简介:AnalternativeindexfortheonsetofsummermonsoonovertheSouthChinaSea(SCS)hasbeendesignedbasedonthereanalysisdataoftheNationalCentersforEnvironmentalPrediction-NationalCenterforAtmosphericResearch(NCEP/NCAR).ItisfoundthatthedifferencebetweenthegeopotentialthicknessoverGuangzhouandManilacanbeusedasanalternativeindexfortheonsetofsummermonsoonovertheSCS.SincetheconvectiveheatingaltersthegeopotentialheightandthedistancebetweenGuangzhouandManilaisofsynopticscaleinthegeostraphicframework,theindexcanrepresentthestrengthofheatingandthefirstbarocliniccellovertheSCS.Bycomparisonbetweendifferentindices,itisfoundthatthesummermonsoononsetovertheSCScanbeascertainedbytheverticalzonalwindshearbetween200hPaand850hPa,thezonalwindat850hPa,theOLRanomaly,andthealternativeindexdefinedinthepresentpaper.Themeridionalwindshearbetween200hPaand850hPaalwaysappearsovertheSCSmuchearlierthanthezonalwindshearandcannotbeusedasanindexunderconsideration.
简介:Inordertoinvestigatetherelationshipbetweenthetraceelementsandthecharacteristicsoftheoysters,weanalyzedthetraceelementspresentinthegermplasmofoystersfromdifferentproducingareasintheJiaozhouBay.Theelementfingerprintswereestablishedtoreflecttheelementalcharacteristicsoftheoysters.Concentrationpatternsoftheelementsweredecipheredbyprinciplecomponentanalysis(PCA)andhierarchicalclusteranalysis(HCA).ThesixregionswerediscriminatedwithaccuracyusingHCAandPCAbasedontheconcentrationof16traceelements.Theelementswereviewedascharacteristicelementsoftheoystersandthefingerprintsoftheseelementscouldbeusedtodistinguishthequalityoftheoysters.