Using high-resolution topography, we link the stratigraphy of layered ice deposits at the north pole of Mars to astronomically driven climate variability. Observations of trough exposures within these deposits are used to construct virtual ice cores at 16 sites, to which we apply wavelet analysis to identify periodicities in layer properties. To confidently relate these periodicities to climatic forcing, we identify overlapping dominant stratigraphic wavelengths and compare their ratios to that of the two dominant modes of insolation variability. The average ratio of stratigraphic wavelengths in the profiles is 1.90.1, lower than the ratio of 2.3 between dominant insolation periodicities. A similar analysis of synthetic stratigraphic profiles created with a climate-driven model of ice and dust accumulation shows that this lower stratigraphic ratio is a natural consequence of time-variable ice accumulation rates.

No / A proxy climate record from a raised bog in County Fermanagh, Northern Ireland, is presented. The record spans the interval between 2850 cal. yr BC and cal. yr AD 1000 and chronological control is achieved through the use of tephrochronology and 14C dating, including a wiggle-match on one section of the record. Palaeoclimatic inferences are based on a combination of a testate amoebae-derived water table reconstruction, peat humification and plant macrofossil analyses. This multiproxy approach enables proxy-specific effects to be identified. Major wet shifts are registered in the proxies at ca. 1510 cal. yr BC, 750 cal. yr BC and cal. yr AD 470. Smaller magnitude shifts to wetter conditions are also recorded at ca. 380 cal. yr BC, 150 cal. yr BC, cal. yr AD 180, and cal. yr AD 690. It is hypothesised that the wet shifts are not merely local events as they appear to be linked to wider climate deteriorations in northwest Europe. Harmonic analysis of the proxies illustrates statistically significant periodicities of 580, 423-373, 307 and 265 years that may be related to wider Holocene climate cycles. This paper illustrates how the timing of climate changes registered in peat profiles records can be precisely constrained using tephrochronology to examine possible climatic responses to solar forcing. Relying on interpolated chronologies with considerable dating uncertainty must be avoided if the climatic responses to forcing mechanisms are to be fully understood.

We present a continuous high-resolution precisely dated multiproxy record of hydroclimate variability at Anjohibe in northwestern Madagascar using speleothem AB13. The record spanned ~4,484 to ~2,863 years BP and showed general agreement with previously published speleothem records from the same approximate location. However, a speleothem record from Rodrigues Island, located ~1,600 km to the east of Madagascar, did not align, suggesting that paleoclimate records from Rodrigues Island may not serve as accurate proxies for northwestern Madagascar, as has been previously suggested. Stalagmite AB13 also provides a detailed record of rainfall variability during the 4.2 ka event, the abrupt climate disturbance associated with the collapse of several early human civilizations. Between ~3,900 – 4,300 years BP, Anjohibe experienced two periods of moderate drying. The most significant climate perturbation in the record was a drought that lasted ~300 years with peak dryness at ~3,000 years BP. This extended drought may have contributed to the reduction of the local perennial wetland environments and thus may have implications for the extirpation of Malagasy pygmy hippopotamuses in this part of the dry deciduous forest.