scholarly journals In Situ Measurements of Surface Winds, Waves, and Sea State in Polar Lows Over the North Atlantic

2019 ◽  
Vol 124 (2) ◽  
pp. 700-718 ◽  
Author(s):  
M. Rojo ◽  
C. Claud ◽  
G. Noer ◽  
A. M. Carleton
Keyword(s):  
North Atlantic ◽  
In Situ Measurements ◽  
Surface Winds ◽  
Sea State ◽  
Polar Lows ◽  
The North ◽  
The North Atlantic

scholarly journals In situ measurements of cloud microphysical and aerosol properties during the break-up of stratocumulus cloud layers in cold air outbreaks over the North Atlantic

2018 ◽  
Vol 18 (23) ◽  
pp. 17191-17206 ◽  
Author(s):  
Gary Lloyd ◽  
Thomas W. Choularton ◽  
Keith N. Bower ◽  
Martin W. Gallagher ◽  
Jonathan Crosier ◽  
...  
Keyword(s):  
Boundary Layer ◽  
North Atlantic ◽  
In Situ Measurements ◽  
Cold Air ◽  
The North ◽  
The North Atlantic ◽  
Break Up ◽  
The Uk ◽  
Cold Air Outbreaks

Abstract. A key challenge for numerical weather prediction models is representing boundary layer clouds in cold air outbreaks (CAOs). One important aspect is the evolution of microphysical properties as stratocumulus transitions to open cellular convection. Abel et al. (2017) have shown, for the first time from in situ field observations, that the break-up in CAOs over the eastern Atlantic may be controlled by the development of precipitation in the cloud system while the boundary layer becomes decoupled. This paper describes that case and examines in situ measurements from three more CAOs. Flights were conducted using the UK Facility for Airborne Atmospheric Measurements (FAAM) British Aerospace-146 (BAe-146) aircraft in the North Atlantic region around the UK, making detailed microphysical measurements in the stratiform boundary layer. As the cloudy boundary layer evolves prior to break-up, increasing liquid water paths (LWPs) and drop sizes and the formation of liquid precipitation are observed. Small numbers of ice particles, typically a few per litre, are also observed. Eventually LWPs reduce significantly due to loss of water from the stratocumulus cloud (SC) layer. In three of the cases, aerosols are removed from the boundary layer across the transition. This process appears to be similar to those observed in warm clouds and pockets of open cells (POCs) in the subtropics. After break-up, deeper convective clouds form with bases warm enough for secondary ice production (SIP), leading to rapid glaciation. It is concluded that the precipitation is strongly associated with the break-up, with both weakening of the capping inversion and boundary layer decoupling also observed.

scholarly journals Estimation of the oceanic pCO<sub>2</sub> in the North Atlantic from VOS lines in-situ measurements: parameters needed to generate seasonally mean maps

2007 ◽  
Vol 25 (11) ◽  
pp. 2247-2257 ◽  
Author(s):  
C. Jamet ◽  
C. Moulin ◽  
N. Lefèvre
Keyword(s):  
North Atlantic ◽  
Mixed Layer Depth ◽  
Chlorophyll Concentration ◽  
In Situ Measurements ◽  
High Pco2 ◽  
Physical Parameters ◽  
Data Set ◽  
The North ◽  
The North Atlantic

Abstract. Automated instruments on board Volunteer Observing Ships (VOS) have provided high-frequency pCO2 measurements over basin-wide regions for a decade or so. In order to estimate regional air-sea CO2 fluxes, it is necessary to interpolate between in-situ measurements to obtain maps of the marine pCO2. Such an interpolation remains, however, a difficult task because VOS lines are too distant from each other to capture the high pCO2 variability. Relevant physical parameters available at large scale are thus necessary to serve as a guide to estimate the pCO2 values between the VOS lines. Satellites do not measure pCO2 but they give access to parameters related to the processes that control its variability, such as sea surface temperature (SST). In this paper we developed a method to compute pCO2 maps using satellite data (SST and CHL, the chlorophyll concentration), combined with a climatology of the mixed-layer depth (MLD). Using 15 401 measurements of surface pCO2 acquired in the North Atlantic between UK and Jamaica, between June 1994 and August 1995, we show that the parameterization of pCO2 as a function of SST, CHL and MLD yields more realistic pCO2 values than parameterizations that have been widely used in the past, based on SST, latitude, longitude or SST only. This parameterization was then used to generate seasonal maps of pCO2 over the North Atlantic. Results show that our approach yields the best marine pCO2 estimates, both in terms of absolute accuracy, when compared with an independent data set, and of geographical patterns, when compared to the climatology of Takahashi et al. (2002). This suggests that monitoring the seasonal variability of pCO2 over basin-wide regions is possible, provided that sufficient VOS lines are available.

scholarly journals In-Situ Measurements of Cloud Microphysical and Aerosol Properties during the Breakup of Stratocumulus Cloud Layers in Cold Air Outbreaks over the North Atlantic

2018 ◽  
Author(s):  
Gary Lloyd ◽  
Thomas W. Choularton ◽  
Keith N. Bower ◽  
Martin W. Gallagher ◽  
Jonathan Crosier ◽  
...  
Keyword(s):  
Boundary Layer ◽  
North Atlantic ◽  
Weather Prediction ◽  
In Situ Measurements ◽  
Cold Air ◽  
The North ◽  
The North Atlantic ◽  
The Uk ◽  
Cold Air Outbreaks

Abstract. A key challenge for numerical weather prediction models is representing boundary layer clouds in Cold Air Outbreaks. One important aspect is the evolution of microphysical properties as stratocumulus transitions to open cellular convection. Abel et al. (2017) has for the first time from in-situ field observations shown that the breakup in cold air outbreaks over the eastern Atlantic may be controlled by the development of precipitation in the cloud system while the boundary layer becomes decoupled. This paper describes that case and examines in-situ measurements from 3 more cold air outbreaks. Flights were conducted using the UK FAAM BAe-146 aircraft in the North Atlantic region around the UK making detailed microphysical measurements in the stratiform boundary layer. As the cloudy boundary layer evolves prior to breakup, increasing liquid water paths, drop sizes and the formation of liquid precipitation is observed. Small numbers of ice particles are also observed. Eventually LWPs reduce significantly due to loss of water from the Sc cloud layer. In 3 of the cases, aerosols are removed from the boundary layer across the transition. This process appears to be similar to those observed in warm clouds and pockets of open cells in the subtropics. After breakup, deeper convective clouds form with bases warm enough for secondary ice production, leading to rapid glaciation. It is concluded that the precipitation is strongly associated with the break-up, with both weakening of the capping inversion and boundary layer decoupling also observed.

scholarly journals North Atlantic warming over six decades drives decreases in krill abundance with no associated range shift

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Martin Edwards ◽  
Pierre Hélaouët ◽  
Eric Goberville ◽  
Alistair Lindley ◽  
Geraint A. Tarling ◽  
...  
Keyword(s):  
North Atlantic ◽  
Range Shift ◽  
The Core ◽  
Krill Abundance ◽  
The North ◽  
Living Space ◽  
Warming Climate ◽  
Two Temperatures ◽  
The North Atlantic

AbstractIn the North Atlantic, euphausiids (krill) form a major link between primary production and predators including commercially exploited fish. This basin is warming very rapidly, with species expected to shift northwards following their thermal tolerances. Here we show, however, that there has been a 50% decline in surface krill abundance over the last 60 years that occurred in situ, with no associated range shift. While we relate these changes to the warming climate, our study is the first to document an in situ squeeze on living space within this system. The warmer isotherms are shifting measurably northwards but cooler isotherms have remained relatively static, stalled by the subpolar fronts in the NW Atlantic. Consequently the two temperatures defining the core of krill distribution (7–13 °C) were 8° of latitude apart 60 years ago but are presently only 4° apart. Over the 60 year period the core latitudinal distribution of euphausiids has remained relatively stable so a ‘habitat squeeze’, with loss of 4° of latitude in living space, could explain the decline in krill. This highlights that, as the temperature warms, not all species can track isotherms and shift northward at the same rate with both losers and winners emerging under the ‘Atlantification’ of the sub-Arctic.

scholarly journals The CORA 5.2 dataset: global in-situ Temperature and Salinity measurements dataset. Data description and validation

2019 ◽  
Author(s):  
Tanguy Szekely ◽  
Jérôme Gourrion ◽  
Sylvie Pouliquen ◽  
Gilles Reverdin
Keyword(s):  
Real Time ◽  
North Atlantic ◽  
Objective Analysis ◽  
Atlantic Basin ◽  
Ocean Variability ◽  
The North ◽  
Error Bar ◽  
The North Atlantic ◽  
Delayed Time

Abstract. We present the Copernicus in-situ ocean dataset of temperature and salinity (version V5.2). The ocean subsurface sampling varied widely from 1950 to 2017, as a result of changes in the instrument technology and development of in-situ observational networks (in particular, tropical moorings, ARGO program). The global ocean temperature data coverage on an annual basis grows thus from 10 % in 1950 (30 % for the North Atlantic basin) to 25 % in 2000 (60 % for the North Atlantic basin) and reaches a plateau exceeding 80 % (95 % for the North Atlantic Ocean) after the deployment of the ARGO program. The average depth reached by the profiles also increases from 1950 to 2017. The validation framework is presented, and an objective analysis-based method is developed to assess the quality of the dataset validation process. Analyses of the ocean variability are calculated without taking into account the data quality flags (raw dataset OA), with the near real time quality flags (NRT dataset OA) and with the delayed time mode quality flags (CORA dataset OA). The comparison of the objective analysis variability shows that the near real time dataset managed to detect and to flag most of the large measurement errors, reducing the analysis error bar compared to the raw dataset error bar. It also shows that the ocean variability of the delayed time mode validated dataset is almost exempt from the random error induced variability.

New species, occurrence records and observations of predation by deep-sea Asteroidea (Echinodermata) from the North Atlantic by NOAA ship Okeanos Explorer

Zootaxa ◽  
2020 ◽  
Vol 4766 (2) ◽  
pp. 201-260 ◽  
Author(s):  
CHRISTOPHER L. MAH
Keyword(s):  
North Atlantic ◽  
Deep Sea ◽  
Substantial Contribution ◽  
The North ◽  
In Situ Observations ◽  
The North Atlantic ◽  
Feeding Observations ◽  
Occurrence Records ◽  
In Situ Feeding

Exploratory cruises by the NOAA Ship Okeanos Explorer have resulted in a substantial contribution in our understanding of deep-sea echinoderm biodiversity, biology, and ecology in the North Atlantic. This includes the description and in situ feeding observations of two, new corallivorous goniasterid species, Evoplosoma nizinskiae n. sp. and Sibogaster bathyheuretor n. sp. Significant in situ observations include a synchronous feeding event including multiple goniasterid asteroids and a cidaroid urchin on a large demosponge, providing new data for understanding echinoderm feeding behavior, including agonistic behavior, in deep-sea settings and new, in situ feeding observations for 28 deep-sea species including the myxasterid Pythonaster atlantidis, the korethrasterid Remaster palmatus and the poorly understood hippasterine goniasterids, Gilbertaster caribaea and Sthenaster emmae. 

scholarly journals In situ observations of air traffic emission signatures in the North Atlantic flight corridor

1997 ◽  
Vol 102 (D9) ◽  
pp. 10739-10750 ◽  
Author(s):  
H. Schlager ◽  
P. Konopka ◽  
P. Schulte ◽  
U. Schumann ◽  
H. Ziereis ◽  
...  
Keyword(s):  
North Atlantic ◽  
Air Traffic ◽  
Traffic Emission ◽  
The North ◽  
In Situ Observations ◽  
The North Atlantic

scholarly journals Comparison of in situ time-series of temperature with gridded sea surface temperature datasets in the North Atlantic

2009 ◽  
Vol 66 (7) ◽  
pp. 1467-1479 ◽  
Author(s):  
Sarah L. Hughes ◽  
N. Penny Holliday ◽  
Eugene Colbourne ◽  
Vladimir Ozhigin ◽  
Hedinn Valdimarsson ◽  
...  
Keyword(s):  
Time Series ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
North Atlantic ◽  
Sea Surface ◽  
The North ◽  
Spatial Coverage ◽  
The North Atlantic

Abstract Hughes, S. L., Holliday, N. P., Colbourne, E., Ozhigin, V., Valdimarsson, H., Østerhus, S., and Wiltshire, K. 2009. Comparison of in situ time-series of temperature with gridded sea surface temperature datasets in the North Atlantic. – ICES Journal of Marine Science, 66: 1467–1479. Analysis of the effects of climate variability and climate change on the marine ecosystem is difficult in regions where long-term observations of ocean temperature are sparse or unavailable. Gridded sea surface temperature (SST) products, based on a combination of satellite and in situ observations, can be used to examine variability and long-term trends because they provide better spatial coverage than the limited sets of long in situ time-series. SST data from three gridded products (Reynolds/NCEP OISST.v2., Reynolds ERSST.v3, and the Hadley Centre HadISST1) are compared with long time-series of in situ measurements from ICES standard sections in the North Atlantic and Nordic Seas. The variability and trends derived from the two data sources are examined, and the usefulness of the products as a proxy for subsurface conditions is discussed.

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