Linkages between Global Vegetation and Climate: An Analysis Based on NOAAAdvanced Very High Resolution Radiometer Data

摘要

Chapter 2 provides an overview of vegetation monitoring with data from the NOAAadvanced very high resolution radiometer (AVHRR). Chapter 3 discusses the limitations of vegetation monitoring with AVHRR data as reported in the literature. Chapter 4 discusses processing of NOAA-AVHRR data by the Global Inventory Monitoring and Modeling System (GIMMS) group into a global Normalized Difference Vegetation Index (NDVI) dataset. Chapter 5 consists of three sections: the correction of the GIMMS NDVI data for sensor degradation, volcanic aerosols, outliers in time-series, solar zenith angle effects, interpolation of missing data, and correction for severe cloud contamination in tropical forests; a landcover classification based on AVHRR NDVI time-series is discussed that is used to derive biome dependent corrections and to assign biome dependent biophysical properties; the estimation of global biophysical parameters--leaf area index and fraction of photosynthetically active radiation absorbed by vegetation--from the corrected NDVI data and the landcover classification. Chapter 6 deals with the unique problems of validating the global biophysical parameter fields. Chapter 7 discusses the sensitivity of the energy, water, and carbon balances to changes in observed vegetation greenness in a general circulation model of the atmosphere. Chapter 8 deals with the effect of doubling the concentration of carbon dixoide on the global climate. Chapter 9 discusses associations between observed vegetation, precipitation, air surface temperature and sea surface temperature and the implications of these associations for the global carbon balance. Chapter 10 highlights the most important findings of this study and evaluates their importance for climate research (with summary in Dutch).