BCCZO -- Dissolved Organic Matter (DOM), Lysimeter Water Samples Chemistry, Groundwater Chemistry -- Gordon Gulch: Lower -- (2013)

OVERVIEW

Description/Abstract

Soil water, groundwater, and streamwater were collected during the 2013 snowmelt season and analyzed for dissolved organic carbon concentration and dissolved organic matter fluorescence.

Creator/Author

Margaret A. Burns|Holly R. Barnard

CZOs

Boulder

Contact

Holly R. Barnard, holly.barnard@colorado.edu

Subtitle

Soil water, groundwater, & stream-water were analyzed for DOC concentration and DOM fluorescence from from lysimeters.

SUBJECTS

Disciplines

Biogeochemistry|Hydrology|Water Chemistry

Topics

Dissolved Organic Matter (DOM)|Lysimeter Water Samples Chemistry|Groundwater Chemistry

Keywords

Dissolved organic matter|fluorescence|PARAFAC|subsurface flow|snow melt|ecohydrology| DOY = Day of Year| DOC = Dissolved Organic Carbon| DOM = Dissolved Organic Matter| FI = Fluorescence Index| HIX = Humification Index| BIX = Freshness Index|

Variables

Day of Year|Depth|DOC|Components GG-SQ1:GG-P2|Percent Protein|Ftot|(GG-P1:GG-P1+GG-P2)|Components C1_DOC:C8_DOC|Percent Protein_DOC|Ftot_DOC|(GG-P1:GG-P1+GG-P2)_DOC|Percent GG-SQ1: Percent GG-P2_DOC|FI|max emission at 370nm|a254nm|HIX|BIX

Variables ODM2

SUVA254|Carbon, dissolved organic|Groundwater Depth|Fluorescence index|Fluorescence, dissolved organic carbon (DOC)|Colored dissolved organic matter

TEMPORAL

Date Start

2013-03-21

Date End

2013-07-18

SPATIAL

Field Areas

Gordon Gulch

Location

Gordon Gulch: Lower

North latitude

40.01455227

South latitude

40.01209702

West longitude

-105.4696267

East longitude

-105.46833459999999

REFERENCE

Citation

Cory, R. M., M.P. Miller, D.M. McKnight, J.J. Guerard, and P.L. Miller (2010). Effect of instrument-specific response on the analysis of fulvic acid fluorescence spectra, Limnol and Oceanography Meth, 8,67–78. Gabor, R.S., M.A. Burns, R.H. Lee, J.B. Elg, C.J. Kemper, H.R. Barnard, and D.M. McKnight. Variations in the chemistry of water-soluble organic matter across a catchment: A spectroscopic investigation. Submitted to: Environ Sci & Techol, 2014. Lawaetz, A J., and C.A. Stedmon (2009). Fluorescence intensity calibration using the Raman scatter peak of water. Applied Spectroscopy, 63(8), 936–940. doi:10.1366/000370209788964548 McKnight, D.M., E.W. Boyer, P.K. Westerhoff, P.T. Doran, T. Kulbe, and D.T. Anderson (2001). Spectrofluorometric characterization of dissolved organic matter for indication of precursor organic material and aromaticity. Limnol and Oceanography, 46(1), 38-48. Ohno, T. (2002). Fluorescence inner-filtering correction for determining the humification index of dissolved organic matter. Environ Sci and Technol, 36(4), 742–6. Parlanti, E., K. Wo, L. Geo, and M. Lamotte (2000). Dissolved organic matter fluorescence spectroscopy as a tool to estimate biological activity in a coastal zone submitted to anthropogenic inputs, Organic Geochemistry, 31, 1765–1781. Wilson, H.F., and M.A. Xenopoulous (2008). Effects of agricultural land use on the composition of fluvial dissolved organic matter. Nature Geoscience, doi: 101038/NGE0391. Zsolnay, A., E. Baigar, M. Jimenez, B. Steinweg, and F. Saccomandi (1999). Differentiating with fluorescence spectroscopy the sources of dissolved organic matter in soils subjected to drying. Chemosphere, 38(1), 45-50.

Publications of this data

Barnard H., Burns M., McKnight D., Gabor R., Brooks P. (2014). Reconciling stream dissolved organic matter with snowmelt-driven subsurface flowpaths in a montane, headwater catchment (Invited). Abstract H53K-03 presented at 2014 Fall Meeting, AGU, San Francisco, CA, 15-19 Dec.

Burns M.A., McKnight M.D., Gabor R.S., Brooks P.D., Barnard H.R. (2013). Transport and Transformation of Dissolved Organic Matter in Soil Interstitial Water Across Forested, Montane Hillslopes. Abstract H23F-1340 presented at 2013 Fall Meeting, AGU, San Francisco, CA, 9-13 Dec.

CZO ID

3894

Award Grant Numbers

Support for data was provided by the U.S. Department of Energy’s Terrestrial Ecosystem Science Program (DOE Award #: DE-SC0006968; PI: Holly - DE-SC0006968

COMMENTS

Comments

Methods:

Samples were collected during the 2013 snowmelt season from soil lysimeters, groundwater wells, and the highest flow in the stream channel in acid-washed and combusted (450°C) glass bottles. Samples were not collected if weather inhibited site access. Groundwater samples were collected by the BcCZO. Locations can be found in the last column.

Water samples were returned to the laboratory and filtered through 0.7m combusted glass fiber filters within 24 hours of collection. Samples were stored in the dark at 4°C until analysis.

UV-vis was run on an Agilent 8453 UV-vis spectrophotometer (absorbance range 190-1100nm). Samples with an absorbance greater than 0.2cm-1 at 254nm were diluted to less than 0.2cm-1. Fluorescence was run on a Horiba Jobin Yvon Fluoromax-3 Fluorometer. Both instruments are part of the McKnight Laboratory Group, Institute of Arctic and Alpine Research, University of Colorado Boulder.

EEMs were created from excitation wavelengths 245-450nm every 10nm and emission 300-550nm every 2nm. Integration time = 0.25s, slitwidth = 5nm. EEMs were then corrected for instrument response and inner-filter effect [Cory et al., 2010; Lawaetz and Stedmon, 2009]. The following spectroscopic indices were retrieved from the corrected EEM:

1. Fluorescence Index: Ratio of emission intensity at 470nm to intensity at 520nm at excitation 370nm [McKnight et al., 2001].

2. Humification Index: Area under the peak from 435-480nm emission dived by the area under the peak from 300-345 emission at excitation 254nm [Zsolnay et al., 1999; Ohno, 2002].

3. Freshness Index: Ratio of the intensity at emission 380nm divided by the maximum intensity between 420nm -435nm at excitation 310nm [Parlanti et al., 2000; Wilson and Zenopoulous, 2008].

An eight component site-specific PARAFAC model was used to analyze the data [Gabor et al. Submitted to Environ Sci & Technol, 2014]. This model was created using Soil leachates that were collected across the north- and south-facing slopes of Gordon Gulch. More detailed information on this model can be found in: [Gabor et al. Submitted to Environ Sci & Technol, 2014].

Dissolved organic carbon (DOC) concentration was measured using Pt-catalyzed high temperature combustion (TOC-V CXN Total Organic Carbon Analyzer, Shimadzu Inc., Kyoto, Japan). Detection limit was 0.07 mg C/L. Within run and run to run precision was 1.33% relative standard deviation of standard duplicates. All DOC analysis was performed in the Kiowa Laboratory at The Institute of Arctic and Alpine Research, University of Colorado Boulder.