Estimates of Upper Ocean Wind Power Input Using In-Situ Wind Measurements from Surface Drifters in the Iceland Basin
Estimates of Upper Ocean Wind Power Input Using In-Situ Wind Measurements from Surface Drifters in the Iceland Basin
Abstract:
The combination of the Global Drifter Program array of Lagrangian satellite-tracked surface drifters with atmospheric reanalysis wind products offers a convenient way to evaluate the global and regional distribution of near-inertial wind power input into the ocean. However, the utility of reanalysis wind products for this type of calculation and errors arising from their limited spatial as well as temporal resolution are seldomly assessed, owing to a lack of simultaneous, in-situ wind measurements.
Here we make use of a novel surface drifter configuration, combining hourly position data with in-situ wind measurements. Drifters were deployed in the Iceland Basin, a region of high storm activity forcing energetic near-inertial oscillations, over the course of two consecutive field seasons in 2018 and 2019.
We compare our in-situ measurements of near-inertial wind power input to that derived from two state-of-the-art, hourly-resolution atmospheric reanalysis wind products. Our results indicate that both reanalysis products tend to overestimate near-inertial wind power input, relative to the drifter observations, by up to a factor of two over the time period considered, with individual storm events making up the bulk of the wind power input. Excluding extreme events during which reanalysis winds strongly exceeded in-situ measurements (equivalent to about 15% of all data points) leads to a reduction of the discrepancy of 50%.
Here we make use of a novel surface drifter configuration, combining hourly position data with in-situ wind measurements. Drifters were deployed in the Iceland Basin, a region of high storm activity forcing energetic near-inertial oscillations, over the course of two consecutive field seasons in 2018 and 2019.
We compare our in-situ measurements of near-inertial wind power input to that derived from two state-of-the-art, hourly-resolution atmospheric reanalysis wind products. Our results indicate that both reanalysis products tend to overestimate near-inertial wind power input, relative to the drifter observations, by up to a factor of two over the time period considered, with individual storm events making up the bulk of the wind power input. Excluding extreme events during which reanalysis winds strongly exceeded in-situ measurements (equivalent to about 15% of all data points) leads to a reduction of the discrepancy of 50%.