Sentences with phrase «radionuclide records»

Figure 5 shows comparisons of the 1/1000 yr (a) and 1/3000 yr (b) low - pass filtered radionuclide records to the dipole moment reconstructions of CALS10k.1 b and the VADMs by Knudsen et al. (2008).

Therefore, cosmogenic radionuclide records can provide independent information about past dipole moment changes, but it is necessary to eliminate the influence of solar variations.

However, the fact that the correlation of the radionuclide records with CALS3k.4 is consistently higher for all filter frequencies than with CALS3k.3 could indicate that the more recent geomagnetic model version indeed provides an improved dipole moment variability estimate.

The cosmogenic radionuclide records have been low - pass filtered by a rectangular function in the frequency domain with different cut - off frequencies in order to minimise the solar influence and to investigate the time scales on which we see common changes in the radionuclide production rates and the geomagnetic field intensity reconstructions.

For the following calculations we use updated versions of the radionuclide records presented in more detail in Muscheler et al. (2004, 2005a).

http://www.realclimate.org/index.php/archives/2005/08/did-the-sun-hit-record-highs-over-the-last-few-decades/ «Regardless of any discussion about solar irradiance in past centuries, the sunspot record and neutron monitor data (which can be compared with radionuclide records) show that solar activity has not increased since the 1950s and is therefore unlikely to be able to explain the recent warming.»

The biggest uncertainties lies in the interpretation of the radionuclide records that can be measured in natural archives such as ice cores in the case of 10Be or tree rings in the case of 14C.

«Any potential [spike] would have both the radionuclide record as well as the SCP one — as well as a few invasive species, bits of microplastic and stable carbon isotopes,» explains geologist Jan Zalasiewicz of the University of Leicester in England and chairman of the working group that is evaluating whether or not to add the Anthropocene to the geologic timescale.

Not exact matches

The Comprehensive Nuclear - Test - Ban Treaty (CTBT) has spawned a globe - girdling network of 300 detector stations that sniff out radionuclides, listen for low - frequency sounds, and record tremors — all to discern whether countries are carrying out clandestine nuclear weapons tests.

The computations show similar long - term variations with the global radionuclides production records from terrestrial archives such as tree rings and ice cores which validate the approach.

Dipole intensity estimates from cosmogenic radionuclide production records, with suitable filtering to minimise the solar influence, have also been included in the comparison to provide independent information about variations in the strength of the geomagnetic field.

Note that like any filtering this can lead to edge effects, i.e. in this case particularly to unreliable trends in the radionuclide - based records towards the youngest several hundred years of the data.

We used the higher resolution CALS3k.3 and CALS3k.4 dipole estimates for comparisons using the same filters on the geomagnetic and the radionuclide dipole reconstructions for the past 3 kyrs (Fig. 6), and computed the correlation coefficients among all four records for the time series with low - pass filters between 1/200 and 1/1000 yrs.

Finally, we include a comparison to past geomagnetic field estimates obtained with multi-centennial to millennial - scale filtering from 14C and 10Be radionuclide production records.