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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.

This report describes the 17th complete occupation of the Drake Passage CTD section, established during the World Ocean Circulation Experiment as repeat section SR1b. It wasfirst occupied by National Oceanography Centre (previously IOSDL and then SOC) in collaboration with the British Antarctic Survey in 1993, and has been re-occupied most years since then. Thirty two full depth stations were performed during JR265: two test stations, and all 30 of the nominal stations for the SR1b Drake Passage section. An initial result is that the estimated total transport measured across the section was 133 Sv which compares well to an average transport measured from the 16 previous UK cruises of 135 Sv (standard deviation of 7 Sv). In conjunction with the hydrographic cruise, a "Waves Aerosol and Gas Exchange Study" (WAGES) intensive observation cruise JR245D was also carried out. WAGES involves continuous measurement of the air-sea turbulent fluxes of CO2, sea spray aerosol, momentum and sensible and latent heat fluxes, plus directional sea-state and whitecap parameters using systems installed on the ship in May 2010. In addition to the continuous measurements, a number of intensive observation periods (IOPs) have been carried out by WAGES staff on board the ship. These involve deployments of a spar buoy to measure wave breaking and an aerial camera system to measure whitecap fraction. The activities of JR254D are summarised here, but are described in detail in a separate cruise report. Cruise JR264 was carried out by NOC-L staff at the same time as JR265 and JR254D. JR264 is also the subject of a separate cruise report. The CTD was an underwater SBE 9 plus unit equipped with the following sensors: dual temperature and conductivity sensors, a pressure sensor encased in the SBE underwater unit, a SBE-43 oxygen probe, an Aquatracka MKIII fluorometer, a transmissometer, an upwardlooking downwelling PAR sensor, and an altimeter. A downward-looking LADCP (RDI Workhorse Monitor 300 kHz) was deployed on all stations. Various underway measurements were obtained, including navigation, VM-ADCP, sea surface temperature and salinity, water depth and various meteorological parameters. A practical aim during this cruise was to update the detailed guides for each of the hydrographic data streams which were first written duringJR195 in 2009. The hydrographic data analysis was performed using "MSTAR", a suite of Matlab programs developed at NOCS by Brian King and used on the JCR for the first time during JR195.

Alignment offsets between anemometers and motion-sensing instruments are a source of uncertainty for eddy correlation flux measurements made at sea. A previously described laboratory technique (Brooks, 2008) has been utilised to determine the pitch, roll and yaw offsets between flux instruments installed on the weathership Polarfront as part of the HiWASE project. Pitch and roll offsets were determined with an uncertainty of between 0.02° and 0.08°. Yaw offsets were determined with an uncertainty of between 0.5° and 1.2°.

Between 1978 and 2009 the Norwegian weather ship Polarfront made continuous meteorological and surface wave measurements at Station M (66oN 2oE). In September 2006, as part of the UK-SOLAS HiWASE project (Brooks et al., 2009) the ship’s 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, the ship's existing ship-borne wave recorder (SBWR) was supplemented by installing a commercial directional wave radar "WAVEX" made by the Norwegian firm MIROS.This report describes the metadata for the HiWASE instrumentation deployed on the OWS Polarfront between September 2006 and December 2009. Sensor serial numbers, dates of sensor changes and problems with sensors are contained in the associated tables.

This report describes the mobilisation and shakedown cruise of the Norwegian weather ship OWS Polarfront in September 2006. The air-sea turbulent flux system "AutoFlux", a commercial wave measurement system "WAVEX" and a number of digital cameras were installed on the ship as part of the UK-SOLAS project "HiWASE" (High Wind Air-Sea Exchanges). These complemented the ship's mean meteorological sensors and a ship-borne wave recorder (SBWR) both run by the Norwegian Meteorological Institute (DNMI) and an underway pCO2 system run by the Bergen Centre for Climate Research (BCCR).The Polarfront and its predecessors have occupied Station M (66º N, 2º E) for over 60 years.The ship is on station all year round, only leaving for an eight hour port call once every 4 weeks, and an annual refit for 5 days in September. The HiWASE instrumentation was installed in early September 2006, prior to the shakedown cruise P162. The various systems operated continuously from September 2006 until December 2009, when DNMI withdrew the ship from operation.This cruise report describes the instrumentation installed on the ship, including that run by DNMI and BCCR as well as the HiWASE systems, and presents an initial analysis of the data quality from the various systems. Preliminary results are given for the air-sea fluxes of momentum, CO2 and sensible and latent heat. These fluxes were directly measured using the inertial dissipation and/or the eddy correlation (covariance) methods, from a suite of fast response sensors installed on the ship's foremast.This report focuses on the systems as installed for the shakedown cruise. However, over the 3 year deployment period various changes were made: these are described in a separate metadata report (Moat et al., 2010).

This report describes the 16th occupation of the Drake Passage CTD section, established duringthe World Ocean Circulation Experiment as repeat section SR1b. It was first occupied byNational Oceanography Centre (previously IOSDL and then SOC) in collaboration with theBritish Antarctic Survey in 1993, and has been re-occupied most years since then. Thirty onefull depth stations were performed during JR195: two test stations, and 29 of the 30 nominalstations for the SR1b Drake Passage section. Two 500 m stations were added as part of POL'scruise JR198.The CTD was an underwater SBE 9 plus unit equipped with the following sensors: dualtemperature and conductivity sensors, a pressure sensor encased in the SBE underwater unit, aSBE-43 oxygen probe, an Aquatracka MKIII fluorometer, a transmissometer, an upwardlookingdownwelling PAR sensor, and an altimeter. A downward-looking LADCP (RDIWorkhorse Monitor 300 kHz) was deployed on all stations, except for the two 500 m stationswhen it was replaced by a 600 kHz LADCP from Bangor University.Various underway measurements were obtained, including navigation, VM-ADCP, sea surfacetemperature and salinity, water depth and various meteorological parameters.

AutoFlux is an autonomous system for making direct measurements of the air-sea exchanges of CO2, momentum and heat. Such measurements are usually restricted to short, dedicated air-sea interaction cruises on research ships which last only a few weeks. In contrast, AutoFlux was recently deployed continuously on the RRS Discovery for two years and is now currently part of a three year measurement programme on the Norwegian weather ship Polarfront. The instrumentation on Polarfront also includes two different wave measurement systems and digital cameras. The various systems are described and initial results presented.

Accurate wind speed measurements from anemometers on research ships are required to obtain high quality air-sea flux measurements. However, the measurements can be biased by the distortion of the airflow over the ship, i.e. the wind speed can either be accelerated or decelerated by the presence of the ship and the flow of air can be displaced vertically over the ship's superstructure. The computational fluid dynamics software VECTIS was used to numerically simulate the airflow over the Ocean Weather Ship Polarfront. The airflow distortion at six anemometer sites has been quantified for a wind speed of 10 ms-1 blowing a) directly over the bows of the ship and b) over the ship’s starboard beam. The wind speed errors ranged fromdecelerations of about 1 % for an airflow directly over the bow to accelerations of 10 % for the beam-on flow.

Wind speed measurements are obtained from anemometers located on research ships. Even though the anemometers are usually positioned in well-exposed locations the presence of the ship’s hull and superstructure distorts the airflow to the anemometer and biases the wind speed measurements. Previous studies have shown biases of up to 10 % for bow-on flows, and that the biases generally increase for other wind directions. Corrections for the effects of the flow distortion are vital, as these data are used for satellite validation and in climate related studies. Therefore, the computational fluid dynamics (CFD) package VECTIS is used to numerically simulate the airflow over ships and derive corrections for this effect.A VECTIS simulation of one ship at one wind direction currently takes approximately one month to perform on a typical UNIX workstation. Therefore, it would be impractical to study the airflow over a large number of research ships and/or a large number of wind directions. A faster method (the “steady-state solver”) for VECTIS simulations has been available for some time, but requires significant increases in computational speed and memory which have only recently become widely available. This report presents a comparison of VECTIS simulations using the steady-state solver with both previous VECTIS studies and in situ wind speed measurements.Use of the steady-state solver requires a higher mesh density but also cuts model convergence times from weeks to days, allowing fine-resolution models to be run without impractical time constraints. The results of this study show that in regions where the flow distortion is high, the increased mesh density results in significant improvement in the comparison between modelled and in-situ wind speeds.

Wind speed and air-sea flux measurements made from instrumentation on ships are affected by the airflow distortion created by the presence of the ship. The airflow can be eitheraccelerated or decelerated depending on the shape of the ship and the location of the anemometer. The computational fluid dynamics (CFD) package VECTIS was used to examinethe extent of the flow distortion at potential anemometer locations on the foremast platform of the RRS "James Cook". This technique has been previously used to study the airflow over many research ships, but this is believed to be the first time it has been applied to a research ship in the design/build stage.CFD modelling of the airflow over the ship showed that the foremast platform of the RRS "James Cook" is a good location to locate instrumentation and make high quality air-sea flux measurements. The wind speed is decelerated by about 2 % of the freestream wind speed for bow-on flows at well-exposed anemometer sites on the foremast platform. For relative wind directions up to ±30° of the bow the airflow is accelerated by up to 5 %.The ship’s anemometers are located on the main mast and are relatively close to the ship’s large satellite communication radome. For winds within 15° of the bow the wind speeds at these anemometer sites are accelerated by up to about 7 %. For wind directions at ±30° the satellite radome has a significant effect on the flow and the wind speeds will be severely biased, with the magnitude of the bias varying rapidly with wind direction and the angle of pitch of the ship. It is strongly recommended that these anemometers be moved higher up and further away from the mast.

Wind speed measurements obtained from ship-mounted anemometers are biased by the distortion of the airflow around the ship's hull and superstructure. These wind speed measurements are used both in numerical weather prediction and in climate studies and need to be known as accurately as possible. This paper presents results from threedimensional CFD studies of the mean airflow over various research ships and a generic tanker/bulk. It will be shown that the bias in the wind speed measurements is highly dependent upon anemometer position and ship shape. CFD results are compared to in situ wind speed measurementsmade from a number of anemometers above the bridge of the RRS Charles Darwin.

An investigation has been carried out to measure mean velocities above a solid block located in a wind tunnel. A Particle Image Velocimetry (PIV) system was used. The purpose of the investigation was to quantify the change in the mean flow speed caused by the bluff body and hence to determine the possible bias in wind speed measurement made from anemometers located above the superstructure of merchant ships. Possible sources of experimental error were investigated and resulted in; a) a blockage ratio correction which varied with position, b) the use of 2-dimensional maps of the free stream flow to obtain reference velocities and c) an estimate of a residual bias of up to 4 % in the PIV wind speed data. The wind speed was accelerated by up to 28 % compared to the free stream (or undistorted) wind speed. Close to the top of the block the wind speed is severely decelerated and the airflow reverses in direction. There was no dependence of either the pattern of the flow or of the magnitude of the wind speed bias on changes in wind directions of up to 30 degrees.

Anemometers on voluntary observing ships (VOS) are usually sited above the bridge in a region where the effects of flow distortion may be large. Until recently it was unclear whether measurements from such anemometers would be biased high or low, and the magnitude of any such bias was not known. This report describes the progress made in determining the effects of flow distortion and hence in predicting the possible bias in such anemometer measurements of the wind speed.

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 R.R.S. James Clark Ross made using the Computational Fluid Dynamics (CFD) software VECTIS. The airflow distortion at a number of anemometer sites has been quantified for wind speeds of 5 m/s and 15 m/s blowing a) directly over the bows of the ship, and b) directly over the port beam (90° to port of the bow). The anemometers in this study were located in the bows of the ship and also on the port bridge wing.For bow-on flows the instrument sites in the bows of the ship experienced relatively small flow distortion. At these sites the flow was accelerated by between -1% to 1% and displaced vertically by between 1.7 m and 2.2 m. In contrast, the instrument sites on the port bridge wing experienced a severely distorted flow. The wind speed error varied rapidly from -40% to 20% depending on the exact location of the instrument, and the vertical displacement varied between 5.3 m and 6.3 m.For flows over the port beam the instrument sites in the bows of the ship experienced moderate flow distortion with wind speed errors of 9 % to 13 % and vertical displacements of between 4.8 m and 5.4 m. The instruments sites located on the port bridge wing experienced wind speed errors of -7.1 % to 2.6 %, and vertical displacements of 9.4 m to 10.4 m.

Wind speed measurements obtained from research ships are prone to systematic errors caused by the distortion of the air flow around the ship’s hull and superstructure. In this report the air flow around the RV Ronald H. Brown is simulated at two relative wind directions using Computational Fluid Dynamics (CFD). The airflow distortion at three anemometer sites has been quantified for wind speed of 15 ms-1 blowing a) directly over the bows of the ship, and b) from 30º to port of the bow. All anemometers in this study were located in the bows of the ship and experienced moderate flow distortion, with the wind speed being decelerated by 1% to 4% depending on the instrument location and the wind direction. The flow had been displaced vertically by about 0.7 m for the bow-on flow and by about 0.9 m for the flow from 30º to port.

This report describes RRS James Clark Ross Cruise 44, called CATS-MIAOW (Circulation And Thermohaline Structure - Mixing, Ice And Ocean Weather). It was funded by the UK Natural Environment Research Council as part of its Arctic Ice and Climate Variability (ARCICE) Thematic Research Programme. The cruise supported projects in hydrography, meteorology and geophysics. The cruise divided into two parts, one hydrographic and one meteorological. The hydrographic work comprised sections under ERS-2 satellite overpasses: two long sections with CTD and lowered ADCP, from Norway to Greenland and from Svalbard to Iceland; and a shorter section across northern Denmark Strait, which was repeated. There was also a near-zonal section in Fram Strait. Bottle samples were taken throughout for salinity, dissolved oxygen and SF6.The meteorological work took place in the marginal ice zone (MIZ) during a 10 day period in the middle of the cruise. While in the MIZ atmospheric profiles were obtained using GPS radiosondes and a tethered balloon system. The AUTOFLUX ship mounted surface fluxes system was also used to measure the surface fluxes of heat, momentum and moisture in addition to the usual mean meteorological variables. A suite of short-wave and long-wave sensors were also employed to measure both up- and down-welling radiation. The AUTOFLUX system operated throughout the cruise, providing surface flux and mean meteorological data in support of the hydrographic work.

This report describes the work undertaken on the AutoFlux system by SOC staff on the RRS James Clark Ross during the UK to Falklands passage between 11 September and 17 October 2000. This work coincided with the Atlantic Meridional Transect (AMT) 11 cruise (JR52) which ended on 11 October 2000, and is described elsewhere (Woodward, 2000). The SOC presence on the ship was sponsored by John King (BAS) as part of his Q3 (Antarctic Climate Processes) science program.The aim of the cruise was to test and develop the AutoFlux air-sea interaction system and its associated prototype instrumentation. The system is intended to provide real-time air-sea fluxes of momentum, sensible heat, latent heat and CO2, in addition to the usual mean meteorological parameters. The fluxes are calculated via the ‘inertial dissipation’ method (Yelland et al., 1998), using data from various fast-response instruments. Most of the instruments used in the system have been well proved during SOC research cruises over the last 10 years or more, but the dedicated sonic temperature sensor and the infra-red H2O/CO2 sensor are prototype instruments developed by colleagues involved in the AutoFlux project (MAST project MAS3-CT97-0108). Likewise, the logging and processing system is itself based on software systems which have been developed at SOC/IOS since the 1980s, but many aspects of the system are new and were tested and developed further during the cruise. By the fourth week of the cruise the system was automatically producing hourly direct measurements of the air-sea fluxes and was sending summary messages of the data back to SOC via the ORBCOMM satellite communications system in near real time.

This report describes an investigation of the air flow around the RV Knorr using the Computational Fluid Dynamics software package "VECTIS" to simulate a flow of air directly over the bows of the ship. Section 2 gives a brief description of the model. This work was undertaken at the request of researchers from the Bedford Institute of Oceanography (BIO), the National Oceanic and Atmospheric Administration (NOAA) and Kiel University who had used the ship to carry meteorological instrumentation on a purpose-built mast (the "lattice tower") during an experiment in the Labrador Sea in the winter of 1997. One advantage of the VECTIS software is the ability to vary the computational mesh density; this allows regions of particular interest to be modelled using a much higher resolution than that employed elsewhere in the model. In the case of the Knorr, the highest mesh density was located around the instrument sites on the lattice tower. In Section 3 the distortion of the air flow to these instrument sites is examined, and the vertical displacement of the flow and the percentage wind speed error is calculated for each site. Section 4 describes the flow at the separate IMET instrument sites on the ship’s foremast and bowmast. The mesh resolution at the IMET sites is not as great as that around the lattice tower since data for the IMET sites were requested towards the end of the study. The results are summarised and discussed in Section 5. University of Kiel (Germany) Bedford Institute of Oceanography (Nova Scotia) NOAA Funded by Naval Postgraduate School.