Sentences with phrase «kyr variations»

Older ice is required to test hypotheses about any consistent long - term CO2 trend and a probable connection with the 500 - kyr variations of the Quaternary carbon cycle found in marine records15.

Not exact matches

Variations in CO2 over the last 420 kyr broadly followed antarctic temperature, typically by several centuries to a millennium (Mudelsee, 2001).

CO2 provides only a minor effect in the obliquity and precession timescale band, but over 30 % of the forcing in the 100 kyr band, so it is a key forcing agent that allows us to explain the magnitude of glacial - interglacial temperature variations.

Strong variations in the geochemical and paleo - ecological composition and genetic signature of the sediments in the Black Sea provide testimony that the conditions in the water column have been far from constant over the past ∼ 7.5 kyr.

Climate in the early Pleistocene1 varied with a period of 41 kyr and was related to variations in Earth's obliquity.

Over very long time periods such that the carbon cycle is in equilibrium with the climate, one gets a sensitivity to global temperature of about 20 ppm CO2 / deg C, or 75 ppb CH4 / deg C. On shorter timescales, the sensitivity for CO2 must be less (since there is no time for the deep ocean to come into balance), and variations over the last 1000 years or so (which are less than 10 ppm), indicate that even if Moberg is correct, the maximum sensitivity is around 15 ppm CO2 / deg C. CH4 reacts faster, but even for short term excursions (such as the 8.2 kyr event) has a similar sensitivity.

The oldest trace of millennial - scale variations in our record is detected between 778 and 752 kyr bp (Fig. 2).

High - frequency variations (black) are five - point running means of the original data [4], whereas the blue curve has a 500 kyr resolution.

These climate oscillations have dominant periodicities, ranging from about 20 to 400 kyr, that coincide with variations in the Earth's orbital elements [26], specifically the tilt of the Earth's spin axis, the eccentricity of the orbit and the time of year when the Earth is closest to the Sun.

Table 1 summarizes mean variation rates of temperature, sea level and GHG concentrations during (A) the last termination (19 — 10 kyr), (B) the Holocene (10 kyr to mid-19th century), (C) mid-19th century to mid-1970s, and (D) mid-1970s to 2005, based on ice core studies [2], IPCC - 2001 and IPCC - 2007 [3], NASA - GISS [4], CSIRO Marine and Atmospheric Research [5], UK Meteorological Office [6] datasets and science journals.

Records of NH temperature variation during the last 1.3 kyr.