QUIGS scientific goals

Key aims

QUIGS aims to:

1. Document and synthesize data on the temporal and spatial patterns of climate responses during Quaternary interglacials and assess the governing processes using numerical models;

2. Assess the relevance of interglacials to understanding future climate change.

Within this framework we will examine (i) warm extremes, (ii) 'cooler' interglacials, and (iii) interglacials of the Early Pleistocene '41kyr-world'.

The drive towards a systematic understanding of interglacials requires targeted model exercises as well specific data sets with improved chronologies (some of which are not available yet). It is therefore, envisaged that the group will run over two 3-year phases: QUIGS1 will formulate reseach questions, identify knowledge gaps that hinder our understanding and steps how to fill these gaps. In close collaboration with PMIP, QUIGS1 will define model protocols and initiate the model runs and data collection needed. Having achieved these objectives in phase 1, QUIGS2, if approved, will attempt to systematically answer the research questions.

In this respect QUIGS will promote closer collaboration between the modeling and data communities, who together will provide expertise on experimental design, data compilations and syntheses, model-data comparisons, and interpretation of results.


Scientific questions and workplan for Phase 1: QUIGS1 (2015-2018)

(1) Warm extremes (Workshop, 2015)

In its final synthesis paper the PIGS Working Group identified the LIG and MIS 11 as the warmest interglacials of the last 800 kyr. Though not exact analogues for future anthropogenic changes, these periods can provide insights into climate processes and feedbacks during periods of ‘excess warmth’. While both interglacials have been considered by previous projects, our aim is to stimulate the work needed for PMIP, and this dictates an early consideration of these periods. Thus, during this first workshop, we will assess emerging data syntheses and recent model experiments (e.g. Capron et al., 2014; Milker et al. 2013; Otto-Bliesner et al., 2013; Loutre et al., 2014). This will allow us to highlight data gaps and promote efforts to fill these gaps. In particular, we will identify critical datasets needed and define the much needed model protocols (including transient simulations).

Although the LIG has received the most emphasis in terms of data and modelling studies, prominent questions remain. In addition, despite much interest on MIS 11, the causes of its interglacial intensity remain poorly understood. There is, therefore, a critical need to synthesize data, to better constrain the timing of changes and to model the carbon cycle in order to address the following questions:

What was the character of the responses of temperature, the hydrologic cycle and monsoons, and sea ice to the orbital forcing during the LIG and MIS 11. How linear are the responses?

What was the character of millennial variability during the LIG and MIS 11? What portion of the response can be attributed to millennial forcings?

(2) Timing and shape of glacial Terminations and the onset of interglacials (Workshop 2016). 

The motivation for this workshop stems from (i) an increased understanding of the temporal shape and spatial pattern of TII and the role of the bipolar seesaw, and (ii) improvements in constraining the timing of earlier Terminations by the speleothem community. The aim would be to put together the best reliable data about the timing of Terminations over the last 800 kyr and to combine them with conceptual models, EMICs and ESMs in order to address the following questions:

What determines the timing of Terminations?

What controls the spatial pattern of changes?

What is the role of millennial-scale variability?

Are Terminations predictable?

(3) Interglacials of the 41kyr-world versus those in the 100kyr-world (Workshop 2017):

Our understanding of glacial-interglacial cycles has been built on a large body of evidence on Middle and Late Pleistocene environments, dominated by 100kyr ice-volume variations. However, any theory of ice ages remains incomplete if it does not include an adequate description and understanding of the mode and tempo of climate variability during the 41kyr-world. Our aim will be to examine whether there are any fundamental differences between interglacials of the 41kyr- and 100kyr-worlds:

Does the distinction between 'saw-toothed'-shaped glacial cycles of the 100kyr-world and more 'symmetric' cycles of the 41kyr-world reflect the influence of ice-sheet size?

What was the duration of interglacials of the 41kyr-world?

Does the association of bipolar seesaw variability with glacial Terminations extend into the 41kyr-world?

Some of these questions could begin to be addressed by existing or currently generated datasets.  Providing a detailed reconstruction of the structure of 41-kyr cycles, the sequence of events at glacial Terminations and an assessment of the role of the bipolar seesaw in promoting deglaciation would represent significant contributions to initiate model runs of Early Pleistocene glacial cycles.