loading page

A Solution for the Tower Effect at the CERES Ocean Validation Experiment (COVE)
  • +2
  • Bryan Fabbri,
  • Gregory Schuster,
  • Fred Denn,
  • Jay Madigan,
  • Robert Arduini
Bryan Fabbri
Science Systems and Applications, Inc. (SSAI)

Corresponding Author:[email protected]

Author Profile
Gregory Schuster
NASA Langley Research Center
Author Profile
Fred Denn
Science Systems and Applications, Inc. (SSAI)
Author Profile
Jay Madigan
Science Systems and Applications, Inc. (SSAI)
Author Profile
Robert Arduini
Science Systems and Applications, Inc. (SSAI)
Author Profile

Abstract

One of the key measurements from the Clouds and the Earth’s Radiant Energy System (CERES) satellite is Earth emitted or longwave (LW) radiation. The CERES Ocean Validation Experiment (COVE), located at Chesapeake Light Station, approximately 25 kilometers east of Virginia Beach, Virginia (coordinates: 36.90N, 75.71W) had provided surface validation for the CERES satellite measurements for many years. Upwelling LW radiation was one of the measurements made at COVE but was complicated due to the Light Station tower being in the upwelling LW instruments field of view. According to our estimates, the Light Station tower alters 15% of the upwelling LW radiation. An unwanted consequence of the tower being in the field of view was the tower radiating effect, particularly noticeable on clear, sunny days. During these days, the tower would radiate extra heat energy by as much as 3% (15 W/m^2) that was measured by the upwelling LW instrument. COVE follows the Baseline Surface Radiation Network requirements and their target uncertainty is 2%. To resolve this issue, we obtain a different upwelling longwave value using data from an infrared radiation thermometer (IRT) and a pyrgeometer that retrieves sea surface temperature (SST) and downwelling longwave respectively. Using an IRT allows conversion from SST to a water emission value and the pyrgeometer provides the reflected flux of the downward longwave radiation. By determining the extent of the undesirable obstruction in the field of view of the upwelling longwave instrument and determining its emissivity could allow others with similar issues to obtain the proper values of upwelling longwave measurements.