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Conditions of Use

The re-use of scientific data has the potential to greatly increase communication, collaboration and synthesis within and among disciplines, and thus is fostered, supported and encouraged. Permission to use this dataset is granted to the Data User free of charge subject to the following terms:

1) Acceptable use. Use of the dataset will be restricted to academic, research, educational, government, recreational, or other not-for-profit professional purposes. The Data User is permitted to produce and distribute derived works from this dataset provided that they are released under the same license terms as those accompanying this Data Set. Any other uses for the Data Set or its derived products will require explicit permission from the dataset owner.
2 ) Redistribution. The data are provided for use by the Data User. The metadata and this license must accompany all copies made and be available to all users of this Data Set. The Data User will not redistribute the original Data Set beyond this collaboration sphere.
3 ) Citation. It is considered a matter of professional ethics to acknowledge the work of other scientists. Thus, the Data User will properly cite the Data Set in any publications or in the metadata of any derived data products that were produced using the Data Set. Citation should take the following general form: Creator, Year of Data Publication, Title of Dataset, Publisher, Dataset identifier. For example:

Shaver, G. 1989. Above ground biomass in acidic tussock tundra experimental site, 1989, Arctic LTER, Toolik, Alaska. Arctic LTER, Marine Biological Lab, Woods Hole, Ma 02543. 1989gsttbm 

4 ) Acknowledgement. The Data User should acknowledge any institutional support or specific funding awards referenced in the metadata accompanying this dataset in any publications where the Data Set contributed significantly to its content. Acknowledgements should identify the supporting party, the party that received the support, and any identifying information such as grant numbers. For example:

Data sets were provided by the Arctic LTER. This material is based upon work supported by the National Science Foundation under Grants #DEB-981022, 9211775, 8702328; #OPP-9911278, 9911681, 9732281, 9615411, 9615563, 9615942, 9615949, 9400722, 9415411, 9318529; #BSR 9019055, 8806635, 8507493.

5 ) Notification. The Data User will notify the Data Set Contact when any derivative work or publication based on or derived from the Data Set is distributed. The Data User will provide the data contact with two reprints of any publications resulting from use of the Data Set and will provide copies, or on-line access to, any derived digital products. Notification will include an explanation of how the Data Set was used to produce the derived work.
6 ) Collaboration. The Data Set has been released in the spirit of open scientific collaboration. Data Users are thus strongly encouraged to consider consultation, collaboration and/or co-authorship with the Data Set Creator.

By accepting this Data Set, the Data User agrees to abide by the terms of this agreement. The Data Owner shall have the right to terminate this agreement immediately by written notice upon the Data User's breach of, or non-compliance with, any of its terms. The Data User may be held responsible for any misuse that is caused or encouraged by the Data User's failure to abide by the terms of this agreement.


While substantial efforts are made to ensure the accuracy of data and documentation contained in this Data Set, complete accuracy of data and metadata cannot be guaranteed. All data and metadata are made available "as is". The Data User holds all parties involved in the production or distribution of the Data Set harmless for damages resulting from its use or interpretation.

Dataset URLs:METADATA: HTML, Rich Text, XML(EML compliant)
DATA: Comma Delimited, Excel file with Metadata and data, Dataset via LTER Data Portal
Dataset ID:2004_ArcticLTER_lakes_chl.02
Dataset Title:Corrected Chlorophyll a data for Toolik Lake and surrounding lakes near the Arctic LTER site during the summer of 2004.
Investigator 1: 
First Name:Anne
Last Name:Giblin
Organization:Marine Biological Laboratory
Address line 2:The Ecosystems Center
Address line 3:7 MBL Street
City:Woods Hole
Zip Code:02543
Investigator 2: 
First Name:Chris
Last Name:Crockett
Address line 2:
Address line 3:
Zip Code:
Investigator 3: 
First Name:Lori
Last Name:Winters
Investigator 4: 
First Name:Sam
Last Name:Kelsey
Associate Investigators:
Keywords:chlorophyll a, pheophytin, arctic lakes, lakes

Corrected Chlorophyll a data for Toolik Lake and surrounding lakes near the Arctic LTER site during the summer of 2004.
For questions about the Metadata and data contact the Investigators.
For information about this web site contact:
Arctic LTER Information Manager
The Ecosystems Center
Marine Biological Lab
7 MBL St
Woods Hole, MA 02543
Phone (508) 289 7496
Online URL:
Data File URL
Data File Name 2004_ArcticLTER_lakes_chl.xls
Beginning Date 5/1/2004
End Date 9/1/2004
Number of Data Records 364
Other Files to Reference
Availability Status
Quality Control Information
Maintenance Description
Log of Changes: Log of changes: 1. A Turner 111 fluorometer was used from 1975-1991. 2. A Turner 450 Fluorometer using a NB 440 filter was used starting in 1992- 1994. 3. A Turner 450 Fluorometer using a NB 430 filter was used starting in 1995 until 1998. 4. Starting in 1998 a Turner Designs 10-Au -005 -CE configured with a chlorophyll optical kit: photomultiplier tube 185 - 870; lamp daylight white, F25T5, 400-600 nm; excitation filter 340-500 nm round bandpass 5-60; emission filter >665 nm round sharpcut 2-64; reference filter 400-700 nm square 1 ND,was used to measure chlorophyll. 5. In 2002 and 2003 comparisons were made using both Whatman GFC filters (1.2um) and GFF filters (0.7um). Additional information about this comparison can be obtained by contacting the Arctic Lakes RA, C. Crockett. 6. In 2003 samples were acidified with 100ul 1N HCL for 90 seconds to determine pheophytin concentration. Data presented represents raw chlorophyll, post acidification values can be obtained by contacting the Arctic Lakes RA, C. Crockett. 7. In 2004 samples were acidified with 300ul of 0.1N HCL for 90 seconds to correct for pheophytin and extracted at 4C. Reported values are in corrected chl a ug/L and pheophytin ug/L. Samples were filtered using Whatman GFF (0.7um) filters, GFC (1.2um) filters have been used in previous years. A detailed protocol can be found at the LTER Arctic Lakes Website. For Archival Use: DATE RECEIVED: September 2004 DATA FILE ENTERED BY: C. Crockett DATA FILE VALIDATION: NAME: 2004tlkibchlr.txt DATE: October 2004
Version 1: Metadata updated to newer version (with sites sheet). Data from individual lakes compiled into one spreadsheet for summer 2004 called "2004_ArcticLTER_lakes_chl". Data columns reordered to match other years. CH 3 Apr 2013.
Version 2: Checked keywords against the LTER network preferred list and replaced non-preferred terms. Jim L 15Jan14
RESEARCH LOCATION:                                                        
Location Name Toolik Toolik inlet bay Toolik inlet Fog lake 2 Fog lake 4 E 01 E 05 E 06 I1 I2 I3 I4 I5 I6 I7 I8 I Swamp I minus I6 headwater lake Green Cabin Lake N 01 N 02 NE 9B S 06 S 07 Select Site or enter New One Select Site or enter New One  
Geographic Description Toolik Field Station, North Slope, Alaska. Surveyed by Sarah Barbrow in 2009, Kling,Cory,Nannen, and Crump in 2010. Toolik inlet Fog 2 Fog 4 Lake E1 Lake E5 Lake E6 I1 I2 I3 I4 I5 I6 I7 I8 I Swamp I minus I6 headwater lake Headwater Lake of the Kupurak River Lake N1 Lake N2, referenceand fertilized sides Lake NE9B Lake S6 Lake S7 Enter Description Enter Description  
Location Bounding Box                                                        
West Bounding Coordinate                                                        
East Bounding Coordinate                                                        
North Bounding Coordinate                                                        
South Bounding Coordinate                                                        
OR if single point location                                                        
Latitude 68.629961 68.625966 68.6256 68.6833333333333 68.68 68.6261956028 68.642611 68.6434270583 68.5687130789 68.5713195633 68.5755366301 68.57956715 68.5873874391 68.5965924039 68.6008747982 68.6101575207 68.610781 68.55634 68.582062 68.53698 68.6398939358 68.6409472345 68.6526454831 68.6293797816 68.6300627447 In Decimal Degrees In Decimal Degrees  
Longitude -149.612633 -149.599022 -149.59605 -149.1 -149.071666666667 -149.555347706 -149.458079 -149.440564592 -149.58807625 -149.565881618 -149.583644456 -149.58405938 -149.589625877 -149.59264335 -149.596582063 -149.582211513 -149.600742 -149.56628 -149.622932 -149.2374 -149.606965643 -149.625086307 -149.599473662 -149.641623295 -149.644441789 In Decimal Degrees In Decimal Degrees  
Elevation 719 719 719 785 754 762 800 792 785 785 774 770 767 754 742 744 736 801 806 883 731 724 747 731 731 In Meters In Meters  
Link to Google Map View on Google Map View on Google Map View on Google Map View on Google Map View on Google Map View on Google Map View on Google Map View on Google Map View on Google Map View on Google Map View on Google Map View on Google Map View on Google Map View on Google Map View on Google Map View on Google Map View on Google Map View on Google Map View on Google Map View on Google Map View on Google Map View on Google Map View on Google Map View on Google Map View on Google Map      
Organisms studied

Water samples are collected at a minimum of the epi, meta, and hypolimnion, samples at other depths are collected as needed dependent on lake and conditions. Toolik Inlet Bay is routinely sampled at depths 1, meta, and 8 meters. Samples are collected in 2-L brown Nalgene bottles and returned to the lab within 2 hours. Water is filtered through a 47 mm Whatman GF/F (0.7 um) glass fiber filter. Filters are placed in 10 ml of chilled, buffered (1 mg/l MgCO-3) 90% acetone and extracted in the dark at approximately 4C (iced in cooler) for 18-24 hours. Chlorophyll a was determined using a Turner Designs 10-Au -005 -CE configured with a chlorophyll optical kit (10-037R). This kit is used for the traditional in-vivo measurement of chlorophyll (Lorenzen) and in-vivo/extractive acidification methods, including Strickland and Parsons, and Standard Methods for Water and Waste Water and EPA 445.

Notes: In 2004 several adjustments were made to the protocol from 2003. Extraction took place at approximately 4C using chilled acetone. A multipoint curve was analyzed using a chl a stock std. A Turner Designs solid standard could then be utilized as a check. Additionally, chl a was corrected for pheophytin following EPA 445 and data is reported in corrected chl a. For more information please reference the chlorophyll protocol available on the Arctic LTER website.

Reference Citations: R.G. Wetzel and G.E. Likens. 1979. Limnological Methods. Saunders.

C E, C = Chlorophyll a concentration in the extract (usually 10ml)
C E, C = Fs(r/r-1)(Rb-Ra)
C E, C = corrected chlorophyll a concentration (ug/L) in the extract solution analyzed
Fs = response factor for the sensitivity setting S
r = the before to after acidification ration of a pure chl a solution (Rb/Ra)
Rb = fluorescence of sample extract before acidification
Ra = fluorescence of sample extract after acidification
C S, C = corrected chl a concentration (ug/L) in the whole water sample
C S, C ={(C E, C x extract volume in L x Dilution Factor)/(sample volume in L)
Pheophytin a
PE = pheophytin a concentration (ug/L) in the sample extract
PE = Fs (r/r-1) (rRa - Rb)
PS = pheophytin a concentration (ug/L) in the whole water sample
PS = (PE x extract volume in L x dilution factor)/(sample volume in L)
Note: if no dilution took place, then DF equals 1

Sampling Description.

Chlorophyll for 2004 Turner Designs 10-Au -005 -CE/ photomultiplier tube 185 - 870/ lamp daylight white , F45T5, 400-600 nm/ exitation filter 340-500 nm round bandpass 5-60/ emmision filter filter >665 nmround sharpcut 2-64/ refererence filter 400-700 nm suare 1 ND

Data Table

Variable Name Variable Description Data Type Units DateTime Format Code Information Missing Value Code
Site Code site code text        
Lake Site of measurement text        
Depth (m) Depth number meter     .=Missing or Not Measured
Date Date datetime   DD-MMM-YY    
Julian Day Julian day number number     .=Missing or Not Measured
Corrected chl a (ug/L) Corrected Chlorophyll a, active chl a number microgramPerLiter     .=Missing or Not Measured
Pheo (ug/L) Pheophytin number microgramPerLiter     .=Missing or Not Measured
Total chl a (ug/L) Total chl a (uncorrected for pheophytin) number microgramPerLiter     .=Missing or Not Measured
PPROD (mgC/m3/d) Rate of primary production (mg availabe C/m3/d) number microgramPerLiterPerDay     .=Missing or Not Measured
Notes Notes text        

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