Data set contains results of chemical analysis of wetfall samples collected on Konza Prairie. Analysis is done by the Central Analytical Lab (CAL), Champaign, IL as part of the National Atmospheric Deposition Program (NADP). NADP data products available on the NADP/NTN web site (nadp.slh.wisc.edu/data/NTN/) include: Annual Data Summaries, Semiannual Data Reports, Annual and Seasonal Averages, Monthly Averages, and Weekly data. Konza Prairie LTER archives and provides the weekly data in electronic form.
Collect wetfall and precipitation for analysis of atmospheric input of nutrients to tallgrass prairie.
Location of Sampling Stations: Headquarters weather station (HQC).
Frequency of Sampling: Weekly, continuous from August 17, 1982.
Variables Measured at KSU laboratory: Amount of precipitation (inches/week), checked against headquarters weighing rain gauge (Ott Pluvio2).
Variables Measured at Central Analytical Laboratory (CAL), Illinois State Water Survey, Champaign, IL: Conductivity of precipitation (mS/cm); pH of precipitation; Concentrations of the following ions (mg/1): SO4, NO3, NH4, Cl, PO4, Na, K, Ca, and Mg.
Methods: The Aerochem Metrics Wet/Dry collector is equipped with a movable lid and a precipitation sensor that electronically signals the lid to uncover a 'wet' side bucket during precipitation events and recover the wet side when precipitation ceases. Every week (Tuesdays), the wet side bucket is replaced with a clean bucket. The previous week's wet bucket is fitted with a clean lid and transported back to campus in a plastic bag and transporting box. On campus, the bucket, lid and contents are weighed. A weekly field form records time and date aon and off, a daily precipitation record of amounts, information about sample contamination and equipment operation. The sample is carefully transferred into a cleaned 1 liter polyethylene bottle (provided by CAL) and then shipped to Central Analytical laboratory (CAL) along with the field form. This procedure is followed every week regardless of the amount of precipitation collected. An example of the field form is shown in Appendix F. More detailed instructions concerning bucket changing, and pH and conductivity determinations are available in the NADP Field Operators Manual located in Bushnell Rm 215. Used collection supplies (lids and buckets) are collected for six weeks and then returned to CAL for cleaned replacements.
Every four weeks, the dry side bucket is also changed and replaced with a clean bucket. No analysis of dryfall is currently done by NADP. As of April 1992, we have requested regular updates of data for our site from the NADP/NTN Coordination Office.
Routine Maintenance: Weekly, the precipitation sensor should be checked for proper operation (if touched, or if a drop of water is placed on the sensor, the lid should move to uncover the wet side bucket). Also, the sensor and moveable lid should be cleaned monthly using distilled water and fine stiff brush. The underside of the lid should be cleaned each month, using a clean Kimwipe and distilled water. The top of the lid should also be kept clean and free of snow or ice accumulation. During freezing weather, rain/ice storms may cause the lid to freeze to either bucket. The frozen lid must be broken free as soon as possible to avoid burning out the motor on the sampler and to assure the quality of the precipitation sample collected. Finally, once a year, the foam underside of the lid should be changed. A new seal will be shipped from NADP automatically.
Before onset of winter, the backup DC battery supply (located in black plastic box on the ground below the collector) should be removed and taken to KSU Vehicle Maintenance to be 'load-tested' for voltage. This was installed on 8-29-91 to provide improved continuation of electrical supply and to protect the collection equipment. The battery is routinely changed every 2 years. Approximately every two to three years NADP will arrange for an inspector to survey the site, calibrate the rain gauges, and observe the operator to determine necessary changes in operations. Last site visit was April 4, 2017.
Note: Missing data are signified with the ".".
Summary of All Changes: Starting January 26, 1993, a one-year study to compare two week collections of precipitation to the on-going weekly collections was initiated at our site. Data was provided in the same manner as the existing set. The two-week sampling study ended on April 4, 1995.
January 04, 2005: pH and conductivity no longer measured at KSU (field pH and field conductivity on data reports and summaries).
April 1, 2011: Daily precipitation amounts now measured by Ott Pluvio² rain gauge at headquarters weather station.
January 01, 2017: Starting Jan 01, 2013, We don't provide the seasonal total data (ANA012), which can be calculated from the weekly data or downloaded form NADP.
For additional metadata information see: http://lter.konza.ksu.edu/sites/default/files/DC.pdf
For additional methods information see: http://lter.konza.ksu.edu/sites/default/files/MM.pdf