# Presentation: 181173

## Land Surface Temperature and Emissivity

- MOD11 Status
- Zhengming Wan
- University of California, Santa Barbara
- December 18, 2001

- MODIS Science Team Meeting

- Z. Wan - 1

## MODIS LST Products

- Credit also to:

- Zhao-liang Li  (GRTR/LSIIT, France),

- William C. Snyder (May 1995 – April 1997), Yulin Zhang (Dec 1994 -), Qincheng Zhang (July 2001 -),

- Pengxin Wang (Sept 2001 -), Xialin Ma (Oct 1997 – Mar 2001), Ruibo Wang (Apr 1998 – May 2001),

- Yuezhong Feng (1997 – 1998), Xiaoning Duan (1994 – July 1999),  Waifun Olivia Au Yeung (1995),

- Cleo Salisbury (summer 1997), Jason Hoss (summer 1998), Patricia Virtucio (1999).

- Special thanks for supports from

- NASA HQ,  EOS Project Office,  MODIS Science Team,  MSST,

- GSFC DAAC,  EDC DAAC,  NSIDC,  MODLAND,  MCST,   SDDT,  MODAPS,  LDOPE,

- NASA/Ames/Airborne Sensor Facility,  NASA/JPL/AVIRIS Team,  NASA Dryden Flight RC,

- Robert Jellison (UCSB/SNARL),  Richard E. Plant (UC Davis),

- Stan Hunewill and Jeff Hunewill (Hunewill Guest Ranch),  Sophie Moreau (ABTEMA, Bolivia),

- Arnaud Yves & Roland Bosseno (IRD, Bolivia),  etc.

- Z. Wan - 2

- Outline of the Presentation

- MODIS LST Algorithms

- Products and a scheme to remove cloud-contaminated

- Validations of L1B TIR bands and LST products

- Applications of the MODIS LST products

- Plan for 2002

- Conclusion of the MOD11 Status

- LST values

- Z. Wan - 3

## MODIS LST Algorithms

- 1. The generalized split-window algorithm

- - coefficients depend on view angle, atmospheric column  water vapor, and surface air temperature.

- (Wan & Dozier, 1996)

- - emissivities estimated from land cover types.

- (Snyder et al., 1998; Snyder & Wan, 1998)

- 2. The MODIS day/night LST algorithm

- (Wan & Li, 1997)

-  retrieve daytime, nighttime, & band emissivities simultaneously with day/night data in seven bands.

- - the range of viewing zenith angle separated into 4 sub-ranges (0-40, 40-52, 52-60, 60-65).

- - be able to adjust the input cwv and Ta values.

- Z. Wan - 4

## MODIS LST Products

- 1. The daily daytime & nighttime 1km LST product retrieved by the split-window method using b31 & b32.

- - MOD11_L2 as granules

- - MOD11A1, L3, as 1km-grid ISIN tiles

- 3. MOD11B1 - daily LST/emissivity product retrieved by the day/night LST method with bands 20, 22-23, 29, 31-33.

- - two SDSs in MOD11B1 for 1km LST aggregated at 5km grids.

- 2. MOD11A2 – 8-day 1km LST product in ISIN tiles.

- Z. Wan - 5

## MODIS LST Products (cont.)

- A. MODIS data used in the LST production: MOD021KM, MOD03, MOD07_L2, MOD10_L2, MOD12Q1, and MOD35_L2.

- B. Only clear-sky pixels at 99% confidence defined by

- MOD35_L2 are processed in the LST production.

- C. A double-screen scheme can be used to remove the

- LST values contaminated with cloud effects

- - screen off 1% by the lower and upper ends of δΤ distributions of the LSTs retrieved by the two methods.

- - screen off 0.5% by the lower and upper ends of the δ(Τday-Tnight) distribution .

- Z. Wan - 6

## |

- Screening off the cloud-contaminated LST values (I)

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## Screening off the cloud-contaminated LST values (II)

- The positive and negative components of the daytime δ(Τ5km – Τ1km) distribution as  RGB.  The points in brightest red and green will be screened off (left image)

- Similarly for the nighttime LST (image in right)

- ®these brightest points are close to the cloud edges!

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## Screening off the cloud-contaminated LST values (III)

- Color composite of the 5km daytime and nighttime LSTs and their difference as RGB in 8-day period of July 20-27, 2001 after the double-screen scheme is applied.

- Color composite of  the 5km emissivities in bands 29, 22, and 20 (image in right).

- Z. Wan - 9

## Examples of the Global MODIS LST Product

- (daytime 3 Aug 2001)

- (nighttime 3 Aug 2001)

- 240K

- 310K

- 250K

- 340K

- (courtesy of the MODLAND browse page)

- Z. Wan - 10

## Validation of the MODIS TIR data and LST products

- Four field campaigns in 2000:

- 1. Early April in Mono Lake and Bridgeport grassland, CA;

- Four field campaigns in 2001:

- 2. May/June in Lake Titicaca, Bolivia;

- 3. Late July in Railroad Valley NV, Mono Lake, the grassland and a rice field in CA;

- 4. Early October in Mono Lake and Bridgeport, CA.

- 1. March-April in Bridgeport CA and Walker Lake in NV;

- 2. mid-late July in Railroad, Mono Lake, and Bridgeport;

- 3. August in Bridgeport and Walker Lake;

- 4. October in Walker Lake and Bridgeport.

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## Validation of the MODIS TIR data and LST products

- Lake Titicaca

- Mono Lake, CA

- Walker Lake, NV

- Rice field in Chico, CA

- Bridgeport grassland, CA

- Snowcover, Bridgeport, CA

- (test sites)

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## Estimated Calibration Bias in MODIS L1B Data

| Band no. | 20 | 21 | 22 | 23 | 29 | 31 | 32 |
| --- | --- | --- | --- | --- | --- | --- | --- |
| A 
δΤ(K)  | +0.63 | +0.70 | +0.15 | -0.08 | -0.12 | +0.09 | +0.05 |
| B
  δΤ(K) | +0.61 | +0.46 | +0.55 | +0.40 | +0.02 | +0.12 | -0.19 |

- A, δΤ in new A-side MODIS L1B data based on Walker Lake, NV field campaign, 10/18/01.
- B, δΤ in old A-side MODIS L1B data based on Lake Titicaca, Bolivia campaign in June 2000.

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- Estimated Calibration Bias in MODIS TIR Bands

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- δΤ (K)

## Validation of the MODIS LST products

- (spatial variations in daytime LST shown in MAS data - 1)

- (variation of ± 5K in grassland -›)

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- (band 45 at 10.95μm)

- MAS data over Bridgeport, CA,10/06/00

- 19:00:40 UTC

## Validation of the MODIS LST products

- (spatial variations in daytime LST shown in MAS data - 2)

- (about a few K in the central part of playa)

- MAS data over Railroad Valley, NV, 23 June 1997

- Z. Wan - 16

- (band 45 at 10.95μm)

- 18:11:18 UTC

| case no. | site | Lat. 
Lon.
 | date
(m/d/y)
time | view zenith azimuth | atmos. 
cwv
(cm) | in situ 
Ts 
(K) (no.) | In situ
Ts
(K) | MODIS
Ts (Ts)
version | MODIS
in situ
Ts(K) |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | A
 | 37.9712oN
119.0014oW | 4/04/00
11:19 PST | 22.38o
-78.35o | 2.2
(0.36) | 283.81 (4) | 0.52 | 284.7 (0.2)
2.4.2 | +0.9 |
| 2 | A
 | 37.9930oN
118.9646oW | 7/25/00
11:18 PST | 22.09o
-79.37o | 2.1 | 296.01 (3) | 0.15 | 296.3 (0.2)
2.5.4 | +0.3 |
| 3 | A
 | 38.0105oN
118.9695oW | 10/06/00
11:11 PST | 11.35o
-78.19o | 1.4
(0.62) | 290.17 (4) | 0.23 | 290.4 (0.1)
2.4.3 | +0.2 |
| 4 | B | 16.2470oS
68.7230oW | 6/15/00
15:26 UTC | 34.3o
-82.7o | 1.1
(0.29) | 285.0 (5) | 0.3 | 285.5 (0.5)
2.5.4 | +0.5 |
| 5 | C | 38.6972oN
118.70802oW | 10/18/01
10:57 PST | 0.74o
-100.23o | 0.81
(0.95) | 290.56 (4) | 0.1 | 290.74 (0.2)
3.0.0 | +0.2 |

- A.	Mono Lake, California
- B.	Lake Titicaca, Bolivia
- C.	Walker Lake, Nevada

- Validation of the 1km MODIS LST Product (I)

- (in lake sites)

- Z. Wan - 17

| 
case no. | 
site | 
Lat. 
Lon. | 
date
(m/d/y)
time | view zenith azimuth | atmos. 
cwv
(cm) | in situ 
Ts 
(K) (no.) | In situ
Ts
(K) | MODIS
Ts (Ts)
version | MODIS
in situ
Ts(K) |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 6 | A | 38.2255oN
119.2680oW | 4/04/00
11:19 PST | 20.00o
-79.38o | 2.6 | 308.2 (4) | 0.9 | 307.3 (2.3)
2.4.2 | -0.9
 |
| 7 | B | 38.2202oN
119.2693oW | 7/27/00
22:09 PST | 11.81o
81.33o | 1.6 | 281.63 (4) | 0.6 | 282.4 (0.4)
2.5.4 | +0.8 |
| 8 | B | 38.2202N
119.2693oW | 7/29/00
21:57 PST | 32.36o
77.56o | 2.4 | 283.24 (4) | 0.6 | 283.0 (0.2)
2.5.4 | -0.2 |
| 9 | C | 39.5073oN
121.8107oW | 7/27/00
22:10 PST | 26.1o
77.3o | 1.4 | 291.20 (1) |  | 292.1 (0.5)
2.5.4 | +0.9 |
| 10 | C | 39.5073oN
121.8107oW | 7/29/00
21:57 PST | 42.67o
75.8o | 3.0 | 293.02 (1) |  | 292.9 (0.8)
2.5.4 | -0.1
 |
| 11 | D | 38.2199oN
119.2683oW | 3/11/01
22:36 PST | 40.48o
-97.32o | 0.4 | 263.50 (2) | 0.2 | 263.7 (0.2)
3.0.0 | +0.2 |

- Bridgeport, California
- Bridgeport, grassland
- Rice field, California
- Bridgeport, snowcover

- Validation of the 1km MODIS LST Product (II)

- (over grassland and rice field)

- Z. Wan - 18

| 
case no. | 
site | 
Lat. 
Lon. | 
date
(m/d/y)
time | view
zenith azimuth | atmos. 
cwv
(cm) | in situ 
Ts 
(K) (no.) | In situ
Ts
(K) | MODIS
Ts (Ts)
(K) | MODIS
Tsc
(K) | Tsc -
in situ
Ts(K) |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | A | 38.2199oN
119.2683oW | 3/11/01
22:36 PST | 40.48o
-97.32o | 0.4 | 263.5 (2) | (0.2) | 263.7
(0.2) | 264.0 | +0.5 |
| 2 | B | 38.4614oN
115.6914oW | 7/27/00
22:09 PST | 15.68o
-98.85o | 0.77
(1.04) | 289.9 (2) | (0.3) | 288.7
(0.1) | 289.3 | -0.6 |
| 3 | B | 38.4617oN
115.6927oW | 7/18/01
10:35 PST | 22.25o
99.48o | 1.25
(0.86) | 321.2 (3) | 0.8 | 318.5 (0.7) | 321.3 | +0.1 |
| 4 | B | 38.4617oN
115.6925oW | 7/19/01
11:17 PST | 47.36o
-75.12o | 1.12 | 321.3 (3)
 | 2.7 | 319.2 (0.5) | 322.0 | +0.7 |
| 5 | B | 38.4617oN
115.6926oW | 7/19/01
22:21 PST | 43.78o
-96.05o | 0.64
 | 287.4 (3) | 0.3 | 286.1 (0.4) | 287.4 | +0.0 |
| 6 | B | 38.4617oN
115.6926oW | 7/20/01
21:26 PST | 44.40o
75.49o | 0.69 | 289.7 (4) | 0.3 | 287.5 (0.2) | 289.6 | -0.1
 |
| 7 | B | 38.4630oN
115.6930oW | 7/21/01
11:05 PST | 32.54o
-77.26o | 0.68
(0.92) | 320.1 (7) | 0.4 | 317.7 (0.4) | 319.8 | -0.3
 |
| 8 | B | 38.4630oN
115.6930oW | 7/23/01
21:57 PST | 5.0o
-98.04o | 1.01 | 290.7 (4) | 0.5 | 288.8 (0.6) | 290.6 | -0.1 |

- Bridgeport  snowcover
- Silt playa in Railroad Valley, Nevada

- Validation of the 1km MODIS LST Product Corrected with 5km LST

- (for the errors due to uncertainties in emissivities, cwv, and Ta)

- Z. Wan - 19

## Validation results of the MODIS LST products

- Z. Wan - 20

## Applications of the MODIS LST product

- • to validate and improve the global meteorological model prediction

- • to estimate the diurnal cycle for global change studies

- • to estimate drought-ness and surface soil moisture

- • used in land cover classification and change studies

- • in estimate and parameterization of surface fluxes

- • to evaluate water requirements of crops

- Z. Wan - 21

## Plan for 2002

- 1. To validate the MODIS LST products with in situ data in the Australia topical site (Hook &Prata).

- 2. To conduct field campaigns in the CA central valley and a few site in the heart land of US in wet seasons.

- 3. To generate LST products from Aqua MODIS data.

- 4. To provide validated LST products.

- Z. Wan - 22

## Conclusion of the MOD11 Product Status

- 1. The LST products were validated within 1K with in situ LSTs in 19 cases (including 14 cases over land sites) in the LST range of 263-322K and the atmospheric cwv range of 0.4-3.0cm.

- 2. Validated MODIS LST products will be generated in the next reprocessing (July 2002?).

- 3. It is expected that the combined use of Terra and Aqua MODIS data will improve the LST quality significantly.

- Z. Wan - 23