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IPC-XI Tutorial Pyrgeometer. Contents. Pyrgeometer energy balance Equations for retrieving longwave irradiance Shaded versus unshaded pyrgeometers. Pyrgeometer setup. Pyrgeometer energy balance. Kipp&Zonen CG4. Eppley PIR. 5µm. 20µm. 40µm. Pyrgeometer energy balance. Kipp&Zonen CG4.
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Contents • Pyrgeometer energy balance • Equations for retrieving longwave irradiance • Shaded versus unshaded pyrgeometers
Pyrgeometer energy balance Kipp&Zonen CG4 Eppley PIR 5µm 20µm 40µm
Pyrgeometer energy balance Kipp&Zonen CG4 Typical values: Net outgoing radiation ~ 100 Wm-2 PIR Dome (∆T=1K) ~18 Wm-2 Eppley PIR
Pyrgeometer equations • Several choices for the radiometric model of a pyrgeometer: Simple Albrecht formula Extended Albrecht (PMOD) NREL formula Fit parameters
Calibration residuals versus WISGresults from 50 Instruments
Unshaded pyrgeometers 1 Dome YSI NIGHT
Unshaded pyrgeometers NIGHT andDAY NIGHT
Unshaded pyrgeometers 1 Dome YSI Proxy: direct solar irradiance
Unshaded pyrgeometers 1 Dome YSI Proxy: direct solar irradiance Proxy: Dome-body temperature
Unshaded pyrgeometers PIR Dome proxy Direct irr proxy
Unshaded pyrgeometers PIR 3 Th. Dome proxy Direct irr proxy R=0.81 Effect is 6 W/m2 per 1kW for this particular pyrgeometer R=0.91 26955 3 dome
Unshaded pyrgeometers CG4 Effect is 5.5 W/m2 per 1kW for this particular pyrgeometer cg4
Summary unshaded pyrgeometers Is there shortwave leakage in the solar blind filters?
IPC-XI Pyrgeometer intercomparison PIR & CG4 Difference to WISG / Wm-2 unshaded shaded
IPC-XI Pyrgeometer intercomparison Only CG4 Difference to WISG / Wm-2