E.) to the recent decades, Greenland Summit temperature increased by 2.9 ± 0.9 °C.
Greenland experienced a temperature minimum around 5,500 years B. Afterwards, the temperature shows a slight increase for 1,500 years (Mid-Holocene Optimum), followed by a cooling into the Little Ice Age with occasional bumps (Fig. From the coldest decades in the Little Ice Age (1740–1780 C.
Blue shades are the Greenland cold episodes as in Fig. After the 8.2 ka event, Greenland temperature reached the Holocene thermal maximum with the warmest decades occurring during the Holocene (2.9 ± 1.4 °C warmer than the recent decades) at 7960 ± 30 years B. Since then, the Summit temperature record exhibits a long-term cooling at a rate of 0.19 ± 0.01 °C per 1000 years towards the present (1.5 ± 0.1 °C cooling in total), agreeing with other estimates from melt layer frequency (1.3 °C) in GISP2 ice core.
(a) Reconstructed temperature from argon and nitrogen isotopes with 2σ error bands. Z-score is a measure of a time series having mean zero and standard deviation of one. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material.
(b) Melt-layer frequency (times per years) in 100 and 500-year RMs with light blue and blue lines, respectively. For filtering of the time series, we used a MATLAB function, “butter”. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.
Here, we reconstruct seasonally unbiased and physically constrained Greenland Summit temperatures over the Holocene using argon and nitrogen isotopes within trapped air in a Greenland ice core (GISP2). Volcanic activity intensifies again towards the Little Ice Age.
We show that a series of volcanic eruptions through the Holocene played an important role in driving centennial to millennial-scale temperature changes in Greenland. Only during the mid-Holocene Optimum were the ocean temperatures in the volcanically unperturbed state (Fig.
Therefore, we conclude that volcanic activity played a critical role in driving centennial to millennial-scale Holocene temperature variability in Greenland and likely beyond.. S9), indicating that abrupt climate change events during the Holocene may result from changes in several forcings (volcanic, solar, and meltwater inputs), with possible synergetic effects.
However, precise understanding of Holocene climate variability on multidecadal to millennial scales has been elusive owing to the lack of adequate archives recording small temperature signals and poorer chronologies further back in time (1988 to 2015; Fig. Green line with 2σ error bands is the reconstructed temperature anomaly. We reconstructed the seasonally unbiased and physically constrained Greenland temperature over the Holocene. 4a–d), which coincide with the reconstructed Greenland temperature decreases, stronger polar atmospheric circulation ([K] in GISP2), and weaker Asian monsoon activity (Fig. P.) is characterized by a lack of large volcanic eruptions (Figs 3 and 4). However, slightly lower temperatures persist at high northern latitudes for a century or longer owing to decreased ocean temperatures, which affect ocean surface and sea-ice formation (Fig. Furthermore, a series of large volcanic eruptions (e.g., 9000–8000 years B. and the Little Ice Age) produces cold periods of centennial to millennial duration (Fig. We also note that the mid-Holocene Optimum (5,500–4,000 years B. Values are relative to averages of the past 1,000 years. Note that the raw volcanic forcing has a different scale. After an abrupt warming at the end of the Younger Dryas period, Greenland temperature gradually decreased toward the Holocene temperature minimum at 11,271 ± 30 years B. (9.2 ± 1.5 °C colder than the recent decades; Preboreal Oscillation), which was followed by another abrupt warming (Figs 2 and 3). Then, Greenland experienced the largest hemispheric-wide negative temperature excursion during the Holocene around 8,200 years B. (c) Modeled NH average temperatures with full forcing (blue) and without volcanic forcing (green) both relative to the average of the past 1000 years from the full forcing run.