<metadata>
  <idinfo>
    <citation>
      <citeinfo>
        <origin>Cristina D. Takacs-VesbachJohn C. Priscu</origin>
        <pubdate>2019-06-20</pubdate>
        <title>Underwater Photosynthetically Active Radiation (PAR) from in-situ Lake Primary Production Experiments in the McMurdo Dry Valleys of Antarctica (1995-2024, ongoing)</title>
        <!-- edition -->
        <geoform>tabular digitial data</geoform>
        <!-- serinfo -->
        <pubinfo>
          <pubplace>McMurdo Dry Valleys LTER</pubplace>
          <publish>McMurdo Dry Valleys LTER</publish>
        </pubinfo>
        <othercit>10.6073/pasta/071b96c4bfcffce918d8a4cd31612d6c</othercit>
        <onlink>https://mcm.lternet.edu/content/underwater-photosynthetically-active-radiation-par-situ-lake-primary-production-experiments</onlink>
        <!--lworkcit -->
      </citeinfo>
      <descript>
        <abstract>As part of the Long Term Ecological Research (LTER) project in the McMurdo Dry Valleys of Antarctica, PAR is measured at one depth during primary production experiments in Dry Valley Lakes. This data set quantifies instantaneous underwater PAR at 10-meter depths in Lakes Bonney and Hoare, and at 7-meter depth in Lake Fryxell (depths vary after 2008, check data file for actual depth). Ambient PAR was also measured at the air-ice interface from each of these lakes.</abstract>
        <supplinf></supplinf>
      </descript>
      <timeperd>
        <timeinfo>
          <rngdates>
            <begdate>
              <caldate>1995-09-14</caldate>
            </begdate>
            <enddate>
              <caldate>2024-12-24</caldate>
            </enddate>
          </rngdates>
        </timeinfo>
        <current>ground condition</current>
      </timeperd>
      <status>
        <progress>Data from these tables was submitted to INSTAAR by John Priscu's team at Montana State University. The raw data files listed under 'file name' are the names of the original ascii text files submitted. Upon arrival at INSTAAR, the data manager fine-tuned the location codes and limno runs to match those provided in the 'locations, dates, codes for lake chemistry, biology samples' file. Because two different approaches were taken in collecting this data (instantaneous PAR and integrated PAR), resulting in measurements that differed in scale (micromol photons/m2/second vs. mol photons m-2 hr-1) and dates (limno run 2 vs limno run 1 of season), the data was separated into two files: instantaneous measurements and integrated measurements. These files were imported into Microsoft Access on INSTAAR's Unix system, and can currently be found there. The files were then exported in ascii, comma delimited text and MS-DOS text (table layout) on the MCM LTER web site. Information for the metadata was obtained from the Metaparlogged9697.rtf and Metaparlogged9798.rtf files. The files were called up using Microsoft Word version 6.0. Text from these files was used to create this page in html format. While processing the 1997-98 data, the data manager noticed that the integrated PAR data contained a jump in the dates provided for the Lake Hoare records. Data collected in limno run HOA9798L1 contained 11/15/1997 and 12/16/1997 dates. Since there is not usually a gap like this for a given limnology run, a correction was necessary. John Priscu and Craig Wolf were contacted in November 1999 to look into this, but since it was the middle of the field season, it took some time to resolve it. On 28-Feb-2000, the HOA9798L1 records showing dates of 12/16/1997 were corrected to 11/16/1997. In 2006, Chris Gardner and Inigo San Gil converted all metadata to EML to comply with interoperability mandates at LTER. In 2014, Inigo San Gil introduced metadata enhancements (publication Date, methods, markup, language, entity level, etc) and placed the metadata into the Drupal Ecological Information Management System.&#160;</progress>
        <update>As needed</update>
      </status>
      <spdom>
        <descgeog>Lake Bonney is a saline lake with permanent ice cover at the western end of Taylor Valley in the McMurdo Dry Valleys of Victoria Land, Antarctica. It is 7 kilometres or 4.3 mi long and up to 900 metres or 3,000 ft wide. A narrow channel only 50 metres or 160 ft wide. Lake Bonney at Narrows separates the lake into East Lake Bonney 3.32 square kilometres or 1.28 sq mi and West Lake Bonney, 0.99 square kilometres or 0.38 sq mi. The west lobe is flanked by Taylor glacier. Valley: Taylor Distance to Sea : 25 Maximum Length (km): 4.8 Maximum Width (km): 0.9 Maximum Depth (m): 37 Surface Area (km^2): 3.32 Ice Thickness Average Surface (m): 3 - 4.5 Volume (m^3 * 10^6): 54.7</descgeog>
        <bounding>
          <westbc>162.536209106445</westbc>
          <eastbc>162.353210449219</eastbc>
          <northbc>-77.697700500488</northbc>
          <southbc>-77.724441528320</southbc>
          <boundingalt>
            <altmin>57m</altmin>
            <altmax>57m</altmax>
            <altunits>meter</altunits>
          </boundingalt>
        </bounding>
      </spdom>
      <spdom>
        <descgeog>The Lake Fryxell basin is formed by a moraine depression in a wider portion of the Taylor Valley. It has a number of moraine islands and shallower areas, as well as several relatively well developed deltas. The lake is fed by at least 10 meltwater streams with a total drainage catchment of 230 km2. The lake is dammed to the southwest by the Canada Glacier and is topographically closed. It is perennially ice covered; during summer months, an ice-free moat generally forms around much of the lake margin. Lake levels have risen ~2 m between 1971 and 1996. There are no surface outflows; the only known water loss is through ice ablation (evaporation, sublimation and physical scouring). Valley: Taylor Distance to Sea : 9 Maximum Length (km): 5.8 Maximum Width (km): 2.1 Maximum Depth (m): 20 Surface Area (km^2): 7.08 Ice Thickness Average Surface (m): 3.3 - 4.5 Volume (m^3 * 10^6): 25.2</descgeog>
        <bounding>
          <westbc>163.259582519531</westbc>
          <eastbc>163.048782348633</eastbc>
          <northbc>-77.597076416016</northbc>
          <southbc>-77.622711181641</southbc>
          <boundingalt>
            <altmin>18m</altmin>
            <altmax>18m</altmax>
            <altunits>meter</altunits>
          </boundingalt>
        </bounding>
      </spdom>
      <spdom>
        <descgeog>Lake Hoare occupies a narrower portion of the Taylor Valley, dammed by the Canada Glacier. It would drain almost completely without this dam. There are a number of islands which may be related to an old terminal of Canada Glacier. The lake is fed primarily from direct runoff from the glacier, as well as meltwater streams. (Lake level rose ~1.5 m between 1972 and 1996). There are no surface outflows; the only known water loss is through ice ablation (evaporation, sublimation and physical scouring). Valley: Taylor Distance to Sea : 15 Maximum Length (km): 4.2 Maximum Width (km): 1 Maximum Depth (m): 34 Surface Area (km^2): 1.94 Ice Thickness Average Surface (m): 3.1 - 5.5 Volume (m^3 * 10^6): 17.5</descgeog>
        <bounding>
          <westbc>162.935836791992</westbc>
          <eastbc>162.784423828125</eastbc>
          <northbc>-77.623085021973</northbc>
          <southbc>-77.639259338379</southbc>
          <boundingalt>
            <altmin>73m</altmin>
            <altmax>73m</altmax>
            <altunits>meter</altunits>
          </boundingalt>
        </bounding>
      </spdom>
      <spdom>
        <descgeog>Lake Miers lies in the Miers Valley. Valley: Miers Distance to Sea : 20 Maximum Length (km): 1.5 Maximum Width (km): 0.7 Maximum Depth (m): 21 Surface Area (km^2): 1.3 Ice Thickness Average Surface (m): 3.4 - 6 Volume (m^3 * 10^6): 2.9</descgeog>
        <bounding>
          <westbc>163.886840820313</westbc>
          <eastbc>163.812332153320</eastbc>
          <northbc>-78.094047546387</northbc>
          <southbc>-78.101478576660</southbc>
          <boundingalt>
            <altmin>240m</altmin>
            <altmax>240m</altmax>
            <altunits>meter</altunits>
          </boundingalt>
        </bounding>
      </spdom>
      <spdom>
        <descgeog>Lake Bonney is a saline lake with permanent ice cover at the western end of Taylor Valley in the McMurdo Dry Valleys of Victoria Land, Antarctica. It is 7 kilometres or 4.3 mi long and up to 900 metres or 3,000 ft wide. A narrow channel only 50 metres or 160 ft wide. Lake Bonney at Narrows separates the lake into East Lake Bonney 3.32 square kilometres or 1.28 sq mi and West Lake Bonney, 0.99 square kilometres or 0.38 sq mi. Valley: Taylor Distance to Sea : 28 Maximum Length (km): 2.6 Maximum Width (km): 0.9 Maximum Depth (m): 40 Surface Area (km^2): 0.99 Ice Thickness Average Surface (m): 2.8-4.5 Volume (m^3 * 10^6): 10.1</descgeog>
        <bounding>
          <westbc>162.354934692383</westbc>
          <eastbc>162.269104003906</eastbc>
          <northbc>-77.714805603027</northbc>
          <southbc>-77.727287292480</southbc>
          <boundingalt>
            <altmin>57m</altmin>
            <altmax>57m</altmax>
            <altunits>meter</altunits>
          </boundingalt>
        </bounding>
      </spdom>
      <keywords>
        <themekt>[term:vocabulary]</themekt>
      </keywords>
      <accconst>None</accconst>
      <ptcontact>
        <cntinfo>&lt;cntorg&gt;McMurdo Dry Valleys LTER&lt;/cntorg&gt; &lt;onlink&gt;http://mcmlter.org/&lt;/onlink&gt; &lt;span property="dc:title" content="McMurdo Dry Valleys LTER" class="rdf-meta element-hidden"&gt;&lt;/span&gt;</cntinfo>
      </ptcontact>
      <datacred>Name: Jade Lawrence Role: field technician Name: Renée F. Brown Role: data manager Name: Amy Chiuchiolo Role: former field crew Name: Inigo San Gil Role: former data manager</datacred>
      <dataqual>
        <logic>Not Applicable</logic>
        <complete>Not Applicable</complete>
        <lineage>
          <method>
            <methtype>Field and/or Lab Methods</methtype>
            <methdesc>A Licor LI-193SA spherical quantum sensor and a LI-190SA flat sensor are attached to a Licor LI-1000 data logger to record underwater PAR and ambient PAR. Underwater PAR data are recorded in the sampling hole covered by the Weatherport, whereas ambient PAR is measured approximately 10 m away from the Weatherport. The Licor LI-1000 queries ambient and underwater PAR at 5 second intervals an records mean PAR data (micromol photons m-2 s-1) every 10 minutes. We began using a LI-1400 at the start of the 1213 season. The Licor LI-1400 queries ambient and underwater PAR at 5 second intervals and records mean PAR data (micromol photons m-2 s-1) every 5 minutes. Starting in the 23/24 season, the LI-1400 datalogger was replaced with a LI-1500 datalogger. Due to increased memory in the new datalogger, we now average both parameters every 60 seconds and log every 60 seconds. Previously, the LI-1400 used a sampling period of 5 seconds and a logging period of 5 minutes. Additional notes: EB0304L1: McKenna: no data available. LICOR was turned off by accident FRX0405L2: No logged PAR data for FRX L2. FRX L2: 1 Dec 04 (0744): PPR incubation put in water; 2 Dec 04 (0815): PPR incubation taken out of water. HOR2223L2: no HOR L2 measurements (no PPR incubation)</methdesc>
          </method>
          <procstep>
            <procdesc>A Licor LI-193SA spherical quantum sensor and a LI-190SA flat sensor are attached to a Licor LI-1000 data logger to record underwater PAR and ambient PAR. Underwater PAR data are recorded in the sampling hole covered by the Weatherport, whereas ambient PAR is measured approximately 10 m away from the Weatherport.The Licor LI-1000 queries ambient and underwater PAR at 5 second intervals an records mean PAR data (micromol photons m-2 s-1) every 10 minutes.We began using a LI-1400 at the start of the 1213 season. The Licor LI-1400 queries ambient and underwater PAR at 5 second intervals and records mean PAR data (micromol photons m-2 s-1) every 5 minutes.Starting in the 23/24 season, the LI-1400 datalogger was replaced with a LI-1500 datalogger. Due to increased memory in the new datalogger, we now average both parameters every 60 seconds and log every 60 seconds. Previously, the LI-1400 used a sampling period of 5 seconds and a logging period of 5 minutes.Additional notes:EB0304L1: McKenna: no data available. LICOR was turned off by accidentFRX0405L2: No logged PAR data for FRX L2. FRX L2: 1 Dec 04 (0744): PPR incubation put in water; 2 Dec 04 (0815): PPR incubation taken out of water.HOR2223L2: no HOR L2 measurements (no PPR incubation)</procdesc>
            <procdate>unknown</procdate>
          </procstep>
        </lineage>
      </dataqual>
      <eainfo>
        <detailed>
          <enttyp>
            <enttypl>PAR_INSTANT</enttypl>
            <enttypd>Photosynthetically active radiation during in-situ experiments</enttypd>
          </enttyp>
          <attr>
            <attrlabl>DATASET_CODE</attrlabl>
            <attrdef>Code to ID the data table</attrdef>
            <attrdefs>The data provider</attrdefs>
            <attrdomv>
              <udom>Code to ID the data table</udom>
            </attrdomv>
          </attr>
          <attr>
            <attrlabl>Limno Run</attrlabl>
            <attrdef>Code for lake's sampling location and date</attrdef>
            <attrdefs>The data provider</attrdefs>
            <attrdomv>
              <udom>Code for lake's sampling location and date</udom>
            </attrdomv>
          </attr>
          <attr>
            <attrlabl>LOCATION NAME</attrlabl>
            <attrdef>Name of lake where measurement was made</attrdef>
            <attrdefs>The data provider</attrdefs>
            <attrdomv>
              <udom>Name of lake where measurement was made</udom>
            </attrdomv>
          </attr>
          <attr>
            <attrlabl>LOCATION CODE</attrlabl>
            <attrdef>Code for site where measurement was made</attrdef>
            <attrdefs>The data provider</attrdefs>
            <attrdomv>
              <udom>Code for site where measurement was made</udom>
            </attrdomv>
          </attr>
          <attr>
            <attrlabl>Collection Date</attrlabl>
            <attrdef>Date on which sample was gathered</attrdef>
            <attrdefs>The data provider</attrdefs>
            <attrdomv>
              <edom>
                <edomv>calendar date/time</edomv>
                <edomvd>mm/dd/yyyy HH:MM</edomvd>
                <edomvds>gregorian calendar</edomvds>
              </edom>
            </attrdomv>
          </attr>
          <attr>
            <attrlabl>DEPTH (m)</attrlabl>
            <attrdef>Distance below the piezometric water level at which measurement was taken.</attrdef>
            <attrdefs>The data provider</attrdefs>
            <attrdomv>
              <rdom>
                <rdommin>1</rdommin>
                <rdommax>60</rdommax>
                <attrunit>meter</attrunit>
                <attrmres>1</attrmres>
              </rdom>
            </attrdomv>
          </attr>
          <attr>
            <attrlabl>UwPAR (umol photons/m2/s)</attrlabl>
            <attrdef>Underwater photosynthetically active radiation</attrdef>
            <attrdefs>The data provider</attrdefs>
            <attrdomv>
              <rdom>
                <rdommin>0</rdommin>
                <rdommax>100</rdommax>
                <attrunit>umolphotons/m2/second</attrunit>
                <attrmres>0.01</attrmres>
              </rdom>
            </attrdomv>
          </attr>
          <attr>
            <attrlabl>Ambient PAR umol photons/m2/s</attrlabl>
            <attrdef>Ambient photosynthetically active radiation</attrdef>
            <attrdefs>The data provider</attrdefs>
            <attrdomv>
              <rdom>
                <rdommin>0</rdommin>
                <rdommax>2000</rdommax>
                <attrunit>umolphotons/m2/second</attrunit>
                <attrmres>0.1</attrmres>
              </rdom>
            </attrdomv>
          </attr>
          <attr>
            <attrlabl>COMMENTS</attrlabl>
            <attrdef>Helpful hints about the sample</attrdef>
            <attrdefs>The data provider</attrdefs>
            <attrdomv>
              <udom>Helpful hints about the sample</udom>
            </attrdomv>
          </attr>
          <attr>
            <attrlabl>FILE NAME</attrlabl>
            <attrdef>Name of file in which data was submitted</attrdef>
            <attrdefs>The data provider</attrdefs>
            <attrdomv>
              <udom>Name of file in which data was submitted</udom>
            </attrdomv>
          </attr>
          <attr>
            <attrlabl>DEPTH MASL</attrlabl>
            <attrdef>Depth referred to the Sea level. Distance below Mean Average Sea Level</attrdef>
            <attrdefs>The data provider</attrdefs>
            <attrdomv>
              <rdom>
                <attrunit>meter</attrunit>
                <attrmres>1</attrmres>
              </rdom>
            </attrdomv>
          </attr>
        </detailed>
      </eainfo>
      <distinfo>
        <distrib>
          <cntinfo>
            <cntporgp>
              <cntorg>McMurdo Dry Valleys LTER</cntorg>
            </cntporgp>
          </cntinfo>
        </distrib>
        <!-- resdesc (object name) -->
        <distliab>The data distributor shall not be liable for innacuracies in the content</distliab>
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              <onlinopt>
                <computer>
                  <networka>
                    <networkr>https://mcm.lternet.edu/sites/default/files/data/mcmlter-lake-par_instant-20251013.csv</networkr>
                  </networka>
                </computer>
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      <metainfo>
        <metd>2019-06-20</metd>
        <metrd>2019-06-20</metrd>
        <metc>
          <cntinfo>
            <cntorg>McMurdo Dry Valleys LTER</cntorg>
            <onlink>http://mcmlter.org/</onlink>
            <span property="dc:title" content="McMurdo Dry Valleys LTER" class="rdf-meta element-hidden"></span>
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        <metstdn>Biological Data Profile of the Content Standards for Digital Geospatial Metadata devised by the Federal Geographic Data Committee.</metstdn>
        <metstdv>Drupal Ecological information Management Systems, version D7, Biological Data Profile module</metstdv>
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    </citation>
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