MERIS Terrestrial Chlorophyll Index

Period: 2002 – 2012

Sensor: MERIS

Frequency: 8 days (2002-2007) & 10 days (2008-2012)

Resolutions: 300m & 1.2 km

Extent: Global

Data can be accessed here.

Algorithm description: MTCI is an index calculated from the reflectance in bands 8,9 and 10 of MERIS sensor as follows:

$MTCI\quad =\quad \frac { { R }_{ Band10 }\quad -\quad { R }_{ Band9 } }{ { R }_{ Band9 }\quad -\quad { R }_{ Band8 } }$

Accuracy: Indirect product evaluation was conducted by Dash et al (2004) using LIBSAIL model and (2) canopy reflectance and chlorophyll content data collection from NASA 1992-1993 field measurements. Direct evaluation was also conducted by Dash (2007, 2010) and Almond (2009) over two areas: (1) Southern Vietnam (forest) and (2) Southern England (cropland/grassland).

Indirect evaluation from NASA data collection showed that MTCI correlates with chlorophyll content with R² of 0.64 and 0.72, respectively for Douglas-fir and Maple tree species. Over Vietnam forest areas strong correlation was found (R²>0.73).

Over spinach plots (greenhouse), MTCI showed correlation (R²) with chlorophyll content of 0.6 on average, 0.66 when plots with white soil background were ignored.

The MTCI is strongly correlated with the red-edge position index (REP) (R² of 0.98 and 0.99). However, contrary to REP (and NDVI) that have an asymptotic relationship with chlorophyll content, MTCI has a near-linear relationship showing better sensitivity to high chlorophyll content.

Limitations:

For low values of LAI (LAI<1-2), the MTCI is less sensitive to chlorophyll content.
Effect of soil background on MTCI is limited, except over white soils. Over white soils the sensitivity of MTCI to chlorophyll content is weak.

Reference:

Dash, J. & Curran, P. J. The MERIS terrestrial chlorophyll index. Int. J. Remote Sens. 25, 5403–5413 (2004).

Dash, J. & Curran, P. J. Evaluation of the MERIS terrestrial chlorophyll index (MTCI). Adv. Space Res. 39, 100–104 (2007).

Dash, J. et al. Validating the MERIS Terrestrial Chlorophyll Index (MTCI) with ground chlorophyll content data at MERIS spatial resolution. Int. J. Remote Sens. 31, 5513–5532 (2010).

Almond, S. F. Validation and application of the MERIS Terrestrial Chlorophyll Index. (Bournemouth University, Fern Barrow, Poole, Dorset, BH12 5BB, UK, 2009).

Curran, P. J. & Dash, J. Algorithm Theoretical Basis Document: Chlorophyll Index Version-2.2. (University of Southampton, 2005).