Relationship between El Nino and summer monsoon rainfall over Pakistan

The present paper deals with the influence of El Nino event on the summer monsoon rainfall over Pakistan. The correlation between monthly rainfall of summer monsoon season and bi-Monthly Multivariate ENSO Index (MEI) has been calculated to see the influence of El Nino on the summer monsoon rainfall. MEI is bimonthly ENSO Index pertaining to the period from first week of previous month to first week of the month under consideration. While study the correlation's with the ENSO events out side the Pacific Ocean MEI is more appropriate than other indices like Southern Oscillation Index (SOI) as MEI integrates complete information on ENSO viz. six oceanic and meteorological variables over the tropical Pacific. The results of the study show that there is a tendency of reduction in summer monsoon rainfall over Pakistan during El Nino years. The deficiency in % rainfall is statistically significant up to 90% level during July and September months. It is interesting to note that Pakistan receives more than normal rainfall during summer monsoon season in the immediate following year after the El Nino event. The correlation analysis is also performed on the summer monsoon months for individual provinces of Pakistan. All provinces receive deficient rainfall during monsoon months. The deficiency in rainfall over Punjab during all monsoon months is significant, whereas the deficiency in rainfall is significant during July and August over NWFP and Sindh respectively. No significant impact of El Nino on the summer monsoon rainfall over Baluchistan is observed.

Variations in northeast Asian environments over the last 350,000 years reconstructed from pollen records from the northwest Pacific Ocean

EXTRACT (SEE PDF FOR FULL ABSTRACT): Recent analyses of terrestrial (pollen) and marine microfossils (foraminifera and radiolaria) in cores V28-204 and RC14-99 from the northwest Pacific Ocean extend the continuous, chronostratigraphically-controlled records of the regional vegetation of the Pacific coast of Japan and offshore marine environments through three full glacial cycles. The high-resolution pollen time series show systematic relationships between fluctuations in Japanese vegetation and global ice volume over the last 350 kyr. ... Comparison with solar insolation at 30°N and with an index of orbital parameters suggests that variation in northeast Asian summer monsoon intensity is related to orbital forcing.

Stable isotopes in paleosols and origins of the Asian monsoon

The stable isotopic composition of buried soil carbonate and organic matter from northern Pakistan and Nepal can be used to reconstruct aspects of the paleoecology of riverine floodplain ecosystems over the past 17 Myr. Probable dry woodland dominated the floodplain biomass of large rivers ancestral to the modern Indus and Ganges up to 7.3 Myr. Between 7.3 and about 6 Myr, tropical grasses gradually displaced woodland and have dominated floodplain biomasses to the present. The paleovegetational transition beginning about 7.3 Myr likely signals the onset of the strongly seasonal precipitation pattern that typifies the monsoonal climate of the region today. One possible analog to the dry woodland soils of the Miocene are found under the Sal woodlands of the northern Indian subcontinent, while undisturbed modern analogs to the Plio-Pleistocene floodplain grasslands can still be found in the Chitwan area of southern Nepal.

Heat budget studies of the north Arabian Sea during summer and winter seasons, 1992

In this study heat budget components and momentum flux for August and January 1992 over the north Arabian Sea are computed. The marine meteorological data measured on board during the cruises of PAK-US joint project (NASEER) are used for the computation. Significant differences were found in the heat budget components as well as in the momentum flux during different monsoon periods over the north Arabian Sea. The latent heat flux was always positive and attributed to the large vapour pressure gradient. The computed moisture and latent heat fluxes in January were higher than August The highest value of latent heat flux 309 W/m2 at station 8 was evaluated. These higher latent heat fluxes were due to the large vapour pressure gradient, air-sea temperature difference, the wind speed, and the prevailing wind direction (from north and northeast). Negative values of sensible heat fluxes in both seasons indicate that the heat transfer was from the atmosphere to the ocean. The negative values of net heat gain indicate that the sea surface field became an energy sink: or the sea surface supplied more energy to the atmosphere than it received from it. Large variation in the momentum flux mainly attributed to the variation in the wind speed. Aerial averages of heat and momentum fluxes were also computed.

Cruise Report: Summer 2008 Ecological Assessment of Stellwagen Bank National Marine Sanctuary NOAA Ship NANCY FOSTER NF-08-09-CCEHBR (June 14-June 21, 2008)

Summary: This cruise report is a summary of a field survey conducted within the Stellwagen Bank National Marine Sanctuary (SBNMS), located between Cape Cod and Cape Ann at the mouth of Massachusetts Bay. The survey was conducted June 14 – June 21, 2008 on NOAA Ship NANCY FOSTER Cruise NF-08-09-CCEHBR. Multiple indicators of ecological condition and human dimensions were sampled synoptically at each of 30 stations throughout SBNMS using a random probabilistic sampling design. Samples were collected for the analysis of benthic community structure and composition; concentrations of chemical contaminants (metals, pesticides, PAHs, PCBs, PBDEs) in sediments and target demersal biota; nutrient and chlorophyll levels in the water column; and other basic habitat characteristics such as depth, salinity, temperature, dissolved oxygen, turbidity, pH, sediment grain size, and organic carbon content. In addition to the fish samples that were collected for analysis of chemical contaminants relative to human-health consumption limits, other human-dimension indicators were sampled as well including presence or absence of fishing gear, vessels, surface trash, marine mammals, and noxious sediment odors. The overall purpose of the survey was to collect data to assess the status of ecosystem condition and potential stressor impacts throughout SBNMS, based on these various indicators and corresponding management thresholds, and to provide this information as a baseline for determining how such conditions may be changing with time. While sample analysis is still ongoing a few preliminary results and observations are reported here. A final report will be completed once all data have been processed. The results are anticipated to be of value in supporting goals of the SBNMS and National Marine Sanctuary Program aimed at the characterization, protection, and management of sanctuary resources (pursuant to the National Marine Sanctuary Reauthorization Act) as well as a new priority of NCCOS and NOAA to apply Ecosystem Based approaches to the Management of coastal resources (EBM) through Integrated Ecosystem Assessments (IEAs) conducted in various coastal regions of the U.S. including the Northeast Atlantic continental shelf. This was a multi-disciplinary partnership effort made possible by scientists from the following organizations:  NOAA, National Ocean Service (NOS), National Centers for Coastal Ocean Science (NCCOS), Center for Coastal Environmental Health and Biomolecular Research (CCEHBR), Charleston, SC.  U.S. Environmental Protection Agency (EPA), National Health and Environmental Effects Research Laboratory (NHEERL), Atlantic Ecology Division (GED), Narragansett, RI.  U.S. Environmental Protection Agency (EPA), National Health and Environmental Effects Research Laboratory (NHEERL), Gulf Ecology Division (GED), Gulf Breeze, FL.  U.S. Geological Survey (USGS), National Wetlands Research Center, Gulf Breeze Project Office, Gulf Breeze, FL.  NOAA, Office of Marine and Aviation Operations (OMAO), NOAA ship Nancy Foster. (31pp) (PDF contains 58 pages)

The distribution of ctenophora in the Patuxent estuary during the summer of 1958

Investigation of Ctenophores in the Chesapeake Bay area, includes some aspects of their life history, growth, reproduction, feeding and food habits, abundance and distribution. the purpose of the entire project is to supplement and add to the biological knowledge and understanding of ctenophores as a group and of the several individual species found int he area to be studied. Includes possible factors involved and implications also being looked at. (PDF contains 33 pages)

The Summer Flounder, Scup, and Black Sea Bass Fishery of the Middle Atlantic Bight and Southern New England Waters

Summer flounder, Paralichthys dentatus, scup, Stenotomus chrysops, and black sea bass, Centropristis striata, cooccur within the Middle Atlantic Bight and off southern New England and are important components of commercial and recreational fisheries. The commercial otter trawl fishery for these species is primarily a winter fishery, whereas the recreational fishery takes place between late spring and autumn. The otter trawl fishery generally targets summer flounder, and less frequently scup, while black sea bass occurs as bycatch. Trips in which all three species were present yielded highest aggregate landings per unit of effort (LPUE) levels and occurred more often than trips landing only one or two species. More than 50% of the trips in the trawl fishery landed at least two of the three species. In contrast, greater than 75% of the recreational landings of each species occurred as a result of trips landing only one species. Differences in the fisheries resulted from the interactions of seasonal changes in species distributions and gear selectivity. (PDF file contains 18 pages.)

Rélations hydrométéorologiques sur les côtes du Golfe de Guinée: influence de l'orientation de la côte

The Gulf of Guinea is remarkable for its abundant precipitations and negative anomalies of the surface water temperature. This originality comes from the southern monsoon which transfers the cold season to the middle of northern summer up to latitude 10 degrees North. Yearly precipitations, which can vary along the coast, are well in correlation with coast crossing air flow (r=0.71) and with the sea-air temperature difference (r=0.72). Precipitations provide a better correlation with surface temperatures (0.72) than with salinities (-0.63). The wind influence upon negative anomaly of the surface temperature is more clear on N-S coast (r=0.98) than on W-E coast (r=0.73) of the Gulf. Temporal correlations calculated on 16 years of observations in Pointe-Noire are in connection with previous spatial correlations. Coastal hydroclimates are thus likely to be deduced from meteorology.

Environmental effects of drought and abstractions of River Wharfe fisheries, summer 1997

This investigation was carried out to provide information on fish stocks and angling activity during 1997 in relation to the drought and, in particular, flows as influenced by Time Limited Licences. These abstractions will be for review in 1999. This report extends and updates the data presented for 1996. Fish population surveys (including eels) were undertaken on the main river and selected tributaries. Angler caught brown trout were examined, angler catch data have been reviewed, and observations by Environment Agency fisheries staff collated. It appeared that in River Wharfe both the fish populations and individual fish appeared to be in good condition and limited changes had occurred since the 1996 survey.

Environmental effects of drought and abstractions of River Ouse fisheries, summer 1997

This survey was the second year of a three year study to examine fish populations in relation to low flows, drought and abstraction in the River Ouse. To fully evaluate the possible effects on fisheries the study set out to encompass fish population surveys from fry to adult stock, analysis of angler catch data, reports from anglers and river reports from Environment Agency Fisheries staff.

River Wharfe fisheries monitoring report - summer 2001

This is a report on monitoring carried out in 2001 specifically in relation to effects of flows and abstractions on fisheries in the River Wharfe. The monitoring is a continuation of that started in relation to the Time Limited Abstraction Licences in 1996 and required by the new licences granted in 1999. It gives information regarding fish populations at a range of sites in the River Wharfe and also two tributary sites. It also gives recommendations for future investigations in relation to both Time Limited Licences and general broader issues.

River Ure fisheries monitoring report - summer 2001

Fish population studies in the River Ure have continued for their sixth successive year in order to examine and evaluate the effects of low flows and drought conditions particularly in relation to the Time Limited Licence abstraction at Kilgram Bridge, currently granted to Yorkshire Water Services. This monitoring report looks at the different fish populations and growth rates in the main river and tributaries, comparing the results to previous years. The report also looks at the general findings from angling, the medium term drought impacts, the abstraction impacts, and recommendations for investigations for 2002.

Larval abundance of summer flounder (Paralichthys dentatus) as a measure of recruitment and stock status

Summer flounder (Paralichthys dentatus) is one of the most economically and ecologically important estuarine-dependent species in the northeastern United States. The status of the population is currently a topic of controversy. Our goal was to assess the potential of using larval abundance at ingress as another fishery independent measure of spawning stock biomass or recruitment. Weekly long-term ichthyoplankton time series were analyzed from Little Egg Inlet, New Jersey (1989–2006) and Beaufort Inlet, North Carolina (1986–2004). Mean size-at-ingress and stage were similar between sites, whereas timing of ingress and abundance at ingress were not similar. Ingress primarily occurred during the fall at Little Egg Inlet and the winter at Beaufort Inlet. These findings agree with those from earlier studies in which at least two stocks (one north and one south of Cape Hatteras) were identified with different spawning periods. Larval abundance at Little Egg Inlet has increased since the late 1990s and most individuals now enter the estuary earlier during the season of ingress. Abundance at Little Egg Inlet was correlated with an increase in spawning stock biomass, presumably because spawning by larger, more abundant fish during the late 1990s and early 2000s provided increased larval supply, at least in some years. Larval abundance at ingress at Beaufort Inlet was not correlated with spawning stock biomass or with larval abundance at ingress at Little Egg Inlet, further supporting the hypothesis of at least two stocks. Larval abundance at Little Egg Inlet could be used as a fishery-independent index of spawning stock size north of Cape Hatteras in future stock assessments. Larval occurrence at Beaufort Inlet may provide information on the abundance of the stock south of Cape Hatteras, but additional stock assessment work is required.

Use of non-natal estuaries by migratory striped bass (Morone saxatilis) in summer

For most migratory fish, little is known about the location and size of foraging areas or how long individuals remain in foraging areas, even though these attributes may affect their growth, survival, and impact on local prey. We tested whether striped bass (Morone saxatilis Walbaum), found in Massachusetts in summer, were migratory, how long they stayed in non-natal estuaries, whether observed spatial patterns differed from random model predictions, whether fish returned to the same area across multiple years, and whether fishing effort could explain recapture patterns. Anchor tags were attached to striped bass that were caught and released in Massachusetts in 1999 and 2000, and recaptured between 1999 and 2007. In fall, tagged striped bass were caught south of where they were released in summer, confirming that fish were coastal migrants. In the first summer, 77% and 100% of the recaptured fish in the Great Marsh and along the Massachusetts coast, respectively, were caught in the same place where they were released. About two thirds of all fish recaptured near where they were released were caught 2–7 years after tagging. Our study shows that smaller (400–500 mm total length) striped bass migrate hundreds of kilometers along the Atlantic Ocean coast, cease their mobile lifestyle in summer when they use a relatively localized area for foraging (<20 km2), and return to these same foraging areas in subsequent ye

The trophic dynamics of summer flounder (Paralichthys dentatus) in Chesapeake Bay

Data on the trophic dynamics of fishes are needed for management of ecosystems such as Chesapeake Bay. Summer flounder (Paralichthys dentatus) are an abundant seasonal resident of the bay and have the potential to impact foodweb dynamics. Analyses of diet data for late juvenile and adult summer flounder collected from 2002−2006 in Chesapeake Bay were conducted to characterize the role of this flatfish in this estuary and to contribute to our understanding of summer flounder trophic dynamics throughout its range. Despite the diversity of prey, nearly half of the diet comprised mysid shrimp (Neomysis spp.) and bay anchovy (Anchoa mitchilli). Ontogenetic differences in diet and an increase in diet diversity with increasing fish size were documented. Temporal (inter- and intra-annual) changes were also detected, as well as trends in diet reflecting peaks in abundance and diversity of prey. The preponderance of fishes in the diet of summer flounder indicates that this species is an important piscivorous predator in Chesapeake Bay.