Download full issue - PanamJAS

More documents

Recommendations

Info

242Á. M. CIOTTI ET ALLIat the BSC are, unfortunately, limited today to12 years of continuous ocean color data data(i.e., SeaWiFs and MODIS/Aqua), and none ourchosen Areas has showed strong positive ornegative Chl trends with time. It is worthmentioning that understanding the impacts of globalchange demands long-term biological observationsand that will be jeopardized for the BCS if thecurrent NASA’s programs are discontinued. Thus,it is imperative to create and maintain new oceancolor programs and to involve the Brazilianscientific community on using and interpreting itspotential products.Seasonal and Meridional Chl variabilityThe seasonal mean Chl per area derived bySeaWiFS and MODIS/Aqua (Table III), place Area3 as a boundary of low Chl that separates gradientstowards north and south. Maximum Chl per areaincreases steeply towards north (3-fold in Area 2 andan order of magnitude in Area 1) occurring duringfall while towards south, Chl gradients were gradualand occurred during winter. In Areas 3 and 4, Chlwas high and similar in fall and winter, and low andsimilar in spring and summer. Area 2 showed asingle and modest Chl peak in the fall. Periods withminimum Chl values also varied meridionaly, andwere observed during spring in Area 1 and duringsummer in Areas 5, 6 and 7.The seasonal and meridional distribution ofmean data coverage per Area and instrument (Tab.III), showed that only half of the 8-Day compositeimages were available most of the year in Area 1and that data coverage was about 13 to 18% duringsummer and 23 to 27% during fall. Area 2 has alsoshowed poor data coverage during summer (29 to33%) and fall (44 to 53%).It was possible to model significant annualcycles in all Areas, except for Area 2 (Table IV).The best fits were found in Areas 7 and 4,suggesting that the main processes for accumulationand loss of phytoplankton biomass operate ratherseasonally, especially in Area 7 (r 2 =0.78). Allremaining Areas showed correlations of 0.52 to 0.58to the annual model, probably a result of importantinter-annual variability as in Area 1 in 2001 andArea 6 during 2007 (Fig. 5), for instance.The meridional patterns of Chl were indeedrelated to the main reported seasonal changes inhydrography. In Area 1, the most prominent featureis the Amazon River discharge, which providesseasonally dissolved colored material, nutrients,sediments and detritus to larger extensions of thecontinental shelf. During the rainy seasons (summerand spring) larger river discharge is combined withchanges in both wind direction (from SE to NE) andin transport rates of the North Brazil Current(Molleri et al. 2010). Both the size and theorientation of the Amazon plume are responsible forthe magnitude and seasonal Chl variability and alsoreflect the amount of particles and dissolved loadthat can interfere in the Chl algorithm performance.Chl changes in Areas 2 and 3 are likely to beassociated with variability in the biologicalprocesses, probably driven by changes in watertemperature and irradiance, since neither major riverflow nor relevant oceanographic features (e.g.,upwelling) are reported for those two areas, whichare the least studied ones of our BSC subdivision. InArea 2, no significant parameters could be found forthe annual variability in Chl (Table IV), whichshowed a fall Chl peak only about 25% higher thanthat for the remaining of the year. Area 3 showed thelowest Chl in comparison to all other Areas, with astrong seasonal cycle. The annual amplitudesdetected by the SeaWiFs time series were 0.04 and0.12 mg.m -3 for Areas 2 and 3, respectively (TableIV). It is important to remember that Area 3 is thesmallest despite occupying over 10 degrees oflatitude.Areas 2 to 4 are also under direct influenceof the seasonal and meridional migration of theInter-Tropical Convergence Zone (ITCZ) in thesouth Atlantic and thus they will likely respond toany mode of change in the wind fields. Northern andweak winds occur in the summer, enhancing verticalstratification that in turn is expected to disfavor Chlaccumulation. In the winter, southern and strongerwinds have been already linked to increases in Chlin Area 4 due to the erosion of the picnocline andconsequent fertilization of the surface layers (Ciottiet al. 2006). In addition, Area 4 comprises theAbrolhos region with a shallow continental shelf,allowing addition of nutrients by ressuspension ofbottom water masses. The seasonal influence ofwind regimes on vertical mixing is suggested by thegood adjustment of the Chl series to the annualmodel (Table IV). Abrolhos, and a number of banksadjacent to Area 4 affect the flow and direction ofthe Brazil Current (BC). As a consequence, the mainflow of the BC shows mesoscale instabilities andmeanders (Gaeta et al. 1999) that have a significantimpact on the circulation of the Areas towards thesouth (Calado et al. 2008, Silveira et al. 2008).Areas 5 and the northern third of Area 6encompass the most studied regions of the BSC (seereview in Castro et al. 2006). Areas 5 and 6 wereseparated at São Sebastião Island latitude because oftheir important distinct oceanographic features. Area5 includes Cabo São Tomé and Cabo Frio, wherePan-American Journal of Aquatic Sciences (2010), 5(2): 236-253
Temporal and meridional variability of Satellite-estimates of surface chlorophyll concentration243Table II. Division for the BSC in subareas based on Castro et al. (2006). For each sensor and area, columns representthe number of 8-Day images with no data; n is the length of each sensor data sets (up to the end 2009 for thoseoperational) for 8-Day images. Also, the total number of Pixels over the delimited continental shelf (20 to 200 m): 9 kmfor OCTS and SeaWiFS and 4 km for CZCS and MODIS/Aqua.Area and latitudinalrangeSeaWIFS(n=568)Modis/Aqua(n=345)OCTS(n=30)CZCS(n=353)Number of 9 KmpixelsNumber of 4 Kmpixels1 - 04N-01S 37 3 3 282 1742 69182 - 01S-05S 35 2 2 240 561 22373- 05S-15S 36 2 0 259 258 10174- 15S-21S 39 2 1 285 656 25875- 21S-24S 39 2 3 298 689 27276- 24S-28S 37 2 0 297 1229 49377- 28S-34S 37 2 0 270 1288 5168Figure 3. Time series of 8-Day median chlorophyll concentration over the seven Areas of the BCS (see Table I forlimits), provided by the four ocean color sensors (see legend) during their respective operation periods.Pan-American Journal of Aquatic Sciences (2010), 5(2): 236-253
Page 3 and 4:
PAN-AMERICAN JOURNAL OF AQUATIC SCI
Page 5 and 6:
Representations in the Brazilian me
Page 7 and 8:
IIM. S. COPERTINO ET ALLIIntroducti
Page 9 and 10:
IVM. S. COPERTINO ET ALLIpollution
Page 11 and 12:
VIM. S. COPERTINO ET ALLIpublic pol
Page 13 and 14:
VIIIM. S. COPERTINO ET ALLINicholls
Page 15 and 16:
XC.A.E. GARCIA & C.A. NOBREimplemen
Page 17 and 18:
Brazilian coastal vulnerability to
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Potential vulnerability of the Braz
Page 31 and 32:
Page 33 and 34:
Page 36 and 37: 192J. L. NICOLODI & R. M. PETERMANN
Page 50 and 51: 206L. F. D. FARACO ET ALLIIntroduct
Page 52 and 53: 208L. F. D. FARACO ET ALLIclimate c
Page 54 and 55: 210L. F. D. FARACO ET ALLIfocused o
Page 56 and 57: 212L. F. D. FARACO ET ALLIIn spite
Page 58 and 59: 214L. F. D. FARACO ET ALLIand ecolo
Page 60 and 61: 216L. F. D. FARACO ET ALLIconsideri
Page 62 and 63: 218L. F. D. FARACO ET ALLITable I.
Page 64 and 65: 220L. F. D. FARACO ET ALLIBadjeck,
Page 66 and 67: 222L. F. D. FARACO ET ALLIParaná,
Page 68 and 69: Status of Eastern Brazilian coral r
Page 70 and 71: 226Z. M. A. N. LEAO ET ALLIVerrill
Page 72 and 73: 228Z. M. A. N. LEAO ET ALLITable I.
Page 74 and 75: 230Z. M. A. N. LEAO ET ALLICruz (20
Page 76 and 77: 232Z. M. A. N. LEAO ET ALLIdistinct
Page 78 and 79: 234Z. M. A. N. LEAO ET ALLIDutra, L
Page 80 and 81: Temporal and meridional variability
Page 82 and 83: 238Á. M. CIOTTI ET ALLIdistributin
Page 84 and 85: 240Á. M. CIOTTI ET ALLIFigure 2. B
Page 88 and 89: 244Á. M. CIOTTI ET ALLIcostal upwe
Page 90 and 91: 246Á. M. CIOTTI ET ALLIfrom Area 7
Page 92 and 93: 248Á. M. CIOTTI ET ALLITable III.
Page 94 and 95: 250Á. M. CIOTTI ET ALLICampbell, J
Page 96 and 97: 252Á. M. CIOTTI ET ALLIfloats. Dee
Page 98 and 99: Regime shifts, trends and interannu
Page 100 and 101: 256FERNANDO E. HIRATA ET ALLIThe st
Page 102 and 103: 258FERNANDO E. HIRATA ET ALLIcompar
Page 104 and 105: 260FERNANDO E. HIRATA ET ALLIUsing
Page 106 and 107: 262FERNANDO E. HIRATA ET ALLIFigure
Page 108 and 109: 264FERNANDO E. HIRATA ET ALLIthis i
Page 110 and 111: 266FERNANDO E. HIRATA ET ALLItal ch
Page 112 and 113: 268D. MUEHE ET ALLIIntroductionThe
Page 114 and 115: 270D. MUEHE ET ALLItrenches were du
Page 116 and 117: 272D. MUEHE ET ALLIging the vegetat
Page 118 and 119: 274D. MUEHE ET ALLIFigure 15. Estim
Page 120 and 121: 276D. MUEHE ET ALLIPetrology, 27: 3
Page 122 and 123: 278A. A. MACHADO ET ALLIdays, it is
Page 124 and 125: 280A. A. MACHADO ET ALLIwas tested
Page 126 and 127: 282A. A. MACHADO ET ALLIthe initial
Page 128 and 129: 284A. A. MACHADO ET ALLIFigure 10.
Page 130 and 131: 286A. A. MACHADO ET ALLIlevel. A ha
Page 132 and 133: 288S. MEDEANIC & I. C. S. CORREAInt
Page 134 and 135: 290S. MEDEANIC & I. C. S. CORREATab
Page 136 and 137:
292S. MEDEANIC & I. C. S. CORREAFig
Page 138 and 139:
294S. MEDEANIC & I. C. S. CORREA(in
Page 140 and 141:
296S. MEDEANIC & I. C. S. CORREAJar
Page 142 and 143:
Representations in the Brazilian me
Page 144 and 145:
300D. HELLEBRANDT & L. HELLEBRANDTT
Page 146 and 147:
302D. HELLEBRANDT & L. HELLEBRANDTF
Page 148 and 149:
304D. HELLEBRANDT & L. HELLEBRANDTc
Page 150 and 151:
306D. HELLEBRANDT & L. HELLEBRANDTT
Page 152 and 153:
308D. HELLEBRANDT & L. HELLEBRANDTB
Page 154 and 155:
Differences between spatial pattern
Page 156 and 157:
312D.F.M GHERARDI ET ALLIface too m
Page 158 and 159:
314D.F.M GHERARDI ET ALLIFigure 3.
Page 160 and 161:
316D.F.M GHERARDI ET ALLIthe Brazil
Page 162 and 163:
318D.F.M GHERARDI ET ALLIAcknowledg
Page 164 and 165:
An essay on the potential effects o
Page 166 and 167:
322F. A. SCHROEDER & J. P. CASTELLO
Page 168 and 169:
Page 170 and 171:
Page 172 and 173:
Page 174 and 175:
Page 176 and 177:
332A. T. LEMOS & R. D. GHISOLFIIntr
Page 178 and 179:
334A. T. LEMOS & R. D. GHISOLFIeros
Page 180 and 181:
336A. T. LEMOS & R. D. GHISOLFITabl
Page 182 and 183:
338A. T. LEMOS & R. D. GHISOLFIFigu
Page 184 and 185:
340A. T. LEMOS & R. D. GHISOLFIOcea
Page 186 and 187:
342M. B. S. F. COSTA ET ALLIcoastal
Page 188 and 189:
344M. B. S. F. COSTA ET ALLIResults
Page 190 and 191:
346M. B. S. F. COSTA ET ALLIlevel i
Page 192 and 193:
348M. B. S. F. COSTA ET ALLIPaulist
Page 194 and 195:
Temporal changes in the seaweed flo
Page 196 and 197:
352CAROLINE DE FAVERI ET ALLITable
Page 198 and 199:
354CAROLINE DE FAVERI ET ALLICallit
Page 200 and 201:
356CAROLINE DE FAVERI ET ALLIcomple
Page 202 and 203:
RIO GRANDE DECLARATION1 st BRAZILIA
Page 204 and 205:
XIVResearchers from Rede Clima and
show all

Download full issue - PanamJAS

Create successful ePaper yourself

Delete template?

Save as template?