Stations North Research Articles

Nitrate Uptake and Primary Production Along the Amazon River Plume Continuum

AbstractThe Amazon River plume (ARP) has been shown to support high rates of nitrogen fixation and primary production. However, nitrogen fixation alone cannot account for total primary production determined in the region, hinting that other nitrogen uptake processes might play a role. For the first time, we measured nitrate uptake rates in the ARP during three cruises in May 2018, June 2019 and April/May 2021, along with primary production rates and an analysis of phytoplankton community composition via high performance liquid chromatography. Based on a classification according to the salt content the region was divided into estuarine (ES), mesohaline (MH) and oceanic (OC) stations. Primary production was light limited near the river mouth at ES stations and was maximal off the coasts of French Guiana and Suriname, where also nitrate uptake was highest with rates of 11.4 mmol m−2 d−1. The role of eddies pinching off a deflecting plume are discussed as possible reason for higher nutrient concentrations at the MH stations. Surprisingly, at most MH stations north of 5°N, nitrate uptake rates were low despite the presence of sufficient substrate concentration (up to 1.44 μM nitrate). Diatoms, dinoflagellates or Synechococcus sp. dominated phytoplankton communities. OC stations showed lowest productivity rates in accordance with oligotrophic conditions. However, rates seem to be sufficient to completely deplete the remaining riverine nitrate, preventing its export to the open ocean.

GIS-based analysis of filling stations in Onitsha north and south local government areas in Anambra State, Nigeria

GIS-based analysis of filling stations in Onitsha north and south local government areas in Anambra State, Nigeria

Photovoltaic-energy storage-integrated charging station retrofitting: A study in Wuhan city

In this study, an evaluation framework for retrofitting traditional electric vehicle charging stations (EVCSs) into photovoltaic-energy storage-integrated charging stations (PV-ES-I CSs) to improve green and low-carbon energy supply systems is proposed. Using existing EVCSs in the “10-minute living circle residential areas” of seven central urban districts in Wuhan city, we comprehensively consider factors such as the site distribution, sky view factor and service population to assess the economic and environmental benefits of PV-ES-I CS systems at different locations and scales. The research results show that the central urban districts have high retrofitting potential, with 44 stations north of the Yangtze River and 20 stations south of the Yangtze River being most suitable for retrofitting. The economic and environmental benefits vary significantly across building types; the retrofitting/construction of PV-ES-I CSs near hotels yields the greatest economic benefit and carbon dioxide emission reduction per unit investment.

Energy Consumption Characteristics Study of Surface Meteorological Observation Station in North and South China

Surface meteorological observation is one of the most important sources of primary data for the meteorological sector and are crucial to the accuracy of weather forecasting. China’s meteorological authorities have built a dense network of surface observation stations, which require a considerable amount of electrical energy to keep the network running normally. There has been a lack of analytical studies dedicated to the energy consumption of surface meteorological observation stations domestically and internationally. This paper selects measured energy consumption data of 4 surface meteorological observation stations in two typical provinces (autonomous regions) in the north and south China over the past two years, and proposes, for the first time, to use the average power of the surface meteorological observation station, adopts the electrical energy consumption calculation method, carries out energy consumption calculation and analysis by month, sub-region and season, derives the characteristics of energy consumption changes of the surface meteorological observation station, and proposes energy saving and consumption reduction measures.

Analysis of Heavy Metals in Shellfish, Sediment, and Waters in Seagrass beds Ecosystem in Selangan Village, Bontang City

Selangan Hamlet is a water area in Bontang City where community activities are very active. Bontang City is an area that has a high utilization of coastal areas such as tourism, cultivation, trade, sea transportation services, and industrial areas. The impact of the industrial area on these waters is the contamination of these waters with heavy metals which will have an impact on aquatic organisms and the surrounding community who ultiize these waters. The purpose of this study was to identify the content of heavy metals lead (Pb), copper (Cu), magnesium (Mg), iron (Fe), and mercury (Hg). This research was conducted in January-June 2023 in Bontang waters, Selangan Hamlet. Sampling involyes analyzing water quality and testing heavy metals such as Cu, Pb, Fe, Mg, and Hg. The samples to be analyzed are water, sediment, seagrass and blood clams. The results of the analysis obtained in these waters, at the four stations, namely the south, east, west and north stations. At all stations in the heavy metal test Cu, Pb, Fe, Mg and Hg heavy metal content is only found in blood clams (Anadara granosa). In water, sediment and seagrass, the values obtained are still in normal conditions.

Current deformation in eastern part of Java derived from GPS observation 2017-2022

The eastern part of Java Island is a prone area with high seismic potential. Geologically, the seismicity in this area is dominated by the subduction zone in southern Java, reverse faults structure in the north extending along east to west part of Java Islands, and normal faults in Pasuruan and Probolinggo. Several studies have indicated the potential of earthquakes associated with these sources. The geodetic technique is employed to monitor the deformation activity in the eastern part of Java to understand the characteristics. We utilized the continuous GPS stations operated by Geospatial Agency of Indonesia (BIG) and processed them using the GAMIT/GLOBK software. The processing incorporates the IGS stations surrounding Indonesia. We also used precise orbit and 2nd-order ionospheric correction. The processing produces the velocity in the ITRF2014 reference frame, which generally indicates the south-eastward velocity up to 29 mm/year, mainly influenced by block rotation. Velocity referenced to the Sunda block shows a distinguished pattern between southern Java and northern Java. The velocity pattern in the southern part of Java tends to move northwest with a velocity variation of 3-6 mm/year, while several north stations show a velocity pattern to the south with a variation of 2-4 mm/yr. The strain analysis shows different patterns between eastern and western regions and different characteristics of southern and northern regions. Mainly the deformation is dominated by the compression due to the subduction in the south. Meanwhile, near to the central Java the deformation patterns significantly change due to the appearance of the east-west extension. The result indicates the different distinguished characteristics of the deformation source in the eastern part of Java. This result will have implications for seismic hazard analysis as a contribution to disaster risk reduction in the future.

Impacts of Cyclones on Arctic Clouds during Autumn in the Early 21st Century

Our study shows that, during 2001–2017, when the sea ice was melting rapidly, cyclone days accounted for more than 50% of the total autumn days at the sounding stations in the Arctic marginal seas north of the Eurasian continent and almost 50% of the total autumn days at the sounding station on the northern coast of Canada. It is necessary to investigate the influence of Arctic cyclones on the cloud fraction in autumn when the sea ice refreezes from its summer minimum and the infrared cloud radiative effect becomes increasingly important. Cyclones at the selected stations are characterized by a narrow maximum rising zone with vertically consistent high relative humidity (RH) and a broad region outside the high RH zone with low RH air from the middle troposphere covering the low troposphere’s high relative humidity air. Consequently, on approximately 40% of the cyclone days, the cloud formation condition was improved from the near surface to the upper troposphere due to the cooling of strong rising warm humid air. Therefore, cyclones lead to middle cloud increases and sometimes high cloud increases, since the climatological Arctic autumn clouds are mainly low clouds. On approximately 60% of the cyclone days, only low cloud formed, but the low cloud formation condition was suppressed due to the mixing ratio decrease induced by cold dry air sinking. As a result, cyclones generally lead to a decrease in low clouds. However, the correlation between the cyclones and low clouds is complex and varies with surface ice conditions.

Optimal Design of a Surface Precipitation Network in Canada

Abstract The surface precipitation network in Canada suffers from large data gaps due to the challenge of covering a large country with a low population density. A proof-of-concept for an optimal network design is proposed to more efficiently estimate precipitation in Canada with the design goal of minimizing the interpolation uncertainty. The network design is based on a statistical model of precipitation that accounts for intermittency and non-Gaussianity of precipitation. Our results indicate that the greatest needs for new stations are in British Columbia, where coastal and mountain climate leads to more uncertainty in precipitation amounts, while the Prairie Provinces (Alberta, Saskatchewan, and Manitoba) could gain efficiencies by reducing their network size. Despite the current low density of stations in the territories north of Canada, these drier and colder regions only have a moderate need for more stations, mostly in the mountainous regions of Yukon. However, from a spatially varying wind undercatch measurement error model, it is shown that these northern regions have greatest need for higher-accuracy measurements. Significance Statement The proposed methodology can guide in the optimal placement of precipitation gauges across a large country such as Canada, which will provide value for money in how rain and snow are monitored.

Concentrations of dissolved dimethyl sulfide (DMS), methanethiol and other trace gases in context of microbial communities from the temperate Atlantic to the Arctic Ocean

Abstract. Dimethyl sulfide (DMS) plays an important role in the atmosphere by influencing the formation of aerosols and cloud condensation nuclei. In contrast, the role of methanethiol (MeSH) for the budget and flux of reduced sulfur remains poorly understood. In the present study, we quantified DMS and MeSH together with the trace gases carbon monoxide (CO), isoprene, acetone, acetaldehyde and acetonitrile in North Atlantic and Arctic Ocean surface waters, covering a transect from 57.2 to 80.9∘ N in high spatial resolution in May–June 2015. Whereas isoprene, acetone, acetaldehyde and acetonitrile concentrations decreased northwards, CO, DMS and MeSH retained substantial concentrations at high latitudes, indicating specific sources in polar waters. DMS was the only compound with a higher average concentration in polar (31.2 ± 9.3 nM) than in Atlantic waters (13.5 ± 2 nM), presumably due to DMS originating from sea ice. At eight sea-ice stations north of 80∘ N, in the diatom-dominated marginal ice zone, DMS and chlorophyll a markedly correlated (R2 = 0.93) between 0–50 m depth. In contrast to previous studies, MeSH and DMS did not co-vary, indicating decoupled processes of production and conversion. The contribution of MeSH to the sulfur budget (represented by DMS + MeSH) was on average 20 % (and up to 50 %) higher than previously observed in the Atlantic and Pacific oceans, suggesting MeSH as an important source of sulfur possibly emitted to the atmosphere. The potential importance of MeSH was underlined by several correlations with bacterial taxa, including typical phytoplankton associates from the Rhodobacteraceae and Flavobacteriaceae families. Furthermore, the correlation of isoprene and chlorophyll a with Alcanivorax indicated a specific relationship with isoprene-producing phytoplankton. Overall, the demonstrated latitudinal and vertical patterns contribute to understanding how concentrations of central marine trace gases are linked with chemical and biological dynamics across oceanic waters.

Polar cod connectivity cruise 2022

The Nansen Legacy Polar Cod Connectivity cruise aimed at unravelling polar cod and capelin population connectivity and relation to the physical and chemical environment in Svalbard’s fjords. The main focus areas were Isfjorden, Kongsfjorden, Storfjorden and the South-East of Svalbard. A total of 36 stations were visited to collect of information on polar cod and capelin vertical and horizontal distribution (using echosounder, pelagic and bottom trawls), their population, life cycle and size structure (observation of maturity, otoliths reading and genetic sampling), as well as their diet (stomachs content, sampling of benthic/planktonic prey). Other studies were conducted in link with the objectives of the research foci RF2 The Human Impacts and RF3 The Living Barents Sea. The cruise was also an opportunity to visit well-known monitoring stations to complete already long time series and investigate seasonal variability. 
 The cruise started November 12th in Longyearbyen and ended in Tromsø on November 22nd, 2022. The first two days and a half were spent on multidisciplinary sampling in thirteen stations distributed in contrasted areas inside Isfjorden. A rockhopper gear strapping was installed after the first bottom trawl to avoid mud and rocks and kept for the whole cruise. There were some difficulties also with the grab which did not always close. It was possible to spend one day sampling Kongsfjorden, thanks to relatively good weather and low sea-ice conditions. However, the presence of cables on the seafloor and irregular and unsuitable bottom types in that fjord did not allow for bottom trawling to sample demersal and benthic communities. After approximately one day of steaming south in good weather conditions, the sampling continued in Storfjorden. However, the shallowest stations north of Storfjorden and on the way out of the fjord towards the South-East of the archipelago could not be sampled due to time constraints and difficult navigational access. Finally, five multidisciplinary stations could be sampled in the South-East of Svalbard before the two-days transit to Tromsø. Overall, most stations were visited. Polar cod largest fish were maturing, but not mature. Further analyses of the samples should unveil potential genetic differences across the fjords, and image analyses of plankton net samples will be able to detect if there were already eggs in the water column at the beginning of the dark season. There was very little signal on the echosounder during most of the cruise, but the extractive sampling revealed a diversity of communities in the different fjords.

Spatial and temporal variation of bacterial population in ambient air particulate matters (PM2.5, PM10 and TSP) of Isfahan city, Iran

Introduction: Airborne particles are considered as an important indicator of outdoor air quality. Many health problems have been linked to high concentrations of Particulate Matters (PMs) and their associated microorganisms. The aim of this study, therefore, was to investigate the population of bacteria in PMs in various times and locations.
 Materials and methods: The PM samples including PM2.5, PM10 and Total Suspended Particles (TSP) were taken from 4 different stations of Isfahan city, Iran on February (cold season) and July (warm season), 2019 using an air sampling pump on culture media. The number of bacterial colonies was counted after 48 h growth in the incubator at 37 oC. The PMs concentration and some morphological characteristics of bacteria were also investigated.
 Results: The highest number of bacterial colonies was in TSP followed by PM10 and PM2.5. The bacterial populations at two stations in north and east. of the region in the warm season were higher than in the cold season, and the respective situation in the other two stations at south and center of the city was reversed, which seems somehow to have been the result of the PMs concentration of difference of pollution sources in various locations and seasons.
 Conclusion: This study highlights the importance of PMs pollution especially PM2.5 (i.e. the main factor affecting the air quality of the study area) as the carrier of microbial pollution in the air which could adversely affect human health.

The Role of Emission Sources and Atmospheric Sink in the Seasonal Cycle of CH4 and δ13-CH4: Analysis Based on the Atmospheric Chemistry Transport Model TM5

This study investigates the contribution of different CH4 sources to the seasonal cycle of δ13C during 2000–2012 by using the TM5 atmospheric transport model, including spatially varying information on isotopic signatures. The TM5 model is able to produce the background seasonality of δ13C, but the discrepancies compared to the observations arise from incomplete representation of the emissions and their source-specific signatures. Seasonal cycles of δ13C are found to be an inverse of CH4 cycles in general, but the anti-correlations between CH4 and δ13C are imperfect and experience a large variation (p=−0.35 to −0.91) north of 30° S. We found that wetland emissions are an important driver in the δ13C seasonal cycle in the Northern Hemisphere and Tropics, and in the Southern Hemisphere Tropics, emissions from fires contribute to the enrichment of δ13C in July–October. The comparisons to the observations from 18 stations globally showed that the seasonal cycle of EFMM emissions in the EDGAR v5.0 inventory is more realistic than in v4.3.2. At northern stations (north of 55° N), modeled δ13C amplitudes are generally smaller by 12–68%, mainly because the model could not reproduce the strong depletion in autumn. This indicates that the CH4 emission magnitude and seasonal cycle of wetlands may need to be revised. In addition, results from stations in northern latitudes (19–40° N) indicate that the proportion of biogenic to fossil-based emissions may need to be revised, such that a larger portion of fossil-based emissions is needed during summer.

Shatin to Central Link cross-harbour railway tunnel in Hong Kong

The Shatin to Central Link is a new 17 km long railway that will connect the three existing railway lines in Hong Kong to enhance connectivity of the railway network. The project includes 12 major civil construction contracts, and construction commenced in 2012. Contract 1121 involves construction of a new Immersed Tube Tunnel, and this 1.7-km long immersed tube tunnel section is the fourth railway link crossing the Harbour. This cross-harbour tunnel section was procured through a design-and-build contract arrangement with early contractor involvement. When completed, the new tunnel section will extend the East Rail Line across the Harbour to a new station in Wan Chai North, terminating at the existing Admiralty Station. A total of 11 immersed tube tunnel elements were cast at the existing Shek O casting basin located in the south-east part of Hong Kong Island. The towing out and immersion operations for this new tunnel were commenced in June 2017 and successfully completed in April 2018. Connection of the immersed tube tunnel elements is complete and rail track installation and electrical and mechanical works inside the tunnel are now underway. This paper discusses the planning and construction of this latest immersed tube tunnel in Hong Kong SAR from the reference design stage to successful completion of the construction.

Validation of the Final Monthly Integrated Multisatellite Retrievals for GPM (IMERG) Version 05 and Version 06 with Ground-Based Precipitation Gauge Measurements across the Canadian Arctic

Abstract To assess the performance of the most recent versions of the Global Precipitation Measurement (GPM) Integrated Multisatellite Retrievals for GPM (IMERG), namely, V05 and V06, in Arctic regions, comparisons with Environment and Climate Change Canada (ECCC) Climate Network stations north of 60°N were performed. This study focuses on the IMERG monthly final products. The mean bias and mean error-weighted bias were assessed in comparison with 25 precipitation gauge measurements at ECCC Climate Network stations. The results of this study indicate that IMERG generally detects higher precipitation rates in the Canadian Arctic than ground-based gauge instruments, with differences ranging up to 0.05 and 0.04 mm h−1 for the mean bias and the mean error-weighted bias, respectively. Both IMERG versions perform similarly, except for a few stations, where V06 tends to agree slightly better with ground-based measurements. IMERG’s tendency to detect more precipitation is in good agreement with findings indicating that weighing gauge measurements suffer from wind undercatch and other impairing factors, leading to lower precipitation estimates. Biases between IMERG and ground-based stations were found to be slightly larger during summer and fall, which is likely related to the increased precipitation rates during these seasons. Correlations of both versions of IMERG with the ground-based measurements are considerably lower in winter and spring than during summer and fall, which might be linked to issues that passive microwave (PMW) sensors encounter over ice and snow. However, high correlation coefficients with medians of 0.75–0.8 during summer and fall are very encouraging for potential future applications.

Milliarcsecond Astrometry for the Galilean Moons Using Stellar Occultations

A stellar occultation occurs when a Solar System object passes in front of a star for an observer. This technique allows the sizes and shapes of the occulting body to be determined with kilometer precision. In addition, this technique constrains the occulting body’s positions, albedos, densities, and so on. In the context of the Galilean moons, these events can provide their best ground-based astrometry, with uncertainties in the order of 1 mas (∼3 km at Jupiter’s distance during opposition). We organized campaigns and successfully observed a stellar occultation by Io (JI) in 2021, one by Ganymede (JIII) in 2020, and one by Europa (JII) in 2019, with stations in North and South America. We also re-analyzed two previously published events: one by Europa in 2016 and another by Ganymede in 2017. We then fit the known 3D shape of the occulting satellite and determine its center of figure. This resulted in astrometric positions with uncertainties in the milliarcsecond level. The positions obtained from these stellar occultations can be used together with dynamical models to ensure highly accurate orbits of the Galilean moons. These orbits can help when planning future space probes aiming at the Jovian system, such as JUICE by ESA and Europa Clipper by NASA. They also allow more efficient planning of flyby maneuvers.

Meroplankton seasonal dynamics in the high Arctic fjord: Comparison of different sampling methods

Meroplankton comprise mainly of pelagic larvae of benthic invertebrates and play an important role as consumers and prey in coastal ecosystems. During a year-round study in Isfjorden (Svalbard Archipelago; >78°N), two locations (stations North and South) were sampled every third month to capture seasonal dynamics of meroplankton at high-latitudes, using different sampling methods (vertically hauled WP2 plankton net, and SCUBA diver-operated: horizontal towed net and underwater suction pump). Independent of sampling methods, seasonality was the factor that explained the largest part of variation in meroplankton composition (31.8%, PERMANOVA). Distinct seasonal abundance peaks were found of the following taxa: Polychaeta larvae and Cirripedia nauplii in spring; Bivalvia veligers, Echinodermata ophioplutei, and Cirripedia cypris during summer; while Bryozoa cyphonautes in autumn. These changes were driven mainly by water temperature, chlorophyll a concentration, and photoperiod, which according to DistLM routine, jointly explained 36.7% of meroplankton variability. Our results support the theory that planktotrophy is an important larval development strategy in some high Arctic taxa, e.g. Bivalvia and Cirripedia. We also observed that the southern part of Isfjorden was more productive and affected by the advection of Atlantic waters; while the northern location was influenced by the sea ice drift, coming from the north-eastern part of the Isfjord system in winter and spring, and was characterised by higher meroplankton abundances. The comparison of the number of taxa collected by each method and multivariate dispersion index between the standard WP2 plankton net and the remaining devices, operated by SCUBA divers, proved that WP2 is the most optimal method to collect meroplankton, especially from deeper waters. However, an underwater, manually operated suction pump would be a good choice in shallow coastal areas, especially with a dense kelp forest, where using a WP2 net is impossible. The joint use of the WP2 net and suction pump gives the highest value of multivariate dispersion index for the total community, as it additionally allows for the collection of demersal and epibenthic animals which are often omitted by standard net sampling methods, so this combination is worth recommending in studying shallow coastal ecosystems.

Ionospheric monitoring with the Chilean GPS eyeball during the South American total solar eclipse on 2nd July 2019

The impact of total solar eclipse of July 2, 2019 on the Ionosphere is studied using 24 Chilean GPS stations north–south of the totality path. The total solar eclipse passed through Coquimbo region from ~ 16:38 CLT (~ 20:38 UTC) to ~ 16:40 CLT (~ 20:40 UTC) and maximum eclipse was observed ~ 16:39 CLT (~ 20:39 UTC). The total electron content (TEC) derived from GPS signals shows peculiar features. At the totality stations TEC variations are small (~ 0.39 TECu), but it shows significant decrease (maximum ~ 2.24 TECu) for stations located south and increase (maximum ~ 3.89 TECu) for the stations located north of totality of the surface. The wavelet analysis of VTEC timeseries shows the presence of strong atmospheric gravity waves (AGWs) of duration ~ 30 to 60 min at the stations located north of totality. Thus, the results suggest an interplay between eclipse effect on the ionosphere plasma density and eclipse generated AGWs induced plasma density perturbation provided the peculiar features.

Mapping Broadcast Media Outlets and Accredited Journalists in Kenya: Towards Understanding News and Information Inequalities

This article reports on a study that attempted to understand news and information inequalities by mapping the distribution of broadcast media outlets, the spread of accredited journalists, and the presence of established news bureaus in the eight regions in Kenya. Further, the study sought to determine the ownership of the broadcast media in Kenya and the trends in ownership and audience reach within the context of commercial interest and public interest dialectics. The study was anchored on the theory of the political economy of the media which looks at power relations that influence the production, distribution and consumption of resources from a critical tradition. Based on the analysis of documents, audience research data, and literature on media representation and socioeconomic and political development, the study revealed that Nairobi County is the news and information hub. It has the most journalists, radio stations and news bureaus, whereas far-flung counties exist in news and information deserts. Central region residents were found to consume the least percentage of the non-local language radio stations as they prefer local language or vernacular radio stations Western, South Nyanza (Nyamira and Kisii) and North Western regions are unique in that their consumption of radio with a national target audience is fairly high when the Average Daily Radio Reach (ADRR) of the top five radio stations is considered. Ownership of the radio market is in the hands of five media organisations that share 43.70% of the ADRR. The establishment, audience reach and ownership trends of these media organisations coupled with the spread of journalists and news bureaus revealed news and information inequalities. The audience reach by broadcast media outlets, even in areas where vernacular radio stations provide a rich diet of media content, seems to be more interested in ownership for profit maximisation at the expense of public interest.

O Observatório Nacional do Rio de Janeiro e a estação magnética de Tatuoca no estado do Pará (1933-1972): Um relato sobre a implantação de uma estação magnética internacional no estado do Pará

Por séculos o campo magnético da terra vem sendo estudado, e a partir da percepção de sua grande influência no planeta e em seus habitantes, fez-se necessário um aprofundamento nas pesquisas. A partir daí começou a serem implantados os primeiros observatórios magnéticos. Este trabalho objetiva fazer uma análise sobre a estação magnética de Tatuoca e seu funcionamento. Para isso, construímos um acervo de informações e análises sobre o Observatório Nacional e sobre as estações e observatórios magnéticos. O Observatório Nacional é a instituição responsável pelos observatórios e estações magnéticas no Brasil desde o século XIX. A construção desse trabalho se deu através de uma metodologia de análise documental, e discussões acerca dos acontecimentos que fizeram parte do desenvolvimento do estudo do campo magnético da terra. Estes documentos citados são verdadeiras relíquias que vem desde a discussão sobre a necessidade de construir uma estação magnética na região mais ao norte de Brasil até um período mais recente, onde é descrito o funcionamento do observatório.

Observed and simulated changes in precipitation seasonality in Argentina

Seasonality in Argentina is examined using precipitation observations from 56 weather stations north of 42°S and CRU gridded precipitation. The Walsh and Lawler Seasonality Index (SI) and Precipitation Concentration Index (PCI) are calculated to determine the different seasonality regimes. The main characteristic is an eastwest gradient, where precipitation tends to be more evenly distributed throughout the different months of the year in the east while rainfall in the west is concentrated in 3 months or less. High replicability values indicate that the wettest month generally occurs during a same period of months in central and northern Argentina. Several stations in eastern humid Argentina have significant positive changes in the mean of seasonality indices between 1961 and 1985 and 1986 and 2010, and increasing trend. In most cases this leads to a change in the regime from rather seasonal with a short dry season to a seasonal regime. Through a PAM Clustering technique a new regionalization of precipitation seasonality is obtained. The mean series in each cluster show a tendency towards more seasonal and highly seasonal regimes in all regions. The SI and PCI indices were calculated using the precipitation outputs of 18 global climate models (GCMs) from the Coupled Model Inter‐comparison Project Phase 5 (CMIP5) to examine the ability of these models to represent seasonality spatial distribution and changes in Argentina. To some extent the spatial distribution of seasonality is captured by models; however, there are considerable discrepancies in the location and extension of the eastwest gradient. The sign and location of trends and changes in the mean SI and PCI are adequately reproduced in only a few models. The low ability of GCMs to represent seasonality and its changes is a consequence of the difficulties GCMs have simulating precipitation characteristics in Argentina reported by different authors.