North In Spring Research Articles

Unstable relationship between spring NAO and summer tropical cyclone genesis frequency over the western North Pacific

The present study reveals the fact that the relationship between the spring (April–May) North Atlantic Oscillation (NAO) and the following summer (June–September) tropical cyclone (TC) genesis frequency over the western North Pacific (WNP) during the period of 1950–2018 was not stationary. It is shown that the relationship between the two has experienced a pronounced interdecadal shift, being weak and insignificant before yet strong and statistically significant after the early 1980s. Next we compare the spring NAO associated dynamic and thermodynamic conditions, sea surface temperature (SST) anomalies, and atmospheric circulation processes between the two subperiods of 1954–1976 and 1996–2018, so as to illucidate the possible mechanism for this interdecadal variation in the NAO-TC connection. During the latter epoch, when the spring NAO was positive, enhanced low-level vorticity, reduced vertical zonal wind shear, intensified vertical velocity and increased middle-level relative humidity were present over the WNP in the summer, which is conducive to the genesis of WNP TCs. When the spring NAO is negative, the dynamic and thermodynamic factors are disadvantageous for the summertime TC formation and development over the WNP. The results of further analysis indicate that the persistence of North Atlantic tri-pole SST anomalies from spring to the subsequent summer induced by the spring NAO plays a fundamental role in the linkage between the spring NAO and summer atmospheric circulation. During the period of 1996–2018, a remarkable eastward propagating wave-train occurred across the northern Eurasian continent, forced by the anomalous SST tri-pole in the North Atlantic. The East Asian jet flow became greatly intensified, and the deep convection in the tropics was further enhanced via the changes of the local Hadley circulation, corresponding to a positive spring NAO. During the former epoch, the spring NAO-induced tri-pole SST anomalies in the North Atlantic were non-existent, and the related atmospheric circulation anomalies were extremely weak, thereby leading to the linkage between spring NAO and WNP TC genesis frequency in the following summer being insignificant.

Joint impact of North Pacific Victoria mode and South Pacific Quadrapole mode on Pacific ITCZ summer precipitation

This study investigates the joint impact of the boreal late winter–early spring North Pacific Victoria mode (VM) and South Pacific Quadrapole (SPQ) mode on the following summer Pacific Intertropical Convergence Zone (ITCZ) precipitation. Here, both observational data and historical simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5) models show that the precipitation anomalies are enhanced when the VM and the SPQ are in phase but are weakened when they are out of phase. The strength of the anomalous vertical velocity (ω) and outgoing longwave radiation also tend to be stronger (weaker) in same-sign (opposite-sign) events. One possible reason for this is that when the VM and the SPQ are in (out of) phase, westerly anomalies over the western–central tropical Pacific are greatly increased (reduced) due to the interactions between preceding North and South Pacific sea surface temperature anomalies, thereby enhancing (reducing) convective upward motion over the western and central Pacific. In addition, an empirical linear regression model is also developed to forecast Pacific ITCZ summer precipitation based on both the late winter–early spring VM and SPQ indices. The combination of the two precursors in North and South Pacific show higher prediction skills than the single VM or SPQ model, which means it is necessary to consider their joint impact when we focus on the Pacific ITCZ precipitation.

Slamming the “Continuing” Moroccan Revolution: Noussayba Lahlou's Bittersweet Verses

AbstractIn this article, I am interested in looking at women's current mobilization techniques in Post-Arab Spring North Africa. To do so, I draw from the existing literature on the case of Egypt which identifies women's contemporary resistance in creative disobedience patterns – that is women's art activism that advocates, concomitantly, for social justice and gender equality. In my attempt to fill an existing gap in the literature, I investigate the existence of such resistance patterns in Morocco, as well as their main characteristics and country specificities. Because (slam) poetry is a traditionally resistant genre in the Arab region, I take as a case study Noussayba Lahlou's slam poetry to explore the political potential of women's slams to advocate for women's rights and sociopolitical liberties in post-Arab Spring Morocco. To do so, I conducted a virtual interview with the artist by administering a structured online questionnaire, alongside a content analysis of eight of her most recent and salient slams. A 24-years-old slam poet from Morocco, Noussayba's revolutionary verses tackle widespread regime abuse and corruption, alongside women's rights and many other social woes in the country.

Atlantic‐Pacific SST Gradient Change Responsible for the Weakening of North Tropical Atlantic‐ENSO Relationship due to Global Warming

AbstractThe changes in the negative relationship between the boreal spring North Tropical Atlantic (NTA) and the subsequent El Nino Southern Oscillation (ENSO) event are examined. While the NTA's triggering of ENSO events has strengthened in the observed period during 1992–2002 compared to 1967–1987, it is projected to be weakened in the Representative Concentration Pathway (RCP) 4.5 scenario. The relative change in the climatological Atlantic sea surface temperature (SST), compared to those in other ocean basins, can explain the negative NTA‐ENSO relationship changes in both the observations and RCP4.5 scenario. In RCP4.5 scenario, the climatological Atlantic SST weakly increases relative to other ocean basins; therefore, the increase in the SST threshold for convection is greater than the increase in Atlantic SST, which suppress Atlantic convection. This suppresses NTA‐related local convection anomalies associated with the weakened negative NTA‐ENSO relationship. In the observed recent decades, the climatological Atlantic SST is further increased than those of other oceans, and thus, the NTA‐related teleconnection is enhanced.

Springtime North Pacific Oscillation and summer sea ice in the Beaufort sea

We investigate the linkage between the spring (April–June) North Pacific Oscillation (NPO) and the following summer sea ice in the Beaufort sea. A positive NPO is characterized by an intensified and northeastward extended Aleutian Low, a strong Beaufort High, and enhanced easterly winds in the Beaufort sea. Concomitantly, while the deepening East Asian trough steers more cyclones from Siberia to the sub-polar Pacific and thus fewer cyclones into the western Arctic Ocean; a weak polar vortex and weak baroclinicity in the Beaufort sea does not favor cyclone activity. In addition, the East Asian trough enhances warm air advection from the Pacific to the Northwestern America. The spring NPO accounts for 29% of interannual variability of the following September sea ice cover in the Beaufort sea and can be used as a potential predictor for ice melting in the Beaufort sea. During a positive NPO, the strong easterly winds over the Beaufort sea enhance ice advection and reduce ice thickness; on the synoptic scale, there are more occurrences of the pack ice becoming detached from the coast due to the strong easterly winds. Moreover, increases in shortwave radiation and longwave radiations accelerate the ice melting.

Inter‐decadal change of the spring North Atlantic Oscillation impact on the summer Pamir–Tienshan snow cover

Known as the “water tower of central Asia” and a crucial component of the Tibetan Plateau (TP), the Pamir–Tienshan snow cover (PTSC) exerts profound impacts on regional and global climate extremes during summer. However, researches on origins of the summer PTSC variability have not attracted adequate attention. In recent works, the spring North Atlantic Oscillation (NAO) has been shown to “prolong” its influence through the North Atlantic tri‐pole sea surface temperature anomalies (Tri‐SSTAs) and affect remote Asian climate in the subsequent summer. The present study discovers that the spring NAO has a significant positive correlation with the summer PTSC in the period 1967–1981, but such connection weakens after 1981. The North Atlantic Tri‐SSTAs induced by the spring NAO during these two epochs can both persist into ensuing summer but excite significantly different downstream atmospheric teleconnections. The Rossby wave train triggered by positive (or negative) Tri‐SSTAs during the 1967–1981 period exhibits an anomalous cyclonic (or anticyclonic) centre over the Pamir–Tienshan region, favouring an excessive (or reduced) PTSC. By contrast, such atmospheric anomaly centre is not evident during the 1982–2014 period. Numerical experiments suggest that westwards shift of the spring NAO northern centre can modulate the Tri‐SSTA pattern via the wind–evaporation–SST feedback, which could further result in the displacement of the atmospheric anomaly centres in the Rossby wave train in summer. Therefore, such change in the spring NAO itself is responsible for the inter‐decadal change of the spring NAO impact on the summer PTSC.

TINJAUAN KUALITAS FISIK, KIMIA DAN MIKROBIOLOGI AIR TAMAN BEJI DESA UBUNG KAJA DENPASAR TAHUN 2018

Abstract: North Ubung Village is one area that has 6 (six) water springs. One of them is the Taman Beji water spring located at Jalan Kendedes Denpasar. This water spring is used by local people for drinking water. In this water spring quality checks have been done, but that is not found. The purpose of this research is to know the physical, chemical and microbiological qualities of Taman Beji North Ubung Village Denpasar. The type of research used to descriptive research. The population and samples in this research is Taman Beji water spring North Ubung Village. Data collected in this research are primary and secondary data. The data were collected using laboratory equipment to measure the physical, chemical and microbiological qualities of Taman Bejis water and the eye protection inspection sheet to assess the protection of the Taman Beji water spring. Physical and microbiological measurements were performed twice (2) an chemical measurement was performed only one (1) time. Based on the results obtained that the physical parameter of Taman Bejis water with temperature 280C dan 290C, the same turbidity results in two measurements of 0,11 NTU, chemical parameter that Ph 7 and hardness 60 mg/l, microbiological parameter of Taman Bejis water measured as much twice with results is Eschericia coli 0/100 ml sample and Total Coliform Bacteria 0/100 ml sample. So that the water of Taman Beji is qualify of Permenkes No. 492/MENKES/PER/IV/2010 about Water Quality Requirement. It is recommended for the community and village apparatus to fix PMA Taman Beji to avoid pollution and not to cause water borne disease if the water is consumed by the community.Keywords : Physical Quality; Chemistry and Water Microbiology

Annual spatio-temporal migration patterns of Hooded Cranes wintering in Izumi based on satellite tracking and their implications for conservation

BackgroundThe Hooded Crane (Grus monacha) is listed as a vulnerable species by IUCN. Knowledge about the migration of the Hooded Crane is still limited. Here we reported the spatio-temporal migration patterns of Hooded Cranes wintering in Izumi, Japan, as well as important stopover areas for their conservation.MethodsFour adult and five subadult cranes, all wintering in Izumi, Japan, were fitted with satellite transmitters (GPS–GSM system) at their stopover sites in northeastern China in 2014 and 2015. We analyzed the time and duration of adults and subadults in spring and autumn migration, as well as the time and duration they stayed in breeding and wintering ground. In addition, we analyzed the land use of the cranes in stopover areas.ResultsAdult cranes took much longer time to migrate both north in spring (mean = 44.3 days) and south in fall (mean = 54.0 days) compared with subadult cranes (15.3 and 5.2 days, respectively). However, the subadults had longer wintering (mean = 149.8 days) and nomadic (breeding season for adults) seasons (mean = 196.8 days) compared with adults (133.8 and 122.3 days, respectively). Three important stopover areas have been identified: the region around Muraviovka Park in Russia, the Songnen Plain in China, and the west coast of South Korea, where cranes spent most of their migration time (62.2 and 85.7% in spring and autumn, respectively). During migration, nomadic period and winter, Hooded Cranes usually stay in croplands for resting and feeding. In non-wintering season, less than 6% of stopover sites were located within protected areas.ConclusionOverall, our results contribute to understanding the annual spatio-temporal migration patterns of Hooded Cranes in the eastern flyway, and planning conservation measures for this species.

Longest sage‐grouse migratory behavior sustained by intact pathways

ABSTRACTExpanding human footprints across the globe are affecting animal migrations by altering their use of traditional routes and exposing them to increased costs of travel. Sustaining migratory behavior among populations requires knowledge of animal movement and space use during this critical life stage. We studied the migratory movements in a population of greater sage‐grouse (Centrocercus urophasianus), an imperiled species endemic to the North American sagebrush steppe, with the longest‐known obligate and annual migration for a grouse: a 240‐km journey between Saskatchewan, Canada, and north central Montana, USA. Remote tracking revealed that stepping‐stone behavior in sage‐grouse is analogous to that of migratory big game populations, which frequent stopover sites along varied and individual routes. Within migratory routes, sage‐grouse chose pathways with gently rolling grasslands and sagebrush flats. Sage‐grouse avoided cropland, making punctuated movements across a 6‐km river valley dominated by cropland and trees. During autumn migration (Oct–Nov), individuals typically spent a day at an average of 9 different stopovers while traveling 41–126 km in 14 days. Sage‐grouse were faithful to winter ranges and timing of autumn migration but demonstrated adaptive behavior in response to heavy snowfalls with no effect on survival. Birds made a mass exodus north in spring (Mar–Apr) to their respective breeding ranges, traveling up to 160 km in 18 days. Migratory pathways were stitched together by an array of public and private lands, with large and intact landscapes composed of native vegetation forming the common thread. Conservation easements and public lands policy that preclude temperate grasslands from being fragmented will be critical in maintaining the largest migratory event observed among gallinaceous species. © 2017 The Wildlife Society.

Assessment of current sanitary indicators in Ayoub hot spring North Khorasan in 2015

Assessment of current sanitary indicators in Ayoub hot spring North Khorasan in 2015

Identification of Long-Range Transport Pathways and Potential Sources of PM10 in Tibetan Plateau Uplift Area: Case Study of Xining, China in 2014

ABSTRACTThe aim of the study is to identify long-range transport pathways that may have an important influence on PM10 levels in plateau uplift area, namely Xining in northwestern China. Cluster analysis was applied to identify the main trajectory groups in horizontal direction and 3D cluster analysis was employed to identify the origins and distributions of major trajectory groups in vertical direction. Potential Source Contribution Function (PSCF) and Concentration-weighted Trajectory (CWT) were applied to identify the major potential source areas (PSA). Based on the temporal and spatial distribution of backward trajectories, four major trajectory pathways were clustered. The results indicated that Xining was easily affected by inland trajectories in four seasons but there were obvious results that different trajectories have dissimilar influences on the mean PM10 concentrations. In horizontal direction, the long-range transport pathways were obvious in spring and winter while a few of long-range transport pathways could be found in summer and autumn. Because wind mainly came from north or west in spring and winter and it was very strong, which had a big influence on the transportation of transport pathways while wind in summer and autumn had a small impact on the transportation of transport pathways. In vertical direction, in the 700 hPa barometric altitude (3000 m) above, air masses in winter and spring with long transport pathways were the most important back-trajectories which had a great influence on Xining city. In summer and autumn, Xining was mainly influenced by airflow distributed below 700 hPa barometric altitude. In spring and winter, eastern Xinjiang, border areas between Gansu and Inner Mongolia and southern Tibet in China with the highest Weight Potential Source Contribution Function (WPSCF) and Weight Concentration-weighted Trajectory (WCWT) values were the dominant potential sources, which demonstrated the contribution from sources outside of Xining were significant. In summer and autumn, WPSCF values outside of Xining were no more than 0.5 (most of them were less than 0.3) and WCWT values were almost lower than 100 µg m–3 in those two seasons, which suggested that there were no main important PSA in those two seasons. Furthermore, the study also revealed that Tibet in China was one of the potential sources of PM10 in Xining.

Playing the ‘Berber’: the performance of Amazigh identities in contemporary Morocco

In the last decade, Amazigh arts, media and scholarship have flourished in Morocco, facilitated by a number of new measures such as the creation of the Institut Royal de la Culture Amazighe in 2003. Performance in particular is contributing to this renewal by disseminating an oral heritage in Amazigh dialects and using local myths and narratives. The development of an ‘Amazigh theatre’ has played a crucial role in restoring the prestige of indigenous dialects and more generally protecting Amazigh traditions from erosion and disappearance. However, because they introduce the notion of identity politics in the Moroccan public realm, Amazigh cultural productions are inherently contentious, threatening the Pan-Arab model promoted throughout North Africa since Independence to ensure national unity. This article aims to discuss the development of Amazigh theatre and its impact as an identity marker and a tool of contestation, in the wider context of post-Arab Spring North Africa.

How far north are migrant birds transporting the tick Ixodes scapularis in Canada? Insights from stable hydrogen isotope analyses of feathers

Lyme disease is emerging in Canada because of northward range expansion of the tick vector Ixodes scapularis. It is hypothesised that I. scapularis feeding on passerine birds migrating north in spring are important in founding new I. scapularis populations leading to northward range expansion. However, there are no studies on how far north I. scapularis may be carried, only inferences from passive tick surveillance. We used stable hydrogen isotope (δ2H) analysis of rectrices collected from northward migrating, I. scapularis-carrying, passerine birds captured in Canada to estimate how far north I. scapularis may be carried. Rectrices are usually grown close to breeding sites and their δ2H values reflect those in the environment, which vary strongly with latitude in North America. Passerines usually return to their breeding or natal sites so δ2H values of rectrices of northward migrating birds can identify the likely latitudinal bands of their intended destinations. In 2006 we analysed δ2H from rectrices of 73 I. scapularis-carrying birds captured at five migration monitoring stations, mainly from southern Ontario. Values of δ2H ranged from −33 to −124‰, suggesting 19/71 (26.7%) birds were destined for latitude band B (the most southerly part of Ontario), 40/71 (56.3%) birds were destined for band C (which extends from southern Ontario, Quebec and the Maritimes to southern James Bay) and 12/71 (16.9%) birds were destined for bands D and E (which extend from northern Ontario and Quebec into the southern Canadian Arctic). This indicates that many I. scapularis-carrying migratory birds in spring have destinations far north in Canada, including some farther north than the current region of climatic suitability for I. scapularis. These findings support the hypothesis that I. scapularis may continue to be spread north by spring migrating passerines. Some thrush species may be particularly implicated in far northward dispersion of I. scapularis.

Climate projections for southern Australian cool-season rainfall: insights from a downscaling comparison

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 62:251-265 (2015) - DOI: https://doi.org/10.3354/cr01276 Climate projections for southern Australian cool-season rainfall: insights from a downscaling comparison Michael R. Grose1,*, Aurel F. Moise2, Bertrand Timbal2, Jack J. Katzfey1, Marie Ekström3, Penny H. Whetton1 1Climate Adaptation Flagship, CSIRO Marine and Atmospheric Research, 107-121 Station St, Aspendale, VIC 3195, Australia 2Centre for Australian Weather and Climate Research, Bureau of Meteorology, GPO Box 1289, Melbourne, VIC 3001, Australia 3CSIRO Land and Water, PO Box 1666, Canberra ACT 2601, Australia *Corresponding author: michael.grose@csiro.au ABSTRACT: The projected drying of the extra-tropics under a warmer climate has large implications for natural systems and water security in southern Australia. The downscaling of global climate models can provide insight into regional patterns of rainfall change in the mid-latitudes in the typically wetter cool season. The comparison of statistical and dynamical downscaling model outputs reveals regions of consistent potential added value in the climate-change signal over the 21st century that are largely related to finer resolution. These differences include a stronger and more regionalised rainfall decrease on west coasts in response to a shift in westerly circulation and a different response further from the coast where other influences are important. These patterns have a plausible relationship with topography and regional drivers that are not resolved by coarse global models. However, the comparison of statistical and dynamical downscaling reveals where the method and the configuration of each method makes a difference to the projection. This is an important source of uncertainty for regional rainfall projections. In particular, the simulated change in atmospheric circulation over the century is different in the dynamical downscaling compared to the global climate model inputs, related in part to a different response to patterns of surface warming. The dynamical downscaling places the border between regions with rainfall increase and decrease further north in winter and spring compared to the global climate models and therefore has a different rainfall projection for southeast mainland Australia in winter and for Tasmania in spring. KEY WORDS: Downscaling · Regional climate models · Precipitation · Climate projections Full text in pdf format PreviousCite this article as: Grose MR, Moise AF, Timbal B, Katzfey JJ, Ekström M, Whetton PH (2015) Climate projections for southern Australian cool-season rainfall: insights from a downscaling comparison. Clim Res 62:251-265. https://doi.org/10.3354/cr01276 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 62, No. 3. Online publication date: February 26, 2015 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2015 Inter-Research.

White-beaked dolphins trapped in the ice and eaten by polar bears

Polar bears (Ursus maritimus) depend on sea ice, where they hunt ice-associated seals. However, they are opportunistic predators and scavengers with a long list of known prey species. Here we report from a small fjord in Svalbard, Norwegian High Arctic, a sighting of an adult male polar bear preying on two white-beaked dolphins (Lagenorhynchus albirostris) on 23 April 2014. This is the first record of this species as polar bear prey. White-beaked dolphins are frequent visitors to Svalbard waters in summer, but have not previously been reported this far north in early spring. We suggest they were trapped in the ice after strong northerly winds the days before, and possibly killed when forced to surface for air at a small opening in the ice. The bear had consumed most parts of one dolphin. When observed he was in the process of covering the mostly intact second dolphin with snow. Such caching behaviour is generally considered untypical of polar bears. During the following ice-free summer and autumn, at least seven different white-beaked dolphin carcasses were observed in or near the same area. We suggest, based on the area and the degree to which these dolphins had decayed, that they were likely from the same pod and also suffered death due to entrapment in the ice in April. At least six different polar bears were seen scavenging on the carcasses. Keywords: White-beaked dolphin; polar bear; caching; Arctic; Svalbard. (Published: 1 June 2015) Citation: Polar Research 2015, 34, 26612,http://dx.doi.org/10.3402/polar.v34.26612

Natural uranium and strontium isotope tracers of water sources and surface water–groundwater interactions in arid wetlands – Pahranagat Valley, Nevada, USA

Near-surface physical and chemical process can strongly affect dissolved-ion concentrations and stable-isotope compositions of water in wetland settings, especially under arid climate conditions. In contrast, heavy radiogenic isotopes of strontium (87Sr/86Sr) and uranium (234U/238U) remain largely unaffected and can be used to help identify unique signatures from different sources and quantify end-member mixing that would otherwise be difficult to determine. The utility of combined Sr and U isotopes are demonstrated in this study of wetland habitats on the Pahranagat National Wildlife Refuge, which depend on supply from large-volume springs north of the Refuge, and from small-volume springs and seeps within the Refuge. Water budgets from these sources have not been quantified previously. Evaporation, transpiration, seasonally variable surface flow, and water management practices complicate the use of conventional methods for determining source contributions and mixing relations. In contrast, 87Sr/86Sr and 234U/238U remain unfractionated under these conditions, and compositions at a given site remain constant. Differences in Sr- and U-isotopic signatures between individual sites can be related by simple two- or three-component mixing models. Results indicate that surface flow constituting the Refuge’s irrigation source consists of a 65:25:10 mixture of water from two distinct regionally sourced carbonate-aquifer springs, and groundwater from locally sourced volcanic aquifers. Within the Refuge, contributions from the irrigation source and local groundwater are readily determined and depend on proximity to those sources as well as water management practices.

Distribution of atmospheric mercury in northern Southeast Asia and South China Sea during Dongsha Experiment

Northern South China Sea (SCS) is adjacent to major atmospheric mercury (Hg) emission source regions; however, studies concerning regional atmospheric Hg distribution and cycling are very limited. Accordingly, measurements of atmospheric Hg were conducted in March and April during the 2010 Dongsha Experiment to study its spatial and temporal distribution. Atmospheric Hg was measured at Hengchun and Dongsha Island (Taiwan), Da Nang (Vietnam), Chiang Mai (Thailand) and over the northern SCS. Atmospheric Hg concentrations ranged between 1.54 and 6.83 ng m−3, mostly higher than the Northern Hemisphere background value. Regional wind fields and backward trajectories indicated that the atmospheric Hg concentrations over northern SCS should principally reflect the export of the East Asian Hg emissions by northeast monsoon. However, significantly elevated Hg concentrations were always observed at Da Nang, possibly due to the influence of local Hg emissions. Chiang Mai is located in the intense biomass burning region in northern Thailand. Therefore, atmospheric Hg concentrations at Chiang Mai reflected the influence of regional biomass burning Hg emissions. Two dust storms were encountered at Dongsha Island, one on March 16 and the other on March 21, with atmospheric Hg enhancements. Compared with the 2008 summer values, elevated Hg levels were observed at Dongsha Island in the spring of 2010. Summer air masses were mainly from the deep SCS, representing relatively clean marine air. On the other hand, air masses were from the north in spring, passing eastern China or Taiwan prior to reaching Dongsha Island. Results of this research thus demonstrated the transport of atmospheric Hg from the East Asian continent to northern SCS by regional monsoon activity in spring, but special events, such as biomass burning and dust storms, can also cause enhancements of ambient Hg levels.

Flood Risk Awareness during the 2011 Floods in the Central United States: Showcasing the Importance of Hydrologic Data and Interagency Collaboration

Floods have long had a major impact on society and the environment, evidenced by the more than 1,500 federal disaster declarations since 1952 that were associated with flooding. Calendar year 2011 was an epic year for floods in the United States, from the flooding on the Red River of the North in late spring to the Ohio, Mississippi, and Missouri River basin floods in the spring and summer to the flooding caused by Hurricane Irene along the eastern seaboard in August. As a society, we continually seek to reduce flood impacts, with these efforts loosely grouped into two categories: mitigation and risk awareness. Mitigation involves such activities as flood assessment, flood control implementation, and regulatory activities such as storm water and floodplain ordinances. Risk awareness ranges from issuance of flood forecasts and warnings to education of lay audiences about the uncertainties inherent in assessing flood probability and risk. This paper concentrates on the issue of flood risk awareness, specifically the importance of hydrologic data and good interagency communication in providing accurate and timely flood forecasts to maximize risk awareness. The 2011 floods in the central United States provide a case study of the importance of hydrologic data and the value of proper, timely, and organized communication and collaboration around the collection and dissemination of that hydrologic data in enhancing the effectiveness of flood forecasting and flood risk awareness.

Northeast China summer temperature and North Atlantic SST

A previous study revealed a close relationship between interannual variations ofnortheast China (NEC) summer temperature and a tripole sea surface temperature (SST)anomaly pattern in the North Atlantic in preceding spring. The present study investigatesthe change in the above relationship and the plausible causes for the change. A tripole SSTindex is defined with its positive value corresponding to positive SST anomalies in thetropics and midlatitudes and negative SST anomalies in the subtropics. The tripole SSTanomaly pattern has a weak correlation with NEC summer temperature during the 1950sthrough the mid‐1970s, in sharp contrast to the 1980s and 1990s. This change is related tothe difference in the persistence of the tripole SST pattern. Before the late 1970s, thetripole SST pattern weakened from spring to summer, and thus, the spring North Atlantictripole SST pattern had a weak connection with NEC summer temperature. On thecontrary, after the late 1970s, the tripole SST pattern displayed a tendency of persistencefrom spring to summer, contributing to circulation changes that affected NEC summertemperature. There are two factors for the persistence of the tripole SST pattern fromspring to summer. One is the North Atlantic air‐sea interaction, and the other is thepersistence of SST anomalies in the eastern equatorial Pacific during the decay ofEl Nino–Southern Oscillation (ENSO). It is shown that the North Atlantic SST anomaliescan have an impact on NEC summer temperature independent of ENSO.

Mesozooplankton community structure and variability in the Scotia Sea: A seasonal comparison

Mesozooplankton distribution and community structure was investigated during 3 cruises to the Scotia Sea in austral spring, summer and autumn. Three mesh sizes of Bongo nets were used during each cruise with a 53 μm mesh net yielding on average 1.76 times higher densities (median 923,000 ind. m −2, 0–400 m) than a 100 μm net and 7.42 times more than a 200 μm net across all cruises. Small copepods dominated numerically across all nets with Oithona spp., Oncaea spp., Ctenocalanus citer and Microcalanus pygmaeus being particularly abundant, with sample densities of up to 3.5×10 6 ind. m −2 recorded within the top 400 m. A more even distribution of biomass among net sizes was apparent, with median net ratios (1.15–1.25) smaller and more even than for abundance. To the south of the Scotia Sea plankton maxima occurred in autumn, consistent with a later spawning in many species, whereas further north, abundance in 53 and 100 μm nets varied little across seasons, although in the 200 μm net there was a clear summer maximum. Median biomass increased through summer and by autumn was twice than found during spring in all parts of the Scotia Sea. Cluster analysis indicated two main station groups in all 3 seasons. To the south of the Southern boundary of the ACC (SB-ACC), Group 1 contained stations, that lay within the seasonal sea-ice zone and where zooplankton abundance and biomass was persistently low. In contrast at Group 2 stations, north of the Southern Antarctic Circumpolar Current Front (SACCF) abundance and biomass was consistently higher. Differences between the two groups were largely apparent at the population rather than at the taxonomic level. LHPR hauls to 1000 m indicated that the large seasonal migrant copepods Calanoides acutus and Rhincalanus gigas were at a more advanced stage of development in the north in spring and summer where they were generally present in the upper water column. In autumn, at all stations, C. acutus was dominated by later stages and was dispersed throughout the water column. Calanus simillimus was only abundant at Group 2 stations with older stages dominant in spring and autumn and younger stages in summer. The influence of environmental factors such as sea-ice, temperature and chlorophyll a biomass (Chl a) which may have influenced the development and seasonal succession of zooplankton populations, is briefly discussed.