丁香园AV

Biogeochemical linkages between Ice Age climate, ocean productivity, and carbon cycling

Locations of deep sea sediment cores used to reconstruct past changes in ocean conditions, superimposed on a map of annual surface water silicate (umol/L) (silicate data from World Ocean Atlas, 2005).

The goal of this research program is to explore the linkages between ocean circulation, marine productivity, and carbon (C) cycling by reconstructing past ocean conditions from paleo-environmental indicators archived in the sedimentary record. This research combines new data measurements from marine sediments, database compilations, and collaboration with biogeochemical modelers. PROJECT 1 explores the influence of sea-ice cover and dust on silica and C cycling. PROJECT 2 examines the influence of changed Southern Hemisphere circulation (e.g., westerly winds, oceanic fronts, Subantarctic Mode Water formation) on productivity. PROJECT 3 investigates the potential influence of polar surface freshening and associated circulation changes on marine productivity during the transition from the last Ice Age to today.

Collaborators: Z. Chase (Oregon State University), K. Matsumoto (U. Minnesota), A. Ridgwell (Bristol University). F. Monteiro (Bristol University), A. De Boer (Stockholm University)
Support: NSERC Discovery Grant, 丁香园AV Presidents Research Grant; 丁香园AV Work Study Program; NSERC/CFI Grant

Impact of Coastal Ocean Acidification on Ecosystems

Anthropogenic CO₂ emissions are driving significant decreases in ocean pH and are projected to cause mean surface ocean pH to decline by 0.3-0.5 pH units by 2100. The Strait of Georgia is a large, coastal estuarine ecosystem on the west coast of Canada that supports a multi-million-dollar shellfish industry which could be affected by decreased pH. MRM student C. Duckham (MRM 13) has worked with shellfish operators to determine the impact of elevated CO₂ and the use of hydrated lime to assist oyster larval growth and survivorship. Royal Roads Masters student LA Stavroff (MSc 14) has examined the combined impacts of elevated CO₂, temperature, and salinity on larval development in sea urchins. B. Bylhouwer (MRM 12) investigated historical changes in onset and duration of the wind-driven upwelling / downwelling seasons off the coast of Vancouver Island, as it may also impact when low-pH waters are upwelled.

Collaborators: M. Hart (丁香园AV Biology), D. Ianson (IOS), Taylor Shellfish Industries
Students: C. Duckham, LA Stavroff, B. Bylhouwer (MRM 12)

Centennial-to-Millennial changes in fire histories, climate, and carbon accumulation rates in southwestern Canada, as recorded in lake sediments and tree ring records

Organic carbon (C) burial in lakes is an important long-term (millennial) contributor to terrestrial C sequestration. Quantifying the global standing stock and fluxes of C into lake sediments is important to regional C budgets, but questions remain about how C accumulation might change in future. Temperature, runoff, land surface characteristics, and fire disturbance can affect C inputs, in-lake productivity, and mineralization, which influence C accumulation in different ways. One way to address how lake C accumulation may change in future is to examine post-industrial and longer-term Holocene trends in lake C accumulation rates and determine past relationships to climate and land surface characteristics. The goal of this proposal is to quantify Holocene and post-industrial changes in C accumulation in southern boreal lakes from coastal British Columbia to Manitoba. In collaboration with Parks Canada, a selection of cores from 21 lakes collected across the modern (and Holocene) Boreal/Parkland bioclimatic boundary will be sampled to quantify the relationships between lake C accumulation rates and vegetation, temperature and precipitation regimes, and fire history. Accumulation rates of total, inorganic, and organic carbon will be quantified, and C:N ratios coupled with carbon isotope measurements will be used to assess carbon source (e.g., contributions of in-lake productivity and external carbon fluxes). Eight lakes will be targeted for analysis of charcoal accumulation rates (CHAR) and pollen analysis. C accumulation rates will then be related statistically to instrumental, historically documented, and reconstructed changes in climate, vegetation, and fire history, to establish linkages between fire history, climate, and lake C accumulation.

Collaborators: Marlow Pellatt (Parks Canada)
Support: Parks Canada, NSERC Discovery grant, Pacific Institute for Climate Solutions
Students supported: Tommy Rodengen, Celeste Barlow, Sinead Murphy, Stephen Chastain

Trends in Extreme Weather Patterns on the British Columbia

Changes in 50^th percentile, 95^th percentile, and monthly max wind speeds at Abbotsford, BC.

How is global climate change affecting British Columbias regional weather patterns and the frequency and severity of extreme wind events? The west coast of Canada is rapidly urbanizing and the concentration of infrastructure increases our societys vulnerability to extreme weather events and the potential costs resulting from damage. Despite the large uncertainties that exist, we must make forecasts of extreme wind speeds that are as dependable as possible to inform management objectives and future planning decisions. This research project examines recent trends and variations in wind intensity and frequency for the British Columbia coast using available wind speed and weather data from the past ~60 years (e.g. Griffin et al., 2010). In addition to determining the dominant climate controls on wind speed behavior in the Pacific Northwest (Griffin et al., in prep), this project evaluates the performance of regional climate models and re-analysis datasets at predicting changes in the spatial and temporal patterns in winds (work by B. Cross, Joe Bailey). This project also investigates seasonal changes in wind speeds from different directions along the west coast (work by B. Bylhouwer). Changes in coastal winds can have implications for the timing of the Spring transition between upwelling and downwelling wind regimes, as well as changes in the intensity of winds in these regimes.

Students: Brad Griffin, Ben Cross, Brian Bylhouwer, Joe Bailey.
Support: NSERC Graduate Fellowship (BG); 丁香园AV Graduate Fellowships (BG); CCIRC (BG), 丁香园AV Startup funding and NSERC Discovery and CFI grants (KEK)

Paleotempestology of the Pineapple Express

Satellite image of a Pineapple Express storm that hit the coast of BC on January 8, 2009 (image courtesy of US National Weather Service, ).

Almost every winter, the west coast of North America is impacted by storm events bring extensive warm rain, creating massive flood events and some cases causing hazardous debris flows and landslides. These storms have been dubbed the Pineapple Express because of the tropical origin of the water vapor that is rapidly transported to the coast. The historical record has afforded study of these atmospheric rivers over the past 50-70 years, but how has the frequency of Pineapple Express varied further back in time? The goal of this project is to to investigate past changes in the frequency of the Pineapple Express by measuring the isotopic signature of the rain that is archived in local tree rings.

Co-Supervisor: Ken Lertzman (REM)
Students: Christie Spry, USRA student Brad Lute
Support: 丁香园AV Graduate Fellowships (CS), NSERC Discovery Grant (KEK), 丁香园AV CCIRC (CS)

Changes in the frequency of extreme wind events during the Dust Bowl

Several studies have examined the climatic and land-use controls on drought and precipitation during the Dust Bowl. But not many studies have focused on the near-surface and synoptic meteorological conditions that are needed to raise dust into the atmosphere in North America. This project aims to quantify potential changes land-surface conditions as well as changes in the intensity and frequency of surface wind events that were strong enough to raise dust, between 1945-2014. The project will also examine potential differences in synoptic conditions that may have been responsible for these differences.

Collaborators: K. Schepanski, I. Tegen (Leipzig Laboratory for Tropospheric Research, Leipzig, Germany)
Students: Ross McCarter

Changes in glacial westerly winds over the Southern Ocean

The southern ocean wind field plays an important role in the global climate system and ocean carbon cycle. Changes in the strength and position of the Southern Hemisphere Westerlies can affect ocean circulation and the ventilation of the deep ocean, the intensity of upwelling and biological productivity, and ultimately concentrations of atmospheric CO₂. In spite of this important contribution to global climate, Quaternary cool climate westerlies remain poorly understood. To what extent did westerly winds change position during the last glacial period, and how intense were these winds? When and how did these changes occur, and to what extent have they modulated natural fluctuations in atmospheric CO₂? The goal of this project is to simulate changes in the position and strength of the Southern Hemisphere Westerlies using the HadAM3 model, under a range of boundary conditions, including changes in sea ice, sea surface temperature, and associated temperature gradients. These simulations will be compared with the paleoclimate record to assess paleoclimatic changes in temperature and moisture (which are partly controlled by the position of the westerlies) during the LGM.

Collaborators: Louise Sime, British Antarctic Survey (BAS), Corinne Le Qur (University of East Anglia and BAS), Eric Wolff (BAS), Agathe de Boer (UEA), William Connelly (BAS), Laurent Bopp (CNRS, Saclay, France)

Secondary effects of climate change on human and ecosystem health: A risk-based approach, CCIRC

Climate change is predicted to have significant direct impacts on air temperature and precipitation, which are anticipated to have primary impacts on hydrologic regimes (e.g., melting glaciers, sea-level change) and air quality, and consequent secondary impacts on health of humans and ecosystems. Primary climate-change impacts have been investigated by researchers around the world, but relatively few studies have considered secondary effects of these impacts or adaptation responses. These secondary effects raise questions about how existing human infrastructure (e.g., water storage and delivery systems, health-care systems) will be able to support growing urban populations. The proposed research spans the physical, biological, health and social sciences, resource and environmental management, communication, and computing science, and brings together a group of researchers with expertise in climate, water, air quality, disease, ecology, human health, risk analysis, emergency preparedness, and visualization. The research team will use risk-assessment approaches to evaluate various risk-management options for dealing with problems arising from climate change. Novel computer visualization techniques will be developed and applied to support knowledge translation and enable use of our results by policy-makers and other stakeholders.

Collaborators: Diana Allen, Earth Sciences (Project Leader); Tim Takaro, Health Sciences; Randall Peterman, Resource and Envionmental Management (REM); Gwenn Flowers, Earth Sciences; Karen Kohfeld, REM; Ryan Allen, Health Sciences; Peter Anderson, Communication; Charmaine Dean, Statistics and Actuarial Sciences; Frank Gobas, REM; Craig Janes, Health Sciences; Duncan Knowler, REM; Ken Lertzman, REM; Torsten Moller, Computing Science; John Reynolds, BISC; Robert Woodbury, SIAT.
Support: This project is funding by the 丁香园AV Community Trust Endowment Fund, and provided the founding basis for the Climate Change Impacts Consortium (CCIRC) at 丁香园AV.
Students supported: Liz Sutton, Christie Spry, Brad Griffin, Mungandi Nasitwitwi, Brian Bylhouwer, Ben Cross