Wave and Anemometer-based Sea Surface Wind (WASWind)

Ship-based measurements of sea surface wind speed displays a spurious upward trend due to increases in anemometer height. To correct this bias, we construct a new sea surface wind dataset from ship observations of wind speed and wind wave height archived in the International Comprehensive Ocean-Atmosphere Data Set (ICOADS). The Wave and Anemometer-based Sea-surface Wind (WASWind) dataset is available at monthly resolution on a 4 degrees by 4 degrees. longitude-latitude grid from 1950 to 2011. It substantially reduces the upward trend in wind speed through height-correction for anemometer-measured winds, rejection of spurious Beaufort winds, and use of estimated winds from wind wave height. The reduced upward trend is smallest among the existing global datasets of in situ observations and comparable with those of reanalysis products. Despite the significant reduction of globally-averaged wind speed trend, WASWind features rich spatial structures in trend pattern, making it a valuable dataset for studies of climate changes on regional scales. Not only does the combination of ship winds and wind wave height successfully reproduce major modes of seasonal-to-decadal variability, but its trend patterns are also physically consistent with sea level pressure (SLP) measurements. WASWind is in close agreement with wind changes in satellite measurements by the Special Sensor Microwave Imager (SSM/I) for the recent two decades. The agreement in trend pattern with such independent observations illustrates the utility of WASWind for climate trend analysis.

基于船舶的海洋表面风速测量显示出因风速计高度增加而导致的虚假上升趋势。为纠正这一偏差，我们从国际综合海洋大气数据集（ICOADS）中归档的风速和风浪高度船舶观测数据构建了一个新的海洋表面风数据集。该Wave and Anemometer-based Sea-surface Wind (WASWind)数据集以月度分辨率，在1950年至2011年间，以4度×4度的经纬度网格形式提供。该数据集通过风速计测量风速的高度校正、虚假蒲福风（Beaufort winds）的剔除以及使用基于风浪高度估计的风速，显著降低了风速上升的趋势。在现有的全球实地观测数据集中，WASWind的风速上升趋势最小，且与再分析产品的风速趋势相当。尽管全球平均风速趋势的降低非常显著，但WASWind在趋势模式上具有丰富的空间结构，使其成为区域尺度气候变化研究的宝贵数据集。不仅船舶风速与风浪高度的结合成功复制了季节至年代际变率的重大模式，其趋势模式也与海平面压力（SLP）测量结果在物理上保持一致。近二十年来，WASWind与特殊传感器微波成像仪（SSM/I）的卫星测量风速变化密切相关。与这种独立观测结果在趋势模式上的吻合，展示了WASWind在气候趋势分析中的实用性。