Abstract
We present a near surface air temperature (NSAT) fused data product over
the contiguous United States using Level 2 data from the Atmospheric
Infrared Sounder (AIRS), on the Aqua satellite, and the Cross-track
Infrared Microwave Sounding Suite (CrIMSS), on the Suomi National
Polar-orbiting Partnership (SNPP) satellite. We create the fused product
using Spatial Statistical Data Fusion (SSDF), a procedure for fusing
multiple datasets by modeling spatial dependence in the data, along with
ground station data from NOAA’s Integrated Surface Database (ISD) which
is used to estimate bias and variance in the input satellite datasets.
Our fused NSAT product is produced twice daily and on a 0.25-degree
latitude-longitude grid. We provide detailed validation using withheld
ISD data and comparison with ERA5-Land reanalysis. The fused gridded
product has no missing data; has improved accuracy and precision
relative to the input satellite datasets, and comparable accuracy and
precision to ERA5-Land; and includes improved uncertainty estimates.
Over the domain of our study, the fused product decreases daytime bias
magnitude by 1.7 K and 0.5 K, nighttime bias magnitude by 1.5 K and 0.2
K, and overall RMSE by 35% and 15% relative to the AIRS and CrIMSS
input datasets, respectively. Our method is computationally fast and
generalizable, capable of data fusion from multiple datasets estimating
the same quantity. Finally, because our product reduces bias, it
produces long-term datasets across multi-instrument remote sensing
records with improved bias stationarity, even as individual missions and
their data records begin and end.