Terrestrial Carbon Sinks for the United States Predicted from MODIS Satellite Data and Ecosystem Modeling

Abstract

A simulation model based on satellite observations of monthly vegetation cover from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to estimate monthly carbon fluxes in terrestrial ecosystems of the conterminous United States over the period 2001-04. United States was estimated as annual net sink of about +0.2 Pg C in 2004. Regional climate patterns were reflected in the predicted annual NEP flux from the model, which showed extensive carbon sinks in ecosystems of the southern and eastern regions in 2003-04, and major carbon source fluxes from ecosystems in the Rocky Mountain and Pacific Northwest regions in 2003-04. As demonstrated through tower site comparisons, net primary production (NPP) modeled with monthly MODIS enhanced vegetation index (EVI) inputs closely resembles both the measured high-and low-season carbon fluxes. Modeling results suggest that the capacity of the NASA Carnegie Ames Stanford Approach (CASA) model to use 8-km resolution MODIS EVI data to predict peak growing season uptake rates of CO 2 in irrigated croplands and moist temperate forests is strong.

Recent global CO<sub>2</sub> flux inferred from atmospheric CO<sub>2</sub> observations and its regional analyses

“…An independent bottom-up estimate by Xiao et al (2008) based on eddy-covariance measurements and supplementary information from MODIS data for most of the North America regions derived a spatial distribution pattern in close agreement with our inversion results. Potter et al (2007) also pinpointed the extensive carbon sink in ecosystems of the southern and eastern regions by using the Carnegie Ames Stanford Approach (CASA) model to simulate the monthly carbon fluxes in terrestrial ecosystems of the United States over the period of [2001][2002][2003][2004]. The low carbon stocks in the forests of the southern and southeastern regions seem hardly to support our findings, but Woodbury et al (2007) elucidated that the spatial patterns of carbon stocks are dissimilar to those of carbon flux in the US from forest inventory data.…”

“…Four background fluxes were considered through another set of forward transport model simulations to calculate the pre-subtracted portions of the CO 2 concentration in order to minimize of the nonlinear effects of the large basis regions (Pickett-Heaps, 2007). These fluxes include (i) the fossil fuel emission field (http://carbontracker.noaa.gov), which was constructed based on (a) the global, regional and national fossil-fuel CO 2 emission inventory from 1871 to 2006 (CDIAC) ) and (b) the EDGAR 4 database for the global annual CO 2 emission on a 1 × 1 • grid (Olivier and Berdowski, 2001); (ii) the hourly terrestrial ecosystem exchange produced by BEPS (Chen et al, 1999), which was driven by NCEP reanalyzed data (Kalnay et al, 1996) and remotely sensed LAI (Deng et al, 2006), and a special treatment was taken to neutralize the annual flux at each grid; (iii) the flux of CO 2 across the air-water interface constructed based on the results of daily CO 2 fluxes using the OPA-PISCES-T model forced by daily wind stress and heat and water fluxes from the NCEP reanalyzed data for 2000 to 2007 (Buitenhuis et al, 2006); and (iv) the monthly mean fire emission available from the Global Emissions Fire Database version 2 (GFEDv2) van der Werf et al, 2006).…”

Net primary production of Chinese fir plantation ecosystems and its relationship to climate

“…On the other hand, satellite remote sensing data can provide nearreal time information regarding vegetation cover, biome type and disturbances . As a result, models using satellite data make NPP estimation simpler and possibly more accurate (Potter et al, 2004;Ruimy et al, 1994;Field et al, 1995;Zhao et al, 2006).…”

Time Series Analysis of Satellie-Measured Vegetation Phenology and Aerosol Optical Thickness over the Korean Peninsula

“…Surface greenness dynamics are associated with the patterns of primary productivity and atmospheric carbon exchange rates on a broad scale (Field et al 1995;Running et al 2004;Potter et al 2007). Vegetation responses to climate change appear strong in Northeast Asia, where diverse forest types and tree species in the region are considered as important carbon sinks.…”