CLIVASH2k - Climate variability in Antarctica and Southern Hemisphere in the past 2000 years

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CLIVASH2k timeline

 Launch
       Synthesis
         
 May 2017  2018  2019  2020  2021

 

Overview

The CLIVASH2k project aims to improve our understanding of large scale modes of climate variability and the mechanisms and drivers of climate change in Antarctica, the sub-Antarctic and the wider Southern Hemisphere during the past 2000 years. We will build upon previous PAGES syntheses documenting changes in Antarctica over the past 1000-2000 years to focus on the mechanisms driving climate variability.

clivash drilling edit
Image: Bradley Markle drilling a shallow ice core in the sub-Antarctic islands. Credit: Joel Pedro.

We plan to address how large-scale modes of atmospheric circulation, such as the Southern Annular Mode (SAM) and the Interdecadal Pacific Oscillation (IPO), influence the climate in Antarctica and the Southern Hemisphere on a regional scale.

We aim to:

(i) enhance current understanding of the dominant modes of variability in each region and whether it is possible to tease out the influence of large-scale changes from local drivers

(ii) produce a multi-proxy reconstruction of climate modes and assess how they have influenced regional climate variability over the past 2000 years.

Community data call - October 2020

As a community, CLIVASH2k feels it is important to expand the current PAGES 2k database. The project's previous data collection efforts – compilations of stable water isotopes (Stenni et al. 2017) and snow accumulation (Thomas et al. 2017) – have been widely used and demonstrate their value to the scientific community. However, studies have demonstrated the benefits of multi-proxy reconstructions. For example, Dalaiden et al. (2020) showed that if we combine δ18Oice and snow accumulation rate we find a better paleoclimate reconstruction than if we use accumulation and δ18Oice records separately. Thus, the addition of chemical data is expected to further enhance our understanding of winds, atmospheric variability, and sea-ice extent in the past.

We invite you to participate in the next step – compiling a database of chemistry from Antarctic ice cores and possibly other archives spanning the past 2k. To initiate the data collection process we held an open CLIVASH2k meeting in August (see first item in "Meeting notes" below for minutes and summary). The consensus was to compile all available records of Na+ and SO42-, ideally as both flux and concentration, at the best available resolution (seasonal to decadal).

img fig clivash2k oct 20
Figure 1: Published (purple) and unpublished (orange) data series. Click to enlarge.

The call is open for both published and unpublished data and we encourage members of the CLIVASH2k community, and beyond, to participate in the data synthesis and interpretation. So far, we managed to collect the following published (purple) and unpublished (orange) data series (see Fig. 1).

However, many more chemical records exist, and we encourage the community to collaborate with us in publishing these valuable archives.

Increasing the spatial of coverage will allow us to investigate the main drivers of chemical deposition in Antarctica, including the role of sea ice, atmospheric circulation and large-scale modes of variability (e.g. SAM, ENSO, IPO). The data compilation will support a range of data-model intercomparisons, model evaluations, and analytical method evaluations (e.g. IC vs ICPMS).

To submit data, please fill in this excel template by 1 December and send it to Elizabeth Thomas: This email address is being protected from spambots. You need JavaScript enabled to view it. and Diana Vladimirova: This email address is being protected from spambots. You need JavaScript enabled to view it. or contact them if you wish to be involved in the data interpretation or analysis.

Meeting notes

> Access the August 2020 meeting notes here

> Read the 1st meeting notes (from POLAR 2018 Conference, published July 2018) here

> Access a pdf presentation about CLIVASH2k, from the January 2018 2k Teleconference here

Learn more and participate

This group is open to anyone who is interested. To participate subscribe to the mailing list or contact the project coordinators.

Subscribe to the CLIVASH2k mailing list here.

Subscribe to the 2k Network mailing list here.


> CLIVASH2k scientific goals

> CLIVASH2k people