Late Maunder Minimum

Using the water isotope-and vapor source distribution (VSD) tracer-enabled Goddard Institute for Space Studies ModelE-R, we examine changing El Niño-Southern Oscillation (ENSO)-like expressions in the hydrological cycle in a suite of model experiments. We apply strong surface temperature anomalies associated with composite observed El Niño and La Niña events as surface boundary conditions to preindustrial and mid-Holocene model experiments in order to investigate ENSO-like expressions in the hydrological cycle under varying boundary conditions. We find distinct simulated hydrological anomalies associated with El Niño-like ("ENSO WARM ") and La Niña-like ("ENSO COOL ") conditions, and the region-specific VSD tracers show hydrological differences across the Pacific basin between El Niño-like and La Niña-like events. The application of ENSO COOL forcings does not produce climatological anomalies that represent the equal but opposite impacts of the ENSO WARM experiment, as the isotopic anomalies associated with ENSO WARM conditions are generally stronger than with ENSO COOL and the spatial patterns of change distinct. Also, when the same ENSO-like surface temperature anomalies are imposed on the mid-Holocene, the hydrological response is muted, relative to the preindustrial. Mid-Holocene changes in moisture sources to the analyzed regions across the Pacific reveal potentially complex relationships between ENSO-like conditions and boundary conditions. Given the complex impacts of ENSO-like conditions on various aspects of the hydrological cycle, we suggest that proxy record insights into paleo-ENSO variability are most likely to be robust when synthesized from a network of many spatially diverse archives, which can account for the potential nonstationarity of ENSO teleconnections under different boundary conditions. 1.1. Proxy δ 18 O Reconstructions Paleoclimatic studies can provide a long-term context for understanding varying ENSO expressions [Jones and Mann, 2004; Gergis et al., 2006], although there remain obstacles to increasing our understanding of ENSO variability through both paleoarchives and model-based approaches. First, precisely dated, wellresolved, readily interpretable proxy records are limited. While oxygen isotope (δ 18 O, δ in permil units, ‰, of the subscripted value relative to a known standard) archives can provide high temporal resolution records from ENSO-impacted areas [Cobb et al., 2003, 2013], proxy δ 18 O is often dependent on multiple, complex climatic δ 18 O. Coral δ 18 O responds to water temperature changes together with rainfall variability, due to the influence of isotopically depleted rainfall on surface ocean composition [Tudhope et al., 2001]. Speleothem LEWIS ET AL.

The knowledge constructed within the project "Klima in Historischen Zeiten" (KIHZ) about the Late Maunder Minimum (LMM), based upon corals, lake and marine sediment records, ice cores and speleothems, is reviewed. The data are compared to a simulation with the climate model ECHO -G. It is found that the LMM was an event of global scale , with a cooling on the entire Northern hemisphere and in the tropics, while a weaker warming may have taken place on the Southern Hemisphere. The model results are mostly consistent with the empirical evidence. However, the empirical data is not very conc lusive so that any claims that the dynamics behind the simulated LMM would equal the dynamics of the real event should be considered with care.

With a state-of-the-art climate model, the effect of time varying solar and volcanic aerosol forcing has been simulated. During the winters 1675-1710, a marked global cooling was simulated. This event mimics, in terms of broad patterns and time mean intensity, the strong cooling “Late Maunder Minimum” (LMM, 1675-1710) in Europe documented in various historical sources and early instrumental timeseries. The modelled LMM is causally related to the solar and volcanic forcing anomalies in the decades preceding and during the LMM creating an almost global cooling and large-scale circulation and sea ice coverage anomalies consistent with the phenomenon known as “Great Salinity Anomaly”.

The knowledge constructed within the project „Klima in Historischen Zeiten“ (KIHZ) about the Late Maunder Minimum (LMM), based upon corals, lake and marine sediment records, ice cores and speleothems, is reviewed. The data are compared to a simulation with the climate model ECHO -G. It is found that the LMM was an event of global scale, with a cooling on the entire Northern hemisphere and in the tropics, while a weaker warming may have taken place on the Southern Hemisphere. The model results are mostly consistent with the empirical evidence. However, the empirical data is not very conclusive so that any claims that the dynamics behind the simulated LMM would equal the dynamics of the real event should be considered with care.

This paper discusses the research carried out to check the climatic characteristics of the late Maunder Minimum (LMM) (ad 1675-1715) in the southwestern part of the Iberian Peninsula and as an aid towards pressure patterns reconstruction in the NE Atlantic and Europe. Documentary evidence reveals that interannual precipitation variability was similar to the present one, although some very severe dry periods occurred (particularly one in 1694). On the other hand, during the LMM there was a higher percentage of cold winter months, some of them with snowfall. A brief comparison is made with other areas from the Mediterranean. The relationships between weather similarities and differences for particular months is analysed in the light of the reconstructed synoptical patterns, and further research into historical climatic change of southern Europe is suggested.