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Uncertainty in the bias adjustments applied to historical sea surface temperature (SST) measurements made using buckets are thought to make the largest contribution to uncertainty in global surface temperature trends. Measurements of the change in temperature of water samples in wooden and canvas buckets used before World War 2 are compared with the predictions of models that have been used to estimate bias adjustments applied in widely-used gridded analyses of SST. The results show that the models are broadly able to predict the dependence of the temperature change of the water over time on the thermal forcing and the bucket characteristics: volume and geometry; structure and material. However, assumptions inherent in the derivation of the models are likely to affect their applicability. We observed that the water sample needed to be fairly vigorously stirred to agree with results from the model, which assumes well-mixed conditions. There were inconsistences between the model results and previous measurements made in a wind tunnel in 1951. The model assumes non turbulent incident flow and consequently predicts an approximately square-root dependence on airflow speed. The wind tunnel measurements, taken over a wide range of airflows, showed a much stronger dependence. In the presence of turbulence the heat transfer will increase with the turbulent intensity: for measurements made on ships the incident airflow is likely to be turbulent and the intensity of the turbulence is always unknown. Taken together these uncertainties are expected to be substantial and may represent the limiting factor for the direct application of these models to adjust historical SST observations. However, both the models and the observations indicate that the most important parameter driving temperature biases in historical bucket measurements is the difference between the water temperature and the wet-bulb temperature. Solar radiation is also important, but not examined in this paper.

Wind speed measurements obtained from anemometers mounted on ships are prone to systematic errors caused by the distortion of the air flow around the ship's hull and superstructure. This report describes the results of simulations of the air flow around the ODEN made using the computational fluid dynamics (CFD) software VECTIS. The airflow distortion at anemometer sites used during the ACSE project has been quantified at a wind speed of 7 ms-1 for a wide range of wind directions: every 10 degrees from bow on to 120 degrees off the bow, and an additional run was undertaken at 150 degrees off the bow. The anemometers used in this study were located in the bows of the ship. The vertical displacements of the airflow at the anemometer sites and at a location of an aerosol intake are included. Wind speed profiles above a motion-stabilised doppler lidar were also obtained.For bow-on flows the anemometers in the bows of the ship experienced relatively small flow distortion. At these sites the flow was decelerated by about 3% of the free stream wind speed. Over the full range of relative wind directions the flow to the METEK sonic is generally accelerated with the largest wind speed biases at flows directly over the beam. The vertical displacement of the airflow increases from around 3 m for flows directly over the bow, to around 6 m for flows over the ship's beam as the lockage of the airflow by the ship becomes greater.The vertical displacement at the aerosol intake location varied from 6m for flows directly over the bow, to around 16 m for flows over the ship's beam. The ship imposes a significant obstacle to the flow and forces a strong vertical velocity in the lowest few tens of meters above the lidar.

The RRS James Clark Ross makes meteorological measurements around Antarctica during the austral summer, in the Arctic during the boreal summer and in the Atlantic during passages between the two poles. In May 2010, as part of the WAGES project the ships existing systems were complemented by the AutoFlux system (Yelland et al., 2009) to measure the transfers of momentum, heat and CO2 between the atmosphere and the ocean. Similarly, a commercial directional wave radar "WAVEX" made by the Norwegian firm MIROS was installed. This report describes the metadata for the WAGES instrumentation deployed on the RRS James Clark Ross between May 2010 and September 2013. Sensor serial numbers, dates of sensor changes and problems with sensors are contained in the associated tables.

Wind speed measurements obtained from anemometers mounted on ships are prone to systematic errors caused by the distortion of the airflow around the ship's hull and superstructure. This report describes the results of simulations of the airflow around the RRS James Clark Ross made using the computational fluid dynamics (CFD) software VECTIS. The airflow distortion at anemometer sites used during the WAGES project has been quantified at a wind speed of 10 m/s for relative wind directions of 0 (bow-on), 10, 20, 30, 50, 70, 90 and 110 degrees off the bow. The anemometers used in this study were located in the bows of the ship. Temperature sensors were located on the port side of the monkey island. For bow-on flows the anemometers in the bows of the ship experienced relatively small flow distortion. At these sites the flow was decelerated by about 1% of the free stream wind speed. Over the full range of relative wind directions the flow to the R3 sonic is generally accelerated with the largest wind speed biases at flows directly over the beam. The vertical displacement of the airflow increases from around 1 to 2 m for flows directly over the bow, to around 5m for flows over the ships beam as the blockage of the airflow by the ship becomes greater.The airflow distortion at the temperature sensor locations above the monkey island was typically greater than the well-exposed foremast locations. These locations experienced wind speed biases from 6% increase for an airflow directly over the bow, to large decelerations of 55 % when the instruments were in the large recirculation region for flows directly over the starboard side.