The early instrumental period, covering the late 18th century and the 19th century, was characterized by prominent external climate forcing perturbations, including but not limited to, the Dalton minimum of solar activity and strong volcanic eruptions (e.g., 1783/84 Laki, 1809 eruption at unknown location, 1815 Tambora, 1835 Cosigüina, 1883 Krakatoa). Climate conditions during this period are illustrated by many environmental archives of climate variability as well as by documentary sources and sparse instrumental observations available from various regions. The peculiar characteristics of this period also stimulated research based on numerical climate models. Beyond their direct impact, the external perturbations likely left longer term imprints on the climate system which might be unrepresented in the initial conditions of the historical simulations (1850 - today), thus affecting their reliability. 

The strong and rather well constrained external forcing together with the abundance of climatic data from three different sources - simulations, proxies and instrumental observations - make the early instrumental period an ideal target for constraining uncertainty in various estimates of regional and sub-regional climate variability and for understanding and bridging the differences between them. Furthermore, the diversity and quality of information available for this period provides a rare opportunity for a (sub-)regional characterization of climate change attribution. Comparative assessments between estimates for the early instrumental period and for other periods characterized by strong external perturbations provide constraints on the range of dynamical climate responses to comparable natural forcing events, and on our knowledge about the mechanisms behind individual episodes.  

We invite submissions addressing climate variability of the early instrumental period, especially on works combining or contrasting different sources of information to highlight or overcome differences in our estimates about the climate of this period. Contributions aiming at exploring the role of the external forcing in climate variations during the period of interest are specially acknowledged . This includes new estimates about climate variability and forcing in this period. Furthermore, we welcome more general submissions about the long term imprints of episodes with strong natural forcing comparable to that in the early instrumental period.