An Assessment of HIRS Surface Air Temperature with USCRN Data

Abstract

Abstract:The surface air temperature retrievals from the High Resolution Infrared Radiation Sounder (HIRS) are evaluated by using observations from the U.S. Climate Reference Network (USCRN) for the period of 2006 to 2013. One year of the USCRN data is also used as ground truth in calibrating retrieval biases. The final retrieval results show that mean biases of HIRS retrievals from comparisons to all surface stations for each year are mostly in the range of˘0.2˝C, and the root mean square difference (RMSD) values are 3.2-3.5˝C. Results for biases of individual stations are mostly within 2˝C. In average, RMSDs are smaller over the eastern U.S. than over the western U.S., smaller at nighttime than at daytime, and smaller at lower elevations. The comparison patterns are consistent from year to year and for different satellites, showing the potential of HIRS data for long-term studies.

Algorithm Development of Temperature and Humidity Profile Retrievals for Long-Term HIRS Observations

“…With the bias patterns similar to those in Figure 9, the tails of the biases are expected to be smoothed out in monthly means that can lead to significantly-reduced RMSEs in monthly means. HIRS derived surface air temperatures were evaluated using USCRN observations [35]. For the years that were not used in developing the calibration scheme, the mean biases of HIRS retrievals for each year are mostly in the range of 0.5-1.0 °C, and the RMSEs are ~1.6 °C.…”

“…HIRS derived surface air temperatures were evaluated using USCRN observations [35]. For the years that were not used in developing the calibration scheme, the mean biases of HIRS retrievals for each year are mostly in the range of 0.5-1.0˝C, and the RMSEs are~1.6˝C.…”

“…Instrumentation is regularly calibrated to National Institute for Standards and Technology standards. HIRS-derived surface temperatures were co-located with a full year of USCRN observations in the development of a linear regression equation for calibrating the retrievals to USCRN observations [35].…”