Elizabeth Kent

National Oceanography Centre, Southampton | NOCS · Marine Physics and Ocean Climate

We present a new gridded data set of air temperature change across global land and ocean extending back to the 1780s. This data set, called the GloSAT reference analysis, has two novel features: it uses marine air temperature observations rather than the sea surface temperature measurements typically used by pre-existing data sets, and it extends f...

The observed temperature record, which combines sea surface temperatures with near-surface air temperatures over land, is crucial for understanding climate variability and change1–4. However, early records of global mean surface temperature are uncertain owing to changes in measurement technology and practice, partial documentation5–8, and incomple...

Accurate historical records of Earth’s surface temperatures are central to climate research and policy development. Widely-used estimates based on instrumental measurements from land and sea are, however, not fully consistent at either global or regional scales. To address these challenges, we develop the Dynamically Consistent ENsemble of Temperat...

The 5-year Ocean Regulation of Climate by Heat and Carbon Sequestration and Transports (ORCHESTRA) programme and its 1-year extension ENCORE (ENCORE is the National Capability ORCHESTRA Extension) was an approximately 11-million-pound programme involving seven UK research centres that finished in March 2022. The project sought to radically improve...

What is already happening? • Sea surface temperature (SST) around the UK generally shows a significant warming trend of around 0.3 degrees per decade over the last 40 years. • Regional variations exist in this trend with surface warming being greatest across the southern North Sea and least across the north-west of the domain. • Warm-season...

The turbulent exchanges, or fluxes, of heat, moisture and momentum between the atmosphere and the ocean play a crucial role in the Earth’s climate system. Direct measurements of turbulent fluxes are very challenging and sparse, and do not span the full range of environmental conditions that exist over the ocean. This means that empirical “bulk form...

Marine air temperatures recorded on ships during the daytime are known to be biased warm on average due to energy storage by the superstructure of the vessels. This makes unadjusted daytime observations unsuitable for many applications including for the monitoring of long-term temperature change over the oceans. In this paper a physics-based approa...

Sea surface temperature is an essential variable for oceanography, meteorology, and climatology. In situ and satellite observations are used together in creating products that meet the requirements for both near-real-time and retrospective, consistent data sets. In situ measurements, particularly those of drifting buoys and moorings, are used to va...

Low-level easterly winds encircling Antarctica help drive coastal currents which modify transport of circumpolar deep water to ice shelves, and the formation and distribution of sea ice. Reanalysis datasets are especially important at high southern latitudes where observations are few. Here, we investigate the representation of the mean state and s...

This paper describes the new International Comprehensive Ocean-Atmosphere Data Set (ICOADS) near-real-time (NRT) Release, (R3.0.2), with greatly enhanced completeness over the previous version (R3.0.1). R3.0.1 had been operationally produced monthly from January 2015 onward, with input data from the World Meteorological Organization (WMO) Global Te...

Low-level easterly winds encircling Antarctica help drive coastal currents which modify transport of circumpolar deep water to ice shelves, as well as the formation and distribution of sea ice. Reanalysis datasets are especially important at high southern latitudes where observations are few. Here, we investigate the representation of the mean stat...

Surface temperature documents our changing climate, and the marine record represents one of the longest widely distributed, observation-based estimates. Measurements of near-surface marine air temperature and sea-surface temperature have been recorded on platforms ranging from sailing ships to autonomous drifting buoys. The raw observations show an...

This paper outlines progress of the Copernicus Climate Change Service's (C3S) Global Land and Marine Observations Database service in securing data sources and introduces the data upload component. We present details of land and marine data holdings inventoried, highlighting priority needs in terms of periods, regions and Essential Climate Variable...

A new data set of Night Marine Air Temperature (NMAT) is presented that builds on the HadNMAT2 data set, which was released in 2013. In a similar manner to HadNMAT2, the new data set (CLASSnmat) provides uninterpolated, monthly global values at a 5° resolution back to 1880. In addition to being extended to the end of 2019, four main developments ar...

Day-to-day variations in surface air temperature affect society in many ways, but daily surface air temperature measurements are not available everywhere. Therefore, a global daily picture cannot be achieved with measurements made in situ alone and needs to incorporate estimates from satellite retrievals. This article presents the science developed...

There is high confidence that there is a consistent picture of long-term warming across the UK continental shelf. • Wider variability at sub-decadal to the decadal scale is important and has an effect on the magnitude and significance of the 30-year trend in Sea-Surface Temperatures (SSTs) across the UK continental shelf. • Short-term variations ar...

The role ships play in atmospheric, oceanic, and biogeochemical observations is described with a focus on measurements made near the ocean surface. Ships include merchant and research vessels; cruise liners and ferries; fishing vessels; coast guard, military, and other government-operated ships; yachts; and a growing fleet of automated surface vess...

Air-sea and air-sea-ice fluxes in the Southern Ocean play a critical role in global climate through their impact on the overturning circulation and oceanic heat and carbon uptake. The challenging conditions in the Southern Ocean have led to sparse spatial and temporal coverage of observations. This has led to a “knowledge gap” that increases uncert...

Turbulent and radiative exchanges of heat between the ocean and atmosphere (hereafter heat fluxes), ocean surface wind stress, and state variables used to estimate them, are Essential Ocean Variables (EOVs) and Essential Climate Variables (ECVs) influencing weather and climate. This paper describes an observational strategy for producing 3-hourly,...

Observations of conditions at the ocean surface have been made for centuries, contributing to some of the longest instrumental records of climate change. Most prominent is the climate data record (CDR) of sea surface temperature (SST), which is itself essential to the majority of activities in climate science and climate service provision. A much w...

The International Comprehensive Ocean-Atmosphere Data Set (ICOADS) is a collection and archive of in situ marine observations, which has been developed over several decades as an international project and recently guided by formal international partnerships and the ICOADS Steering Committee. ICOADS contains observations from many different observin...

Existing estimates of sea surface temperatures (SSTs) indicate that, during the early twentieth century, the North Atlantic and northeast Pacific oceans warmed by twice the global average, whereas the northwest Pacific Ocean cooled by an amount equal to the global average1–4. Such a heterogeneous pattern suggests first-order contributions from regi...

A new analysis of sea surface temperature (SST) observations indicates notable uncertainty in observed decadal climate variability in the second half of the twentieth century, particularly during the decades following World War II. The uncertainties are revealed by exploring SST data binned separately for the two predominant measurement types: “eng...

In the Bay of Bengal (BoB), surface heat fluxes play a key role in monsoon dynamics and prediction. The accurate representation of large-scale surface fluxes is dependent on the quality of gridded reanalysis products. Meteorological and surface flux variables from five reanalysis products are compared and evaluated against in situ data from the RAM...

The Bay of Bengal (BoB) plays a fundamental role in controlling the weather systems that make up the South Asian summer monsoon system. In particular, the southern BoB has cooler sea surface temperatures (SST) that influence ocean–atmosphere interaction and impact the monsoon. Compared to the southeastern BoB, the southwestern BoB is cooler, more s...

Lack of reliable observational metadata represents a key barrier to understanding sea surface temperature (SST) measurement biases, a large contributor to uncertainty in the global surface record. We present a method to identify SST measurement practice by comparing the observed SST diurnal cycle from individual ships with a reference from drifting...

AbstractObservations are the foundation for understanding the climate system. Yet, currently available land meteorological data are highly fractured into various global, regional and national holdings for different variables and timescales, from a variety of sources, and in a mixture of formats. Added to this, many data are still inaccessible for a...

Global surface temperature changes are a fundamental expression of climate change. Recent, much-debated variations in the observed rate of surface temperature change have highlighted the importance of uncertainty in adjustments applied to sea surface temperature (SST) measurements. These adjustments are applied to compensate for systematic biases a...

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 are compared with the predictions of models...

The International Comprehensive Ocean-Atmosphere Data Set (ICOADS) provides the main archive for surface marine observations for the past approximately 150 years. ICOADS ship identifier (ID) information is often missing or unusable, preventing the linking of reports to an individual ship. A method for the reconstruction of ship voyages in ICOADS is...

We highlight improvements to the International Comprehensive Ocean-Atmosphere Data Set (ICOADS) in the latest Release 3.0 (R3.0; covering 1662–2014). ICOADS is the most widely used freely available collection of surface marine observations, providing data for the construction of gridded analyses of sea surface temperature, estimates of air–sea inte...

The in situ surface marine climate observing system includes contributions from several different types of observing platforms. Most observations come from mobile platforms, e.g. ships or surface drifting buoys. Climate applications using marine observations often require fields of environmental parameters to be constructed on regular spatiotempora...

Published online subject to final type-setting and images KEY HEADLINES • The first MCCIP ARC in 2006 reported following what was then the warmest year globally in 2005 (0.26°C higher than the 1981-2010 average). • Since 2005, new global record temperatures have been set in 2010 and then in each successive year 2014, 2015 and 2016. In these last th...

This chapter examines past and present studies of variability and changes in atmospheric variables within the North Sea region over the instrumental period; roughly the past 200 years. The variables addressed are large-scale circulation, pressure and wind, surface air temperature, precipitation and radiative properties (clouds, solar radiation, and...

This chapter discusses past and ongoing change in the following physical variables within the North Sea: temperature, salinity and stratification; currents and circulation; mean sea level; and extreme sea levels. Also considered are carbon dioxide; pH and nutrients; oxygen; suspended particulate matter and turbidity; coastal erosion, sedimentation...

Drifting buoy sea-surface temperature (SST) records have been used to characterize the diurnal variability of ocean temperature at a depth of order 20 cm. We use measurements covering the period 1986–2012 from the International Comprehensive Ocean-Atmosphere Data Set (ICOADS) version 2.5, which is a collection of marine surface observations that in...

Satellite-based microwave sensors have, since the 1980s, provided a means to retrieve near-surface marine specific humidity (qa), accurate estimation of which is necessary for climate and air–sea interaction applications. Seven satellite measurement-derived monthly mean humidity datasets are compared with one another and with a dataset constructed...

The evidence of climate change from observations of the atmosphere and surface has grown significantly during recent years. At the same time new improved ways of characterizing and quantifying uncertainty have highlighted the challenges that remain for developing long-term global and regional climate quality data records. Currently, the obser¬vatio...

The accurate estimation of near‐surface marine‐specific humidity is necessary for climate and air–sea interaction applications. Available estimates of monthly mean‐specific humidity spanning the past 50‐years are based on a variety of sources including in situ observations, atmospheric reanalyses and datasets that blend many different data sources....

Relative to the underlying warming trend during the 20th century the surface waters averaged over the north Atlantic were cool in the period between 1900 and 1930, warm from 1930 to 1960, cool between the late 1960s and 1990 and then warm from 1990 to present. The warming observed in the last three decades has been particularly strong in parts of t...

The accurate estimation of marine wind speed is important for climate and air–sea interaction applications. There are many datasets of monthly mean wind speeds available based either on in situ measurements, satellite retrievals, atmospheric reanalysis assimilating both in situ and satellite data and blended datasets combining some or all of these...

An updated version of the Met Office Hadley Centre’s monthly night marine air temperature dataset is presented. It is available on a 5˚ latitude-longitude grid from 1880 as anomalies relative to 1961-1990 calendar-monthly climatological average night marine air temperature (NMAT). Adjustments are made for changes in observation height; these depend...

A new record of sea surface temperature (SST) for climate applications is described. This record provides independent corroboration of global variations estimated from SST measurements made in situ. Infrared imagery from Along-Track Scanning Radiometers (ATSRs) is used to create a 20 year time series of SST at 0.1° latitude-longitude resolution, in...

Differences between Quick Scatterometer (QuikSCAT) level-2b wind vectors from the Jet Propulsion Laboratory [JPL; the Direction Interval Retrieval with Thresholded Nudging (DIRTH) product] and from the Remote Sensing Systems Co. (RSS; smoothed versions 3.0 and 4.0) for one sample month are presented. Each dataset is derived from the same observatio...

Several topics that were covered during a meeting that took place at Met Office, on behalf of the UK government, in Turkey in February 2010, are presented. The meeting focused on the changing interests of climate scientists in the datasets. One of the requirements is openness and transparency of the data that involves hard work to ascertain provena...

The methods used to calculate a new in situ global dataset of air–sea exchanges, called the NOCS Flux Dataset v2.0, are described. The fluxes have been derived from in situ weather reports from Voluntary Observing Ships (VOS) covering the period 1973–2006. The reports have been adjusted for known biases and residual uncertainties estimated. The dat...

Release 2.5 of the International Comprehensive Ocean-Atmosphere Data Set (ICOADS) is a major update (covering 1662–2007) of the world's most extensive surface marine meteorological data collection. Building on extensive national and international partnerships, many new and improved contributing datasets have been processed into a uniform format and...

Ocean assimilation systems synthesize diverse in situ and satellite data streams into four-dimensional state estimates by combining the various observations with the model. Assimilation is particularly important for the ocean where subsurface observations, even today, are sparse and intermittent compared with the scales needed to represent ocean va...

This paper reviews the current state of observation, parameterization and evaluation of surface air-sea energy and gas fluxes, and sea ice, for the purposes of monitoring and predicting the state of the global ocean. The last 10 years have been marked by the development of more accurate parameterizations of turbulent fluxes, in particular COARE-3....

Climatological products are required for monitoring and studying global climate change and accurately identifying secular trends over the past two centuries. These products require consistent and well-characterised observational data and metadata from the earliest ship observations and from the modern ocean observing system. Maintaining and develop...

Flux products quantifying exchanges between ocean and atmosphere are needed for forcing models, understanding ocean dynamics, investigating the ocean’s role in climate, and assessing coupled models. Research experiments are essential to improve flux parameterizations, and longer research deployments are required to sample rare events. Urgently need...

Measurements of sea surface temperature (SST) are an important climate record, complementing terrestrial air temperature observations, records of marine air temperature, ocean subsurface temperature, and ocean heat content. SST has been measured since the 18th century, although observations are sparse in the early period. Historically, marine obser...

Release 2.5 of the International Comprehensive Ocean-Atmosphere Data Set (ICOADS) is a major update (covering 1662-2007) of the world's most extensive surface marine meteorological data collection. Building on extensive national and international partnerships, many new and improved contributing datasets have been processed into a uniform format and...

There are many challenges in blending historical and modern observations of sea surface temperature (SST) into homogenous gridded data sets suitable for use in climate research. Many of these problems can be avoided if proper choices are made during design and deployment phases of new instrumentation and observing systems, as specified in the Globa...

The Voluntary Observing Ships (VOS) Scheme is an observing program for marine meteorology, continuing a record extending back centuries. VOS are an important component of the surface observing system, providing air and sea surface temperatures, humidity, pressure, wind speed and direction, cloud cover, waves, ice and weather data. Observational met...

The International Comprehensive Ocean-Atmosphere Data Set (ICOADS) is an archive of in situ marine surface observations and products, which has been developed over 25 years. The current Release 2.5 spans 1662-2007 and has preliminary monthly updates for 2008 onwards. ICOADS is a worldwide respected reference dataset, combining data from multiple su...

Merchant, cruise, and research vessels make unique contributions to marine data collection using automated oceanic and atmospheric monitoring systems. The programs making these observations are reviewed along with the wide range of applications to atmospheric and oceanic research and operations. A vision for the next decade outlines where increment...

The exchange, or flux, of heat between the oceans and atmosphere is an important driver of the global oceanic and atmospheric circulations but remains poorly quantified. Direct measurement of heat flux remains a research activity and so global heat flux datasets are generated using observations of winds, air and sea temperatures and humidity as inp...