Sentences with phrase «hemispheric mean»

There is little Arctic amplification (relative to the global or hemispheric mean) in the summer months because the extra energy goes into evaporation and melting, while at the same time the extra sensible heat content of the oceans will eventually work its way into the atmosphere and have implications for the timing of seasonal re-growth in ice.

The results were surprisingly robust, not only for the hemispheric mean O3 increase, but also for the increase in global mean OH reported as a decrease in the CH4 lifetime.

Correlation structures in surface temperature Another extension is to examine the lagged and cross-correlation structure of observed and simulated hemispheric mean temperature as in Wigley et al., (1998a).

Kaufmann and Stern (1997) examine the lagged - covariance structure of hemispheric mean temperature and find it consistent with unequal anthropogenic aerosol forcing in the two hemispheres.

Year - to - year variability is so large for an area the size of the United States that it is not essential to find an external mechanism for the deviation from the hemispheric mean.

Variations in the Atlantic Multi-decadal Oscillation (see Section 3.6.6 for a more detailed discussion) could account for some of the evolution of global and hemispheric mean temperatures during the instrumental period; Knight et al. (2005) estimate that variations in the Atlantic Multi-decadal Oscillation could account for up to 0.2 °C peak - to - trough variability in NH mean decadal temperatures.»

However, the evidence is not sufficient to support a conclusion that hemispheric mean temperatures were as warm, or the extent of warm regions as expansive, as those in the 20th century as a whole, during any period in medieval times (Jones et al., 2001; Bradley et al., 2003a, b; Osborn and Briffa, 2006).»

[Response: I'll assume you're simply unaware of the fact that extensive tests of precisely this issue were provided in the previous article by Mann et al (2008)(covered by RealClimate previously) which used both «RegEM with TTLS» and «CPS» to reconstruct hemispheric mean temperatures.

And much better than to infilling with hemispheric mean.

In practice, this method, though not recommended, does not appear to unduly influence reconstructions of hemispheric mean temperature; reconstructions performed without using principal component analysis are qualitatively similar to the original curves presented by Mann et al. (Crowley and Lowery 2000, Huybers 2005, D'Arrigo et al. 2006, Hegerl et al. 2006, Wahl and Ammann in press).»

1) «Phil and I have recently submitted a paper using about a dozen NH records that fit this category, and many of which are available nearly 2K back — I think that trying to adopt a timeframe of 2K, rather than the usual 1K, addresses a good earlier point that Peck made w / regard to the memo, that it would be nice to try to «contain» the putative «MWP», even if we don't yet have a hemispheric mean reconstruction available that far back» Michael Mann http://bit.ly/9d06xq

Variations in the Atlantic Multi-decadal Oscillation (see Section 3.6.6 for a more detailed discussion) could account for some of the evolution of global and hemispheric mean temperatures during the instrumental period (Schlesinger and Ramankutty, 1994; Andronova and Schlesinger, 2000; Delworth and Mann, 2000); Knight et al. (2005) estimate that variations in the Atlantic Multi-decadal Oscillation could account for up to 0.2 °C peak - to - trough variability in NH mean decadal temperatures.

«In practice, this method, though not recommended, does not appear to unduly influence reconstructions of hemispheric mean temperature; reconstructions performed without using principal component analysis are qualitatively similar to the original curves presented by Mann et al..»

this region in turn has provided a large part of the variance of the hemispheric mean temperature observed in the past century»

The uncertainties associated with reconstructing hemispheric mean or global mean temperatures from these data increase substantially backward in time through this period and are not yet fully quantified.

We found generally that proxy data for that region show little correlation with hemispheric mean temperature.

Method 1: «The composite - plus - scale (CPS) method, «a dozen proxy series, each of which is assumed to represent a linear combination of local temperature variations and an additive «noise» component, are composited (typically at decadal resolution;...) and scaled against an instrumental hemispheric mean temperature series during an overlapping «calibration» interval to form a hemispheric reconstruction.

â $ ¦ â $ ¦ Phil and I have recently submitted a paper using about a dozen NH records that fit this category, and many of which are available nearly 2K backâ $ «I think that trying to adopt a timeframe of 2K, rather than the usual 1K, addresses a good earlier point that Peck made w / regard to the memo, that it would be nice to try to â $ œcontainâ $ the putative â $ œMWPâ $, even if we donâ $ ™ t yet have a hemispheric mean reconstruction available that far backâ $ ¦.

Similarly, a Bayesian study of hemispheric mean temperatures from 1900 to 1996 finds decisive evidence for an aerosol cooling effect (Smith et al., 2003).

Under most scenarios of late 20th century and future anthropogenic radiative forcing, a steady, rather than accelerating, rise in global and hemispheric mean temperature is predicted over timescales of decades.

In fact, the available instrumental temperature records, when formed into a hemispheric mean, closely match the reconstructions.

Its only in the hemispheric mean because of the cancellation properties of proxy noise and regional climate noise, where the signal for individual volcanic cooling events becomes clear.

In the global or hemispheric mean, the differences were imperceptible (since the US is only a small fraction of the global area).

[Response: What is being reconstructed is the hemispheric mean temperature anomaly for any one year.

Modelers of course do not compare just hemispheric mean series, but the actual spatial patterns of estimated and observed climate changes in past centuries.

Modelers now are comparing not just hemispheric mean series, but the actual spatial patterns of estimated and observed climate changes in past centuries.

That notwithstanding, Huang et al, 2008 come to a similar conclusion as other recent studies (e.g. AR4 and Mann et al, 2008) regarding the «MWP» — that while it is indeed evident in hemispheric mean reconstructions, it does not reach the level of the warmth of recent decades.

The increase in the early 20th century is well known from the instrumental record of global and hemispheric mean temperatures (which extends back into the mid 19th century).

The uncertainties associated with reconstructing hemispheric mean or global mean temperatures from these data increase substantially backward in time through this period and are not yet fully quantified.

The increase in the early 20th century is well known from the instrumental record of global and hemispheric mean temperatures (which extends back into the mid 19th century).

However, this would increase the seasonal differences in the Southern Hemisphere and tend to make both hemispheric means less consistent with the land data.

It is not enough to look at global or hemispheric means of surface temperature and note that the models are not that far from producing internal variability of the right magnitude — perhaps most existing models only do this once in a blue moon, but I can imagine increasing the variance at low frequencies by a factor of two, say, so that the required magnitude is achieved more frequently.

But the choice of the two hemispheric means for this analysis is arbitrary.

In the GISTEMP index, the tables of zonal, global, hemispheric means are computed by combining the 100 subbox series for each box of the equal area grid, then combining those to get 8 zonal mean series, finally from those we get the Northern (23.6 - 90ºN), Southern and tropical means, always using the same method.

Comparison of empirical evidence with proxy - based reconstructions demonstrates that natural factors appear to explain relatively well the major surface temperature changes of the past millennium through the 19th century (including hemispheric means and some spatial patterns).

Since the Polish data is a such a small fraction of the globe (and there are a few Polish stations in any case via RBSC or GCOS), this doesn't make much difference to hemispheric means or regional climate.

Not exact matches

Aside from humans, no other animal that has been studied, not even monkeys or apes, has proved to use such hemispheric specialization for sound processing — meaning that the left brain is better at processing fast sounds, and the right processing slow ones.

As discussed elsewhere on this site, modeling studies indicate that the modest cooling of hemispheric or global mean temperatures during the 15th - 19th centuries (relative to the warmer temperatures of the 11th - 14th centuries) appears to have been associated with a combination of lowered solar irradiance and a particularly intense period of explosive volcanic activity.

As alluded to in our post, one important issue is the possibility that changes in El Nino may have significantly offset opposite temperature variations in the extratropics, moderating the influence of the extratropical «Little Ice Age» and «Medieval Warm Period» on hemispheric or global mean temperatures (e.g. Cobb et al (2003).

HARE: And this really challenges that because dogs also have a left hemispheric bias for processing words with meaning.

«This really challenges that, because dogs also have a left hemispheric bias for processing words with meaning,» Hare says.

As alluded to in our post, one important issue is the possibility that changes in El Nino may have significantly offset opposite temperature variations in the extratropics, moderating the influence of the extratropical «Little Ice Age» and «Medieval Warm Period» on hemispheric or global mean temperatures (e.g. Cobb et al (2003).

At the hemispheric - mean scale, the «Little Ice Age» is only a moderate cooling because larger offsetting regional patterns of temperature change (both warm and cold) tend to cancel in a hemispheric or global mean.

«Our estimate for the mean soot effect on spectrally integrated albedos in the Arctic (1.5 %) and Northern Hemisphere land areas (3 %) yields a Northern Hemisphere forcing of 0.3 W m2 or an effective hemispheric forcing of 0.6 W m2.»

That local changes are necessarily representative of the global (or hemispheric in this case) mean, is wrong.

Only by amalgamating all of the records we have (after correcting for known problems, such as discussed below) can we have an idea what the regional, hemispheric or global means are doing.

This is true both with respect to hemispheric - mean temperature changes and spatial patterns of climate change (see our previous discussions of this precise point here (see 4th paragraph and figure 2), here (see 8th paragraph), and here (see final paragraph).

Globally, the mean temperature of the Martian atmosphere is particularly sensitive to the strength and duration of hemispheric dust storms, (see for example here and here).

We further estimate that, in most northern hemispheric regions, these changes in the likelihood of extreme summer mean WBGT are roughly an order of magnitude larger than the corresponding changes in the likelihood of extreme hot summers as simply measured by surface air temperature.

Using WBGT as a measure of environmental conditions conducive to heat stress, we show that anthropogenic influence has very substantially increased the likelihood of extreme high summer mean WBGT in northern hemispheric land areas relative to the climate that would have prevailed in the absence of anthropogenic forcing.