LTER network Toolik Field Station MBLhome page

Sun and Moon

Toolik Weather Graphs

Arctic LTER Weather Stations

Toolik Webcam

Animated Gif of yesterday's Webcam

Arctic LTER Inhouse login

  Our web site has beed moved. Please update your bookmarks for the new site.

Arctic LTER Database

Arctic LTER Database

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:1993_ArcticLTER_lakes_chl.02
Dataset Title:Total Chlorophyll a and primary production data for Toolik Lake and surrounding lakes near the Arctic LTER site during the summer of 1993
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:Michael
Last Name:Miller
Address line 2:
Address line 3:
Zip Code:
Investigator 3: 
First Name:Neil
Last Name:Bettez
Investigator 4: 
First Name:Mark
Last Name:Dornblaser
Investigator 5: 
First Name:Patricia
Last Name:O'Hara
Associate Investigators:
Keywords:chlorophyll a, pheophytin, arctic lakes, lakes
Abstract:Total Chlorophyll a and primary production data for Toolik Lake and surrounding lakes near the Arctic LTER site during the summer of 1993.
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 1993_ArcticLTER_lakes_chl.xls
Beginning Date 5/1/1993
End Date 9/1/1993
Number of Data Records 400
Other Files to Reference
Availability Status
Quality Control Information
Maintenance Description
Log of Changes: Log of changes: A new Turner 450 Fluorometer was used during the summer of 1992 in place of the old Turner 111 Fluorometer used in previous years. For Archival Use: DATE RECEIVED: 1-27-95 DATA FILE ENTERED BY: DATA FILE VALIDATION: NAME: Neil Bettez DATE: 1-27-95
Version 1: Metadata updated to newer version (with sites sheet). Data from individual lakes compiled into one spreadsheet for summer 1993 called "1993_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 E 01 I1 INTO I3 I1 outlet I2 INTO I3 I2 outlet I3 outlet I4 INTO I5 I4 outlet I5 INTO I6 I5 outlet I6 I6 outlet I6 inlet west I7 INTO I9 I7 outlet I8 I8 headwater I8 inlet I8 INTO I9 I8 outlet Milkyway upper N 01 N 02 NE 12 NE 9B S 11 S 06  
Geographic Description Toolik Field Station, North Slope, Alaska. Toolik inlet E1 I1 INTO I3 I1 OUT I2 INTO I3 I2 OUT I3 OUT I4 INTO I5 I4 OUT I5 INTO I6 I5 OUT I6 I6 OUT I6 WEST I7 INTO I9 I7 OUT I8 I8 HEAD I8 IN I8 INTO I9 I8 OUT MILKYWAY N1 Lake N2; N2R= reference side, N2T= fertilized side NE12 NE9B S11 S6  
Location Bounding Box                                                            
West Bounding Coordinate                                                            
East Bounding Coordinate                                                            
North Bounding Coordinate                                                            
South Bounding Coordinate                                                            
OR if single point location                                                            
Latitude 68.629961 68.6256 68.6261956028 68.574 68.572296 68.57478333 68.572546 68.57754 68.58423333 68.58143 68.59491667 68.589087 68.5965924039 68.598684 68.59688333 68.61818333 68.60183 68.6101575207 68.5736666666667 68.60853333 68.61838333 68.6114075339 68.62016667 68.6398939358 68.6409472345 68.65 68.6526454831 68.630148049 68.6293797816 In Decimal Degrees
Longitude -149.612633 -149.59605 -149.555347706 -149.583566 -149.581014 -149.58205 -149.570268 -149.582003 -149.5836 -149.5861 -149.586316 -149.589219 -149.59264335 -149.599853 -149.60125 -149.596766 -149.596713 -149.582211513 -149.537166666667 -149.587633 -149.5965 -149.590131872 -149.568166 -149.606965643 -149.625086307 -149.616666666667 -149.599473662 -149.650579145 -149.641623295 In Decimal Degrees
Elevation 719 719 762 774 785 774 785 774 770 770 754 767 754 754 754 728 742 744 808 744 728 744 739 731 724 699 747 750 731 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 View on Google Map View on Google Map View on Google Map View on Google Map  
Organisms studied

Water samples were collected weekly at 0,1,3,5,8,12,16 meter depths in the lakes. The water was
returned to the lab where it was filtered through a 47 mm Whatman GF/C glass fiber filter. The filters
were then placed in 10 ml of 90% acetone and extracted in the dark for 24 hours. The samples were
then read on a Turner 450 Fluorometer with a left side emission window of 10x and a right side activation
window of 30x.

Notes: The flurometer was calibrated using a standard curve made using chlorophyll a from Anacystis nidulans purchased from Sigma and quantified using a spectrophotometer.

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

Sampling Description.


total 1x reading = avg reading/(left side emission window*gain) total chlor a (ug/l) = 9.3962*(total 1x reading)+.0454 total chlor a ug/L in sample = (total chlor a)*(ml acetone/1000)/(ml filtered/1000)

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        

Please contact with questions, comments, or for technical assistance regarding this web site.