Arctic2k scientific goals and key questions


Goals

The general goals of the Arctic2k working group were to generate and synthesize high-resolution paleoclimate data to assess and elucidate both the timing and variability of the Arctic climate change during the last 2000 years.

Expanding the arctic proxy data collection with published records was a key goal between 2014-2017. While the database was primarily populated with temperature records during Phase 1, a large effort was needed to collect, review, and format high-resolution precipitation and humidity records.

The second and ultimate goal of Phase 2 of the project was to produce multi-proxy based spatial reconstructions for temperature, precipitation and humidity. Such Arctic climate reconstructions were critical for the planned data-model experiments with PMIP3 simulations.

The goals and proposed timeline for Phase 2 were:

- Final version of database: 2016

- Regional temperature field reconstructions

- Correlation of sea ice and spatial reconstructions in the Arctic: 2015

- Moisture/circulation reconstructions: 2015-2016

- Prevailing atmospheric pressure field reconstructions: 2015-2016

- Forcing signal analysis: 2015-2016

 

Key questions

- Is the 20th century warming of the Arctic unprecedented in the last 2000 yr? Were temperatures in Medieval times warmer than those of the last several decades, and if so, what was the spatial pattern of temperature anomalies?

- What is the multi-decadal to century scale variability in Arctic temperature and hydroclimate?

- What are the spatial-temporal modes of climatic variability, including the Arctic Oscillation, on time scales ranging from inter-annual to centennial? How persistent are they beyond the instrumental record? What is the rate of change?

- How do the extreme mean climate states of the historical record (i.e. LIA & MWP) relate to these long-term modes of Arctic climate variability?

- What are the frequencies of extreme events in the Arctic?

- What are the critical thresholds in the arctic system?

- Was natural climate variability in the Arctic in the past also generally amplified in comparison with mid-latitudes?

- What portion of the Arctic-wide and regional temperature changes during the last 2 kyr can be explained by changes in solar irradiance and volcanic activity, and what portion is related to internal adjustments of the climate system?