Mechanisms of Fast Changes in Physical and Biological Fields along Primorye Coast in the Japan Sea

Transcription

1 Mechanisms of Fast Changes in Physical and Biological Fields along Primorye Coast in the Japan Sea V.Lobanov, V.Zvalinsky, P.Tishchenko, A.Salyuk, S.Ladychenko, S.Zakharkov and Shtraikhert V.I.Il ichev Pacific Oceanological Institute, Far Eastern Branch, Russian Academy of Sciences, Vladivostok, Russia

2 Main geographic features Primorye coast Japan Sea -Deep semi-isolated isolated basin (35 m), narrow shelf -Along slope current, shelf waves, coastal eddies -Monsoon winds, upwelling -Strong seasonal variation of SST, SSS and stratification Владивосток

3 Изменение у м. Крас с 22 августа по 25 октября (суточное осреднение) дата Изменнение БК с 22 августа по 3 октября (суточное осреднение) теспература Изменение МВАТ с 26 августа по 23 октября (суточное осреднение) дата температура дата температура Short-term term variation of water temperature along Primorye Coast POI and TINRO moorings data 23: Abrupt short-term term variations the same magnitude as seasonal ones - of C Vladivostok Nakhodka Major impact on : - Fishery and aquaculture (sea-urchin, laminaria,, shell-fishes) - Biodiversity - Recreation and health etc.

4 Objectives to understand main physical processes responsible for abrupt changes of water circulation, stratification and biological parameters along Primorye coast in Fall season Data - two repeated ship surveys October 12-November, 2 (CTD, chemical and plankton sampling) - NOAA AVHRR infrared images - SeaWiFS ocean color images - hydrometeorological data

5 PICES JES Cruise PICES JES Cruise 2, r/v Professor Gagarinskiy 1 leg - Oct (blue line) 2 leg Oct 31 Nov 3 (red line) Vladivostok Preobrazhenie Rudnaya Pristan' Olga 23 2 Velikaya Kema Samarga Hakodate Measurements: CTD, DO, Nitrates, Nitrites, Phosphates, Silica, ph, Alkalinity, Chl-a, DF, PP, plankton

6 leg - Oct leg Oct 31 Nov 3 Vladivostok Preobrazhenie Rudnaya Pristan' Olga 23 2 Velikaya Kema Samarga Upwelling Winds Hakodate direction wind speed Coastal station Gamov October October NCEP/NCAR Oct. QuickScat

7 leg - Oct leg Oct 31 Nov 3 SST Changes on Satellite Images direction wind speed Coastal station Gamov October October 2 NCEP/NCAR Oct. QuickScat Formation of coastal eddies and upwelling event off Primorye on NOAA AVHRR infrared images

8 SST Changes on Satellite Images Wind induced upwelling - Mesoscale eddies formation - Fast cooling, convection o C 5. o C Formation of coastal eddies and upwelling event off Primorye on NOAA AVHRR infrared images Slow decrease of SST on the shelf and fast drop

9 Hydrographic sections: different changes in subsurface layers at coastal stations S1 S S1 S2 L1 L2 Formation of coastal eddies and upwelling event off Primorye on NOAA AVHRR infrared images Changes in T, S, density and nutrients along the sections S1 and over 2-3 weeks period : Upwelling and convective mixing off Preobrazhenie (13E) T, o C S1 1 m m S1: Intrusion of deep sea water onto the shelf of Peter the Great Bay

10 ,, Chl-a a and Primary Production Chl-a filtration and spectrometer; Photic layer depth Secchi disc; PP radiocarbon marker, PP- calculated on Chl-a, DF, Asn, Fln, PAR (Zvalinsky et al., 19, 22); Nutrients, ph, Talk (pco2, DIC) 1 2 3, / Shallow, / () 2(23) 6(92) 3(36) 61(66) (66) 62(6) (7) 63(26) 31(9) (15) 1(629) 1(125) 19(15) 27(12) 1 1 L1 L2 Vertical profiles of Chl a increase and deepening of max at shallow stations Deep (15) 9(15) 5(15) 52(335) 53(235) Shallow Deep Total Leg L1 L2 L1 L2 L1+L2 Chl (mg/m 3 ) Chl (mg/m 2 ) Range Daylight, (hour) PAR (mol/m 2 d) PP(mgС/m 2 d) Range % % % , % , % % Increase of Chl and PP between L1 and L2 by ~-6% in the shelf area

11 L1 Chl-a, pco2, Nutrients L /NO NO 3 SiO pco 2 Chl Станция Z=7 SiO pco Chl /NO SiO NO 3 pco 2 Chl T SiO pco Chl T Станция 9 Z= /NO T Chl 2 SiO NO 3 6 Z= 5 pco 2 SiO pco Chl /NO SiO NO 2 3 T pco Z=26 SiO Chl pco Chl - Gradual increase of nutrients by L2 caused by weakened stratification and uplift of picnocline - L1: PP was limited by low nutrients, esp. Nitrates - pco2 profiles: increased production in upper layer and destruction in lower layer on L2 Vertical profiles of T, pco2, NO3, SiO and Chl a for some stations before and after upwelling

12 , / I L1-11(52-5) 2-7 (59-63) от берега, км Vladivostok 63 2 Preobrazhenie Chl-a a and Primary Production Olga (37-3), / (2-7) II 52-5(-11) S1 37-3(12-1) 12 яние, км Chl a content in a photic layer along the sections in situ (more increasing in the west) L2 Chl a SeaWiFS data S ПП (мгс/м2/день)_i ПП (мгс/м2/день)_ii_a L1 L Primary Production in a photic layer before after

13 Changes in water mass structure and stratification: upwelling, eddies and convection S1 T, o C S1 1 m m MLD, m S1 L L before after before after Intrusion area, wide shelf: -Uplift of picnocline Upwelling area, narrow shelf: -Vertical mixing On shore intrusion Upwelling, divergence -Mixing of upper layer -Nutrients supply -Decrease stratification -Nutrients supply wide shelf narrow shelf -Decrease MLD -Increase MLD S1 Eddy

14 Conclusion 1. The major processes responsible for abrupt changes of physical and biological Physical parameters of processes the Primorye coast and in their Fall season impact are: to ecosystem Wind induced upwelling Eddies formation Cooling and Convection Upward fluxes of nutrients Enchanced local upwelling Off-shore transport of shelf water, Ventilation of coastal zone On-shelf intrusions of deep sea water, nutrients supply Mixing of upper layer, changing stratification 2. These may have both positive and negative impact on ecosystem - enrichment processes (mixing, upwelling, etc.) - concentration processes (convergence, frontal shear, water column stability, etc.) - processes favoring retention within (or drift toward) appropriate habitat. - abrupt decrease of T during spawning period mortality of laminaria seeds and sea urchin larvae - enhanced cross shelf transport dispersal of larvae off the shelf, decrease of future stocks.

15 Thank you!