COUPLED PHYSICAL BIOGEOCHEMICAL MODELS

Transcription

1 COUPLED PHYSICAL BIOGEOCHEMICAL MODELS

2 Upwelling CONCEPTUAL MODEL OF EUTROPHICATION IN THE COASTAL OCEAN Nutrient/ Acid Deposition Local Emissions HABs! Phytoplankton Blooms Senesce and Settling Respiration: Hypoxia & Acidification Outfall Pipe Nutrients High p(co 2 ) Low O 2 Low ph U Symptoms of Eutrophication: Chlorophyll a/ Primary Production Harmful Algal Blooms/Toxins Dissolved Oxygen Carbonate Chemistry/ ph

3 ARE ANTHROPOGENIC NUTRIENTS IMPORTANT IN AN UPWELLING DOMINATED REGION? California coastal waters are dominated by upwelling, therefore anthropogenic nutrients are not a primary driver Local anthropogenic inputs can exacerbate global drivers, potentially pushing DO and ph to ecological tipping-points

4 OCEAN NUTRIENTS PROGRAM: KEY RESEARCH QUESTION What are the relative contributions of three major drivers of symptoms of eutrophication and acidification/hypoxia in the SCB and beyond: 1. Anthropogenic inputs 2. Natural climate variability 3. Anthropogenically induced climate change First step, Bight 8 Nutrient Source Comparison

5 RELATIVE CONTRIBUTION OF ANTHROPOGENIC NUTRIENTS VARIES BY SCALE! BIGHT-WIDE SCALE Upwelling is the largest source LOCAL SCALE Nitrogen loads are equivalent

6 WHAT IS THE FATE OF ANTHROPOGENIC NUTRIENTS? NITROGEN FORM MATTERS Sources have equal magnitudes but the form of nitrogen is different: Upwelled nitrogen is 9% nitrate Effluent nitrogen is 8-9% ammonia Nitrate is primary form of inorganic N in the watercolumn Where did the ammonium go? Dissolved Inorganic Nitrogen (um) S Nitrate Ammonia S = Surface D = Below CHL max S D S D S D S D

7 OCSD DIVERSION: NITROGEN FORMS ARE ELEVATED AROUND OCEAN OUTFALLS NO 3 Depth (m) NH 4 Depth (m) /2/ DON Depth (m) NH 4 Depth (m) DON Depth (m) DON 9/2/ DON Ammonia Nitrate Before Diversion During Diversion NH 4 Depth (m) /2/212 Concentrations in mm 9/2/212

8 Station WASTEWATER AMMONIUM IS RAPIDLY S228 NITRIFIED S222 S227 S225 S223 9/2/212 While forms of nitrogen are initially different, rapid nitrification means the dominant form of inorganic N will be nitrate Station S222 S S227 S S S /6/212 1/3/212 S222 Isotopic evidence that effluent nitrate is incorporated into algal biomass Station S228 S S S S S226 1/3/ Nitrification Rate (nmol L -1 d -1 ) S225 1/17/212 9/2/212 Surface Subeuphotic

9 Upwelling CONCEPTUAL MODEL OF EUTROPHICATION IN THE COASTAL OCEAN Nutrient/ Acid Deposition Local Emissions Phytoplankton Blooms Nutrients High p(co 2 ) Low O 2 Low ph Senesce and Settling How big is the Respiration: Hypoxia & Acidification effect??? Outfall Pipe Take U away: Nearshore, anthropogenic nutrients and upwelling are equivalent Effluent ammonium is nitrified rapidly, so N looks just like upwelling Incorporated into biomass

10 MODELING PROGRAM GOALS ADDRESS OUR KEY RESEARCH QUESTION Develop OAH model of California Current System (CCS), with regional downscaling So. California Bight, Central Coast, and the Oregon Coast Use the model to understand the relative contributions of : Natural climate variability Anthropogenically-induced climate change Anthropogenic inputs Transmit these findings to coastal zone water quality and marine resource managers

11 MODELING APPROACH Enhance existing models Validate the models and quantify uncertainty Run climate change and management scenarios Outreach to inform management actions

12 ENHANCE EXISTING MODELS Physical model: Downscale to smaller spatial scales and move the model closer to shore Biogeochemistry: Improve the carbonate chemistry and develop important feedback loops with zooplankton (pteropods) Inputs: Customize the model to conditions in each of the intensification zones

13 Availability of local data for validation is key to reducing model uncertainty Biogeochemical Model Phytoplankton Zooplankton Good Data is Rare and Patchy: DO and ph Nutrients Detritus Biogeochemical Processes Data on ph and saturation Temperature and Salinity Patterns Turbulent Mixing and Eddy formation Physical Model Current Speed and Direction Density Variations Wind Speed and Direction Good Data is Relatively Abundant: CTD Data Mooring Data Glider Data Upwelling and Downwelling

14 VALIDATE MODEL USING BOTH STATE DATA AND RATE/PROCESS DATA Bight 13 Process Studies Compare sources and fate of nitrogen in effluent impacted regions to minimallyimpacted regions

15 RUN CLIMATE CHANGE AND MANAGEMENT SCENARIOS Current day with and without anthropogenic nutrient reductions Future climate change (IPCC 25-27), with and without anthropogenic nutrient reductions Additional modeling scenarios will be informed through discussion with managers The details are important and we need your input!

16 LEVEL OF INTERACTION WITH MANAGEMENT AUDIENCES WILL VARY BY SCALE West Coast Wide: Will coordinate through the West Coast Governor s Alliance Will use OAH expert panel for high level technical review SCB Downscaled Region: Will develop stakeholder advisory committee This committee will provide both technical and management feedback throughout the project Will probably meet once or twice a year for three years

17 CONSENSUS NEEDED ON ENDPOINTS OF CONCERN TO INTERPRET MODEL OUTPUT What are the appropriate indicators and endpoints? Are Ocean Plan standards relevant? How much is too much? What is the duration and extent that is significant enough to warrant regulation? Don t want the modelers to make that call for you you want to define this for them to interpret model output. First stakeholder meeting targeted for May 216.