# Deglacial North East Pacific Radiocarbon and Boron Isotope Data from MD02-2489 #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # NOTE: Please cite original publication, online resource and date accessed when using this data. # If there is no publication information, please cite Investigator, title, online resource and date accessed. # # Online_Resource: http://www.ncdc.noaa.gov/paleo/study/16648 # # Online_Resource: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/rae2014/rae2014-t6.txt # # Archive: Paleoceanography # #-------------------------------- # Contribution_Date # Date: 2014-06-18 #-------------------------------- # Title: Deglacial North East Pacific Radiocarbon and Boron Isotope Data from MD02-2489 #-------------------------------- # Investigators: Rae, J.W.B.; Sarnthein, M.; Foster, G.L.; Ridgwell, A.; Grootes, P.M.; Elliott, T. #-------------------- # Description and Notes: # The data given here include age models, boron isotope data analysed by MC-ICPMS, and radiocarbon data analysed by AMS. # # Keywords from PI: Radiocarbon; Boron isotopes; North Pacific; Deglacial CO2; Deep water formation; #-------------------- # Publication # Authors: Rae, J.W.B., M. Sarnthein, G.L. Foster, A. Ridgwell, P.M. Grootes, and T. Elliott # Journal_Name: Paleoceanography # Published_Title: Deep water formation in the North Pacific and deglacial CO2 rise # Published_Date_or_Year: 2014 # Volume: # Pages: # DOI: 10.1002/2013PA002570 # Abstract: Deep water formation in the North Atlantic and Southern Ocean is widely thought to influence deglacial CO2 rise and climate change; here we suggest that deep water formation in the North Pacific may also play an important role. We present paired radiocarbon and boron isotope data from foraminifera from sediment core MD02-2489 at 3640 m in the North East Pacific. These show a pronounced excursion during Heinrich Stadial 1, with benthic-planktic radiocarbon offsets dropping to ~350 years, accompanied by a decrease in benthic δ11B. We suggest this is driven by the onset of deep convection in the North Pacific, which mixes young shallow waters to depth, old deep waters to the surface, and low-pH water from intermediate depths into the deep ocean. This deep water formation event was likely driven by an increase in surface salinity, due to subdued atmospheric/monsoonal freshwater flux during Heinrich Stadial 1. The ability of North Pacific Deep Water (NPDW) formation to ex plain the excursions seen in our data is demonstrated in a series of experiments with an intermediate complexity Earth system model. These experiments also show that breakdown of stratification in the North Pacific leads to a rapid ~30 ppm increase in atmospheric CO2, along with decreases in atmospheric δ13C and Δ14C, consistent with observations of the early deglaciation. Our inference of deep water formation is based mainly on results from a single sediment core, and our boron isotope data are unavoidably sparse in the key HS1 interval, so this hypothesis merits further testing. However we note that there is independent support for breakdown of stratification in shallower waters during this period, including a minimum in δ15N, younging in intermediate water 14C, and regional warming. We also re-evaluate deglacial changes in North Pacific productivity and carbonate preservation in light of our new data, and suggest that the regional pulse of export production observe d during the Bølling-Allerød is promoted by relatively stratified conditions, with increased light availability and a shallow, potent nutricline. Overall, our work highlights the potential of NPDW formation to play a significant and hitherto unrealized role in deglacial climate change and CO2 rise. #-------------------------------- # Funding_Agency: # Funding_Agency_Name: Natural Environment Research Council # Grant: NE/I017240/1, NE/C00876X/2 #-------------------------------- # Funding_Agency: # Funding_Agency_Name: NOAA/UCAR Climate and Global Change Postdoctoral Fellowship Program # Grant: #-------------------------------- # Funding_Agency: # Funding_Agency_Name: Deutsche Forschungsgemeinschaft # Grant: #-------------------------------- # Site Information: # Site_Name: MD02-2489 # Location: Eastern Pacific Ocean # Northernmost_Latitude: 54.39 # Southernmost_Latitude: 54.39 # Easternmost_Longitude: -148.92 # Westernmost_Longitude: -148.92 # Elevation: -3640 #-------------------------------- # Data Collection # Collection_Name: MD02-2489 Tab6-14C Benthic R14 # Oldest_Year: 18663 # Most_Recent_Year: 11920 # Time_Unit: cal yr BP # Core_Length: # Notes: Table 6: benthic 14C data for MD02-2489 #-------------------------------- # Chronology: # #-------------------------------- # Variables # # Data variables follow (have double marker- "##") # Data line variables format: Variables list, one per line, shortname-tab-nine components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) ## depth_cm depth,,,cm,,,,,N ## age_calkaBP-d18 age,,,calendar kyr before 1950AD,,,using d18O ties,,N ## age_calkaBP-plat age,,,calendar kyr before 1950AD,,,plateau-tuned,,N ## age_14C.raw-ben age,raw conventional 14C benthic forams,,14C years before 1950AD,,paleoceanography,,,N ## age_14C.raw-ben_err age,raw conventional 14C benthic forams,1-sigma error,14C years before 1950AD,,paleoceanography,,,N ## age_14C.raw-plank age,raw conventional 14C planktic forams,,14C years before 1950AD,,paleoceanography,,,N ## age_14C.raw-plank_err age,raw conventional 14C planktic forams,1-sigma error,14C years before 1950AD,,paleoceanography,,,N ## age_14C.raw-offset age,raw conventional 14C benthic - planktic,,14C years before 1950AD,,paleoceanography,,,N ## age_14C.raw-offset_err age,raw conventional 14C benthic - planktic,1-sigma error,14C years before 1950AD,,paleoceanography,,,N ## D14C-ben Delta 14C,benthic forams,,per mil VPDB,,paleoceanography,relative to VPDB standard and corrected for mass dependent isotope fractionation,,N ## DD14C-ben Delta Delta 14C,Difference between benthic foraminifera and the contemporaneous atmosphere units,,per mil VPDB,,paleoceanography,,,N ## age_ben-atm age,difference between benthic foraminifera and the contemporaneous atmosphere units,,14C years before 1950AD,,paleoceanography,,,N ## notes notes,,, ,,,,,C # Data: # Missing Value: depth_cm age_calkaBP-d18 age_calkaBP-plat age_14C.raw-ben age_14C.raw-ben_err age_14C.raw-plank age_14C.raw-plank_err age_14C.raw-offset age_14C.raw-offset_err D14C-ben DD14C-ben age_ben-atm 96 11920 11920 12205 30 11080 60 1125 67 -74 -262 2061 UCI 103234 110 12898 12898 13145 30 11870 30 1275 42 -73 -281 2187 UCI 103235 119 13151 13151 13320 35 12120 70 1200 78 -65 -274 2126 UCI 103236 129 13548 13968 13640 80 12675 35 965 87 -57 -257 1991 KIA 36127 164 14571 14864 14790 90 12872 90 1918 127 -75 -312 2402 KIA 36128 173.5 14934 15339 15620 100 13877 80 1743 128 -129 -399 3116 KIA 36129 185.5 15476 15872 15590 110 14060 80 1530 136 -66 -365 2725 KIA 37658 196 15950 16257 15810 110 14283 80 1527 136 -38 -359 2620 KIA 36710 200 16199 16384 15080 100 14414 90 666 135 86 -238 1640 KIA 36130 205 16510 16700 15450 100 15103 90 347 135 77 -258 1776 KIA 36711 212.5 16977 17064 16190 120 15500 95 690 153 39 -329 2273 KIA 37659 217.5 17289 17245 17090 135 15350 90 1740 162 -35 -412 2938 KIA 36131 229 17940 17883 18120 120 16603 100 1517 156 -82 -484 3502 KIA 36132 250 18663 19000 18470 130 17000 80 1470 153 -41 -445 3147 KIA 36133