02119nas a2200217 4500008004100000245007600041210006900117260001200186520131800198653001101516653003001527653002801557653002201585653002401607653001201631653001801643100002401661700002101685700002001706856017501726 2020 eng d00aGIS tool to predict photosynthetically active radiation in a Dry Valley0 aGIS tool to predict photosynthetically active radiation in a Dry c04/20203 a

Understanding primary productivity is a core research area of the National Science Foundation's Long-Term Ecological Research Network. This study presents the development of the GIS-based Topographic Solar Photosynthetically Active Radiation (T-sPAR) toolbox for Taylor Valley. It maps surface photosynthetically active radiation using four meteorological stations with ~20 years of data. T-sPAR estimates were validated with ground-truth data collected at Taylor Valley's major lakes during the 2014–15 and 2015–16 field seasons. The average daily error ranges from 0.13 mol photons m-2 day-1 (0.6%) at Lake Fryxell to 3.8 mol photons m-2 day-1 (5.8%) at Lake Hoare. We attribute error to variability in terrain and sun position. Finally, a user interface was developed in order to estimate total daily surface photosynthetically active radiation for any location and date within the basin. T-sPAR improves upon existing toolboxes and models by allowing for the inclusion of a statistical treatment of light attenuation due to cloud cover. The T-sPAR toolbox could be used to inform biological sampling sites based on radiation distribution, which could collectively improve estimates of net primary productivity, in some cases by up to 25%.

10aArcMap10aautomated weather station10adigital elevation model10aice-covered lakes10aMcMurdo Dry Valleys10aR model10aTaylor Valley1 aAcosta, Dimitri, R.1 aDoran, Peter, T.1 aMyers, Madeline uhttps://www.cambridge.org/core/journals/antarctic-science/article/gis-tool-to-predict-photosynthetically-active-radiation-in-a-dry-valley/BD0BE4FF6A8F3DAAF32D69879728707802072nas a2200193 4500008004100000245010300041210006900144260005100213490000900264520138000273653003401653653004201687653002201729653002401751653001201775100002401787700002201811856004501833 2016 eng d00aModeling Surface Photosynthetic Active Radiation in Taylor Valley, McMurdo Dry Valleys, Antarctica0 aModeling Surface Photosynthetic Active Radiation in Taylor Valle aChicago, ILbUniversity of Illinois at Chicago0 vM.S.3 a

Understanding primary productivity is a core research area of the National Science Foundation’s Long-Term Ecological Research Network. This study maps surface Photosynthetically Active Radiation (PAR) using long term data collected by a meteorological network in the McMurdo Dry Valleys. Four stations with ~20 years of records were used to correct T-sPAR, a topographic surface PAR model. Maximum expected daily surface PAR at meteorological stations was calculated for Taylor Valley, through statistical analysis of location records using a local regression model that included 84% of all observations. Expected values represent daily surface PAR under cloudless conditions. Daily measured and expected PAR was used to model cloud coverage at each location, corroborating that overcast conditions are positively correlated with proximity to the ocean. Ground-truth data collected for TaylorValley’s major lakes during the 2015/2016 field season were used to validate T-sPAR estimates. The final model approximates total seasonal surface PAR for the Taylor Valley basin. Bi- monthly maps estimate total surface PAR by lake to assist in future sampling site selection. Finally, a user interface was developed to estimate total daily surface PAR by coordinate or surface based on a user input date.

 

10adigital elevation model (DEM)10ageographical information system (GIS)10aice-covered lakes10ameteorological data10aR model1 aAcosta, Dimitri, R.1 aBerkelhammer, Max uhttp://indigo.uic.edu/handle/10027/21180