Drivers of Ocean Iron Stress Variability in High-Nutrient,Low-Chlorophyll Regions from Ocean Color  

作　　者：James S.Lin Robert T.Letscher 

机构地区：[1]Ocean Process Analysis Lab,University of New Hampshire,Durham,NH,USA [2]Department of Earth Sciences,University of New Hampshire,Durham,NH,USA

出　　处：《Ocean-Land-Atmosphere Research》2024年第1期43-56,共14页海洋-陆地-大气研究(英文)

基　　金：supported by US NSF award 2049590 to R.T.L.

摘　　要：Determining the seasonal,interannual,and decadal trends of Fe stress in oceanic regions helps quantify the variability in marine nutrient limitations.However,seasonally resolved time-series measurements of dissolved Fe from 3 high-nutrient,low-chlorophyll regions(equatorial Pacific[EQ],subarctic North Pacific[SNP],and Southern Ocean[SO])are limited to nonexistent.Here,we compared the temporal variability in nonphotochemical quenching satellite-based fluorescence quantum yields(NPQ-correctedϕsat),a remote sensing estimate of phytoplankton Fe stress,from 2 decades(January 2003 to December 2022)of monthly ensemble Moderate Resolution Imaging Spectroradiometer-Aqua satellite data with different modes of interannual climate variability.Climatological NPQ-correctedϕsat was in the following ascending order:SO(1.51%±0.39%,mean±SD),SNP(2%±0.13%),and EQ(2.70%±0.16%).The seasonal variability in Fe stress was±5.6%in the EQ,±8.51%in the SNP,and±19.56%in the SO(n=240).EQ Fe stress was correlated with the negative-phase Multivariate El Niño-Southern Oscillation Index Version 2 and positive-phase Southern Oscillation Index,indicating more Fe stress during La Niñas and at colder sea surface temperatures.The SNP region was positively correlated with the North Pacific Gyre Oscillation,indicating more Fe stress at lower sea level heights and upwelling.The SO exhibited seasonally Fe-replete zones;these may be linked to Fe-laden dust and shelf input that are spatially heterogeneous and concentrated around landmasses,whereas sea ice limited data coverage in winter.For both the SNP and SO,monthly chlorophyll and other productivity metrics helped predict future or contemporaneous Fe stress.Fe stress predictability at interannual scales was possible using sea surface temperature and sea level height anomalies,but finer-scale spatial coverage and added observational data are needed to partition climate oscillation effects.

关 键 词：SEASONAL INTERANNUAL WINTER 

分 类 号：P73[天文地球—海洋科学]