Land-Contamination Compensation for QuikSCAT Near-Coastal Wind Retrieval

The QuikSCAT scatterometer is used to accurately retrieve winds over the ocean at both high (2.5 km) and low (25 km) resolutions. In near-coastal regions, land contamination of measurements results in inaccurate wind estimates using current techniques. Here, we show that identifying land-contaminated measurements allows wind retrieval to be accurately achieved in near-coastal regions using QuikSCAT data at up to 2.5-km resolution using the AVE algorithm. To identify and remove land contamination, two metrics are compared, namely, the minimum distance to land and the land contribution ratio (LCR). The LCR is used as a metric to identify and remove land-contaminated backscatter sigma^o measurements before wind retrieval by discarding measurements with LCR values above a threshold. LCR thresholds used to remove land-contaminated measurements are determined using Monte Carlo simulations and set during processing using a lookup table based on the local wind speed, land brightness, and the cross-track swath location. Wind retrieval from sigma^o fields generated using the LCR is more accurate closer to the coast than previously achieved using both low- and high-resolution processing.