Sentences with phrase «occur at time scales»

The smallness of that variation from peak to trough of a single cycle has caused considerable doubt as to how significant changes in the air temperatures could occur at time scales of up to a century but the net energy delivery effect of a change of length does not appear to have been properly investigated.

Not exact matches

Similarly, the death of God that occurred at the Crucifixion is but a particularized form of what is happening on a universal scale in our time.

«We now have a way to study this process in real time at the scale it's occurring, which will help scientists better understand the process and possibly optimize it,» says David Shapiro, a physicist with the Advanced Light Source who helped Chueh develop the technique at the facility.

Using the naturally occurring uranium - lead isotope decay system, which is used for age determinations on geological time - scales, the authors deduced that these events took place at least 3.02 billion years ago.

It is one of the heaviest - known elements, yet it does not occur naturally because all of its isotopes are radioactive and decay rapidly on a geological time scale,» said the study's lead author, François Tissot, UChicago PhD» 15, now a W.O. Crosby Postdoctoral Fellow at the Massachusetts Institute of Technology.

He believes that no one has thought of combining the two theories before because it's not an intuitive idea to look at how the effects of changing patterns of ocean circulation, which occur on time scales of thousands of years, would effect global silicate weathering, which in turn controls global climate on time scales of 100s of thousands of years.

«As Earth continues to warm, it may be approaching a critical climate threshold beyond which rapid and potentially permanent — at least on a human time - scale — changes not anticipated by climate models tuned to modern conditions may occur,» the report says.

How Hektor became a Trojan asteroid, located at only 5 times the Earth — Sun distance, is probably related to the large scale reshuffling that occurred when the giant planets were still migrating,» said Julie Castillo - Rogez, researcher at the Jet Propulsion Laboratory, California Institute of Technology.

These separate proteins should be useful for monitoring cellular events occurring at varied time scales.

... Polar amplification explains in part why Greenland Ice Sheet and the West Antarctic Ice Sheet appear to be highly sensitive to relatively small increases in CO2 concentration and global mean temperature... Polar amplification occurs if the magnitude of zonally averaged surface temperature change at high latitudes exceeds the globally averaged temperature change, in response to climate forcings and on time scales greater than the annual cycle.

Well, it is unfortunate, though probably not coincidental, that the modern record starts at the same time that significant modifications of atmopsheric composition (greenhouse gases, aerosols etc.) were occuring on a global scale.

C is not constant for the dT» / dt equation to apply because heat penetrates through different parts of the climate system (different depths of the ocean in particular) over different time scales (also, if T» is supposed to be at some reference location or the global average at some vertical level, T» at other locations will vary; C will have to be an effective C value, the heat per unit change in the T» at the location (s) where T» occurs)

This is fine for estimates at annual and decadal time scales, but as you approach the timespan covered by each core, you run a serious risk of starting to remove part of the climatic variation, thereby under - estimating the total amount that occurred, with the loss being greatest at the longest time scales (i.e. lowest frequency variation).

Science - based study of fire impacts often occurs at scales of time and space that differ from those that are relevant to wildfire management decisions.

Abstract — 2008 Climate and wildfires in the North American boreal forest... Climate controls the area burned through changing the dynamics of large - scale teleconnection patterns (Pacific Decadal Oscillation / El Niño Southern Oscillation and Arctic Oscillation, PDO / ENSO and AO) that control the frequency of blocking highs over the continent at different time scales......... Since the end of the Little Ice Age, the climate has been unusually moist and variable: large fire years have occurred in unusual years, fire frequency has decreased and fire — climate relationships have occurred at interannual to decadal time scales...... http://rstb.royalsocietypublishing.org/content/363/1501/2315.short ----------------------

Smaller - scale deployments have occurred at a variety of locations, particularly such well - studied sites as the University of Hawai`i at Mānoa's Hawaii Ocean Time - series (HOT) station, where long biogeochemical records from floats (Figure 1) can be calibrated against shipboard measurements.

Large - scale climate variations, such as the Pacific Decadal Oscillation (PDO), El Niño - Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO), are occurring at the same time as the global climate is changing.

''... worked with two sediment cores they extracted from the seabed of the eastern Norwegian Sea, developing a 1000 - year proxy temperature record «based on measurements of δ18O in Neogloboquadrina pachyderma, a planktonic foraminifer that calcifies at relatively shallow depths within the Atlantic waters of the eastern Norwegian Sea during late summer,» which they compared with the temporal histories of various proxies of concomitant solar activity... This work revealed, as the seven scientists describe it, that «the lowest isotope values (highest temperatures) of the last millennium are seen ~ 1100 - 1300 A.D., during the Medieval Climate Anomaly, and again after ~ 1950 A.D.» In between these two warm intervals, of course, were the colder temperatures of the Little Ice Age, when oscillatory thermal minima occurred at the times of the Dalton, Maunder, Sporer and Wolf solar minima, such that the δ18O proxy record of near - surface water temperature was found to be «robustly and near - synchronously correlated with various proxies of solar variability spanning the last millennium,» with decade - to century - scale temperature variability of 1 to 2 °C magnitude.»

Led by Dr. James E. Hansen from 1981 to 2013, research at GISS emphasized a broad study of global change, which is an interdisciplinary initiative addressing natural and man - made changes in our environment that occur on various time scales — from one - time forcings such as volcanic explosions, to seasonal / annual effects such as El Niño, and on up to the millennia of ice ages — and that affect the habitability of our planet.

Several analyses of ring width and ring density chronologies, with otherwise well - established sensitivity to temperature, have shown that they do not emulate the general warming trend evident in instrumental temperature records over recent decades, although they do track the warming that occurred during the early part of the 20th century and they continue to maintain a good correlation with observed temperatures over the full instrumental period at the interannual time scale (Briffa et al., 2004; D'Arrigo, 2006).

When assessing changes in ENSO, it must be recognised that an El Niño - like pattern can apparently occur at a variety of time - scales ranging from interannual to inter-decadal (Zhang et al., 1997), either without any change in forcing or as a response to external forcings such as increased CO2 (Meehl and Washington, 1996; Knutson and Manabe, 1998; Noda et al., 1999a, b; Boer et al., 2000b; Meehl et al., 2000b).