Purchase Knob (Lat: 35.586157°; Long: -83.072477°; Elev: 1493 m) is one of the main monitoring sites for IPHEx 2014 campaign, and also one of the permanent positions where precipitation dynamics have been studied since 2007 by Dr. Ana P. Barros' research group from Duke University with the help and support of the Great Smoky Mountains National Park.
Before IPHEx, precipitation observations were taken with the following instrumentation:
- Tipping Bucket Rain Gauges, beginning in May 2008
- OTT Pluvio Rain Gauge, beginning in January 2012
- PARSIVEL (P1) disdrometer
- Micro-Rain Radar
- Flux tower
For IPHEx 2014, the following additional instrumentation was installed:
- 2 - channel Microwave Radiometer
- PARSIVEL (P2) disdrometer