Draft

GLOBEC Climate Committee Report: 9-24-2000 (DRAFT)

Committee chair and lead author: NJ Mantua

Climate committee members:

Phyllis Stabeno, Bill Pearcy, Arnold Gordon, Peter Wiebe, Zack Powell, Greg Lough, Mike Dagg, Bruce Wright, Bob Francis, Mike Dagg, Yochanan Kushnir

I. Introduction:

A. Goals of this report - (1) Develop a blueprint science plan to advance GLOBEC's climate-scale research activities, (2) * Identify obstacles to "making the climate connection", and (3) Outline approaches for overcoming those obstacles in the short-term and in the longer-term.

B. The GLOBEC way to date:

* The GLOBEC way has been based on the recognition that physical flow fields exert strong controls on the distribution of larval fish, phytoplankton and zooplankton; GLOBEC goals are to determine how physical environment influences the early life stages of marine species; the approach has focused on "building the tools" to mechanistically link environmental parameters to marine ecosystem parameters through the following activities:

- Process studies at micro- to mesoscales (from turbulence to tidal fronts and eddies (up to 10km)

- Broadscale surveys (LTOP)

- Retrospective data analysis (seasonal, interannual to interdecadal timescales, relatively coarse spatial scales (100-1000 km)

- Modeling

- Synthesis

* Cautionary note: long-term monitoring and field studies required to sample in the face of variable environmental conditions; even so, it's unlikely that these studies will "see" all the possible states of the system.

C. Outstanding climate issues (General):

1. Have key environmental parameters been identified for the study area? Are they the same for different species, or do they vary? e.g. zooplankton and stratification, fish larvae and eddies, temperature-related habitat and migratory predators?

2. Are there connections between well-known large scale patterns of climate variability and the environments (and key environmental parameters) of interest?

** Empirical studies have identified a number of statistically significant relationships between indices for large scale climate variations (O(1000km)) and large-to-local scale marine ecosystem variations .... Examples: NAO and Atlantic calanus (and cod?); PDO and the North-South inverse production pattern in Pacific salmon; ENSO and Nekton in the NE Pacific; Impact of Antarctic wind patterns on community structure (salps versus krill);

3. Is the GLOBEC toolbox good enough to begin making ecosystem predictions given environmental scenarios? What about predictability of the key environmental parameters?

* climate community has demonstrated some skill in ENSO predictions, how does that translate into regional predictions?

Other questions:

-- Georges Bank and the NAO?

-- Gulf of Alaska and PNA/PDO, ENSO, other?

-- California Current and PNA/PDO, ENSO, other?

-- Southern Ocean and the Antarctic Circumpolar Wave?

-- Gulf of Mexico and ENSO, PDO?

-- global scale teleconnections linking study areas?

* IPCC and USGCRP efforts include ongoing assessments of potential impacts of global warming (anthropogenic climate change) on marine ecosystems. Is GLOBEC ready to add such assessments as a new program element? (Do climate models have sufficient resolution to provide useful information for GLOBEC studies?)

* Impacts of variations in Atmospheric Iron transports?

D. The way forward:

1. Synthesis: Synthesis will help identify what we do and do not understand about fundamental biological processes. It may be that community structure and species compositions are not simply driven by physical forcing.

2. Modeling: a nested hierarchy of physical and biological models offers a promising route for bridging the disparate temporal and spatial scales of large scale climate variations and local scale ecosystem processes.

* Sensitivity analyses

* Environmental change scenarios (as in IPCC and USGCRP efforts)

II. Overview of Physical Forcing on Ocean Dynamics

A. Regional impacts of hemispheric to global scale ocean-atmosphere interactions on marine environments

1. ENSO

2. North Atlantic Oscillation/Arctic Oscillation (NAO/AO)

3. Pacific interdecadal variability (PDO/NPO)

4. Antarctic Circumpolar Wave (AACW)

5. Thermohaline circulation

B. Key parameters:

1. Sea water density

* temperature and salinity (precip, runoff, and evaporation) impacts on stratification, ice melt, buoyancy-driven currents, frontal zone positions

2. Wind: impacts mixing, ekman transport, upwelling, downwelling, gyre circulation

3. Sea level: impacts on coastal currents

III. GLOBEC Modelling Targets:

A. Can the biophysical models developed in GLOBEC studies reproduce the following features of marine ecosystems:

1. Spatial distribution of target marine species, i.e. a biogeography of the ocean basins? Have we identified and quantified the physical influences (controls?) that determine community structure?

2. Temporal variability in marine ecosystems

* The mean seasonal cycle (e.g. spring blooms, copepod diapause, seasonal migration and fish spawning patterns)

* Interannual variability

* Interdecadal variability

B. Can ocean (physical) models faithfully reproduce important environmental features (Beardsley's question)?

- Seasonal recirculating eddy over Georges Bank?

- Transient Gulf Stream eddies?

- Haida Eddies in the Gulf of Alaska?

- Anticyclonic eddies in the Calif. Current?

Can the models handle points A and B from above? (getting these features "on average" and in terms of variability)

C. Can models be expected to simulate "regime shifts", in which community structures undergo rapid, dramatic reorganizations to new quasi-stable states?

D. Depending on the ability to address A, B, and C, can the models be used to examine the impacts of enhanced greenhouse forcing (using anthropogenic climate change scenarios)? (THE KEY point of all that GLOBEC is trying to do (MF))

IV. Climate impacts assessments on GLOBEC study regions; key parameters by region (from an IPCC look at anthropogenic climate change scenarios, or a more general assessment? Regardless, I list the key parameters identified in an earlier draft for this report)

    A. Georges Bank/Northwest Atlantic

    1. temperature
    2. precipitation
    3. wind fields
    4. circulation

    B. California Current

    1. temperature
    2. precipitation
    3. sea level
    4. winds
    5. frequency and intensity of tropical ENSO events

    C. Coastal Gulf of Alaska

    1. temperature
    2. precipitation and runoff
    3. winds
    4. frequency and intensity of tropical ENSO events

    D. Southern Ocean

    1. temperature
    2. precipitation
    3. wind
    4. frequency and intensity of tropical ENSO events

V. Strategies for linking GLOBEC studies to climate scale processes

1. Nesting of process studies with Broad/Meso-scale Measurement programs ** conduct sensitivity analyses?

2. Linking retrospective studies to process and Broad/Meso-scale Measurement programs

3. Making the Climate Connection

The relationship between observations made during GLOBEC field programs to forcing factors on broader space and time scales -- can these provide a specific mapping between our observations and macroscopic measures of climate?

a. Georges Bank/NW Atlantic changes in temperature and salinity connections with NAO?

b. Northeast Pacific regime shifts

-- connections to PDO and/or ENSO?

c. ENSO events and their impacts on the NE Pacific

-- compare and contrast the 1997/98 El Nino with the 1998/2000 La Nina

d. Southern Ocean and Sea Ice

-- changes in production characteristics of the system

4. Modeling strategies?

-- use arrays of 1-d process models (NPZ?) forced with output of nested physical models (mesoscale circ. model in a large scale ocean GCM?)

-- simulations using fully 4-d biophysical models

-- blend statistical and dynamical modeling tools?

Appendix (?)

A1. Availability of historic gridded climate information

1. Long-term measures for the marine environment

a. COADS: comprehensive atmosphere-ocean data set surface marine reports

*surface winds *sea level pressure *cloudiness *sea surface temperatures (monthly summary stats on a 2x2 grid 1854-present, 1x1 grid since 1960)

b. Satellite SSTs (1x1 deg grid since Nov 1981 (Reynolds Optimally Interpolated blended SSTs))

c. TOPEX/POSEIDON altimetry data: sea surface heights for Oct 1992-present

d. Satellite winds (seascat, quickscat)

e. Ocean color (CZCS, SeaWIFS)

A2. evaluation of existing information using space-time templates (a task for the synthesis committee? I'm thinking we could do parallel evaluations of existing climate information on the different time/space scales for each GLOBEC study region, then overlay those with existing GLOBEC info for the same study regions, and highlight overlaps and gaps in information)