Analyzing History to Project and Manage the Future:

Transcription

1 Analyzing History to Project and Manage the Future: Simulating the Effects of Climate on Long Island Sound s Physical Environment And Living Marine Resources; Yr2 report Nickitas Georgas, Penelope Howell, Vincent Saba, Justin Schulte, Alan Blumberg, Philip Orton, Larry Yin, Yu Jiang, Yifan Wang, Rubin Paredes, Ziyi Wu, and Yulin Zhao. Stevens Institute of Technology, CT DEEP, NOAA POC: ngeorgas@stevens.edu LISS Management Meeting. Bridgeport, CT. 01/20/2016.

2 Research Summary 34 years of MAB and LIS physical habitat reconstructed with numerical physics model (NYHOPS ). Model Validation. Climate drivers of the LIS Physical Habitat. Physical Habitat constraints on LIS Fisheries. Near-term Projections and Long Term Transient Climate Response. 2

3 Data (mostly) New York Harbor Observing and Prediction System (NYHOPS) monthly 3D water temperature data (79-13). (Stevens) CT DEEP LIS Trawl Survey (84-08), and T/S (90-13). (CTDEEP) Monthly T/S climatology: MOCHA 2.0 (Rutgers). 3

4 NYHOPS 3D hindcast for LIS: NYHOPS dynamic physical model forcing includes: 6-minute tides and hourly offshore water level anomalies 3hrly 2D NARR Surface Meteorology (NCEP) Daily, Reconstructed River Discharges and River Temperatures Monthly SODA T/S boundary conditions at shelf break (UMD/TA&M) + WWTP & Power Plants 4

5 Our Forecast for Bridgeport: on minor, extremely low chance moderate 5

6 34 years of Nor easters and Hurricanes The Battery NY

7 NYHOPS LIS Hindcast Salinity Movie >> Animation

8 3D Temperature and Salinity Validation OBS: CTDEEP ( ) MOD: NYHOPS ( ) Reference Climatology Model: MOCHA

9 NYHOPS vs observations ( ) Water emperature Salinity

10 Against Observations and MOCHA (C)

11 To the edge of LIS 11

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13 The Sound responds to climate forcing N/S E/W

14 Warming Trends ( C/decade) NYHOPS Hindcast at Millstone But, more recently: for ; DEEP data period LIS-wide air temperature trend is: 0.72 ± 0.22 C/decade LIS-wide surface water T trend is: 0.64 ± 0.16 C/decade LIS-wide bottom water T trend is: 0.56 ± 0.16 C/decade

15 The future? 2xCO2 Transient Climate Response Bottom Temperature 15

16 NYHOPS 2xCo2 (1% annual increase) TCR Assumptions Monthly NYHOPS Hindcast Forcing Climatology + Monthly deltas from CM2.6 Constant 1% annual increase in CO2 levels. Unchanged median river flows [CM 2.6 delta functions for water yield were not statistically different in the first 20 versus the last 20 years]. River temperatures based on delta of closest surface water temperatures. Treatment plant and power plant effluent flow and temperatures held constant to their present monthly averages. Submarine Groundwater Discharge sources not included (very little info). Model bathymetry held constant. Tidal harmonics too. GFDL CM 2.6 projected sea level rise only based on thermal expansion; no ice loss considered. NYHOPS forced by monthly projected winds [poor assumption on mixing and sensible/latent heat fluxes, especially in the winter]

17 Transient Climate Response of LIS to CO2-doubling (1% annual increase) Climate Variable TCR Comments (Increase) Surface Air Temperature +2.6 C +1.6 C (July) to +3.2 C (March) SST at Shelf Break +2.6 C +0.8 C (July) to +3.6 C (December) Bottom Temp. at Shelf Break +3.8 C +3.2 C (Match) to +4.5 C (November) SST over LIS (*) +3.9 C +2.7 C (August) to +5.0 C (January) Bottom Temp. in LIS (*) +3.7 C +2.2 C (July) to +5.2 C (January) (*) TCR is likely overestimated due to the lack of variability in wind forcing. 17

18 LIS forced mostly by surface heat fluxes Percent of bottom temperature variability explained by air temperature in LIS NYHOPS Hindcast

19 LIS temperatures influenced by PDO Tendencies: Positive PDO > Cold LIS Negative PDO > Warm LIS Climate Teleconnections More ( ) SST anom. More (+) SST anom. LIS Thermal Habitat Forcing Climate/Fisheries Effects More (+) PDO anom. More (-) PDO anom. 19

20 Correlation between November PDO Index and June bottom water temperature anomaly

21 PDO switched to (+) phase lately

22 Bottom temperature outlook June 2016 Forecast Following Previous November

23 Correlation between 500-hPa geopotential height and the PDO Index Jet stream during positive PDO phase

24 Spring Warm Guild outlook Summer PDO Index of previous year and Spring Warm Guild Spring 2016 Forecast Previous Summer

25 Spring Cold Guild outlook Summer PDO Index of previous year and Spring Cold Guild Spring 2016 Forecast Previous Summer

26 Distribution of Fish and American Lobster in Long Island Sound with Changing Bottom Water Temperature Connecticut Department of Energy and Environmental Protection

27 COLD TEMPERATE GUILD WARM TEMPERATE GUILD

28 Cold-Temperate Species Abundance By Bottom Temperature, SPRING LIS SURVEY (species: four-spot flounder, long horn sculpin, ocean pout, four-beard rockling, sea raven, windowpane flounder) R 2 = 0.34 CV = 42.3 All 5-yr time interval ANOVAs significant with similar abundance*temperature pattern. Note: Box plot shows 75 th -25 th quartile as upper and low edge of box, median as center line, diamond as mean. Vertical lines show maximum and minimum observations up to 1.5 IQR, circles are outlier observations beyond 1.5 IQR.

29 Warm-Temperate Species Abundance by Bottom Temperature, SPRING LIS SURVEY (species: hogchoker flounder, northern kingfish, northern puffer, northern searobin, striped searobin, smallmouth flounder) R 2 = 0.54 CV= All 5-yr time interval ANOVAs significant with similar abundance*temperature pattern. Note very low abundance below 6 0 C.

30 Fall Survey Catches: All Abundance by Temperature ANOVAs were not significant (at alpha=0.05) Cold-Temperate Species Warm-Temperate Species

31 Abundance By Temperature means (+/- SE) were fitted to a 2-order polynomial and the fitted values were rescaled from 0 to 1 to generate Habitat Suitability Indices similar to Manderson s butterfish analyses (58 th SAW Assessment Report). Mean WT: Solid lines are LS Mean values, Dotted lines are polynomial fits; blue = mean; green = mean+se; orange = mean-se HS Index: Dashed lines = +/- se transformed to HS Index Note Warm-temperate species abundance truncated at 6 0 C to better fit low abundance below 8 0 C. Mean LN_WT of Cold Temeprate Species - Spring Mean LN_WT of Warm Temeprate Species - Spring Mean LN_Wt (KG) per Tow y = x x y = x x y = x x Bottom Temperature ( 0 C) Mean LN_WT (KG) per Tow y = x x y = x x y = x x Bottom Temeprature ( 0 C) abitat Suitability Index Cold Temperate Species - Spring HS Index Bottom Temperature ( 0 C) bitat Suitability Index Warm Temperate Species - Spring HS Index Bottom Temeprature ( 0 C)

32 For the Cold Temperate Fish Guild, ~55-70% of total spring Area*Days had preferred temperatures. For the Warm Temperate Fish Guild, ~25-45% of total spring Area*Days had preferred temperature There is not trend in the Cold Guild data; there is an upward trend in the Warm Guild data. An HSI=0.8 was chosen as the lower threshold of preferred temperature

33 Looking further into the trend in temperature HSI by guild, each year s area*days were divided into 4 types, which are presented below as percentages of total spring area*days. Type 1 =Area*day with Cold HSI<0.8 and Warm HSI<0.8 (preferred for neither guild) Type 2 =Area*day with Cold HIS>0.8 and Warm HSI<0.8 (preferred for cold guild only) Type 3 =Area*day with Cold HIS>0.8 and Warm HIS>0.8 (preferred for both guilds) Type 4 =Area*day with Cold HSI<0.8 and Warm HIS>0.8 (preferred for warm guild only)

34 Although the percent of spring Area*Days unsuitable (HSI <0.3) for warm guild fish is far greater than for cold guild fish, the former is declining (R 2 =0.15, P=0.013) while the latter is increasing (R 2 =0.19, P=0.006), especially in the last few years.

35 Research done with LIS lobsters following the die off showed that the animals go into respiratory stress at temperatures >20 0 C, and die if high temperature continues for a long duration. The graph below illustrates why rising bottom temperature is considered the primary reason for the 1999 lobster die off and continued failure to rebuild.

36 Dissecting stressful days and stressful area, we again see that 1999 was the first year with both a long duration and wide area of stressful temperature. It has since been eclipsed by conditions in Both duration (days/yr) and extent (ave area/yr) have an increasing trend: Days - R 2 =0.29, F=14.7, p<0.001 Area - R 2 =0.15, F= 6.9, p=0.013 and are highly correlated (R = 0.61, df=33, p=0.0001)

37 2xCO2 TCR SCENARIO Fish Guilds Type 1 = preferred for neither guild Type 2 = preferred for Cold guild only Type 3 = preferred for both guilds Type 4 = preferred for Warm guild only

38 2xCO2 TCR SCENARIO Fish Guilds Type 1 = preferred for neither guild Type 2 = preferred for Cold guild only Type 3 = preferred for both guilds Type 4 = preferred for Warm guild only Percent area*days preferred for the Cold guild only (type 2) increases slightly (36% to 40%) because of large decline (35% to 10%) in very cold area*days (type 1). Percent area*days preferred for the Warm guild only (type 4) increases 3-fold (6% to 21%). Percent area*days preferred for both guilds (type 3) increases by a third (23% to 30%), increasing the probability of competition between the two.

39 2xCO2 TCR SCENARIO Lobster The percent area*days above the preferred temperature range more than doubles (from 21% to 34%). The percent area*days within the preferred temperature range remains essentially unchanged (24% to 26%) as the percent area*days below the preferred temperature range declines (55% to 40%).

40 Temperature Comparisons

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44 Conclusions A validated physical model hindcast allows for an unprecedented look into the past, to help understand the marine ecospace future. Water temperatures in the Long Island Sound are (tele)connected to the global climate forcing. Connection in relatively shallow LIS appears straightforward, through air temperature. The long term global warming trend, modulated by climate variability such as the Pacific Decadal Oscillation, has caused shifts in guild distribution and species abundance. The future trend appears to be that of an opportunistic growth of the warm guild as its suitable habitat continues increasing and its unsuitable habitat decreases. The Pacific Decadal Oscillation index is correlated to both air and water temperature, as well as fish abundance, in the Long Island Sound. Strong negative PDO phase in the summer leads to warming of water temperatures that leads to warm guild peaks during the following spring. This finding leads to a possibility for future LMR seasonal outlooks. 52

45 Acknowledgements; Thank you! Project Number: R/CE-33-NYCT Project Title: Analyzing history to project and manage the future: Simulating the effects of climate on Long Island Sound's physical environment and living marine resources. Yu Jiang: NYHOPS Historic Reconstruction Larry Yin: NYHOPS validation Justin Schulte: Climate teleconnections and correlations to fishery abundance Penny Howell: CT DEEP data, HSI development, correlations to habitat Vince Saba: GFDL CM 2.6 2xCO2 IPCC scenario The NYHOPS hindcast simulations were performed by Stevens researchers at the High Performance Computing Center of the City University of New York, College of Staten Island (CUNY HPCC). POC: 53