Comparison with soil moisture measurements from Amazonia

So far, the analysis has shown that requiring concistency with observed vegetation cover has had an impact on the simulated soil water content in large parts of the tropics, with a tendency towards greater maximum soil water storage. In fact, it has been discovered that often trees in tropical rainforests can survive prolonged dry periods by developing very deep roots Nepstad et al., 1994 , with important consequences for the soil water balance. It has also been argued that, at least in water...

Effective Mass Extinction Efficiency b

The mass extinction efficiency b for each aerosol component represents the conversion factor, which multiplied with the aerosol component mass, determines the component aerosol optical depth. Inversely, data for aerosol mass and for the associated aerosol optical depth permit a derivation of the 'effective' mass extinction efficiency. These 'effective' b of models are compared in Table 12. Table 12. Comparison of mass extinctions efficiencies b (m g2) in models ( - indicate typical range)_...

Satellite Data Processing

The satellite data used are from the NOAA Global Vegetation Index (GVI) archive Gutman et al., 1995 for 1989 and 1990, and with a resolution of 1 7 latitude by longitude. Subsequent data processing by CESBIO Berthelot et al., 1994 includes conversion to reflectances, and atmospheric correction using the SMAC code Rahman and Dedieu, 1994 . Although most of the cloud contamination in the original daily AVHRR fields have already been removed in the GVI archive by selecting maximum contrast between...

Surface characteristics and meteorological variables

To calculate the resistances, several surface characteristics are needed. Local roughness length for momentum is determined by eddy correlation measurements at lower height in IMGRASS site. The reference height is taken as 2 meters. The regional effective values of z0m are estimated by fitting wind-speed measurements at different levels to the logarithmic velocity profiles using least-square method and taking for higher and denser canopy and d 0 for the lower and sparse covered canopy. Blending...

Conclusion And Recommendations

In this study, the surface energy partitioning has been modelled by a rather simple one-layer resistance approach for the region of Sicily and for the period 1989-1992. The aim was to characterise the moisture availability for the whole island with a spatial resolution of about one kilometre and a time-step of a few days. The results provide a general description of spatial and temporal behaviour of the energy balance components, that correspond to the pattern to be expected for a Mediterranean...

Advances In Global Change Research

Martin Beniston, Institute of Geography, University of Fribourg, Perolles, Switzerland B. Allen-Diaz, Department ESPM-Ecosystem Sciences, University of California, Berkeley, CA, U.S.A. R.S. Bradley, Department of Geosciences, University of Massachusetts, Amherst, MA, U.S.A. W. Cramer, Department of Global Change and Natural Systems, Potsdam Institute for Climate Impact Research, Potsdam, Germany. H.F. Diaz, NOAA ERL CDC, Boulder, CO, U.S.A. S. Erkman, Institute for Communication and Analysis of...

Watershed characteristics

2.1.1 Geographical and morphological characteristics The Valmasino watershed (Fig. 1) is located in the Central Alps at the border between Italy and Switzerland and it is situated between latitudes 46 09' N and 46 17' N and longitudes 9 34' E and 9 45' E. The upstream drainage area measures 188 km2 with important glaciers located in the upper part. Its physiographical characteristics are formed by four valleys with the main Masino river flowing from north to south and four lower order valley...

The HadAM3 models

The same procedure as above is in the following applied to the HadAM3 model, which is the latest model version of the Hadley Centre. This model is particularly interesting, as it has been running both without aerosols and with a (simple) aerosol climatology. This allows the specific assessment of the effects of a simple aerosol climatology on the shortwave radiation budgets, as discussed in details in Cusack et al. (1998). Figure 3. As Figure 2, but for HadAM3 with and without aerosol Figure 3....

The models ECHAM3 Arpege HadAM2

4.1.1 Assessment of surface radiation budgets To obtain a reference dataset for the assessment of the GCM absorbed shortwave radiation at the surface, the observed values of the incoming shortwave radiation from GEBA had first to be weighted with their associated surface albedos. They were taken from the albedo climatology provided by the Surface Radiation Budget Project SRB (Darnell et al. 1992) as described in Section 2. The differences between the absorbed surface solar radiation calculated...

List of contributors

BASIST, NOAA-NCDC, Asheville, North Carolina, USA. M. BENISTON, Department of Geography, University ofFribourg, Switzerland. P. A BRIVIO, Telerilevamento - IRRS, CNR, Milan, Italy. G. BUCINI, Space Applications Institute, Joint Research Center, Ispra (Varese), Italy. D. R. CAHOON, NASA Langley Research Center, Atmospheric Sciences Division, Hampton, Virginia, USA. M. CHIN, NASA-Goddard, GIT, Greenbelt, Maryland, USA. C. COLLET, Department of Geography, University ofFribourg, Switzerland. R....

Mass conversion theory

The conversion of a component aerosol mass m into a component aerosol optical depth rby a model is expressed by the mass extinction efficiency b, defined as where re is the effective radius, p is the aerosol density and Q is the extinction efficiency. Given a component (dry) mass m (no aerosol water), these three aerosol properties, and Q (in addition to ambient relative humidity and to permitted aerosol humidification) are critical for the derivation of component optical depths. Figure 8a-d....

Mapping Dry and Wet Snow

Although several snow extent products are currently available (Grody and Basist, 1996 Carrol et al., 1999 Ramsay, 1998 Robinson et al., 1999) there is only one product that maps both dry and wet snow extent at near real time on a global, daily basis. The Near real-time Ice and Snow Extent (NISE) product, produced by the University of Colorado's National Snow and Ice Data Center (NSIDC), is a daily, gridded map of sea ice concentrations and snow extent for both the Northern and Southern...

Michel M Verstraete

Space Applications Institute, Joint Research Centre, Ispra (VA), Italy NEW YORK, BOSTON, DORDRECHT, LONDON, MOSCOW eBook ISBN 0-306-48149-9 Print ISBN 0-7923-6801-0 New York, Boston, Dordrecht, London, Moscow Print 2001 Kluwer Academic Publishers Dordrecht No part of this eBook may be reproduced or transmitted in any form or by any means, electronic, mechanical, recording, or otherwise, without written consent from the Publisher Created in the United States of America Visit Kluwer Online at and...