scholarly journals Delayed Start of the Respiratory Syncytial Virus Epidemic at the End of the 20/21 Northern Hemisphere Winter Season, Lyon, France

2021 ◽  
Author(s):  
Jean-sebastien Casalegno ◽  
Etienne Javouhey ◽  
Dominique Ploin ◽  
Martine Valette ◽  
Remi Fanget ◽  
...  
Keyword(s):  
At Risk ◽  
Respiratory Syncytial Virus ◽  
Northern Hemisphere ◽  
Winter Season ◽  
Late Season ◽  
Syncytial Virus ◽  
Ongoing Surveillance ◽  
Hemisphere Winter ◽  
Pharmaceutical Interventions ◽  
Northern Hemisphere Winter

AbstractThe implementation of Non Pharmaceutical Interventions (NPI), triggered by the emergence of covid-19, decrease the RSV circulation. Data, from our ongoing surveillance; show a late introduction of RSV at the end of December and a 4 month delayed epidemic start without significant change in our NPI policy. This data indicates that RSV still have the potential to give a late season outbreak in northern hemisphere. RSV surveillance should be reinforced and RSV Pharmaceutical Interventions maintained for at risk neonate

scholarly journals Transmission of paediatric respiratory syncytial virus and influenza in the wake of the COVID-19 pandemic

2021 ◽  
Vol 26 (29) ◽  
Author(s):  
Thomas C. Williams ◽  
Ian Sinha ◽  
Ian G. Barr ◽  
Maria Zambon
Keyword(s):  
Respiratory Syncytial Virus ◽  
Northern Hemisphere ◽  
Winter Season ◽  
Open Data ◽  
Health Service Delivery ◽  
Space Planning ◽  
Paediatric Hospital ◽  
Vaccine Trials ◽  
Syncytial Virus ◽  
Ongoing Surveillance

The non-pharmaceutical interventions implemented to slow the spread of SARS-CoV-2 have had consequences on the transmission of other respiratory viruses, most notably paediatric respiratory syncytial virus (RSV) and influenza. At the beginning of 2020, lockdown measures in the southern hemisphere led to a winter season with a marked reduction in both infections. Intermittent lockdowns in the northern hemisphere also appeared to interrupt transmission during winter 2020/21. However, a number of southern and northern hemisphere countries have now seen delayed RSV peaks. We examine the implications of these unpredictable disease dynamics for health service delivery in Europe, such as paediatric hospital and intensive care bed space planning, or palivizumab prophylaxis. We discuss the challenges for RSV vaccine trials and influenza immunisation campaigns, and highlight the considerable research opportunities that have arisen with the SARS-CoV-2 pandemic. We argue that the rapid advances in viral whole genome sequencing, phylogenetic analysis, and open data sharing during the pandemic are applicable to the ongoing surveillance of RSV and influenza. Lastly, we outline actions to prepare for forthcoming influenza seasons and for future implementation of RSV vaccines.

scholarly journals Linking horizontal and vertical transports of biomass fire emissionsto the tropical Atlantic ozone paradox during the Northern Hemisphere winter season: climatology

2004 ◽  
Vol 4 (2) ◽  
pp. 449-469 ◽  
Author(s):  
G. S. Jenkins ◽  
J.-H. Ryu
Keyword(s):  
South America ◽  
West Africa ◽  
Northern Hemisphere ◽  
Outgoing Longwave Radiation ◽  
Winter Season ◽  
Longwave Radiation ◽  
Tropical Atlantic ◽  
Hemisphere Winter ◽  
Column Ozone ◽  
Northern Hemisphere Winter

Abstract. During the Northern hemisphere winter season, biomass burning is widespread in West Africa, yet the total tropospheric column ozone values (<30DU) over much of the Tropical Atlantic Ocean (15°N-5°S) are relatively low. At the same time, the tropospheric column ozone values in the Southern Tropical Atlantic are higher than those in the Northern Hemisphere (ozone paradox). We examine the causes for low tropospheric column ozone values by considering the horizontal and vertical transport of biomass fire emissions in West Africa during November through March, using observed data which characterizes fires, aerosols, horizontal winds, precipitation, lightning and outgoing longwave radiation. We have found that easterly winds prevail in the lower troposphere but transition to westerly winds at pressure levels lower than 500hPa. A persistent anticyclone over West Africa at 700hPa is responsible for strong easterly winds, which causes a net outflow of ozone/ozone precursors from biomass burning in West Africa across the Atlantic Ocean towards South America. The lowest outgoing longwave radiation (OLR) and highest precipitation rates are generally found over the central Atlantic, some distance downstream of fires in West Africa making the vertical transport of ozone and ozone precursors less likely and ozone destruction more likely. However, lightning over land areas in Central Africa and South America can lead to enhanced ozone levels in the upper troposphere especially over the Southern tropical Atlantic during the Northern Hemisphere winter season.

scholarly journals Linking horizontal and vertical transports of biomass fire emissions to the Tropical Atlantic Ozone Paradox during the Northern Hemisphere winter season: climatology

2003 ◽  
Vol 3 (5) ◽  
pp. 5061-5098
Author(s):  
G. S. Jenkins ◽  
J.-H. Ryu
Keyword(s):  
West Africa ◽  
Northern Hemisphere ◽  
Outgoing Longwave Radiation ◽  
Winter Season ◽  
Longwave Radiation ◽  
Tropical Atlantic ◽  
Fire Emissions ◽  
Hemisphere Winter ◽  
Column Ozone ◽  
Northern Hemisphere Winter

Abstract. During the Northern hemisphere winter season, biomass burning is widespread in West Africa, yet the total tropospheric column ozone values (<30 DU) over much of the Tropical Atlantic Ocean (15° N–5° S) are relatively low. At the same time, the tropospheric column ozone values in the Southern Tropical Atlantic are higher than those in the Northern Hemisphere (ozone paradox). We examine the causes for low tropospheric column ozone values by considering the horizontal and vertical transport of biomass fire emissions in West Africa during November through March, using observed data which characterizes fires, aerosols, horizontal winds, precipitation, lightning and outgoing longwave radiation. We have found that easterly winds prevail in the lower troposphere but transition to westerly winds at pressure levels lower than 500 hPa. A persistent anticyclone over West Africa at 700 hPa is responsible for strong easterly winds, which causes a net outflow of ozone/ozone precursors from biomass burning in West Africa across the Atlantic Ocean towards South America. The lowest outgoing longwave radiation (OLR) and highest precipitation rates are generally found over the central Atlantic, some distance downstream of fires in West Africa making the vertical transport of ozone and ozone precursors less likely and ozone destruction more likely. However, lightning over land areas in Central Africa and South America can lead to enhanced ozone levels in the upper troposphere especially over the Southern tropical Atlantic during the Northern Hemisphere winter season.

scholarly journals Predictability Changes of Stratospheric Circulations in Northern Hemisphere Winter

2016 ◽  
Vol 94 (1) ◽  
pp. 7-24 ◽  
Author(s):  
Tomoko ICHIMARU ◽  
Shunsuke NOGUCHI ◽  
Toshihiko HIROOKA ◽  
Hitoshi MUKOUGAWA
Keyword(s):  
Northern Hemisphere ◽  
Hemisphere Winter ◽  
Northern Hemisphere Winter

scholarly journals Polar stratospheric cloud observations by MIPAS on ENVISAT: detection method, validation and analysis of the northern hemisphere winter 2002/2003

2005 ◽  
Vol 5 (3) ◽  
pp. 679-692 ◽  
Author(s):  
R. Spang ◽  
J. J. Remedios ◽  
L. J. Kramer ◽  
L. R. Poole ◽  
M. D. Fromm ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Detection Method ◽  
Michelson Interferometer ◽  
The Arctic ◽  
Spectral Signature ◽  
Winter Period ◽  
Second Phase ◽  
Good Correspondence ◽  
Hemisphere Winter ◽  
Northern Hemisphere Winter

Abstract. The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on ENVISAT has made extensive measurements of polar stratospheric clouds (PSCs) in the northern hemisphere winter 2002/2003. A PSC detection method based on a ratio of radiances (the cloud index) has been implemented for MIPAS and is validated in this study with respect to ground-based lidar and space borne occultation measurements. A very good correspondence in PSC sighting and cloud altitude between MIPAS detections and those of other instruments is found for cloud index values of less than four. Comparisons with data from the Stratospheric Aerosol and Gas Experiment (SAGE) III are used to further show that the sensitivity of the MIPAS detection method for this threshold value of cloud index is approximately equivalent to an extinction limit of 10-3km-1 at 1022nm, a wavelength used by solar occultation experiments. The MIPAS cloud index data are subsequently used to examine, for the first time with any technique, the evolution of PSCs throughout the Arctic polar vortex up to a latitude close to 90° north on a near-daily basis. We find that the winter of 2002/2003 is characterised by three phases of very different PSC activity. First, an unusual, extremely cold phase in the first three weeks of December resulted in high PSC occurrence rates. This was followed by a second phase of only moderate PSC activity from 5-13 January, separated from the first phase by a minor warming event. Finally there was a third phase from February to the end of March where only sporadic and mostly weak PSC events took place. The composition of PSCs during the winter period has also been examined, exploiting in particular an infra-red spectral signature which is probably characteristic of NAT. The MIPAS observations show the presence of these particles on a number of occasions in December but very rarely in January. The PSC type differentiation from MIPAS indicates that future comparisons of PSC observations with microphysical and denitrification models might be revealing about aspects of solid particle existence and location.

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