Research Projects

• Tropical Pacific Climate & Hydrology Since the Last Glacial Maximum
• El Niño variations since the last glacial maximum
• SST reconstructions from alkenones in Eastern Equatorial Pacific sediments
• Paleohydrologic reconstructions from molecular & isotopic  changes in tropical Pacific lake, bog & ocean sediments

• Galapagos 2004 - El Junco Lake, San Cristobal Island
• Galapagos 2008 - Isabela & Floreana Lakes & Lagoons
  
• Kiribati-Northern Line Islands:  Christmas (Kiritimati) & Washington (Teraina) Islands 2005
• Palau 2004
• Panama Basin
• Clipperton Atoll 2008
• Marshall Islands 2009
• Kosrae, FSM 2009
  

• Publications:
  

• Sachs, J.P., Sachse, D., Smittenberg, R.H., Zhang, Z., Battisti, D.S., Golubic, S., (2009) "Southward movement of the Pacific intertropical convergence zone AD 1400-1850." Nature Geoscience, 2(7): 519-525.
• Koutavas & Sachs (2008) Northern timing of deglaciation in the eastern equatorial Pacific from alkenone paleothermometry, Paleoceanography Vol. 23: PA4205, doi:10.1029/2008PA001593.
• Sachse & Sachs (2008) Inverse relationship between D/H fractionation in cyanobacterial lipids and salinity in Christmas Island saline ponds. Geochimica et Cosmochimica Acta Vol.72: 793-806.
• Pahnke, Sachs, Keigwin, Timmermann, Xie (2007) Eastern tropical Pacific hydrologic changes during the past 27,000 years from D/H ratios in alkenones, Paleoceanography Vol. 22, PA4214, doi:10.1029/2007PA001468.
• Smittenberg & Sachs (2007) Purification of dinosterol for hydrogen isotopic analysis using high-performance liquid chromatography–mass spectrometry Journal of Chromatography A Vol. 1169: 70-76.
• Zhang, Metzger & Sachs (2007) Biomarker evidence for the co-occurrence of three races (A, B and L) of Botryococcus braunii in El Junco Lake, Galápagos,  Organic Geochemistry Vol. 38: 1459-1478.
• Saenger, Smittenberg, Miller, Sachs (2006) A Physico-chemical survey of inland lakes and saline ponds: Christmas Island (Kiritimati) and Washington (Teraina) Islands, Republic of Kiribati Saline Systems Vol. 2(1): 8 
• Sachs & Smittenberg (2005) Reconstructing the History of El Niño from Galapagos Lakes EAPSpeaks, MIT-EAPS Newsletter Vol. 1(1).
• Koutavas, Lynch-Stieglitz, Marchitto, Sachs (2002) El Niño–Like Pattern in Ice Age Tropical Pacific Sea Surface Temperature Science Vol. 297: 226-230.

• Developing the D/H ratio of algal lipids as salinity and water isotopic indicators
• Culture studies (freshwater & marine)
• Batch cultures:  Video of culturing procedure by Zhaohui Zhang (a large 617 MB file!)

Inside of batch culturing chamber

• Continuous cultures

Chemostat Culture of Emiliania huxleyi, July 2007

• Field Studies:  Saline Lakes of Canada's Western Great Plains & Utah's Great Salt Lake (2007), Cargill-Newark Salt Works (2008), Christmas Island (2005), Chesapeake Bay (2006)

• Schwab & Sachs (2009) The measurement of D/H ratios in alkenones and their isotopic heterogeneity. Organic Geochemistry Vol. 40: 111-118.
• Zhang, Z., J.P. Sachs, A. Marchetti (2009) Hydrogen isotope fractionation in freshwater and marine algae: II. Temperature and nitrogen-limited-growth-rate effects. Organic Geochemistry Vol. 40(3): 428-439.
• Bühring, S.I., R.H. Smittenberg, D. Sachse, J.S. Lipp, S. Golubic, J.P. Sachs, K.-U. Hinrichs, R.E. Summons (2009) "A hypersaline microbial mat from the Pacific Atoll Kiritimati: insights into composition and carbon fixation using biomarker analyses and a 13C-labeling approach." Geobiology 7: 1-16.
• Bowman & Sachs (2008) Chemical and physical properties of some saline lakes in Alberta and Saskatchewan, Saline Systems. Vol. 4:3.
• Sachse & Sachs (2008) Inverse relationship between D/H fractionation in cyanobacterial lipids and salinity in Christmas Island saline ponds, Geochimica et Cosmochimica Acta Vol.72: 793-806.
• Zhang & Sachs (2007) Hydrogen isotope fractionation in freshwater algae:  I. Variations among lipids and species, Organic Geochemistry Vol. 38: 582-608.
• Smittenberg & Sachs (2007) Purification of dinosterol for hydrogen isotopic analysis using high-performance liquid chromatography-mass spectrometry. Journal of Chromatography A, 1169(1-2), 70-76.
• Englebrecht & Sachs (2005) Determination of sediment provenance at drift sites using hydrogen isotopes and unsaturation ratios in alkenones, Geochimica et Cosmochimica Acta Vol. 69(17): 4253-4265

• Holocene climate of the Northwest Atlantic Ocean
• Cooling of the slopewaters east of the US & Canada

• Sachs (2007) Cooling of Northwest Atlantic slope waters during the Holocene, Geophysical Research Letters Vol. 34: L03609, doi: 10.1029/2006GL028495.
• Keigwin, Sachs, Rosenthal, Boyle (2005) The 8200 year B.P. event in the slope water system, western subpolar North Atlantic Paleoceanography Vol. 20: PA2003, doi:10.1029/2004PA001074
• Keigwin, Sachs & Rosenthal (2003) A 1600-year History of the Labrador Current off Nova Scotia Climate Dynamics Vol. 21(1): 53-62.

• Glacial temperatures of southern mid-latitudes

• Pahnke & Sachs (2006) Sea surface temperatures of southern middle-latitudes 0-160 ky BP, Paleoceanography Vol. 21: PA2003, doi:10.1029/2005PA001191
• Sachs & Anderson (2003) Fidelity of alkenone paleotemperature reconstructions in southern Cape Basin sediment drifts Paleoceanography Vol. 18(4): 1082
• Stenni et al. (2003) A late-glacial high resolution site and source temperature record derived from the EPICA Dome C isotope records (East Antarctica), Earth and Planetary Science Letters Vol. 217: 183-195.
• Sachs, Anderson & Lehman (2001) Glacial surface temperatures of the southeast Atlantic Ocean. Science Vol. 293: 2077-2079.

• Expression of Heinrich Events in the Southern Hemisphere

• Sachs & Anderson (2005) Increased Subantarctic ocean productivity during Heinrich Events, Nature Vol. 434: 1118-1121.
• Sachs (2005) Context: Off the grid Quaternary Science Reviews Vol. 24(16-17): 1779-1780.

• The origin of fine particles in sediment drifts
• Biomarker D/H & sediment 231Pa/230Th at the Bermuda Rise
• • Englebrecht & Sachs (2005) Determination of sediment provenance at drift sites using hydrogen isotopes and unsaturation ratios in alkenones Geochimica et Cosmochimica Acta Vol. 69(17): 4253-4265.

People

Julian Sachs - Principal Investigator

 Orest Kawka - Lab Manager / Research Scientist II

 Dr. Juzhi Hou - UW PCC Postdoctoral Fellow

 Dr. Ines Mügler - Humboldt Postdoctoral Fellow

 Dan Nelson - Graduate Student

Alyssa Atwood - Graduate Student, NSF Graduate Fellow & UW PCC Fellow

Nemiah Ladd - Graduate Student

Recent Alumni

Matthieu Carre - JISAO Postdoctoral Fellow

Brittany Demianew - Research Scientist I

Valerie Schwab - Swiss NSF Postdoctoral Fellow

Dirk Sachse - Humboldt Postdoctoral Fellow

Rienk Smittenberg - Comer Postdoctoral Fellow

Katharina Pahnke - Comer Postdoctoral Fellow

Zhaohui Zhang - Comer Postdoctoral Fellow

Jessie Kneeland - Graduate Student

Casey Saenger - Graduate Student

Recent Undergraduate Researchers

Jeff Bowman - Levinson & Mary Gates Scholar

Eric Battisti
Brittany Demianew
Carie Frantz
Evan Howard
Brittany Kimball
Daniel Luksic
Jen Nomura

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Lab Photos
(We like to snowboard & ski!)

Crystal Mountain - April 5, 2009
L to R:  Julian, Dan, Mt. Rainier, Alyssa, Orest

Mt. Baker Powder Day - March 31, 2008

L to R:  Alyssa, Julian, Dan

Mt. Baker Powder Day - April 11, 2007

L to R:  Orest, Rienk, Valerie, Matthieu, Julian, Dirk

• When:  June 3-25, 2008
• Where:  Floreana & Isabela Islands
• Who:  Julian Sachs, Alyssa Atwood, Dan Nelson, Simon Haberle
• Why 1:  Core the sediments of lakes & lagoons for Holocene rainfall reconstruction
• Why 2:  Lead US Congressional Delegation from the House Science & Technology Committee interested in climate change

Tools & Techniques

-Molecular fossils (biomarkers)

Molecular D/H, 13C/12C, 15N/14N

Isotope-Ratio-Monitoring Gas Chromatography - Mass Spectrometry (irmGC-MS)

High-Performance Liquid Chromatography - Mass Spectrometry (HPLC-MS) 

Gas Chromatography - Mass Spectrometry (GC-MS)

Gas Chromatography - FlameIonization Detection (GC-FID)

High-Performance Liquid Chromatography (HPLC)