Modes of variability in the arctic system
The focus of this online discussion is climate
variability and its effects on the arctic
environment and people.
A major goal of ARCSS research over the past decade has been the development of a predictive understanding of the arctic climate system, including its multiple modes of variability across timescales, its interactions with human systems, and its relationship with the global climate system. This requires elucidating fundamental mechanisms governing climate behavior, monitoring variability, and improving knowledge of the sensitivities of climate patterns to changes in forcing, including their interactions with and responses to anthropogenic forcing. An example of a major research initiative developing in this area is the interagency Study of Environmental Arctic Change (SEARCH)
ARCSS, SEARCH and Modes of Variability
Historically the ARCSS Program has focused on the response of the Arctic system to climate change. SEARCH seeks to understand environmental change in the Arctic, particularly with respect to a complex of seemingly related, decadal-scale, large spatial scale changes in the Arctic system that has been occurring recently. SEARCH has avoided setting hard boundaries on what may be considered part of this complex and will have to examine unrelated changes in the system to understand the complex. Thus boundaries between ARCSS and SEARCH are difficult to define. Briefly stated, though, ARCSS studies the system, and SEARCH is aimed at understanding a particular response of the system. Jamie Morison, chair of the SEARCH science steering committee, has characterized this as SEARCH being similar to a class project for ARCSS. Because of the long-term observations, application aspects, and other anticipated requirements, SEARCH will require interagency support beyond ARCSS.
In general, SEARCH will be looking at larger-scale and longer-term modes of variability. A major issue for both programs is how variability at various scales interact to produce change at a given place and time. For example, the weather on a particular day at Barrow will be affected somewhat by the large-scale, longer-term modes of variability, but substantially by other smaller scale, higher frequency events. Ecosystem responses are likely to be even more complicated, due to coupling among modes of variability of different time and spatial scales. For example, a small magnitude but large-scale change in ocean circulation may change water conditions beyond a certain (as yet undefined) threshold, resulting in a major ecosystem change. If the air temperature changes, the treeline may advance, but probably at a slower rate than the isotherms move.
Other research efforts within the ARCSS Program also are focused on understanding the impacts of variability in the Arctic system. One of the primary goals of the emerging pan-Arctic Community-wide Hydrological Analysis and Monitoring Program (Arctic-CHAMP) is to document changes to the arctic water cycle, thereby contributing a hydrological component to the study of variability in the Arctic system. The nascent Nearshore and Coastal Processes Initiative is focusing on the impacts of variability in the nearshore and coastal zones of the Arctic. Still in the early stages of planning, the research program described in Biophysical Feedbacks and Transitions in the Arctic Regional System could investigate more fully the interaction of the biotic and physical parts of the arctic terrestrial and marine environments in order to understand the impacts of variability on ecosystems and societies in the Arctic.
Forum questions:
1. SEARCH Implementation:
For each of the 1) Arctic Ocean, 2) Marine Ecosystem, and 3) Terrestrial Ecosystem
A major goal of ARCSS research over the past decade has been the development of a predictive understanding of the arctic climate system, including its multiple modes of variability across timescales, its interactions with human systems, and its relationship with the global climate system. This requires elucidating fundamental mechanisms governing climate behavior, monitoring variability, and improving knowledge of the sensitivities of climate patterns to changes in forcing, including their interactions with and responses to anthropogenic forcing. An example of a major research initiative developing in this area is the interagency Study of Environmental Arctic Change (SEARCH)
ARCSS, SEARCH and Modes of Variability
Historically the ARCSS Program has focused on the response of the Arctic system to climate change. SEARCH seeks to understand environmental change in the Arctic, particularly with respect to a complex of seemingly related, decadal-scale, large spatial scale changes in the Arctic system that has been occurring recently. SEARCH has avoided setting hard boundaries on what may be considered part of this complex and will have to examine unrelated changes in the system to understand the complex. Thus boundaries between ARCSS and SEARCH are difficult to define. Briefly stated, though, ARCSS studies the system, and SEARCH is aimed at understanding a particular response of the system. Jamie Morison, chair of the SEARCH science steering committee, has characterized this as SEARCH being similar to a class project for ARCSS. Because of the long-term observations, application aspects, and other anticipated requirements, SEARCH will require interagency support beyond ARCSS.
In general, SEARCH will be looking at larger-scale and longer-term modes of variability. A major issue for both programs is how variability at various scales interact to produce change at a given place and time. For example, the weather on a particular day at Barrow will be affected somewhat by the large-scale, longer-term modes of variability, but substantially by other smaller scale, higher frequency events. Ecosystem responses are likely to be even more complicated, due to coupling among modes of variability of different time and spatial scales. For example, a small magnitude but large-scale change in ocean circulation may change water conditions beyond a certain (as yet undefined) threshold, resulting in a major ecosystem change. If the air temperature changes, the treeline may advance, but probably at a slower rate than the isotherms move.
Other research efforts within the ARCSS Program also are focused on understanding the impacts of variability in the Arctic system. One of the primary goals of the emerging pan-Arctic Community-wide Hydrological Analysis and Monitoring Program (Arctic-CHAMP) is to document changes to the arctic water cycle, thereby contributing a hydrological component to the study of variability in the Arctic system. The nascent Nearshore and Coastal Processes Initiative is focusing on the impacts of variability in the nearshore and coastal zones of the Arctic. Still in the early stages of planning, the research program described in Biophysical Feedbacks and Transitions in the Arctic Regional System could investigate more fully the interaction of the biotic and physical parts of the arctic terrestrial and marine environments in order to understand the impacts of variability on ecosystems and societies in the Arctic.
Forum questions:
1. SEARCH Implementation:
For each of the 1) Arctic Ocean, 2) Marine Ecosystem, and 3) Terrestrial Ecosystem
- What are the dominant modes of
variability?
- How might the dominant modes of variability
be determined?
- Given the dominant modes of variability,
what are optimum observation points?
- In what cases are variations in some other part of the Arctic system likely to drive variations of a mode so far or in such a nonlinear way as to constitute a regime shift? Understanding such cases is critical to extending our knowledge of the modes of variability to explaining possible future states.
- What are the modes of variability of the
Arctic system that are not large-scale and low
frequency?
- How do the modes of variability of the
system at the various scales interact?
- What is their relative importance for a
given region?
- How can we distinguish the modes of
variability at different scales from our
measurements?
- How can we know which modes of variability at which scales affect various parts of society?
- How can the pool of paleoclimate data be
increased, and better integrated with data from
contemporary observations?
- Can paleo data be used to help
differentiate anthropogenically-driven changes
from those driven by various natural processes,
cyclical or otherwise?
- How can archaeological studies be
integrated with other types of paleo-
(botanical, bio-geographic, climatic, etc.)
research?
- What can we learn about human responses to climate change, sustainable or otherwise, and how can we best use this information for public education and policy purposes?
- What research about variability in the
arctic system is of the highest priority for
policy and decision makers who must cope with
the impacts of future arctic/global climate
change?
- How can we best apply our current understanding of the various modes of variability to help society?