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During the last twenty years global trade with plants and plant products lead to the invasion of numerous plant pathogenic fungi and oomycetes into new areas. Following their establishment, these invasive microorganisms are causing economic damage in agriculture, forestry and horticulture. Monilinia fructicola(G. Winter)Honey, Eutypella parasitica R. W. Davidson & R. C. Lorenz and Phytophthora lateralis Tucker & Milbrath are examples of plant pathogens which have spread into new areas during the last two decades. Until the beginning of 20th century, the natural range of M. fructicola, E. parasitica and P. lateralis was the North American continent. From 2007 to 2015, these species were found for the first time in Croatia, within the official surveys in national plant quarantine activities. P. lateralis was found in 2015 on Chamaecyparis lawsoniana in Koprivnica-Križevci County. E. parasitica was recorded in Croatia in 2007, in forests near Slovenia, but in 2015 it was found for the first time on maples (Acer spp.) in the city of Zagreb, in an urban environment. M. fructicola was found for the first time on peaches and nectarines in 2012 in Split-Dalmatia County, but the subsequent surveys revealed the presence of this fungus in other parts of Croatia as well. The pathway of M. fructicola, E. parasitica and P. lateralis introduction into Croatia is not known. Invasion and establishment of these fungi and oomycetes are showing some limitations of todays' plant quarantine system, offering insufficient protection from such types of biological invasions.

The large-scale mean circulation of the Atlantic Ocean is examined using a general circulation model (GCM) and its approximate adjoint. A cost function is specified that requires the model inputs to be consistent with hydrographic observations and observed air-sea fluxes of heat and freshwater, whereas the velocity field has to adjust to the modified thermohaline initial and boundary conditions. The optimized, quasi-steady model state is closer to the observed circulation state than previous prognostic steady-state models of comparable resolution. However, it is only partially consistent with the error estimates derived from the observations. In the western boundary region large deviations of the optimized surface fluxes from the observations occur. Additionally, the heat release of the ocean shows unrealistically high values at around 60N. At quasi-equilibrium, in large parts of the thermocline values for temperature and salinity along the Gulf Stream and the North Atlantic current are significantly lower than those in the hydrographic data, thus tending toward winter-time conditions. The model produces a meridional overturning cell with maximum values of 16 to 23 Sv for different experiments. The corresponding heat transports reach maximum values between 0.83 and 1.07 X 10 5 W. Model deficiencies like the inappropriate spatial and temporal resolution obviously prevent realistic estimates of water mass distributions and surface fluxes not only in the area of the western boundary current. Another shortcoming of the presented results is the parameterization of eddies and subgrid-scale processes by poorly known diffusion coefficients. To overcome these problems at least partly, future models based on the adjoint method should have a seasonal and increased spatial resolution.

The end of the Middle Pleistocene Transition (MPT, ~ 800-670 thousand years before present, ka) was characterised by the emergence of large glacial ice-sheets associated with anomalously warm North Atlantic sea surface temperatures enhancing moisture production. Still, the direction and intensity of moisture transport across Eurasia towards potential ice-sheets is poorly constrained. To reconstruct late MPT moisture production and dispersal, we combine records of upper ocean temperature and pollen-based Mediterranean forest cover, a tracer of westerlies and precipitation, from a subtropical drill-core collected off South-West Iberia, with records of East Asia summer monsoon (EASM) strength and West Pacific surface temperatures, and model simulations. Here we show that south-western European winter precipitation and EASM strength reached high levels during the Marine Isotope Stage 18 glacial. This anomalous situation was caused by nearly-continuous moisture supply from both oceans and its transport to higher latitudes through the westerlies, likely fuelling the accelerated expansion of northern hemisphere ice-sheets during the late MPT. © 2023, The Author(s). This research used samples collected during the Expedition no. 339 “Mediterranean Outflow“ of the Integrated Ocean Drilling Program (IODP). M.F.S.G. acknowledges funding from the GPR Human Past (University of Bordeaux). A.B. thanks Deutsche Forschungsgemeinschaft (DFG), project BA 3809/8. C.Z. acknowledges funding from IODP France and J.M.P.-M. from the Junta de Castilla y León and the European Regional Development Fund (Grant CLU-2019-03). T.R. acknowledges funding from FCT through projects Hydroshift (PTDC/CTA-CLI/4297/2021), WarmWorld (PTDC/CTA-GEO/29897/2017), UIDB/04326/2020, UIDP/04326/2020, LA/P/0101/2020 and EMSO-PT (POCI-01-0145-FEDER-022157). We thank Vincent Hanquiez for drawing Fig. and Ludovic Devaux for pollen sample preparation.

Harvesting characteristics (size composition and catch rates) of the U. S. and Spanish fleets are examined in light of gear and operating (time-area) practices latitude and between in the north Atlantic between 40° and 50° north 20° and 50° west longitude, The two fleets have approached and overlapped operations in this area between 1983 and 1985. During 1986 the degree of overlap continued to increase. Se examinan las características (composición por tallas y tasas de capturas) de la captura de las flotas española y estadounidense, a la luz de los artes empleados y del tipo de operación llevada a cabo (tiempo-zona) en el Atlántico Norte, entre 40 - 50º de latitud Norte y 20- 50º grados de longitud Oeste. Las operaciones de ambas flotas han estado bastante cerca nas y se han solapado en esta zona durante el periodo 1983-85. En 1986 cont1nuó en aumento el grado de solapamiento. Les caractéristiques d'exploitation (composition de taille et taux de capture) des flottilles américaine et espagnole sont examinées à la lumière des engins et méthodes normalement employés dans l'Atlantique nord entre 40º et 50°N de latitude, et 20º et 50ºW de longitude. La pêche de ces deux flottille s'est rapprochée, et même recoupée, dans ce secteur entre 1983 et 1985. En 1986, le degré de chevauchement a continué de s'accroitre.

As highly mobile predators with extensive home ranges, some shark species often utilize a continuum of habitats across the continental shelf ranging from the surf zone to the open ocean. For many species, these cross-shelf distributions can change depending on ontogeny or seasonal conditions. Recent research has confirmed a white shark (Carcharodon carcharias) summer nursery off Long Island, New York; however, habitat characterization of this nursery has not yet been conducted nor has fine-scale analysis of vertical behavior. Between 2016 and 2019, 21 young-of-the-year and juvenile white sharks were fitted with satellite and acoustic tags to examine distribution and selection for a suite of oceanographic variables during their late summertime (i.e., August to October) residence in the New York Bight. Horizontal position estimates were used to extract a suite of environmental measurements via remote sensing platforms and were linked with vertical profiles to produce three-dimensional movements for a subset of individuals also fitted with pop-up satellite archival tags (n = 7). Sharks exhibited horizontal movements parallel to Long Island’s southern shoreline and coastal New Jersey, with distances from 0.1 to 131.5 km from shore. Log-likelihood chi-square analyses determined selection for waters with underlying bathymetry of 20–30 m, sea surface temperatures between 20.0 and 22.0°C, sea surface salinities between 31.0 and 32.0 ppt, and chlorophyll-a concentrations between 2.0 and 8.0 mg⋅m–3. Multiple individuals also traversed the mid- to outer shelf region after leaving the Montauk tagging area. Vertical depth profiles illustrated oscillations between the surface and 199 m of water, with an average swimming depth of 9.2 ± 8.9 m. Water column temperatures during these oscillations ranged between 7.9 and 26.2°C (mean = 19.5 ± 2.0°C) with several individuals traversing highly stratified regions presumably associated with a mid-shelf cold pool adjacent to the Hudson Shelf Valley. These results suggest young white sharks exhibit connectivity between the immediate shoreline and mid-continental shelf region, where they play important ecological roles as predators on a variety of species. Our study improves characterization of essential fish habitat for young white sharks and provides new insights into their reliance on this productive continental shelf ecosystem.

Worldwide, a growing number of modern coastal marine ecosystems are increasingly exposed to suboxic‐ or even anoxic conditions. Low seawater oxygen levels trigger significant ecosystem changes and may result in mass mortality of oxygen‐sensitive biota. The applicability of observations from recent (anthropogenically influenced) suboxic coastal settings to fossil anoxic shallow‐marine environments is, however, as yet poorly explored. The test case documented here are upper Barremian to lower Aptian strata in the Lusitanian Basin (Ericeira section, Portugal). These are characterized by the transient demise of rudist–coral communities and the rapid establishment of microencruster facies in the vacant ecological niches. The hypothesis is tested that the temporal expansion of the microencrusting organism Lithocodium aggregatum took place in response to platform‐top seawater oxygen depletion. We critically discuss the outcome of a multi‐proxy palaeoseawater redox approach (e.g. Rare Earth Elements (REEs), U isotopes and palaeoecology) and put the robustness of the proxies applied here to the test. This is done by considering issues with these methods in general but also emphasizing the significance of terrigenous contamination and fractionation effects. Data shown here document that evidence for coastal seawater oxygen depletion in the prelude of Oceanic Anoxic Event (OAE) 1a is lacking, and hence, anoxia was not the driving mechanism for the demise of rudist–coral ecosystems in the proto‐North Atlantic platform setting studied here. In contrast, well‐oxygenated early Aptian platform‐top water masses are proposed for this site. Geologically short (decades to millennia) fluctuations in seawater oxygen levels cannot be excluded, however. But even if these took place, they offer no explanation for the Kyr to Myr‐scale patterns discussed here. The present paper is relevant as it sheds light on the complexity of mechanisms that drive punctuated Early Cretaceous coral–rudist ecosystem turnover, and assess strengths and weaknesses of redox proxies applied to ancient shallow‐marine platform carbonates., Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659

This study examines the influence of the Atlantic Multidecadal Oscillation (AMO) on the Choco Low-level Jet (CJ) variations during the 1983&ndash, 2016 period. Considering the September&ndash, November (SON) 925 hPa zonal wind index in the CJ core, a significant breakpoint occurs in 1997 with larger values after 1997. The changes in the CJ and Caribbean Low-Level Jet (CLLJ), and their related ocean-atmospheric patterns and impacts on precipitation over Colombia were analyzed considering separately the 1983&ndash, 1996 and 1998&ndash, 2016 periods, which overlap the cold and warm AMO phases, respectively. During the 1998&ndash, 2016 period, the negative sea surface temperature (SST) anomalies in the tropical Pacific Ocean and the positive ones in the Caribbean Sea and Tropical North Atlantic (TNA) strengthen the CJ and weaken the CLLJ, and moisture is transported into Central and Western Colombia increasing the rainfall there. Our results indicate that part of the CJ strengthening after 1997 was due to a higher percentage of intense CJ events coinciding with La Ni&ntilde, a events during the warm AMO and cold Pacific Decadal Oscillation (PDO) background. However, the AMO-related SST and sea level pressure (SLP) variations in the TNA seem to be more crucial in modulating the CJ and CLLJ intensities, such that CJ is weakened (intensified) and CLLJ is intensified (weakened) before (after) 1997. As far as we know, the relations of the CJ and CLLJ intensities to the AMO phases were not examined before and might be useful for modeling studies.

A stalagmite from Dim Cave in southern Turkey contains a climate record documenting rapid and significant changes in amounts of precipitation between similar to 132 ka and similar to 128 ka, during the penultimate glacial - interglacial transition. Some U-Th dates have been compromised by carbonate dissolution but rigorous selection and tuning to delta O-18 records from other speleothems has generated a robust age model. Growth rate was initially very slow but a rapid increase at similar to 129 ka was accompanied by strong negative trends in delta O-18 and delta C-13, a combination implying the onset of much wetter conditions. Isotopic values at similar to 129 ka suggest that groundwater recharge rates and biogenic activity in the soil zone exceeded those of the early Holocene. A significant isotopic enrichment event at similar to 128 ka, during which there was alternating aragonite and calcite deposition, documents a strong drying event with a duration of similar to 200 years. A concurrent decrease in Sr-87/Sr-86 ratios indicates increased groundwater residence times and the cumulative evidence suggests amounts of rainfall fell from well above to slightly below present-day levels. Similar delta O-18 enrichment events are present in coeval speleothem records from southwest France and the Northern Alps, and these, together with pollen evidence from Italy, Greece and the Iberian margin of drier conditions at this time, imply that a climate anomaly extended across the northern Mediterranean borderlands. The timing, duration and structure of this episode are consistent with marine evidence of strong North Atlantic cooling early in the last interglacial and there is a resemblance to the Holocene 8.2 ka event recorded globally in many proxy-climate archives.

Short-term hypoxia in epeiric water masses is a common phenomenon of modern marine environments and causes mass mortality in coastal marine ecosystems. Here, we test the hypothesis that during the early Aptian, platform-top hypoxia temporarily established in some of the vast epeiric seas of the central Tethys and caused, combined with other stressors, significant changes in reefal ecosystems. Potentially interesting target examples include time intervals characterized by the demise of lower Aptian rudist–coral communities and the establishment of microencruster facies, as previously described from the central and southern Tethys and from the proto-North Atlantic domain. These considerations are relevant as previous work has predominantly focused on early Aptian basinal anoxia in the context of Oceanic Anoxic Event (OAE) 1a, whereas the potential expansion of the oxygen minimum zone (OMZ) in coeval shallow-water environments is underexplored. Well-known patterns in the δ13C record during OAE 1a allow for a sufficiently time-resolved correlation with previously studied locations and assignment to chemostratigraphic segments. This paper presents and critically discusses the outcome of a multi-proxy study (e.g., rare earth elements (REEs), U isotopes, and redox-sensitive trace elements) applied to lower Aptian shallow-water carbonates today exposed in the Kanfanar quarry in Istria, Croatia. These rocks were deposited on an extensive, isolated high in the central Tethys surrounded by hemipelagic basins. Remarkably, during chemostratigraphic segment C2, the depletion of redox-sensitive trace elements As, V, Mo, and U in platform carbonates, deposited in normal marine oxic waters, record the first occurrence of basinal, organic-rich sediment deposition in which these elements are enriched. During the C3 segment, seawater oxygen depletion established on the platform top as indicated by the patterns in Ce/Ce* and U isotopes. Shifts in redox-sensitive proxies coincide with the expansion of microencruster facies. Segment C4 witnesses the return to normal marine reefal faunas on the platform top and is characterized by patterns in redox-sensitive proxies typical of normal marine dissolved oxygen levels. It remains unclear, however, if platform-top hypoxia resulted from the expansion and upwelling of basinal, oxygen-depleted water masses or if spatially isolated, shallow hypoxic water bodies formed on the platform. Data shown here are relevant as they shed light on the driving mechanisms that control poorly understood faunal patterns during OAE 1a in the neritic realm and provide evidence on the intricate relation between basinal and platform-top water masses.

This study examines the longitude-dependent decadal changes and trends of ozone for the boreal winter months during the period of 1960–2000. These changes are caused primarily by changes in the planetary wave structure in the upper troposphere and lower stratosphere. The decadal changes and trends over 4 decades of geopotential perturbations, defined as a deviation from the zonal mean, are estimated by linear regression with time. The decadal changes in longitude-dependent ozone were calculated with a simple transport model of ozone based on the known planetary wave structure changes and prescribed zonal mean ozone gradients. For December of the 1960s and 1980s a statistically significant Rossby wave track appeared over the North Atlantic and Europe with an anticyclonic disturbance over the Eastern North Atlantic and Western Europe, flanked by cyclonic disturbances. In the 1970s and 1990s statistically significant cyclonic disturbances appeared over the Eastern North Atlantic and Europe, surrounded by anticyclonic anomalies over Northern Africa, Central Asia and Greenland. Similar patterns have been found for January. The Rossby wave track over the North Atlantic and Europe is stronger in the 1980s than in the 1960s. For February, the variability of the regression patterns is higher. For January we found a strong alteration in the modelled decadal changes in total ozone over Central and Northern Europe, showing a decrease of about 15 DU in the 1960s and 1980s and an increase of about 10 DU in the 1970s and 1990s. Over Central Europe the positive geopotential height trend (increase of 2.3 m/yr) over 40 years is of the same order (about 100 m) as the increase in the 1980s alone. This is important to recognize because it implies a total ozone decrease over Europe of the order of 14 DU for the 1960–2000 period, for January, if we use the standard change regression relation that about a 10-m geopotential height increase at 300 hPa is related to about a 1.4-DU total ozone decrease.

This cruise report details the scientific programme for the Scottish Association for Marine Science (SAMS) led by Professor Stuart Cunningham on RSS Discovery DY053. This cruise is a contribution to the international Overturning in the Subpolar North Atlantic Programme (OSNAP). Two additional scientific teams (from Rosenstiel School of Marine and Atmospheric Sciences, and Woods Hole Oceanographic Institution / Ocean University of China) participated in this cruise. SAMS objectives were to recover and redeploy moorings in the Rockall Trough, measuring temperature, salinity, currents and bottom pressure and; recover Seaglider SG605 ‘’Bowmore’’ in the Hatton-Rockall Basin. The OSNAP array deployed since July 2014 is purposefully designed to provide a continuous record of the full-water column, trans-basin fluxes of heat, mass and freshwater in the subpolar North Atlantic, on a section from Newfoundland to Greenland to Scotland.

International audience; The climatic origin of astronomically induced sedimentary cycles in the Mediterranean and adjacent areas during the late Neogene and Quaternary remains puzzling; as cycles have been linked to concomitant but seasonally opposite changes in African summer monsoon precipitation (Eastern Mediterranean sapropels) and Atlantic regulated winter-precipitation (carbonate cycles on the Atlantic side of the Mediterranean). Particularly, little is known about the cyclic sedimentation on orbital time scales in the Western Mediterranean, with the prime exception of the Messinian sapropels from the Sorbas basin (southern Spain).Here we show that regular alternations in Pliocene downhole logs from the industrial drill-site Muchamiel-1, located along the Balearic Promontory in the Western Mediterranean, are related to eccentricity (bundles) and to obliquity and precession cycles (basic meter-scale alternations). We establish an astronomically based age model for the interval between 5.33 and 2.8 Ma, by first correlating cycle bundles to eccentricity and then the basic dominantly precession-related cycles to the 65°N summer insolation of La2004. The striking bed-to-bed similarities between the Muchamiel-1 well-logs and other records from both the Atlantic margin and the Central Mediterranean suggest that the same climatic forcing was responsible for the formation of carbonate cycles across the Western Mediterranean and adjacent Atlantic. We conclude that formation of alternating carbonate-rich/carbonate-poor beds was controlled by Western Mediterranean cyclogenetic mechanisms as well as by peri-Mediterranean precipitation associated with changes in the North Atlantic System (NAS). These findings highlight the importance of peri-Mediterranean precipitation on the sedimentary cyclicity by dictating terrigenous (clay) supply and potentially on the hydrology of the basin by providing additional freshwater required for sapropel formation. Consequently, cyclic sedimentation in the Mediterranean results from the combined effect of precipitation changes driven by (i) the North African monsoon, (ii) the Atlantic system, and (iii) intrabasinal Mediterranean atmospheric dynamics.

December–March climatologies of precipitation and vertically integrated water vapor transport were analyzed and compared to find the main paths by which moisture is fed to high-rainfall regions in the Southern Hemisphere in this season. The southern tropics (20°S–0°) exhibit high rainfall and receive ample moisture from the northern trades, except in the eastern Pacific and the Atlantic Oceans. This interhemispheric flow is particularly important for Amazonian rainfall, establishing the North Atlantic as the main source of moisture for the forest during its main rainy season. In the subtropics the rainfall distribution is very heterogeneous. The meridional average of precipitation between 35° and 25°S is well modulated by the meridional water vapor transport through the 25°S latitude circle, being greater where this transport is from the north and smaller where it is from the south. In South America, to the east of the Andes, the moisture that fuels precipitation between 20° and 30°S comes from both the tropical South and North Atlantic Oceans whereas between 30° and 40°S it comes mostly from the North Atlantic after passing over the Amazonian rain forest. The meridional transport (across 25°S) curve exhibits a double peak over South America and the adjacent Atlantic, which is closely reproduced in the mean rainfall curve. This corresponds to two local maxima in the two-dimensional field of meridional transport: the moisture corridor from Amazonia into the continental subtropics and the moisture flow coming from the southern tropical Atlantic into the subtropical portion of the South Atlantic convergence zone. These two narrow pathways of intense moisture flow could be suitably called “aerial rivers.” Their longitudinal positions are well defined. The yearly deviations from climatology for moisture flow and rainfall correlate well (0.75) for the continental peak but not for the oceanic peak (0.23). The structure of two maxima is produced by the effect of transients in the time scale of days.

With the purpose of revealing the actual advantages of the new source function that was earlier proposed in [5] for use in numerical wind wave models, its testing and verification was carried out by means of modification of the WAM (Cycle-4) model. The verification was performed on the basis of a comparison of the results of wave simulation for a given wind field with the buoy observation data obtained in three oceanic regions. In the Barents Sea, this kind of comparison was made for wave observations from a single buoy with an interval of 6 hours for a period of 3 years. In two regions of the North Atlantic, the comparison was performed for 3 buoys in both regions for observation periods of 30 days with an interval of 1 hour. Estimations of the simulation accuracy were obtained for a series of wind wave parameters, and they were compared with the original and modified WAM model. Advantages of the modified model consisting of the enhancement of the calculation speed by 20-25% and a 1.5- to 2-fold increase in the simulation accuracy for the significant wave height and the mean period were proved. � MAIK Nauka 2008.

International audience; Recent analyses of Amazon runoff and gridded precipitation data suggest an intensification of the hydrological cycle over the past few decades in the following sense: wet season precipitation and peak river runoff (since ∼1980) as well as annual mean precipitation (since ∼1990) have increased, while dry season precipitation and minimum runoff have slightly decreased. There has also been an increase in the frequency of anomalously severe floods and droughts. To provide context for the special issue on Amazonia and its forests in a warming climate we expand here on these analyses. The contrasting recent changes in wet and dry season precipitation have continued and are generally consistent with changes in catchment-level peak and minimum river runoff as well as a positive trend of water vapor inflow into the basin. Consistent with the river records, the increased vapor inflow is concentrated to the wet season. Temperature has been rising by 0.7 ∘ C since 1980 with more pronounced warming during dry months. Suggestions for the cause of the observed changes of the hydrological cycle come from patterns in tropical sea surface temperatures (SSTs). Tropical and North Atlantic SSTs have increased rapidly and steadily since 1990, while Pacific SSTs have shifted during the 1990s from a positive Pacific Decadal Oscillation (PDO) phase with warm eastern Pacific temperatures to a negative phase with cold eastern Pacific temperatures. These SST conditions have been shown to be associated with an increase in precipitation over most of the Amazon except the south and southwest. If ongoing changes continue, we expect forests to continue to thrive in those regions where there is an increase in precipitation with the exception of floodplain forests. An increase in flood pulse height and duration could lead to increased mortality at higher levels of the floodplain and, over the long term, to a lateral shift of the zonally stratified floodplain forest communities. Negative effects on forests are mainly expected in the southwest and south, which have become slightly drier and hotter, consistent with tree mortality trends observed at the RAINFOR Amazon forest plot network established in the early 1980s consisting of approximately 150 regularly censused 1ha plots in intact forests located across the whole basin.

Dimethylsulfide (DMS) atmospheric and oceanic concentrations and eddy covariance air/sea fluxes were measured over the N. Atlantic Ocean during July 2007 from Iceland to Woods Hole, MA, USA. Seawater DMS levels north of 55 degrees N ranged from 3 to 17 nM, with variability related to the satellite-derived distributions of coccoliths and to a lesser extent, chlorophyll. For the most intense bloom region southwest of Iceland, DMS air/sea fluxes were as high as 300 mu mol m(-2) d(-1), larger than current model estimates. The observations imply that gas exchange coefficients in this region are significantly greater than those estimated using most gas transfer parameterizations. South of 55 degrees N, DMS levels were lower and the gas transfer coefficients were similar to those observed in other regions of the ocean. The data suggest that DMS emissions from the bloom region may be significantly larger than current estimates. The anomalous gas exchange coefficients likely reflect strong near-surface, water column DMS gradients influenced by physical and biological processes

The North Atlantic Marine Boundary Layer Experiment (NAMBLEX), involving over 50 scientists from 12 institutions, took place at Mace Head, Ireland (53.32° N, 9.90° W), between 23 July and 4 September 2002. A wide range of state-of-the-art instrumentation enabled detailed measurements of the boundary layer structure and atmospheric composition in the gas and aerosol phase to be made, providing one of the most comprehensive in situ studies of the marine boundary layer to date. This overview paper describes the aims of the NAMBLEX project in the context of previous field campaigns in the Marine Boundary Layer (MBL), the overall layout of the site, a summary of the instrumentation deployed, the temporal coverage of the measurement data, and the numerical models used to interpret the field data. Measurements of some trace species were made for the first time during the campaign, which was characterised by predominantly clean air of marine origin, but more polluted air with higher levels of NOx originating from continental regions was also experienced. This paper provides a summary of the meteorological measurements and Planetary Boundary Layer (PBL) structure measurements, presents time series of some of the longer-lived trace species (O3, CO, H2, DMS, CH4, NMHC, NOx, NOy, PAN) and summarises measurements of other species that are described in more detail in other papers within this special issue, namely oxygenated VOCs, HCHO, peroxides, organohalogenated species, a range of shorter lived halogen species (I2, OIO, IO, BrO), NO3 radicals, photolysis frequencies, the free radicals OH, HO2 and (HO2+ΣRO2), as well as a summary of the aerosol measurements. NAMBLEX was supported by measurements made in the vicinity of Mace Head using the NERC Dornier-228 aircraft. Using ECMWF wind-fields, calculations were made of the air-mass trajectories arriving at Mace Head during NAMBLEX, and were analysed together with both meteorological and trace-gas measurements. In this paper a chemical climatology for the duration of the campaign is presented to interpret the distribution of air-mass origins and emission sources, and to provide a convenient framework of air-mass classification that is used by other papers in this issue for the interpretation of observed variability in levels of trace gases and aerosols.