THE CONTINENTAL SHELF IN FRONT OF NAYARIT IS LOCATED IN THE NORTHERN LIMIT OF THE TROPICAL EASTERN PACIFIC, CHARACTERIZED BY CONSTITUTING A CONVERGENCE ZONE OF DIFFERENT MASSES OF WATER, FORMING AN AREA OF SIGNIFICANT HYDROGRAPHIC VARIABILITY. BASED ON SATELLITE REMOTE SENSING DATA AND REANALYSIS BETWEEN 2003 AND 2019 OF SEA SURFACE TEMPERATURE (SST), WIND STRESS, EKMAN VELOCITY, AND GEOSTROPHIC VELOCITY, THE CONTRIBUTION OF THE SEASONAL CYCLE TO THE VARIABILITY OF THE STUDY AREA WERE ANALYZED THROUGH CLIMATOLOGICAL MEANS, HOVMO ?HLER DIAGRAMS, AND EMPIRICAL ORTHOGONAL FUNCTIONS. THE RESULTS SHOW THAT IN THE ZONE IN FRONT OF MATANCHE ?N BAY (21.5 N) AND THE ADJACENT CONTINENTAL SHELF, THERE IS A CORE OF WARM SURFACE WATER. THE DISTRIBUTION OF THE SST IS EXPLAINED BY THE SEASONAL PATTERN OF MERIDIONAL/ZONAL VARIABILITY IN THE THERMAL GRADIENT, WHERE THE EOFS SHOW THE INFLUENCE OF THE ANNUAL SCALE IN BOTH MODES, WITH THE ONLY DIFFERENCE BEING THAT THE FIRST DESCRIBES THE MERIDIONAL GRADIENT AS THE DOMINANT SIGNAL (66.2%), AND THE SECOND SHOWS THE ZONAL BEHAVIOR OF THE THERMAL GRADIENT (16.6%). THE SUMMER WEAKENING OF THE WIND STRESS AND EKMAN SPEED IS THE PRODUCT OF THE IRREGULAR SHAPE OF THE COASTLINE, THE EXTENSION OF THE CONTINENTAL SHELF, AND THE DIVERGENCE OF THE NORTH AMERICAN MONSOON AROUND 21N, WHEREAS DURING THE REST OF THE YEAR AN INTENSIFICATION OF THESE PARAMETERS PREVAILED IN FRONT OF CABO CORRIENTES. ON THE OTHER HAND, THE INTENSE GEOSTROPHIC FLOW IN SUMMER DOES NOT CONTRIBUTE TO THE INCREASE IN SST ON THE CONTINENTAL SHELF BECAUSE IT DIVERGES AROUND 22.5N. LIKEWISE, DURING THE WINTER, THE FORMATION OF A CYCLONIC GEOSTROPHIC GYRE LOCATED INSIDE THE CONTINENTAL SHELF, BETWEEN THE COAST AND THE MAR? ?AS ISLANDS, STANDS OUT. 2022 COSPAR. PUBLISHED BY ELSEVIER B.V. ALL RIGHTS RESERVED.

TURBIDITY IS A GOOD INDICATOR TO DETERMINE THE QUALITY OF THE WATER; IT IS A MEASURE OF THE NUMBER OF PARTICLES IN SUSPENSION IN THE WATER. USING OCEAN COLOR DATA, WE ANALYZED THE SEASONAL VARIABILITY OF TURBIDITY IN FRONT OF THE CAMPECHE BANK AND PART OF THE CONFLUENCE ZONE OF THE COASTAL CURRENTS COMING FROM THE TAMAULIPAS-VERACRUZ AND CAMPECHE PLATFORMS [94°W-87.6° W AND 18°N-24°N]. THE EXTENDED PLATFORM HAS SEVERAL RIVER DISCHARGES THAT ARE STRONGLY INFLUENCED BY WINDS AND THE LOOP CURRENT COMING FROM THE STRAIT OF YUCATAN. 2003-2020 WAS ANALYZED USING SATELLITE IMAGES (REFLECTANCE, CHLOROPHYLL, SEA SURFACE TEMPERATURE, AND ALTIMETRY), REANALYZED WINDS AND DISCHARGES FROM THE GRIJALVA-USUMACINTA RIVER SYSTEM. WE USED SEASONAL CLIMATOLOGIES, HOVMOLLER DIAGRAMS, AND ORTHOGONAL AND COMPLEX EMPIRICAL FUNCTIONS TO DESCRIBE THE DATA. IN ADDITION, THROUGH THE ?COASTAL AND REGIONAL OCEAN COMMUNITY MODEL-CROCO) THE SURFACE FIELDS OF SALINITY AND VELOCITY WERE INCORPORATED INTO THE ANALYSIS. THE RESULTS INDICATED THAT THE SEASONAL TURBIDITY AND ITS INTENSIFICATION IN AUTUMN AND WINTER ON THE WESTERN SIDE OF THE CAMPECHE PLATFORM ARE DUE MAINLY TO THE CONTRIBUTION OF INTENSE FLOWS FROM THE GRIJALVA-USUMACINTA WHICH IS FURTHER DYNAMICALLY MIX IN AUTUMN BY THE SOUTHWEST WINDS, THE CYCLONIC GYRES, AND THE RETURN CURRENTS. IN SPRING-SUMMER, THE SAME FORCING PERSISTS; HOWEVER, THE TURBIDITY DECREASES DUE TO THE INEFFECTIVENESS OF THE INTENSE ZONAL WINDS TO PRODUCE EKMAN TRANSPORT.

THE CHILEAN GOVERNMENT IS DEVELOPING A COMPREHENSIVE CLIMATE CHANGE POLICY FOR FISHERIES AND AQUACULTURE, INCLUDING INSTITUTIONAL, RESEARCH AND CAPACITY BUILDING, TO REDUCE VULNERABILITY AND IMPROVE ADAPTATION IN ORDER TO MAKE THIS ECOSYSTEM SERVICES MORE RESILIENT TO FUTURE CHANGES. THIS IS ILLUSTRATED BY SEVERAL CASE STUDIES. THE OCCURRENCE OF COLD, ACIDIC AND HYPOXIC UPWELLING SEAWATER AND ENSO EVENTS ALONG THE CHILEAN COAST SUGGESTS IMPORTANT IMPACT UPON RESOURCES TARGETED BY BENTHIC FISHERIES. THE DISTRIBUTION AND ABUNDANCE OF CALCIFIERS SPECIES SUCH AS CONCHOLEPAS CONCHOLEPAS (LOCO) AND BIVALVES (SCALLOPS, MUSSELS, CLAMS) ARE THREATENED BY OCEAN ACIDIFICATION PROJECTED FOR UPWELLING REGIONS, WHILE MACROALGAE (KELPS) ARE HIGHLY VULNERABLE TO WARMER CONDITIONS. WITH A2 AND 4×CO2 CLIMATE CHANGE IPCC SCENARIOS, THE ESTIMATED SEA SURFACE TEMPERATURE (SST) CHANGES FOR ENGRAULIS RINGENS (ANCHOVY), STRANGOMERA BENTINCKI (COMMON SARDINE) AND TRACHURUS MURPHYI (JACK MACKEREL) FISHING AREAS SHOWED AN INCREASE BY 0.58°C?1.59°C AND 0.62°C?2.51°C FOR BOTH FISHING AREAS UNTIL 2065, RESPECTIVELY. BASED ON THE A2 CLIMATE CHANGE AND THE FISHING EFFORT SCENARIOS, ANCHOVY AND COMMON SARDINE LANDINGS WOULD DECREASE, AND JACK MACKEREL LANDINGS WOULD INCREASE, MILDLY. IN CHANGE, THE 4×CO2 CLIMATE CHANGE, AND FISHING EFFORTS SCENARIOS, SHOWED INCREASES ONLY IN JACK MACKEREL LANDINGS. THE FINAL CHAPTER SHOWS THE CURRENT STATE OF CHILEAN AQUACULTURE, ANALYZES THE AVAILABLE INFORMATION ON MAJOR CLIMATE FORCINGS AND ESTABLISH SCENARIOS OF POTENTIAL IMPACTS ON MAIN FARMED RESOURCES AND ON PRODUCTIVE ACTIVITIES. THE ADAPTATIONS THAT SHOULD BE CONSIDERED TO FACE THE FUTURE CLIMATE SCENARIO ALONG CHILEAN COAST ARE ADDRESSED.

THE MEJILLONES PENINSULA (23°S) IS A STRUCTURAL ZONE EXTENDING MORE THAN 40 KM OFF THE NORTH COAST OF CHILE GIVING SHAPE TO THE BAYS OF MEJILLONES AND MORENO WHICH ARE ORIENTED TO THE NORTH AND SOUTH OF THE PENINSULA, RESPECTIVELY. THE MESOSCALE OCEANOGRAPHIC VARIABILITY ASSOCIATED WITH THE PENINSULA WAS ANALYZED UTILIZING SATELLITE INFORMATION ON SEA SURFACE TEMPERATURE, CHLOROPHYLL-A CONCENTRATION, GEOSTROPHIC CURRENTS AND EKMAN TRANSPORT. THE ROLE OF THE SHAPE OF MEJILLONES PENINSULA IN THE ANNUAL AND INTERANNUAL OCEANOGRAPHIC VARIABILITY OF THE PARAMETERS IS REVEALED BY MEANS OF HOVMÖLLER DIAGRAMS AND EMPIRICAL ORTHOGONAL FUNCTIONS. THE LATITUDINAL DECREASE OF TEMPERATURE AND CHLOROPHYLL IS ABRUPTLY INTERRUPTED BY THE PENINSULA. THE FORM AND ORIENTATION OF THE MEJILLONES AND MORENO BAYS FAVOR THE RETENTION OF UPWELLED WATERS AND THE BIOLOGICAL PRODUCTION REFLECTED IN THE HIGH CHLOROPHYLL CONCENTRATION. THIS OCCURS INDEPENDENTLY OF THE PREDOMINANT TEMPERATURE AND EKMAN TRANSPORT IN THE HEAD AND SOUTH OF THE PENINSULA. THE PENINSULA INTERRUPTED AND DEVIATES TO THE WEST THE TRAJECTORY OF THE JET STREAM, WHICH VARIES SEASONALLY IN INTENSITY AND COULD GO MORE THAN 100 KM FROM THE COAST. IN ADDITION, THE RESULTS SHOW THE EXISTENCE OF CRITICAL LATITUDE (~ 22.8°S) OR TRANSITION IN WHICH THERE IS A MARKED CHANGE IN THE LATITUDINAL DISTRIBUTION OF EKMAN TRANSPORT.

TURBIDITY IS A KEY INDICATOR OF WATER QUALITY. IT HAS BIOTIC EFFECTS DUE TO LOW PENETRATION OF LIGHT INTO THE WATER SUCH AS PHOTOSYNTHESIS REDUCTION. THE SEASONAL AND INTERANNUAL VARIABILITY OF TURBIDITY IN THE EASTERN TROPICAL PACIFIC COAST OF MEXICO WERE ANALYZED USING OCEAN COLOR DATA. THE REGION HAS AN EXTENDED CONTINENTAL SHELF, WITH SEVERAL RIVER DISCHARGES AND MARKED SEASONAL PATTERNS OF WIND. REMOTE SENSING DATA (1998 TO 2017) OF REFLECTANCE, WIND, RAINFALL, AND RIVER DISCHARGES WERE ANALYZED THROUGH HOVMÖLLER DIAGRAMS AND EMPIRICAL ORTHOGONAL FUNCTIONS. THE RESULTS INDICATED THAT WIND STRESS EXPLAINED 76% OF THE TURBIDITY VARIANCE, WHILE 8% WAS EXPLAINED BY RIVER DISCHARGES AND RAINFALL. IN WINTER, TURBIDITY IS INTENSIFIED BY RESUSPENSION MECHANISMS IN FRONT OF THE SOUTHERN RIVER MOUTHS. IN SPRING, TURBIDITY INCREASES DUE TO PHYTOPLANKTON PARTICULATE CONCENTRATIONS ENHANCED BY COASTAL UPWELLING. DURING SUMMER AND AUTUMN, WIND STRESS IS WEAKER AND RIVER DISCHARGES INCREASE, THUS TURBIDITY INCREASES IN FRONT OF NORTHERN RIVER MOUTHS. EL NIÑO-SOUTHERN OSCILLATION GENERATES TURBIDITY ANOMALIES BY ALTERATION OF RAINFALL AND WIND STRESS. DESPITE THE PROXIMITY OF THE RIVER MOUTHS, THE COASTAL WATER TURBIDITY IS EXPLAINED BY DIFFERENT PROCESSES, WHICH NEED TO BE ASSESSED IN COASTAL MANAGEMENT.

SURFACE OCEANIC FRONTS ARE REGIONS CHARACTERIZED BY HIGH BIOLOGICAL ACTIVITY. HERE, SEA SURFACE TEMPERATURE (SST) FRONTS ARE ANALYZED FOR THE PERIOD 2003?2019 USING THE MULTI-SCALE ULTRA-HIGH RESOLUTION (MUR) SST PRODUCT IN NORTHERN PATAGONIA, A COASTAL REGION WITH HIGH ENVIRONMENTAL VARIABILITY THROUGH RIVER DISCHARGES AND COASTAL UPWELLING EVENTS. SST GRADIENT MAGNITUDES WERE MAXIMUM OFF CHILOÉ ISLAND IN SUMMER AND FALL, COHERENT WITH THE HIGHEST FRONTAL PROBABILITY IN THE COASTAL OCEANIC AREA, WHICH WOULD CORRESPOND TO THE FORMATION OF A COASTAL UPWELLING FRONT IN THE MERIDIONAL DIRECTION. INCREASED GRADIENT MAGNITUDES IN THE INNER SEA OF CHILOÉ (ISC) WERE FOUND PRIMARILY IN SPRING AND SUMMER. THE FRONTAL PROBABILITY ANALYSIS REVEALED THE HIGHEST OCCURRENCES WERE CONFINED TO THE NORTHERN AREA (NORTH OF DESERTORES ISLANDS) AND AROUND THE SOUTHERN BORDER OF BOCA DEL GUAFO. AN EMPIRICAL ORTHOGONAL FUNCTION ANALYSIS WAS PERFORMED TO CLARIFY THE DOMINANT MODES OF VARIABILITY IN SST GRADIENT MAGNITUDES. THE MERIDIONAL COASTAL FRONTS EXPLAINED THE DOMINANT MODE (78% OF THE VARIANCE) OFF CHILOÉ ISLAND, WHICH DOMINATES IN SUMMER, WHEREAS THE SST FRONTS INSIDE THE ISC (SECOND MODE; 15.8%) WERE FOUND TO DOMINATE IN SPRING AND EARLY SUMMER (OCTOBER?JANUARY). FUTURE EFFORTS ARE SUGGESTED FOCUSING ON HIGH FRONTAL PROBABILITY AREAS TO STUDY THE VERTICAL STRUCTURE AND VARIABILITY OF THE COASTAL FRONTS IN THE ISC AND ITS ADJACENT COASTAL OCEAN.

AN ANALYSIS OF THE MAIN REMOTLY SENSED OCEANOGRAPHIC VARIABLES WAS CONDUCTED TO CHARACTERIZE THE DOMINANT DRIVERS THAT MODULATE THE SPATIAL-TEMPORAL VARIABILITY OF COASTAL PHYTOPLANKTON BIOMASS IN THE NORTHERN LIMIT OF THE EASTERN TROPICAL PACIFIC. THE PHYTOPLANKTON BIOMASS WAS ANALYZED USING MONTHLY AVERAGE SATELLITE CHLOROPHYLL (CHLO) CONCENTRATION DATA FROM MODIS SENSORS FOR THE PERIOD 2003?2017. OCEANOGRAPHIC CONDITIONS WERE ANALYZED BY CONSIDERING (I) SEA SURFACE TEMPERATURE (SST) HIGH-RESOLUTION DATA FROM THE GHRSST PROJECT, (II) WIND STRESS CALCULATED WITH DATA FROM THE ZONAL AND MERIDIONAL COMPONENTS OF THE CCMP PRODUCT, (III) CLIMATOLOGICAL PRECIPITATION, AND (IV) CLIMATOLOGICAL RIVER FLOW. CHLO TIME SERIES AND SPATIAL VARIABILITY WERE ANALYZED USING HOVMÖLLER DIAGRAMS AND EMPIRICAL ORTHOGONAL FUNCTIONS (EOF), RESPECTIVELY. A STRONG SEMI-ANNUAL SIGNAL IN CHLO CONCENTRATION ALONG THE COAST WAS OBSERVED: THE FIRST PEAK OCCURS IN WINTER-SPRING (5.0 MG·M?3) AND A SECOND ONE IN SUMMER-AUTUMN (6.5 MG·M?3). A HIGH YEAR-ROUND AVERAGE OF CHLO CONCENTRATION (3.0?15.0 MG·M?3) WAS MAINTAINED BY A 10 KM WIDE ALONG-SHORE COAST, WITH MAXIMUM VALUES SPATIALLY ASSOCIATED WITH RIVER MOUTHS, OF WHICH SANTIAGO RIVER REGISTERED THE HIGHEST CHLO VALUES (20.0 MG·M?3). SURFACE OCEANOGRAPHIC CONDITIONS SHOWED A MARKED ANNUAL CYCLE WITH WARMER CONDITIONS (30?31 °C) FROM JULY TO OCTOBER AND COLDER ONES (23?24 °C) FROM DECEMBER TO APRIL; DURING THE COLD PERIOD, SEASONAL WIND STRESS STIMULATED COASTAL UPWELLING. THE EOF SHOWED THAT 70% OF CHLO CONCENTRATION VARIABILITY WAS CONTROLLED BY THE SEMI-ANNUAL PATTERN, WHICH RESPONDED TO COASTAL UPWELLING CONDITIONS DURING COLD PERIOD, WHILE RIVERS OUTFLOWS INFLUENCED HIGH CHLO CONCENTRATION DURING THE WARM PERIOD. THESE RESULTS HIGHLIGHTED THE IMPORTANCE FOR LAND-OCEAN INTERFACE TO SUSTAIN COASTAL ECOSYSTEMS BIOLOGICAL PRODUCTION AND THE MAJOR ROLE OF WATERSHEDS AS SOURCES OF NUTRIENTS TO MAINTAIN HIGH BIOLOGICAL PRODUCTION DURING WARM PERIO

THE INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE (IPCC, GENEVA, SWITZERLAND) REPORTS THAT CLIMATIC ZONING REQUIRES NEW METHODOLOGIES TO DISCRIMINATE HOMOGENEOUS AREAS DUE TO NEW SCENARIOS GENERATING GLOBAL CLIMATIC CHANGE. THE OBJECTIVE OF THIS STUDY WAS TO PERFORM CLIMATIC ZONING BY ANALYZING SPATIAL AND TEMPORAL VARIABILITY OF LAND SURFACE TEMPERATURE (LST) AND THE NORMALIZED DIFFERENCE VEGETATION INDEX (NDVI). THE 20-YR SEQUENCE OF MODIS (LST AND NDVI) IMAGES WAS ANALYZED BY HARMONIC ANALYSIS, EMPIRICAL ORTHOGONAL FUNCTIONS (EOFS), AND CONTINUOUS WAVELET CROSS-CORRELATION FUNCTIONS. ANNUAL HARMONIC ANALYSIS IDENTIFIED AGROCLIMATIC ZONES FROM AMPLITUDE AND PHASE, THIS RESULT WAS VALID FOR THE TWO FIRST EOF MODES THAT ACCOUNT FOR 74% OF THE ANNUAL SIGNAL. WAVELET CROSS-CORRELATIONS BETWEEN THE NDVI AND LST TEMPORAL SERIES SHOWED A WIDEBAND HIGH-POWER SPECTRUM ASSOCIATED WITH THE ANNUAL CYCLE. FINALLY, THE METHODOLOGIES APPLIED TO LST AND NDVI IMAGES ALLOWED THE IDENTIFICATION OF AGROCLIMATIC ZONES. THE STUDY AREA INCLUDED DIFFERENT DRYLAND ZONES (COASTAL, INTERIOR, AND FOOTHILL), IRRIGATED VALLEYS, AND FORESTS. © 2015 INSTITUTO DE INVESTIGACIONES AGROPECUARIAS, INIA. ALL RIGHTS RESERVED.

MEASUREMENTS OF CURRENTS, WAVES AND WINDS WERE MADE IN SENO DE RELONCAVÍ, CORCOVADO GULF, (PACIFIC COAST/WEST AREA) OF CHILOÉ AND THE DARWIN CANAL INLET. THESE OBSERVATIONS WERE COMPLEMENTED WITH HISTORICAL DATA, WITH THE AIM OF DETERMINING WIND, CURRENT AND WAVE EXTREME VALUES AND LOCAL VARIABILITY NORTH OF THE PATAGONIC FJORDS IN CHILE. RESULTS SHOWED THE PREDOMINANCE OF THE NORTH WIND AND LOCAL WAVE REGIME (HS < 0.5 M) FOR THE NORTH COAST OF SENO DE RELONCAVÍ. THE WEST OF CHILOÉ IS CHARACTERIZED BY LONG WAVES (HS > 2 M) ORIGINATING IN THE PACIFIC AND THE DOMINANCE OF THE SOUTH AND SOUTHEAST WIND DRIVEN BY REGIONAL CIRCULATION. IN THE AREA OF CORCOVADO GULF AND THE DARWIN CANAL INLET, THE WIND FOLLOWS THE DIRECTION OF THE TOPOGRAPHY, WHILE AT ITALIA ISLAND LOCAL WAVES ARE PREDOMINANT (HS < 0.5 M). IN CORCOVADO GULF A COMBINED LOCAL AND LONG WAVE REGIME (HS ~2M) WAS OBSERVED. FURTHERMORE, RESULTS SHOWED THAT THE TIDE IS THE MAIN COASTAL CURRENT FORCING MECHANISM IN THE AREA OF THE FJORDS AND CANALS, DIFFERING FROM THAT AT CHILOÉ AND ITALIA ISLAND (PACIFIC COAST/WEST AREA), WHERE WIND IS THE MAIN DRIVER OF COASTAL CIRCULATION. DIFFERENCES FOUND BETWEEN BOTH ZONES, ESPECIALLY BETWEEN INLET AND OFF THE COAST ZONES, NORTH OF THE PATAGONIC FJORDS IN CHILE, ARE EVIDENCE THAT THE TOPOGRAPHY PLAYS A FUNDAMENTAL ROLE IN THE WIND AND CURRENT DIRECTIONS.