 m @ 2.5 – 6 km
500 m @ 6 – 20 km

Accuracy

Sensitivity @ altitude

1.5 dB *≤–5 dBZ @ 0.5 km – 1 km≤–15 dBZ @ 1 km – 2.5 km≤–20 dBZ @ 2.5 km – 6 km≤–24 dBZ @ 6 km – 20 km• Requirements are frequency agnostic• Enhancements to be studied: Second frequency, narrowswath, passive measurements if Ka band, LDR

Figures at left courtesy of Matt McLinden
9AOS-Sky Radiometer Requirements
Microwave Radiometer: 89-700 GHz

Courtesy of Matt McLinden
Courtesy of Yuli Liu, UMBC

Cross-track scanning, ≥750 km swath
FOV ≤10 km at nadir, ≤20 km at edge of swath

Baseline Requirements
Bands (# Channels)

Accuracy (K)Polarization

89-113 GHz (1)≤ 0.5 K

118 GHz (3)≤ 0.75 K

183.3 GHz (3)≤0.75 K

165/205 GHz (1)≤0.75 K

310 GHz (3)325.2 or 380.2 GHz (2)≤ 1.5 K
≤ 1.5 K

Target: Dual
Minimum: Single

640-700 GHz (1)≤ 1.5 K

Dual

Target: Dual
Minimum: Single

Target: Dual
Minimum: SingleSub-mm wavelengths bring a cloudsensitivity that is new for NASA missions
10AOS Polarimeter Requirements
UV-VIS-NIR-SWIR Multi-angle Polarimeter
Example AOD from HARP
Cloud-top properties available
also

Baseline Requirements
Type and/or Wavelength
range (nm)UV: 350 – 390 nm1
VIS: 410 – 750 nm
Hyperangle: 660 – 870 nm
Water Vapor: ~940nm
SWIR Cirrus: ~1380
VNIR-SWIR: 870 – 1570 nm

Number ofspectralchannels
1211
13300 km swath width
0.5 km IFOV (at nadir)

Number ofviewing angles
per pixel
101060101010

CSA Contributions
Canadian Space Agency Longwave-Far Infrared
Imaging Radiometer (4-73 mm),Aerosol/Moisture Limb Sounding

AOS-Sky [US led)
AOS-Storm [US led)Summary of AOS Measurements & Timeline
Polar orbit

Inclinedorbit(diurnalvariations)Sun-synch
1330 LTAN
NET Dec 2031

55° inclination
NLT March 2029

AOS-Storm, JAXA PMM, and CNES
C2OMODO:2019• Ku-Doppler radar
Polar• dTB/dt (~mm-wavelength)• Backscatter lidar
AOS-Sky, CSA HAWCsat:• Cloud-profiling Doppler radar
Inclined• Backscatter lidar• sub-mm radiometer• Polarimeter• Longwave radiometer• Limb sounder (aerosol+moisture)

2023

2031

2027

Possible
extendedmissionCloudSat/CALIPSO

AOS-Sky +HAWCsat

Possible
extendedmissionEnd of GPM
station keeping
Suborbital
fuel

CSA

GPM

INCUS

PMM
AOSStorm

campaigns
after launches
Possible extended mission
Possible
extendedmission

JAXA CNES
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