New Products from combined MODIS/AIRS

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Nov 3, 2013 (4 years and 4 days ago)

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New Products from combined MODIS/AIRS



Jun Li, Chian
-
Yi Liu, Allen Huang, Xuebao Wu, and Liam Gumley




Cooperative Institute for Meteorological Satellite Studies

Space Science and Engineering Center


University of Wisconsin
-
Madison

1225 West Dayton Street, Madison, Wisconsin

International EOS/NPP Direct Readout
Meeting, 3


6 October 2005

Benevento, Italy


New products for IMAPP from combined MODIS/AIRS



MODIS classification mask


AIRS sub
-
pixel cloud detection products using MODIS data
(Li et al. 2004a
-
JAM)


Single FOV Cloud/Aerosol property products from AIRS
radiances (Li et al. 2004b
-

JAM; 2005a
-

JAM) with the
help of MODIS (cloud mask, cloud phase mask, cloud
classification mask, etc.)


AIRS cloud
-
clearing radiance products using multi
-
band
MODIS clear radiances (Li et al. 2005b


IEEE TGARS)


AIRS sub
-
pixel cloud
detection and
characterization using
MODIS (Li et al. 2004a
-

JAM).



Use MODIS cloud mask (1
km) for AIRS single field
-
of
-
view (SFOV) clear mask



Use MODIS cloud phase mask
(1 km) for AIRS SFOV cloud
phase mask



Use MODIS cloud
classification mask (1 km) for
AIRS SFOV cloud
classification mask

Aqua MODIS RGB Natural Color; 17
September 2003: Hurricane Isabel

MODIS 1 km cloud mask

MODIS confident clear pixels are counted
for AIRS clear coverage !

Clear

Cloudy

AIRS clear coverage

Unknown





Mixed Phase





Ice Clouds





Water Clouds





Clear

MODIS cloud phase mask with 1 km
spatial resolution

AIRS cloud phase mask with 13.5
km resolution (mixed phase clouds
appear frequently !)

AIRS Window BT(K)

Water Land L. Cld Mid Cld L. Cld H. Cld H. Cld Mid Cld Mid. Cld

F3

F2

F1

MODIS 1km classification mask superimposed to the AIRS
footprints of the study area. The MODIS classification mask
gives the cloud layer information with each AIRS footprint.


Cloud property products from AIRS radiances (Li et
al. 2004b
-

JAM; 2005a
-

JAM)

with help of
MODIS


MODIS cloud mask is used for AIRS SFOV clear/cloudy
detection


MODIS cloud phase mask is used for AIRS SFOV phase
determination


Cloud properties are retrieved from from AIRS radiances
with a physical algorithm (Minimum Residual Method)

Fast
Cloudy

Radiative Transfer Model

Observed HES Radiance Measurements

CTP: Cloud
-
Top Pressure; ECA: Effective Cloud Amount at 10 wavenumbers

CPS: Cloud Particle Size in diameter; COT: Cloud Optical Thickness at 0.55
µm

Minimum Residual (MR) algorithm for cloud property retrieval (Li
et al. 2004b
-

JAM; 2005a
-

JAM
)

Cost function

clear

cloudy

COT, CPS (window region):

790


1130 cm
-
1


CTP and ECA (CO2 region):

670


790 cm
-
1


COT=10.0

COT=5.0

COT=1.0

COT=0.05

CPS=10

CPS=20

CPS=30

CPS=50

AIRS BT(K) @ 901.69 cm
-
1

1km MODIS classification mask
superimposed to AIRS footprints

F1: Thick ice clouds

F1: CTP=258, CPS=33.90, COT=1.62

AIRS window BT image over North
America region

AIRS cloud
-
top pressure retrieval

with help
of MODIS cloud mask

AIRS cloud optical thickness retrieval

with
help of MODIS cloud mask and cloud phase
mask

Validation of cloud properties


Compare with MODIS natural color image


Compare with MODIS classification results


Ground measurements


Lidar observation


MODIS/AIRS

Spatial resolution:

MODIS CTP: 5 km

AIRS CTP: 13.5 km

GOES CTP: 10 km

AIRS CTH (m)

Barrow

Box A

MPACE
: Mixed Phase Artic
Cloud Experiment

Granule 223, 17 October 2004

CTP comparison with Lidar

AIRS time is 22:17:32

MODIS CTH=5.5 km; AIRS CTH=7.6 km

Vertical
Layers

AIRS Effective Radius=38.6 um

AIRS time = 22:17:32 UTC

AIRS OD=1.44

Desert Vs Dust aerosol

Dust

MODIS (BT11
-

BT12)

Desert

AIRS window BT

MODIS

Natural

color

Dust/aerosol

Desert

Low surface emissivity @ 8.9 um over desert


Negative slope between 11 and 12 um


Synergy of MODIS/AIRS is expected to improved aerosol/dust
products which are useful for regional applications

Derive AIRS cloud
-
cleared radiances using
MODIS/AIRS cloud
-
clearing algorithm


MODIS multi
-
spectral IR clear radiances within
AIRS sub
-
pixel are used for AIRS cloud
-
clearing on
SFOV basis (Li et al. 2005b, IEEE
-
TGARS)



MODIS clear radiances within AIRS sub
-
pixel are
used for Quality Control (QC) on AIRS cloud
-
clearing

Aqua MODIS IR SRF Overlay on AIRS Spectrum

Direct spectral relationship between IR MODIS and AIRS provides unique
application of MODIS in AIRS cloud_clearing !

Optimal imager/sounder

cloud
-
clearing Methodology

(Li et al. 2005;
IEEE Trans. On Geoscience and Remote sensing, June issue
).

N
*
is solved from 9 MODIS band (22,
24, 25, 28, 30, 31, 32, 33, 34) are used



8

5

4

3

2

1

6

7

(1)
CCR is obtained on single
footprint basis (3 by 3 box
moves by single footprint

(2)
MODIS clear radiances are
used for QC

AIRS clear

(13.5 km)

AIRS clear + CC
-
S

(13.5 km)

MODIS clear

(1 km)

AIRS single FOV profile retrieval versus ECMWF analysis

Cloud contaminated

Cloud
-
cleared

Clear neighbor

Temperature

Water Vapor Mixing Ratio

Contaminated by thin clouds !!

Cloud
-
cleared (MODIS/AIRS)

Temperature RMS difference between AIRS and ECMWF~ 250 thin cloud FOVs

Clear Neighbor

1.
There are potential new products from combined
MODIS/AIRS, especially the SFOV cloud property
products that include AIRS cloud mask, cloud phase
mask, cloud layer information mask, etc.

2.
AIRS SFOV cloud
-
cleared radiances will be derived
using MODIS/AIRS cloud
-
clearing approach.

3.
Efforts are also on deriving AIRS SFOV sounding
products under both clear and cloudy skies with help
of existing MODIS products.



Summary