Atmospheric response to observed intraseasonal tropical sea surface temperature anomalies

The major tropical convective and circulation features of the intraseasonal or Madden-Julian Oscillation (MJO) are simulated as a passive response to observed MJO sea surface temperature (SST) anomalies in an atmospheric general circulation model (AGCM), strengthening the case for ocean-atmosphere interactions being central to MJO dynamics. However, the magnitude of the surface fluxes diagnosed from the MJO cycle in the AGCM, that would feed back onto the ocean in a coupled system, are much weaker than in observations. The phasing of the convective-dynamical model response to the MJO SST anomalies and the associated surface flux anomalies is too fast compared to observations of the (potentially) coupled system, and would act to damp the SST anomalies

Observed Changes in the Lifetime and Amplitude of the Madden–Julian Oscillation Associated with Interannual ENSO Sea Surface Temperature Anomalies

The Madden-Julian Oscillation (MJO) is analysed using the reanalysis zonal wind and satellite outgoing longwave radiation-based indices of Wheeler and Hendon for the 1974-2005 period. The average life time of MJO events varies with season, being 36 days for events whose central date occurs in December, and 48 days for events in September. The life time of the MJO in the equinoctial seasons (March-May and October-December) is also dependent on the state of the El Nino-Southern Oscillation (ENSO). During October-December it is only 32 days under El Nino conditions, increasing to 48 days under La Nina conditions, with similar values in northern spring. This difference is due to faster eastward propagation of the MJO convective anomalies through the Maritime Continent and western Pacific during El Nino, consistent with theoretical arguments concerning equatorial wave speeds. The analysis is extended back to 1950 by using an alternative definition of the MJO based on just the zonal wind component of the Wheeler and Hendon indices. A rupture in the amplitude of the MJO is found in 1975, at the same time as the well known rupture in the ENSO time series, that has been associated with the Pacific Decadal Oscillation. The mean amplitude of the MJO is 16% larger in the post-rupture period (1976-2005) compared to the pre-rupture period (1950-1975). Before the 1975 rupture, the amplitude of the MJO is a maximum (minimum) under El Nino (La Nina) conditions during northern winter, and a minimum (maximum) under El Nino (La Nina) conditions during northern summer. After the rupture, this relationship disappears. When the MJO-ENSO relationship is analysed using all year round data, or a shorter data set, as in some previous studies, no relationship is found

Notes on the Biology of Invasive Lionfish (Pterois sp.) from the Northcentral Gulf of Mexico

The first confirmed sightings of lionfish in the Gulf of Mexico occurred in 2010 (Schofield 2010), where they were reported in the southern GOM off the Yucatan Peninsula, Mexico (Aguilar-Perera and Tuz-Sulub 2010); in 2012 more than 1,500 lionfish were collected from northern GOM locations ranging from Florida to Texas (Fogg et al. 2013). However, other than visual observations (mostly from recreational divers), there is relatively little information on the biology and ecology of lionfish in the northern GOM. The life history of invasive species can vary as they colonize new habitats and areas (Bøhn et al. 2004); thus, biological parameters described for lionfish along the US southeast coast, the Bahamas, and the Caribbean may differ as the species invades the GOM. Recently, Fogg et al. (2013) provided information on length-weight and sex ratios of northern GOM lionfish. Here, we report biological data from 4 lionfish captured during fishery-independent sampling in nearshore GOM waters off Alabama in May 2012

Evaluating Management Actions for Spotted Seatrout, Cynoscion nebulosus, in Mississippi with an Age-Structured Projection Model

Spotted seatrout, Cynoscion nebulosus, is an important recreational fishery in the coastal waters of the Gulf of Mexico and is the most sought after gamefish in coastal Mississippi. The management of C. nebulosus is state-specific, and unlike other similarly managed species, data on both population structure and movement support the existence of local sub-stocks. It is important for each state to clearly examine its own sub-stock in the context of its own state fishery in order to properly manage for local sustainability. We used an age-structured assessment model to examine the status (1993–2005) of the Mississippi C. nebulosus population and to project forward several probable management actions (i.e., length limits) while also accounting for uncertainty in both fishing mortality and annual recruitment. Model results suggest annual fishing mortality for Mississippi C. nebulosus is close to Fmsy, but that spawning stock biomass (SSB) is not below SSBmsy. This suggests the sub-stock is currently stable, but with high fishing pressure and a high dependence on annual recruitment to the fishery. Projections suggest that when uncertainty in angler effort and annual recruitment are included in the analysis, more conservative management actions are warranted in order to achieve both higher fishery yield and stable SSB

Distribution of testate amoebae in salt marshes along the North American East Coast

Reproduced with permission of the publisher. © 2006 Cushman Foundation for Foraminiferal ResearchThis study describes the distribution of testate amoebae in three North American East Coast salt marshes (Leipsic River marsh, Delaware, USA; Little River marsh, Maine, USA; and Little Dipper Harbour marsh, New Brunswick, Canada). Five zones are recognized in the high salt marsh. With increasing marine influence, these zones are characterized by the following succession of dominant taxa: Valkanovia elegans, Tracheleuglypha dentata, Centropyxis cassis type, C. platystoma type and Difflugia pristis type. Most species occur in all three marshes, and their general vertical distribution is comparable. The results are also comparable with those obtained from British salt marshes, suggesting that salt-marsh testate amoebae have similar distributions on both sides of the Atlantic Ocean. The precision of the sea-level indicative value of testate amoebae in fossil salt-marsh sediments is a function of the local mean tidal range (MTR). Results of this study show that testate amoebae can indicate former sea levels with a precision of ±0.04 m in the Leipsic River marsh (MTR = 1.75 m), ±0.09 m in the Little River marsh (MTR = 2.6 m), and ±0.18 m in the Little Dipper marsh (MTR = 5.8 m)

Real-time extraction of the Madden-Julian oscillation using empirical mode decomposition and statistical forecasting with a VARMA model

A simple guide to the new technique of empirical mode decomposition (EMD) in a meteorological-climate forecasting context is presented. A single application of EMD to a time series essentially acts as a local high-pass filter. Hence, successive applications can be used to produce a bandpass filter that is highly efficient at extracting a broadband signal such as the Madden-Julian Oscillation (MJO). The basic EMD method is adapted to minimize end effects, such that it is suitable for use in real time. The EMD process is then used to efficiently extract the MJO signal from gridded time series of outgoing longwave radiation (OLR) data. A range of statistical models from the general class of vector autoregressive moving average (VARMA) models was then tested for their suitability in forecasting the MJO signal, as isolated by the EMD. A VARMA (5, 1) model was selected and its parameters determined by a maximum likelihood method using 17 yr of OLR data from 1980 to 1996. Forecasts were then made on the remaining independent data from 1998 to 2004. These were made in real time, as only data up to the date the forecast was made were used. The median skill of forecasts was accurate (defined as an anomaly correlation above 0.6) at lead times up to 25 days

Spatio-Temporal Distribution of Larval Gobiosoma Bosc in Waters Adjacent to Natural and Altered Marsh-Edge Habitats of Mississippi Coastal Waters

Larval naked gobies, Gobiosoma bose, were collected monthly from October 1995 to September 1997 by beam plankton trawl from waters adjacent to natural Juncus/Spartina marsh-edge, natural sandy beach and altered Juncus/Spartina marsh-edge habitats in Mississippi coastal waters. Altered marsh habitats consisted of two bulkheaded stations and one stretch of riprap. Abundances were significantly higher in waters adjacent to natural marsh-edge habitats than in those adjacent to altered habitats in year one (P = 0.011), suggesting that the physical nature of alteration may have caused reduced habitat suitability. Abundances also varied seasonally, with summer conditions of high water temperature, increasing tide height, intermediate depth, low dissolved oxygen, and clear skies being significantly related to high abundance of postflexion G, bose in each year (r(2) = 0.481 and 0.276, respectively). Year two abundances were lower than those of year one and not significantly different among habitats. There was also a noticeable shift in the reproductive strategy of G. bose from a bimodal pattern in year one to a single reproductive peak in year two. This study illustrates the importance of natural Juncus/Spartina marsh-edge habitat to G. bose reproduction/recruitment and by extension to the community structure of the Back Bay/Davis Bayou estuarine ecosystem

Revisiting the need for a literature search narrative: A brief methodological note

This is the author accepted manuscript. The final version is available from Wiley via the DOI inthis recordIn this method note, we question if the primary search strategy in a systematic review should be accompanied by a search narrative. A search narrative could offer a conceptual and contextual report on the search strategy, which we suggest might benefit the peer review of literature searches and increase engagement with, and discussion of, the literature search strategy from review stakeholders, topic experts, and lay users of research. Search narratives would also increase the transparency of decision-making in literature searching.Centre for Outcomes Research and Effectiveness (CORE)National Institute for Health Research (NIHR)Cochrane Common Mental Disorders (CCMD) Grou

Movements of Spotted Seatrout (Cynoscion nebulosus) in Mississippi Coastal Waters Based on Tag–Recapture

Movement patterns of spotted seatrout (Cynoscion nebulosus) were evaluated in Mississippi coastal waters by an angler-based tagging study from 1995 through 1999. During this period, 505 anglers tagged 15,206 spotted seatrout, the majority of which (84%) did not meet the state\u27s legal minimum size limit of 14 inches (356 mm) total length. Overall, 408 (2.7%) tagged fish were recaptured and reported to project personnel. Over 90% of these recaptured fish moved less than 10 km from site of tagging to site of recapture (mean = 3.0 ± 0.41 km), and 82% moved less than 3 km. The greatest movement from tagging to recapture site by any fish was 60 km over a period of 200 d, and only three fish (0.7%) moved 50 km or more. Study results suggest that spotted seatrout in Mississippi waters comprise a nonmigratory fish stock, as has been found for this species in coastal waters of neighboring states along the U.S. Gulf of Mexico