Retrieved wind speed from the Orbiting Carbon Observatory-2

• Main Authors: R. R. Nelson, A. Eldering, D. Crisp, A. J. Merrelli, C. W. O'Dell
• Format: Article
• Language: English
• Published: Copernicus Publications 2020-12-01
• Series: Atmospheric Measurement Techniques
• Online Access: https://amt.copernicus.org/articles/13/6889/2020/amt-13-6889-2020.pdf

<p>Satellite measurements of surface wind speed over the ocean inform a wide variety of scientific pursuits. While both active and passive microwave sensors are traditionally used to detect surface wind speed over water surfaces, measurements of reflected sunlight in the near-infrared made by the Orbiting Carbon Observatory-2 (OCO-2) are also sensitive to the wind speed. In this work, retrieved wind speeds from OCO-2 glint measurements are validated against the Advanced Microwave Scanning Radiometer-2 (AMSR2). Both sensors are in the international Afternoon Constellation (A-Train), allowing for a large number of co-located observations. Several different OCO-2 retrieval algorithm modifications are tested, with the most successful being a single-band Cox–Munk-only model. Using this, we find excellent agreement between the two sensors, with OCO-2 having a small mean bias against AMSR2 of <span class="inline-formula">−</span>0.22 <span class="inline-formula">m s⁻¹</span>, an RMSD of 0.75 <span class="inline-formula">m s⁻¹</span>, and a correlation coefficient of 0.94. Although OCO-2 is restricted to clear-sky measurements, potential benefits of its higher spatial resolution relative to microwave instruments include the study of coastal wind processes, which may be able to inform certain economic sectors.</p>