Workshop 6 : Ocean Ecologies and their Physical Habitats in a Changing Climate
(June 20,2011 - July 1,2011 )
Organizers
The goal of the workshop is to bring together biologists studying ocean and polar ecologies; oceanographers, biogeochemists, and climate scientists studying the changing physical habitats; and mathematicians with ecological and physical expertise. The two-way feedback interactions between ocean ecological systems and their physical environments have the potential to dramatically impact both marine biodiversity, and the planetary response to the changing atmosphere. The types of mathematics used to model ecological and physical processes are typically quite different. One of the exciting aspects of this workshop, and a reason to run it at MBI, is that we anticipate interesting new mathematical challenges arising from combining these different approaches to focus on modeling the feedback interactions between the ecological and physical systems.
The workshop will focus on two main themes:
1. Polar and sea ice ecologies
2. Phytoplankton and the carbon cycle.
These themes are particularly timely in that the impact of climate change on these systems has been quite pronounced. Moreover, these areas are further tied together through the interplay of a wide range of the length scales involved, from microscopic to many kilometers over oceanic regions. As with all aspects of mathematics and climate change, this is an emerging area, and part of the reason for running the workshop is to help identify the mathematical challenges and opportunities the emerging topics present.
Accepted Speakers
Stephen Ackley
Geol. Sciences, University of Texas
Chris Cosner
Department of Mathematics, University of Miami
Bruno Delille
Astrophysics, Geophysics and Oceanography, Universite de Liege
Arjen Doelman
Mathematisch Instituut, Leiden University
Alan Hastings
Environmental Sci. and Policy, University of California, Davis
Nicole Jeffery
Ocean Dynamics, Sea Ice Microstructure, and Polar Biogeochemistry, Los Alamos National Laboratory
Isaac Klapper
Department of Mathematical Sciences, Montana State University
Keith Lindsay
Climate and Global Dynamics Division, National Center for Atmospheric Research
Nicole Lovenduski
Institute of Arctic and Alpine Research , University of Colorado
Irina Marinov
Department of Earth and Environmental Science, University of Pennsylvania
Péter Molnár
Dept. of Ecology and Evolutionary Biology, Princeton University
Leonid Polyak
Byrd Polar Research Center, The Ohio State University
Keith Promislow
Mathematics, Michigan State University
Nicholas Record
School of Marine Sciences, University of Maine
Emily Shuckburgh
Polar Oceans, British Antarctic Survey
Walker Smith
Biological Sciences, VA Institute of Marine Science, College of William & Mary
David Thomas
Marine Research Center, Finnish Environment Institute
Lonnie Thompson
Earth Sciences, The Ohio State University
Rebecca Tien
Department of Evolution, Ecology, and Organismal Biology, The Ohio State University
Jean-Louis Tison
Glaciologie, Université Libre de Bruxelles
Martin Vancoppenolle
Georges Lemaitre Centre for Earth and Climate Research, Universit'e Catholique de Louvain
Ariane Verdy
Physical Oceanography, Scripps Institution of Oceanography
Patricia Yager
Department of Marine Sciences, University of Georgia
Antonios Zagaris
Applied Mathematics, University of Twente
- Mon, Jun 20, 2011
- Tue, Jun 21, 2011
- Wed, Jun 22, 2011
- Thu, Jun 23, 2011
- Fri, Jun 24, 2011
- Sat, Jun 25, 2011
- Sun, Jun 26, 2011
- Mon, Jun 27, 2011
- Tue, Jun 28, 2011
- Wed, Jun 29, 2011
- Thu, Jun 30, 2011
- Fri, Jul 1, 2011
- Full Schedule
| Monday, June 20, 2011 | |
|---|---|
| Time | Session |
| 09:00 AM 10:15 AM | David Thomas - Factors Controlling Plankton Ecology No description available. |
| 10:45 AM 12:00 PM | Alan Hastings - Ecological Modeling Some underlying issues of modeling in ecology 2 species predator prey dynamics and analysis Aquatic ecological systems - basic issues NPZ modeling basics NPZ "applications" and extensions |
| 02:00 PM 03:30 PM | Alan Hastings - Ecological Modeling Some underlying issues of modeling in ecology 2 species predator prey dynamics and analysis Aquatic ecological systems - basic issues NPZ modeling basics NPZ "applications" and extensions |
| Tuesday, June 21, 2011 | |
|---|---|
| Time | Session |
| 12:00 AM 11:00 AM | Lonnie Thompson - A Glacier Paleoclimate Perspective for the last 10,000 years from the World's Highest Mountains No description available. |
| 09:00 AM 10:15 AM | Stephen Ackley - Biology/Physics Interface in Sea Ice No description available. |
| 10:45 AM 12:00 PM | Ken Golden - Sea Ice Structure and Processes No description available. |
| 03:30 PM 04:30 PM | Lonnie Thompson - A Glacier Paleoclimate Perspective for the last 10,000 years from the World's Highest Mountains No description available. |
| Wednesday, June 22, 2011 | |
|---|---|
| Time | Session |
| 09:00 AM 10:15 AM | Emily Shuckburgh - Ocean Transport and Mixing Part 2 of a two-part introduction to the mathematics of ocean dynamics, transport and mixing. |
| 10:45 AM 12:00 PM | Emily Shuckburgh - Ocean Transport and Mixing Part 2 of a two-part introduction to the mathematics of ocean dynamics, transport and mixing. |
| Thursday, June 23, 2011 | |
|---|---|
| Time | Session |
| 09:00 AM 10:15 AM | Nicole Lovenduski - Air-Sea Carbon Dioxide Exchange No description available. |
| 10:45 AM 12:00 PM | Jean-Louis Tison - Gas Transport thru' Sea Ice No description available. |
| 02:00 PM 03:00 PM | Nicole Lovenduski, Jean-Louis Tison, Jean-Louis Tison - Air-Sea Carbon Dioxide Exchange No description available. |
| Friday, June 24, 2011 | |
|---|---|
| Time | Session |
| 09:00 AM 10:15 AM | Walker Smith - Phytoplankton Role, Growth, and Fate No description available.... |
| 10:45 AM 12:00 PM | Arjen Doelman - Phytoplankton-Nutrient Modeling No description available.... |
| 02:00 PM 03:00 PM | Arjen Doelman, Walker Smith, Walker Smith - Phytoplankton-Nutrient Modeling No description available.... |
| Saturday, June 25, 2011 | |
|---|---|
| Time | Session |
| Sunday, June 26, 2011 | |
|---|---|
| Time | Session |
| Monday, June 27, 2011 | |
|---|---|
| Time | Session |
| 09:00 AM 10:00 AM | Ken Golden - Sea Ice Structure and Processes No description available. |
| 10:30 AM 11:30 AM | Bruno Delille - Overview of CO2 dynamics within sea ice No description available. |
| 02:30 PM 03:30 PM | Leonid Polyak - Paleo-perspective of the development of sea ice and related biota in the Arctic Ocean The Arctic environment is experiencing a rapid change due to the ongoing climate warming, with an especially high rate of temperature increase in the Arctic. The core of this change is the cryosphere destruction: an abrupt decrease in sea ice extent and volume, intensified glacier melting, and degradation of the permafrost. These processes profoundly affect the entire Arctic natural system including cascading effects on the Arctic Ocean food web. Recent years have witnessed changes in biogeochemical cycling and primary production patterns in various parts of the Arctic Ocean and intrusions of low-latitude biota into the high Arctic. For a proper evaluation of these changes and their future projection, they need to be considered in the context of long-term development of the Arctic environments beyond the scope of historical observations. Sediments from the Arctic Ocean floor hold the long-time archive of the history of sea ice, oceanic circulation, and related biological conditions. Investigation of sediment cores collected from multiple sites across the Arctic Ocean provide insights into paleoceanographic variations during the last several 100,000 years, with a yet longer-time record now available from a central Arctic Ocean site. In this talk I will give an overview of these geological studies with a focus on implications for the development of sea ice and effects on the Arctic Ocean biota. |
| 04:00 PM 05:00 PM | Péter Molnár - An energy budget framework to address polar bear population viability under climate change The vulnerability of polar bears to climate warming is well-established, and most polar bear populations are expected to decline substantially under expected climatic scenarios. However, until recently, only qualitative expectations were phrased in the literature (along with actual observations of declines in body condition, survival, reproduction and abundance); quantitative predictions of future abundances under climate change scenarios were missing. Such predictions are difficult to achieve because population models, and by extension population viability analyses, require knowledge of how reproduction and survival will change under future environmental conditions. For polar bears, this cannot be measured directly because past and predicted conditions differ substantially. Here, I will outline a framework that circumvents this problem: Most climate warming effects on polar bears can be understood as changes in their energy budget, either through increased movement costs or through decreased energy intake. Dynamic energy budget models can capture these effects and predict changes to reproduction and survival as a function of changes in energy expenditure and/or intake. Because energy budget models focus on physiological processes, they can be developed and tested under current environmental conditions. The output of these models can then serve as input to traditional population models that synthesize predictions of reproduction and survival into predictions of abundance. I will illustrate this approach with two examples, using data from western Hudson Bay to derive predictions for certain components of survival and reproductive success. I will then outline challenges that need to be addressed to advance the framework, including the need to develop a full energy budget model for polar bears (to address all components of survival and reproduction), the need to incorporate prey dynamics into the single-species framework (to more accurately quantify changes to the energy intake and expenditure of polar bears), and the need for sea ice models that operate on a regional rather than global scale (to more accurately link biological processes to future environmental conditions). The generality of the framework and its applicability to other species will also be discussed. |
| Tuesday, June 28, 2011 | |
|---|---|
| Time | Session |
| 09:00 AM 10:00 AM | Patricia Yager - Climate Connections to Marine Ecosystems - From The Amazon To Antarctica No description available. |
| 10:30 AM 11:30 AM | Antonios Zagaris - Phytoplankton growth in oligotrophic oceans: Linear theory In this talk, we will present analytic results concerning phytoplankton growth under nutrient-light co-limitation. The model we employ consists of two reaction-advection-diffusion PDEs for the plankton and nutrient concentrations and incorporates self-shading effects. In the first part of this talk, we will work with a single spatial dimension (depth) and look closely into the linear stability problem for the trivial steady state (no phytoplankton). Using our results, we will identify the emergence of two distinct localized patterns: benthic layers (BLs), corresponding to the localization of plankton close to the bottom of the water column, and deep-chlorophyll maxima (DCMs), corresponding to localization in a thin region interior to the water column. This first part will close with an ecological interpretation of our findings. In the second half, we will extend our model to account for an extra, horizontal dimension and include diffusion and (depth-dependent) advection along this new dimension. We will then investigate the corresponding linear stability problem and derive a condition for the relative sizes of horizontal diffusivity and advection, under which horizontally modulated DCMs may be expected to appear. |
| 01:30 PM 02:30 PM | Arjen Doelman - Phytoplankton-Nutrient Modeling No description available.... |
| 01:30 PM 02:30 PM | Ariane Verdy - Evolution of phytoplankton cell size in a variable environment The size of phytoplankton cells determines their competitive ability, sinking rate, and potential to export carbon to the deep ocean. Observations suggest that small phytoplankton species dominate the equatorial and subtropical oceans while larger species are more abundant in subpolar regions. To understand this pattern, we have developed an allometric model for the evolution of phytoplankton cell size. The model shows that increasing body size can be a successful adaptation, even in the absence of temporal variability or predation. The evolutionarily stable strategy is set by the allometric relationships for nutrient uptake kinetics and by metabolism. In a simple chemostat model, fluctuations in resource supply increase the optimal cell size. I will discuss the organization of phytoplankton communities along a latitudinal gradient in nutrient supply, sea surface temperature, and insolation. |
| Wednesday, June 29, 2011 | |
|---|---|
| Time | Session |
| 09:00 AM 10:00 AM | Martin Vancoppenolle - Brine-biogeochemistry interactions in Sea Ice The polar oceans have already experienced significant ecosystem shifts associated with sea ice retreat. Earth system models suggest that major changes in marine ecosystems and biogeochemistry will keep on going through the 21st century. However, future projections of the polar oceans are subject to some of the largest uncertainties. Among the sources of uncertainty is the role of sea ice: Earth system models consider sea ice as biologically inert, while observations indicate active biogeochemistry in sea ice. Hence, developing a realistic sea ice biogechemistry model component seems necessary. The fact that sea ice is so prone to microbial life is due to the fact that compared to freshwater ice, sea ice is highly porous. Practically, sea ice can be viewed as a matrix of solid ice with liquid inclusions of brine. Depending on permeability, brine inclusions are connected or not with the underlying ocean. The brine network is ventilated by brine drainage mechanisms, supplying or flushing out nutrients. In this presentation, based on observations and models, I will contextualize, explain and show how to model one fundamental aspect of biogeochemistry in sea ice, namely how biogeochemistry in sea ice is coupled with liquid brine dynamics. |
| 10:30 AM 11:30 AM | Chris Cosner - No title No description available. |
| 01:30 PM 02:30 PM | Keith Promislow - Title coming soon No description available. |
| 04:00 PM 05:00 PM | Irina Marinov - Predicting the behavior of ocean ecology in a changing climate: from simple theory to global climate models Climate driven changes to the physical structure of the ocean will modify oceanic temperature, light, and nutrients, essential ingredients for the growth of ocean phytoplankton. In turn, resulting changes in phytoplankton growth and community structure will affect export production, deep ocean carbon storage, and ultimately atmospheric carbon. The questions I work on at present are: How will changes in temperature, light and nutrients affect phytoplankton growth rates and biomass and will they impact more the small phytoplankton or the large phytoplankton? What will be the resulting consequences for biological production and the carbon cycling in the ocean? I propose from theoretical arguments a " critical nutrient hypothesis " , i.e. that in the low nutrient regions roughly corresponding to 40S 40N, future nutrient decreases due to increasing stratification will affect more small phytoplankton biomass than diatoms, with consequences for export production and the carbon cycle. I expect the opposite behavior in the high nutrient high latitudes, with future nutrient decreases affecting more diatoms than small phytoplankton. More broadly, I propose an analytical framework linking changes in nutrients, light and temperature with changes in phytoplankton biomass and assess these theoretical considerations against coupled model projections (1980-2100) from one of the leading US IPCC-class Earth System models, the NCAR CCSM3.1. |
| Thursday, June 30, 2011 | |
|---|---|
| Time | Session |
| 09:00 AM 10:00 AM | Isaac Klapper - Modeling of Microbial Biofilms and Mats No description available. |
| 10:30 AM 11:30 AM | Rebecca Tien - The Decline of Calanus finmarchicus in the Gulf of Maine: Using Modeling to Investigate the Relative Role of Top-down Verses Bottom-up Processes During the 1990s the Gulf of Maine (GOM) underwent an ecosystem regime shift associated with an increase in freshwater inputs. This freshening has been linked to increased phytoplankton abundance, which in turn positively affected the growth of zooplankton and, consequently, many pelagic fish populations. Calanus finmarchicus is one of the most abundant species of zooplankton in the GOM and so is an important prey source for many species higher up the food chain such as herring and the North Atlantic right whale. While reproduction for C. finmarchicus was high during this period, abundance of the later stages of the surface population was paradoxically low. Adult herring preferentially feed on the later copepodid stages; it is therefore possible that increased herring presence exerted top-down control on C. finmarchicus. An alternative hypothesis is that the changes in phytoplankton abundance during the 1990s impacted recruitment of C. finmarchicus into the later stages. Specifically, phytoplankton variability may impact whether C. finmarchicus remain at the surface to reproduce or enter into a resting state until the following year, emerging to take advantage of the spring bloom. Using three simple differential equation models, we examined the interplay of top-down verses bottom-up processes on the observed changes in seasonal patterns of surface populations of late-stage C. finmarchicus. |
| 01:30 PM 02:30 PM | Nicholas Record - Toward a grand unified theory of copepods Pelagic copepods are the dominant mesozooplankton in much of the world's oceans. They form a crucial link in the transfer of energy from primary production to upper trophic levels, and they are a significant contributor to vertical carbon flux through migration and fecal pellets. Much effort has gone into studying the effects of climate change on individual species. The effects of changing conditions on communities and assemblages are not as well understood. Answering this kind of question requires the development of a more general mathematical framework. Copepod morphologies are very similar across species. Differences between species are better described by how life history strategies are parameterized. By formulating these strategies with mechanistic equations, we can build a copepod model that is general enough to describe a wide range of species. Each species is represented by a digital chromosome of parameters, so that different sets of parameter values map to different species. This framework allows us to span scales from individually-based processes to system level properties such as biodiversity and size spectra. We can explore how temperature, resource availability, and mortality regimes structure modeled copepod communities. |
| Friday, July 1, 2011 | |
|---|---|
| Time | Session |
| 12:00 AM 11:00 AM | Raj Saha - No lecture title available No description available |
| 09:00 AM 10:00 AM | Raj Saha - No lecture title available No description available |
| 10:30 AM 11:30 AM | Keith Lindsay - No lecture title available No description available |
| Name | Affiliation | |
|---|---|---|
| Ackley, Stephen | Stephen.ackley@utsa.edu | Geol. Sciences, University of Texas |
| Auger Methe, Marie | marie.auger-methe@ualberta.ca | |
| Balasuriya, Sanjeeva | sanjeeva.balasuriya@conncoll.edu | Department of mathematics, Connecticut College |
| Barry, Anna | annab@math.bu.edu | Department of Mathematics and Statistics & Center for BioDynamics, Boston University |
| Bhaganagar , Kiran | kiran.bhaganagar@utsa.edu | Department of Mechanical Engineering, University of Texas |
| Cosner, Chris | gcc@math.miami.edu | Department of Mathematics, University of Miami |
| Cutler, Emma | ecutler@bowdoin.edu | Mathematics, Bowdoin College |
| Delille, Bruno | Bruno.Delille@ulg.ac.be | Astrophysics, Geophysics and Oceanography, Universite de Liege |
| Doelman, Arjen | doelman@math.leidenuniv.nl | Mathematisch Instituut, Leiden University |
| Gao, Min | min.gao@Vanderbilt.Edu | Math, Vanderbilt University |
| Ghazaryan, Anna | ghazarar@muohio.edu | Mathematics, Miami University |
| Golden, Ken | golden@math.utah.edu | Department of Mathematics, University of Utah |
| Hastings, Alan | amhastings@ucdavis.edu | Environmental Sci. and Policy, University of California, Davis |
| Iams, Sarah | siams@cornell.edu | Center for Applied Mathematics, Cornell University |
| Jeffery, Nicole | njeffery@lanl.gov | Ocean Dynamics, Sea Ice Microstructure, and Polar Biogeochemistry, Los Alamos National Laboratory |
| Jiayun, Zhou | jiayzhou@ulb.ac.be | Laboratoire de Glaciologie - DSTE, Universite libre de Bruxelles |
| Jones, Christopher | ckrtj@amath.unc.edu | Department of Mathematics, University of North Carolina, Chapel Hill |
| Kaper, Hans | kaper@mcs.anl.gov | n/a, Mathematics and Climate Research Network |
| Klapper, Isaac | klapper@math.montana.edu | Department of Mathematical Sciences, Montana State University |
| Leite, Maria | mleite@ou.edu | Mathematics and Statistics, University of South Florida |
| Lin, Joyce | joyce.lin@utah.edu | Department of Mathematics, University of Utah |
| Lindsay, Keith | klindsay@ucar.edu | Climate and Global Dynamics Division, National Center for Atmospheric Research |
| Lovenduski, Nicole | nicole.lovenduski@colorado.edu | Institute of Arctic and Alpine Research , University of Colorado |
| Ma, Yiping | yiping.m@gmail.com | Physics, University of California, Berkeley |
| Marinov, Irina | imarinov@sas.upenn.edu | Department of Earth and Environmental Science, University of Pennsylvania |
| Maultsby, Bevin | bevinmaultsby@yahoo.com | Mathematics, University of North Carolina, Chapel Hill |
| McGehee, Richard | mcgehee@tc.umn.edu | Mathematics, University of Minnesota |
| Molnar, Peter | pmolnar@ualberta.ca | Dept. of Ecology and Evolutionary Biology, Princeton University |
| Mueller-Stoffels, Marc | mmuellerstoffels@alaska.edu | Physics Department, University of Alaska |
| Oganyan, Anna | aoganyan@georgiasouthern.edu | Mathematical Sciences, Georgia Southern University |
| Orum, Chris | orum@math.utah.edu | Mathematics, University of Utah |
| Pandit, Shubha | spandit@uwindsor.ca | Department of Biological Sciences, University of Windsor |
| Polyak, Leonid | polyak.1@osu.edu | Byrd Polar Research Center, The Ohio State University |
| Promislow, Keith | kpromisl@math.msu.edu | Mathematics, Michigan State University |
| Record, Nicholas | nrecord@gmri.org | School of Marine Sciences, University of Maine |
| Saha, Raj | rajsaha@physics.unc.edu | Physics & Astronomy, University of North Carolina, Chapel Hill |
| Scott, Sherry | sherry.scott@mu.edu | mathematics, Marquette University |
| Shuckburgh, Emily | emsh@bas.ac.uk | Polar Oceans, British Antarctic Survey |
| Smith, Walker | wos@vims.edu | Biological Sciences, VA Institute of Marine Science, College of William & Mary |
| Thomas, David | d.thomas@bangor.ac.uk | Marine Research Center, Finnish Environment Institute |
| Thompson, Lonnie | thompson.3@osu.edu | Earth Sciences, The Ohio State University |
| Tien, Rebecca | rtien@mbi.osu.edu | Department of Evolution, Ecology, and Organismal Biology, The Ohio State University |
| Tison, Jean-Louis | jtison@ulb.ac.be | Glaciologie, Université Libre de Bruxelles |
| Vancoppenolle, Martin | vancop@astr.ucl.ac.be | Georges Lemaitre Centre for Earth and Climate Research, Universit'e Catholique de Louvain |
| Verdy, Ariane | ariane.verdy@gmail.com | Physical Oceanography, Scripps Institution of Oceanography |
| Wackerbauer, Renate | rawackerbauer@alaska.edu | physics, University of Alaska |
| Widiasih, Esther | ewidiasih@math.arizona.edu | Mathematics, University of Arizona |
| Xiong, Wei | xiong@ima.umn.edu | Institute for Mathematics and Its Applications, University of Minnesota |
| Yager , Patricia | pyager@uga.edu | Department of Marine Sciences, University of Georgia |
| Zagaris, Antonios | zagaris@cwi.nl | Applied Mathematics, University of Twente |
| Zeeman, Mary Lou | mlzeeman@bowdoin.edu | Department of Mathematics, Bowdoin College |
Biology/Physics Interface in Sea Ice
No description available.
Questions/panel with morning speakers
No description available.
No title
No description available.
Overview of CO2 dynamics within sea ice
No description available.
Phytoplankton-Nutrient Modeling
No description available....
Phytoplankton growth in oligotrophic oceans: Weakly nonlinear theory
In this talk, we will consider the problem of bifurcating DCMs under nutrient-light co-limitation from a weakly nonlinear point of view. In particular, we will work with the plankton-nutrient model in one spatial dimension introduced in A. Zagaris's talk and investigate the weakly nonlinear stability problem for these bifurcating DCMs.
The most intriguing mathematical aspect of this problem concerns the existence of an infinite number of eigenvalues tightly clustered around the origin. Although the corresponding modes are latent (non-bifurcating), they have to be included in the analysis as they interact nonlinearly with active (bifurcating) modes.
We will present explicit asymptotic results valid both close to and far from the bifurcation point, verifying that the bifurcating DCM is stable. Then, we will see that the latent modes have a decisive impact on the dynamics, solely through nonlinear interactions and although a strictly linear point of view dictates that they should be utterly irrelevant. In fact, the bifurcating stable DCM is soon annihilated in a saddle-node bifurcation induced by these latent modes, offering its place to a secondary pattern.
The most intriguing mathematical aspect of this problem concerns the existence of an infinite number of eigenvalues tightly clustered around the origin. Although the corresponding modes are latent (non-bifurcating), they have to be included in the analysis as they interact nonlinearly with active (bifurcating) modes.
We will present explicit asymptotic results valid both close to and far from the bifurcation point, verifying that the bifurcating DCM is stable. Then, we will see that the latent modes have a decisive impact on the dynamics, solely through nonlinear interactions and although a strictly linear point of view dictates that they should be utterly irrelevant. In fact, the bifurcating stable DCM is soon annihilated in a saddle-node bifurcation induced by these latent modes, offering its place to a secondary pattern.
Questions/panel with morning speakers
No description available.
Sea Ice Structure and Processes
No description available.
Questions/panel with morning speakers
No description available.
No title
No description available.
Ecological Modeling
Some underlying issues of modeling in ecology
2 species predator prey dynamics and analysis
Aquatic ecological systems - basic issues
NPZ modeling basics
NPZ "applications" and extensions
2 species predator prey dynamics and analysis
Aquatic ecological systems - basic issues
NPZ modeling basics
NPZ "applications" and extensions
Intoductions and questions/panel with morning speakers
Panel discussion with morning speakers David Thomas and Alan Hastings
Modeling of Microbial Biofilms and Mats
No description available.
No lecture title available
No description available
Air-Sea Carbon Dioxide Exchange
No description available.
Questions/panel with morning speakers
No description available.
Predicting the behavior of ocean ecology in a changing climate: from simple theory to global climate models
Climate driven changes to the physical structure of the ocean will modify oceanic temperature, light, and nutrients, essential ingredients for the growth of ocean phytoplankton. In turn, resulting changes in phytoplankton growth and community structure will affect export production, deep ocean carbon storage, and ultimately atmospheric carbon.
The questions I work on at present are: How will changes in temperature, light and nutrients affect phytoplankton growth rates and biomass and will they impact more the small phytoplankton or the large phytoplankton? What will be the resulting consequences for biological production and the carbon cycling in the ocean?
I propose from theoretical arguments a " critical nutrient hypothesis " , i.e. that in the low nutrient regions roughly corresponding to 40S 40N, future nutrient decreases due to increasing stratification will affect more small phytoplankton biomass than diatoms, with consequences for export production and the carbon cycle. I expect the opposite behavior in the high nutrient high latitudes, with future nutrient decreases affecting more diatoms than small phytoplankton. More broadly, I propose an analytical framework linking changes in nutrients, light and temperature with changes in phytoplankton biomass and assess these theoretical considerations against coupled model projections (1980-2100) from one of the leading US IPCC-class Earth System models, the NCAR CCSM3.1.
The questions I work on at present are: How will changes in temperature, light and nutrients affect phytoplankton growth rates and biomass and will they impact more the small phytoplankton or the large phytoplankton? What will be the resulting consequences for biological production and the carbon cycling in the ocean?
I propose from theoretical arguments a " critical nutrient hypothesis " , i.e. that in the low nutrient regions roughly corresponding to 40S 40N, future nutrient decreases due to increasing stratification will affect more small phytoplankton biomass than diatoms, with consequences for export production and the carbon cycle. I expect the opposite behavior in the high nutrient high latitudes, with future nutrient decreases affecting more diatoms than small phytoplankton. More broadly, I propose an analytical framework linking changes in nutrients, light and temperature with changes in phytoplankton biomass and assess these theoretical considerations against coupled model projections (1980-2100) from one of the leading US IPCC-class Earth System models, the NCAR CCSM3.1.
An energy budget framework to address polar bear population viability under climate change
The vulnerability of polar bears to climate warming is well-established, and most polar bear populations are expected to decline substantially under expected climatic scenarios. However, until recently, only qualitative expectations were phrased in the literature (along with actual observations of declines in body condition, survival, reproduction and abundance); quantitative predictions of future abundances under climate change scenarios were missing. Such predictions are difficult to achieve because population models, and by extension population viability analyses, require knowledge of how reproduction and survival will change under future environmental conditions. For polar bears, this cannot be measured directly because past and predicted conditions differ substantially. Here, I will outline a framework that circumvents this problem: Most climate warming effects on polar bears can be understood as changes in their energy budget, either through increased movement costs or through decreased energy intake. Dynamic energy budget models can capture these effects and predict changes to reproduction and survival as a function of changes in energy expenditure and/or intake. Because energy budget models focus on physiological processes, they can be developed and tested under current environmental conditions. The output of these models can then serve as input to traditional population models that synthesize predictions of reproduction and survival into predictions of abundance. I will illustrate this approach with two examples, using data from western Hudson Bay to derive predictions for certain components of survival and reproductive success. I will then outline challenges that need to be addressed to advance the framework, including the need to develop a full energy budget model for polar bears (to address all components of survival and reproduction), the need to incorporate prey dynamics into the single-species framework (to more accurately quantify changes to the energy intake and expenditure of polar bears), and the need for sea ice models that operate on a regional rather than global scale (to more accurately link biological processes to future environmental conditions). The generality of the framework and its applicability to other species will also be discussed.
Paleo-perspective of the development of sea ice and related biota in the Arctic Ocean
The Arctic environment is experiencing a rapid change due to the ongoing climate warming, with an especially high rate of temperature increase in the Arctic. The core of this change is the cryosphere destruction: an abrupt decrease in sea ice extent and volume, intensified glacier melting, and degradation of the permafrost. These processes profoundly affect the entire Arctic natural system including cascading effects on the Arctic Ocean food web. Recent years have witnessed changes in biogeochemical cycling and primary production patterns in various parts of the Arctic Ocean and intrusions of low-latitude biota into the high Arctic. For a proper evaluation of these changes and their future projection, they need to be considered in the context of long-term development of the Arctic environments beyond the scope of historical observations. Sediments from the Arctic Ocean floor hold the long-time archive of the history of sea ice, oceanic circulation, and related biological conditions. Investigation of sediment cores collected from multiple sites across the Arctic Ocean provide insights into paleoceanographic variations during the last several 100,000 years, with a yet longer-time record now available from a central Arctic Ocean site. In this talk I will give an overview of these geological studies with a focus on implications for the development of sea ice and effects on the Arctic Ocean biota.
Title coming soon
No description available.
Toward a grand unified theory of copepods
Pelagic copepods are the dominant mesozooplankton in much of the world's oceans. They form a crucial link in the transfer of energy from primary production to upper trophic levels, and they are a significant contributor to vertical carbon flux through migration and fecal pellets. Much effort has gone into studying the effects of climate change on individual species. The effects of changing conditions on communities and assemblages are not as well understood. Answering this kind of question requires the development of a more general mathematical framework. Copepod morphologies are very similar across species. Differences between species are better described by how life history strategies are parameterized. By formulating these strategies with mechanistic equations, we can build a copepod model that is general enough to describe a wide range of species. Each species is represented by a digital chromosome of parameters, so that different sets of parameter values map to different species. This framework allows us to span scales from individually-based processes to system level properties such as biodiversity and size spectra. We can explore how temperature, resource availability, and mortality regimes structure modeled copepod communities.
No lecture title available
No description available
No lecture title available
No description available
Ocean Transport and Mixing
Part 2 of a two-part introduction to the mathematics of ocean dynamics, transport and mixing.
Ocean Dynamics
Part 1 of a two-part introduction to the mathematics of ocean dynamics, transport and mixing.
Phytoplankton Role, Growth, and Fate
No description available....
Questions/panel with morning speakers
No description available.
Questions/panel with morning speakers
No description available.
Factors Controlling Plankton Ecology
No description available.
A Glacier Paleoclimate Perspective for the last 10,000 years from the World's Highest Mountains
No description available.
A Glacier Paleoclimate Perspective for the last 10,000 years from the World's Highest Mountains
N/A
The Decline of Calanus finmarchicus in the Gulf of Maine: Using Modeling to Investigate the Relative Role of Top-down Verses Bottom-up Processes
During the 1990s the Gulf of Maine (GOM) underwent an ecosystem regime shift associated with an increase in freshwater inputs. This freshening has been linked to increased phytoplankton abundance, which in turn positively affected the growth of zooplankton and, consequently, many pelagic fish populations. Calanus finmarchicus is one of the most abundant species of zooplankton in the GOM and so is an important prey source for many species higher up the food chain such as herring and the North Atlantic right whale. While reproduction for C. finmarchicus was high during this period, abundance of the later stages of the surface population was paradoxically low. Adult herring preferentially feed on the later copepodid stages; it is therefore possible that increased herring presence exerted top-down control on C. finmarchicus. An alternative hypothesis is that the changes in phytoplankton abundance during the 1990s impacted recruitment of C. finmarchicus into the later stages. Specifically, phytoplankton variability may impact whether C. finmarchicus remain at the surface to reproduce or enter into a resting state until the following year, emerging to take advantage of the spring bloom. Using three simple differential equation models, we examined the interplay of top-down verses bottom-up processes on the observed changes in seasonal patterns of surface populations of late-stage C. finmarchicus.
Gas Transport thru' Sea Ice
No description available.
Questions/panel with morning speakers
No description available.
Questions/panel with morning speakers
No description available.
Brine-biogeochemistry interactions in Sea Ice
The polar oceans have already experienced significant ecosystem shifts associated with sea ice retreat. Earth system models suggest that major changes in marine ecosystems and biogeochemistry will keep on going through the 21st century. However, future projections of the polar oceans are subject to some of the largest uncertainties. Among the sources of uncertainty is the role of sea ice: Earth system models consider sea ice as biologically inert, while observations indicate active biogeochemistry in sea ice. Hence, developing a realistic sea ice biogechemistry model component seems necessary.
The fact that sea ice is so prone to microbial life is due to the fact that compared to freshwater ice, sea ice is highly porous. Practically, sea ice can be viewed as a matrix of solid ice with liquid inclusions of brine. Depending on permeability, brine inclusions are connected or not with the underlying ocean. The brine network is ventilated by brine drainage mechanisms, supplying or flushing out nutrients.
In this presentation, based on observations and models, I will contextualize, explain and show how to model one fundamental aspect of biogeochemistry in sea ice, namely how biogeochemistry in sea ice is coupled with liquid brine dynamics.
The fact that sea ice is so prone to microbial life is due to the fact that compared to freshwater ice, sea ice is highly porous. Practically, sea ice can be viewed as a matrix of solid ice with liquid inclusions of brine. Depending on permeability, brine inclusions are connected or not with the underlying ocean. The brine network is ventilated by brine drainage mechanisms, supplying or flushing out nutrients.
In this presentation, based on observations and models, I will contextualize, explain and show how to model one fundamental aspect of biogeochemistry in sea ice, namely how biogeochemistry in sea ice is coupled with liquid brine dynamics.
Evolution of phytoplankton cell size in a variable environment
The size of phytoplankton cells determines their competitive ability, sinking rate, and potential to export carbon to the deep ocean. Observations suggest that small phytoplankton species dominate the equatorial and subtropical oceans while larger species are more abundant in subpolar regions. To understand this pattern, we have developed an allometric model for the evolution of phytoplankton cell size. The model shows that increasing body size can be a successful adaptation, even in the absence of temporal variability or predation. The evolutionarily stable strategy is set by the allometric relationships for nutrient uptake kinetics and by metabolism. In a simple chemostat model, fluctuations in resource supply increase the optimal cell size. I will discuss the organization of phytoplankton communities along a latitudinal gradient in nutrient supply, sea surface temperature, and insolation.
Climate Connections to Marine Ecosystems - From The Amazon To Antarctica
No description available.
Phytoplankton growth in oligotrophic oceans: Linear theory
In this talk, we will present analytic results concerning phytoplankton growth under nutrient-light co-limitation. The model we employ consists of two reaction-advection-diffusion PDEs for the plankton and nutrient concentrations and incorporates self-shading effects.
In the first part of this talk, we will work with a single spatial dimension (depth) and look closely into the linear stability problem for the trivial steady state (no phytoplankton). Using our results, we will identify the emergence of two distinct localized patterns: benthic layers (BLs), corresponding to the localization of plankton close to the bottom of the water column, and deep-chlorophyll maxima (DCMs), corresponding to localization in a thin region interior to the water column. This first part will close with an ecological interpretation of our findings.
In the second half, we will extend our model to account for an extra, horizontal dimension and include diffusion and (depth-dependent) advection along this new dimension. We will then investigate the corresponding linear stability problem and derive a condition for the relative sizes of horizontal diffusivity and advection, under which horizontally modulated DCMs may be expected to appear.
In the first part of this talk, we will work with a single spatial dimension (depth) and look closely into the linear stability problem for the trivial steady state (no phytoplankton). Using our results, we will identify the emergence of two distinct localized patterns: benthic layers (BLs), corresponding to the localization of plankton close to the bottom of the water column, and deep-chlorophyll maxima (DCMs), corresponding to localization in a thin region interior to the water column. This first part will close with an ecological interpretation of our findings.
In the second half, we will extend our model to account for an extra, horizontal dimension and include diffusion and (depth-dependent) advection along this new dimension. We will then investigate the corresponding linear stability problem and derive a condition for the relative sizes of horizontal diffusivity and advection, under which horizontally modulated DCMs may be expected to appear.
Ecological Modeling
Factors Controlling Plankton Ecology
Biology/Physics Interface in Sea Ice
Sea Ice Structure and Processes Ken Golden No description available.
Phytoplankton growth in oligotrophic oceans: Weakly nonlinear theory Arjen Doelman In this talk, we will consider the problem of bifurcating DCMs under nutrient-light co-limitation from a weakly nonlinear point of view. In particular, we will work with the plankton-nutrient model in one spatial dimension introduced in A. Zagaris�
Biology/Physics Interface in Sea Ice Stephen Ackley No description available.
Phytoplankton growth in oligotrophic oceans: Linear theory Antonios Zagaris In this talk, we will present analytic results concerning phytoplankton growth under nutrient-light co-limitation. The model we employ consists of two reaction-advection-diffusion PDEs for the plankton and nutrient concentrations and incorporates sel
Gas Transport thru' Sea Ice Jean-Louis Tison No description available.
Climate Connections to Marine Ecosystems - From The Amazon To Antarctica Patricia Yager No description available.
Ocean Transport and Mixing Emily Shuckburgh Part 2 of a two-part introduction to the mathematics of ocean dynamics, transport and mixing.
Paleo-perspective of the development of sea ice and related biota in the Arctic Ocean Leonid Polyak The Arctic environment is experiencing a rapid change due to the ongoing climate warming, with an especially high rate of temperature increase in the Arctic. The core of this change is the cryosphere destruction: an abrupt decrease in sea ice extent
Ocean Dynamics Emily Shuckburgh Part 1 of a two-part introduction to the mathematics of ocean dynamics, transport and mixing.
Overview of CO2 dynamics within sea ice Bruno Delille No description available.
Intoductions and questions/panel with morning speakers Alan Hastings Panel discussion with morning speakers David Thomas and Alan Hastings
Questions/panel with morning speakers Arjen Doelman, Walker Smith, Walker Smith No description available.
Phytoplankton-Nutrient Modeling Arjen Doelman No description available....
Phytoplankton Role, Growth, and Fate Walker Smith No description available....
Questions/panel with morning speakers Nicole Lovenduski, Jean-Louis Tison, Jean-Louis Tison No description available.
Questions/panel with morning speakers Stephen Ackley, Ken Golden No description available.
Toward a grand unified theory of copepods Nicholas Record Pelagic copepods are the dominant mesozooplankton in much of the world's oceans. They form a crucial link in the transfer of energy from primary production to upper trophic levels, and they are a significant contributor to vertical carbon flux t
Modeling of Microbial Biofilms and Mats Isaac Klapper No description available.
Ecological Modeling
Alan Hastings Some underlying issues of modeling in ecology
2 species predator prey dynamics and analysis
Aquatic ecological systems - basic issues
NPZ modeling basics
NPZ "applications" and extensions
Predicting the behavior of ocean ecology in a changing climate: from simple theory to global climate models Irina Marinov Climate driven changes to the physical structure of the ocean will modify oceanic temperature, light, and nutrients, essential ingredients for the growth of ocean phytoplankton. In turn, resulting changes in phytoplankton growth and community structu
Factors Controlling Plankton Ecology David Thomas No description available.
Title coming soon Keith Promislow No description available.
A Glacier Paleoclimate Perspective for the last 10,000 years from the World's Highest Mountains Lonnie Thompson No description available.
Brine-biogeochemistry interactions in Sea Ice Martin Vancoppenolle The polar oceans have already experienced significant ecosystem shifts associated with sea ice retreat. Earth system models suggest that major changes in marine ecosystems and biogeochemistry will keep on going through the 21st century. However, futu
No lecture title available Keith Lindsay No description available
Evolution of phytoplankton cell size in a variable environment Ariane Verdy The size of phytoplankton cells determines their competitive ability, sinking rate, and potential to export carbon to the deep ocean. Observations suggest that small phytoplankton species dominate the equatorial and subtropical oceans while larger sp