The PAP observatory is situated in the Northeast Atlantic away from the continental slope and Mid Atlantic Ridge. The site is an open ocean time-series representing processes in the North Atlantic Drift Region and accessible from many EU ports.

Latitude and Longitude: 49.0°N 016.5°W
Depth: 4850m
Oceanographic Region: Northeast Atlantic

Physical setting: The PAP observatory lies south of the main stream of the North Atlantic Current and is subject to return flows from this coming from the West and Northwest. An intermittent stream of cyclonic and anticyclonic mesoscale eddies cross the site extending sometimes several thousand metres into the water column. The winter condition at the site is of a mixed layer as deep as 800m driven by convective overturning although throughout the winter there are short periods of stability during which the mixed layer may only be a few tens of metres thick.

The PAP sustained observatory is about 300 miles southwest of Ireland.

Ocean observatories measure properties of the seawater such as temperature, salinity and carbon dioxide. They can continuously record data every few hours for weeks, months and even years.

Observatories are typically made of a single column of strong wire stretching from the sea surface to the sea floor. Scientific instruments, sensors, are attached in clusters like mini constellations all the way down the wire. Sensors can also be attached to equipment including landers that are positioned on the seafloor. The equipment remains submerged in seawater for months on end, transmitting information by satellite or storing information inside the sensor until it is picked up by scientists venturing out to sea.

Variable (*r-t) Depths measured (m) Sensor(s) used
Atmosphere/Sea surface (from 2010)
Wind speed and direction atmosphere Gill acoustic sensor and revolution magnetic compass
Relative humidity atmosphere Rotronic Hygroclip R/S sensor
Air and sea surface temperature atmosphere and surface (approx. 1.5m depth) Electrical Resistance Thermometer (ERT)
Atmospheric pressure atmosphere Druck RPT350 pressure sensor
wave height/period surface Datawell heave sensor (17.5 min average)
Water column (autonomous since 2002)


(2002–2008 additional microcats from 40–1000m)
40, 60, 75, 90, 110, 130, 150, 200, 250, 300, 1000

Microcat (Seabird SBE-37 IMPs)


(2002–2008 additional microcats from 40–1000m)
40, 60, 75, 90, 110, 130, 150, 200, 250, 300, 1000

Microcat (Seabird SBE-37 IMPs)
Chl-A* 25* Fluorometer (WETLabs FLNTUSB; Turner Cyclops)
Nitrate* 25*


NAS3 (chemical) not functioning since Sept 2010

PAR* (Irradiance) surface* and 25* Satlantic OCR-507 ICSW and OCR-507 R10W + Bioshutter2
Dissolved CO2* 25* ProOceanus CO2-Pro
Dissolved O2 25 (new in 2010; no real-time since Sept 2010) Aandera optode
Current 25 (new in 2010; no real-time since Sept 2010) Aanderaa RCM (30m) ADCP (4800m)
Turbidity* 25* WETLabs FLNTUSB
Pressure* 25* Microcat + fluorometer
POC (sub-surface mooring) 3000, 3050, 4700 McLane Sediment Trap
Zooplankton sampler 25 (testing in 2009 and May–September 2010) McLane ZPS
Total dissolved gas pressure 25* ProOceanus GTD-Pro
  Seafloor (4800m depth) since 1989  
Images seafloor digital camera (time-lapse)
Marine fauna seafloor e.g., trawls, corers, camera, hydrophone
Sediment (geochemistry) seafloor trawls, corers, camera

Since 1985, this environmental study site in the Northeast Atlantic has become a major focus for international and interdisciplinary scientific research and monitoring including water column biogeochemistry, physics and benthic biology. Since 2002, a mooring has been in place with sensors taking a diverse set of biogeochemical and physical measurements of the upper 1000m of the water column.

One of the very few images of HMS PorcupineOne of the very few images of HMS Porcupine

Some of these data are transmitted in near real-time via satellite. The PAP site is now part of the EuroSITES network of European Deep ocean observatories which will integrate and enhance nine time-series sites and carry out science missions to develop new sensors and techniques for observing the changing oceans.

The name ‘Porcupine’

The name ‘Porcupine’ is taken from the naval survey vessel HMS Porcupine which was engaged on scientific expeditions in the NE Atlantic and Mediterranean in 1869 and 1870. She make the first ever deep ocean dredge for living creatures in 1869 resulting in the naming of the Porcupine Bank off the west coast of Ireland. The Porcupine Abyssal Plain is the deep flat region to the south of the Porcupine Bank.

Cruises to the PAP site

Below is a list of the cruises to the PAP site from the present BACK RO 1985

Principal scientist Vessel Cruise No. Dates File
Ruhl RRS James Cook JC165 19 May - 12 June 2018 bodc CSR
(cruise report not yet available)
Lampitt RRS Discovery DY077 14 Apr - 01 May 2017 bodc or nora (12MB)
Stinchcombe RRS Discovery DY050 17 Apr – 08 May 2016 bodc or nora (12MB)
Lampitt RRS Discovery DY032 20 Jun – 08 Jul 2015 bodc or eprints (7MB)
Lampitt MV Meteor M108 04–24 Jul 2014 bodc or eprints (7MB)
Lampitt RRS James Cook JC087 31 May – 18 Jun 2013 bodc or eprints (6MB)
Lampitt RRS James Cook JC085 14–29 Apr 2013 bodc or eprints (13MB)
Lampitt RRS James Cook JC071 29 Apr – 12 May 2012 bodc or eprints (7MB)
Ruhl RRS James Cook JC062 24 Jul – 29 Aug 2011 bodc or eprints (11MB)
Campbell RV Celtic Explorer CE10005 16–24 Sep 2010 bodc or eprints (123MB)
Lampitt RRS James Clark Ross JCR221 26 May – 05 Jun 2010 bodc or eprints (64MB)
Sanders RRS Discovery D341 08 Jul – 13 Aug 2009 bodc or eprints (9MB)
Lampitt RV Celtic Explorer CE0716 19–25 Jun 2007 bodc or eprints (5MB)
Lampitt RRS Discovery D296 14 Jul – 23 Jul 2005 bodc or eprints (64MB)
  RRS Discovery D284t 02/09/2004  
Lampitt RRS Charles Darwin CD158 15 Jun – 28 Jun 2004 bodc or eprints (12MB)
Müller FS Poseidon PO306 23 Nov – 12 Dec 2003 bodc (1MB)
Lampitt FS Poseidon PO300-1 4 July – 16 June 2003 bodc or eprints (1MB)
Priede RRS Discovery D266 27 Sep – 24 Oct 2002 bodc CSR (cruise report missing)
Collins RRS Discovery D260 06/03/2002 Aberdeen University
Bagley RRS Discovery D255 14/08/2001 Aberdeen University
  RRS Discovery D252 13/04/2001  
Collins RRS Discovery D250 15 Sep – 10 Oct 2000 bodc (0.59 MB)
Lampitt RRS Challenger CH147c 04/10/1999  
Billett RRS Challenger CH142 19 Apr – 19 May 1999 bodc (1.98MB)
Sibuet RRS Discovery D237 25 Sep – 08 Oct 1998 bodc or eprints (3.0MB)
Duinveld RV Pelagia Pelagia 123 02/09/1998 NIOZ, Netherlands
Priede RRS Discovery D236 23/08/1998 Aberdeen University
Pfannkuche MV Meteor Me 42/2 17/07/1998 IFM-GEOMAR, Kiel, Germany
Rice RRS Discovery D231 28 Feb – 30 Mar 1998 bodc or eprints (7.5MB)
Billett RRS Challenger CH135 15–30 Oct 1997 bodc or eprints (4.1MB)
Priede RRS Challenger CH134 11/08/1997 NOL
Bett RRS Discovery D229 02–31 Jul 1997 bodc or eprints (5.7MB)
Rice RRS Discovery D226 12 Mar – 10 Apr 1997 bodc or eprints (5.6MB)
Rice RRS Discovery D222 29 Aug – 24 Sep 1996 bodc or eprints (7.3MB)
Pfannkuche MV Meteor Me 36/6 09/10/1996 IFM-GEOMAR, Kiel, Germany
Hemleben MV Meteor Me 36/5 07/09/1996 IFM-GEOMAR, Kiel, Germany
Graff MV Meteor Me 36/4 20/08/1996 GEOMAR, Kiel, Germany
Lampitt RRS Discovery D217 27/09/1995 eprints
Pfannkuche MV Meteor MO 30/1 07/09/1994 FM-GEOMAR, Kiel, Germany
Pugh RRS Charles Darwin CD85 11/04/1994 IOS
Bodungen FS Poseidon PO 200/7 23/06/1993 IFM-GEOMAR, Kiel, Germany
Lampitt RRS Charles Darwin CD172 29 Aug - 11 Sep 1992 eprints
  RRS Challenger CD94 29/07/1992  
Thiel MV Meteor Me 21/1 16/03/1992 Hamburg University, Germany
Bett RRS Challenger CH111 29 Mar – 25 Apr 1994 bodc or eprints (1.6MB)
Rice RRS Challenger CH79 12 May – 03 Jun 1991 bodc or eprints (1.9MB)
Rice RRS Discovery D185 18 Aug – 17 Sep 1989 bodc or eprints (2.1MB)
Roe RRS Challenger CH8/86 25 Nov – 18 Dec 1986 bodc or eprints (1.0MB)
Thurston RRS Challenger CH6A/85 13–28 Jun 1985 bodc or eprints (1.3MB)


Cruises to the JGOFS NABE

Cruise Principal Scientist Affiliation Start date
Discovery 175 P.R. Pugh IOS 18/06/1988
Discovery 181 R.T. Pollard IOS 18/04/1989
Atlantis 119/2 S. Honjo WHOI, USA 26/03/1989
Atlantis 119/4 J. Marra LDGO, USA 19/04/1989
Meteor 10/2 J. Lenz IFM, Kiel, Germany 05/05/1989
Discovery 182 M.J. Fasham IOS 08/05/1989
Atlantis 119/5 H. Ducklow WHOI, USA 18/05/1989
Discovery 183 R.P. Harris PML 11/06/1989
Discovery 184 I.N. McCave Cambridge University 23/07/1989
FRG     18/08/1989
Discovery 185 A.L. Rice IOS 18/08/1989
Tyro 1 H.J.W. de Baar NIOZ, Netherlands 22/08/1989
Discovery 190 A.J. Watson PML 22/04/1990
Discovery 191 M.V. Angel IOS 11/05/1990
Charles Darwin 53 G.B. Shimmield Edinburgh University 18/09/1990
Meteor 21/1 H. Thiel Hamburg University 16/03/1992
Meteor 21/3 J. Duinker IFM, Kiel, Germany 09/05/1992
Meteor 21/6 O. Pfannkuche GEOMAR, Kiel, Germany 26/07/1992
Meteor 26/1 K. Kremling IFM, Kiel, Germany 24/08/1993

There is a growing need for evermore accurate climatic models to predict future climate change and the impact this will have on human settlement, the insurance industry, fisheries, agriculture and nature at large.

Long term observations at fixed points in the open oceans are essential to provide high quality and high resolution data to increase our knowledge of how our oceans function, how they are changing and how this may impact on the climate.

Why was the Porcupine Abyssal Plain (PAP) chosen as a location?

The PAP site lies in the Northeast Atlantic ff the southwest coast of Ireland. There are several advantages to the PAP location which make it an ideal locality for an open ocean observatory.

  • A true open ocean site: It is as far as possible from the continental slope and the mid-Atlantic ridge reducing the effects of downslope sediment transport and the influence of the continental shelf.
  • Flat seabed: This facilitates a variety of types of benthic sampling  and reduces spatial heterogeneity.
  • Proximity to European ports despite being a remote abyssal location. This is advantageous for maintaining the mooring.
  • Low water column current speeds: This reduces the effects of advection.
  • CO2: This site displays a relatively high uptake of CO2 from the atmosphere which is relevant to issues of global climate change.