Sentences with phrase «on tree ring densities»

Huybers comments on tree ring densities, which have much lower variances than widths, even after conversion to dimensionless «standardized» form.

Of the other two reconstructions, one (Jones et al., 1998) was based on a much smaller number of proxies, whereas the other (Briffa et al., 2001) was based solely on tree ring density series from an expansive area of the extratropics, but reached back only to AD 1400.

Not exact matches

This changing climate sensitivity may be the result of other environmental factors that have, since the 1950s, increasingly acted to reduce tree - ring density below the level expected on the basis of summer temperature changes.

As Bradley points out, tree growth, and hence the width and density of tree rings, depends on many factors, including the tree species and age, the availability of stored food in the tree and nutrients in the soil, the full range of climatic variables (sunshine, precipitation, temperature, wind speed, humidity); and their distribution throughout the year.

tree growth, and hence the width and density of tree rings, depends on many factors, including the tree species and age, the availability of stored food in the tree and nutrients in the soil, the full range of climatic variables (sunshine, precipitation, temperature, wind speed, humidity); and their distribution throughout the year.»

There is a well known problem with a certain class of tree ring density records that briffa et al have worked on.

You are incorrect on any number of issues — tree ring width and density proxies are not in the same units and there is a lot of variation in the amount of variance in the N. American network.

Networks of tree ring width and tree ring density chronologies are used to infer past temperature changes based on calibration with temporally overlapping instrumental data.

Furthermore, we note that Jones et al. (1998), get similar results for the recent changes using an almost completely different tree - ring network based on wood density from high latitude trees.

Two sets of correlations are shown: one based only on the subfossil series and the other including the living tree material whose precise elevations are not known and have been set here to a constant elevation of 250 m. None of the correlations is significant indicating that there is little evidence for an elevation influence on ring density and hence little age - dependent bias in the temperature reconstruction arising out of the differences in sample heights shown in Figure 4.»

The variation of summer temperatures was similarly reconstructed on the basis of the density of the trees» annual growth rings.

For the reconstruction discussed in the emails (based on tree ring width in Briffa et al 1999) was superceded by a subsequent study (Briffa 2000, based on tree - ring density) as seen in the final figure above.

Does anyone know enough about tree - ring density measurement methodology to comment on this?

tree growth, and hence the width and density of tree rings, depends on many factors, including the tree species and age, the availability of stored food in the tree and nutrients in the soil, the full range of climatic variables (sunshine, precipitation, temperature, wind speed, humidity); and their distribution throughout the year.»

As Bradley points out, tree growth, and hence the width and density of tree rings, depends on many factors, including the tree species and age, the availability of stored food in the tree and nutrients in the soil, the full range of climatic variables (sunshine, precipitation, temperature, wind speed, humidity); and their distribution throughout the year.