Focus 2 - Rationale and Goals


Rationale

Information on past climate dynamics at the regional scale allows us to better assess the consequences of current and future changes in climate by providing a context for observed and measured climatic-environmental change, long-term records to analyze multi-decadal and slower processes, and benchmark scenarios for general circulation models. Consequently, Focus 2 places a strong emphasis on regional studies that consider past climate dynamics on seasonal to millennial timescales. Studies in this focus include multi-proxy reconstructions of the key climate parameters and transient paleo-runs with models of different complexity and resolution.

This procedure allows the investigation of how the specific patterns, modes and regimes of climate variability changed over time, and provides the opportunity to study how strongly regional patterns are dominated by internal variability of the climate system. In close coordination with Focus 1, Focus 2 addresses these questions by including regions that currently have low data density, such as the tropics and the southern hemisphere. In addition, Focus 2 provides regional-scale information that builds the basis for global-scale integrative studies within Focus 3, and for analysis of the climate-environment interaction with humans on historical timescales in Focus 4.


Goals

Focus 2 sets six main goals:

1. Develop datasets that describe the patterns of past climate change and climate variability at the regional scale, including the major climate state variables, such as air pressure, temperature, precipitation or precipitation minus evaporation (P-E) and atmospheric and oceanic circulation patterns, for the last 2 kyr and wherever possible during the last glacial cycle (last 130 kyr).

2. Examine the regional response of marine and terrestrial ecosystems to large-scale changes in the climate system. Activities towards this goal are coordinated with Focus 4 and offer links with the DIVERSITAS program.

3. Better understand the mechanisms (natural and anthropogenic forcing, internal variability, feedbacks, sensitivity) operating in the climate system that determined regional variations, including abrupt and extreme climate events, of climate and environment over the past 130 kyr (see figure).

4. Understand the modes of variability, such as ENSO/PDO, NAO/AMO, the teleconnections between them (see figure), and their influence on regional climate history.

5. Carry out ensemble simulations of past climate variability with suitable climate models of different complexity, in close coordination with the reconstruction activities and with Focus 1 and CCT 3.

6. Support improvements in model development and data-model comparison approaches to better constrain the drivers and mechanisms of regional climate change on different timescales.