Self-organizing maps identify windows of opportunity for seasonal European summer predictions

We combine a machine learning method and ensemble climate predictions to investigate windows of opportunity for seasonal predictability of European summer climate associated with the North Atlantic jet stream. We particularly focus on the impact of North Atlantic spring sea surface temperatures (SST) on the four dominant atmospheric teleconnections associated with the jet stream: the summer North Atlantic Oscillation (NAO) in positive and negative phases, the Atlantic Ridge (At. Ridge), and Atlantic Low (At. Low). We go beyond standard forecast practices by not only identifying these atmospheric teleconnections and their SST precursors but by making use of these identified precursors in the analysis of a dynamical forecast ensemble. Specifically, we train the neural network-based classifier Self-Organizing Maps (SOM) with ERA-20C reanalysis and combine it with model simulations from the Max Planck Institute Earth System Model in mixed resolution (MPI-ESM-MR). We use two different sets of 30-member hindcast ensembles initialized every May, one for training and evaluation between 1902 and 2008, and one for verification between 1980–2016, respectively. Among the four summer atmospheric teleconnections analyzed here, we find that At. Ridge simulated by MPI-ESM-MR shows the best agreement with ERA-20C, thereby representing with its occurrence windows of opportunity for skillful summer predictions. Conversely, At. Low shows the lowest agreement, which might limit the model skill for early warning of warmer than average summers. In summary, we find that spring SST patterns identified with a SOM analysis can be used to guess the dominant summer atmospheric teleconnections at initialization and guide a sub-selection of potential skillful ensemble members. This holds especially true for At. Ridge and At. Low and is unclear for summer NAO. We show that predictive skill in the selected ensemble exceeds that of the full ensemble over regions in the Euro-Atlantic domain where spring SST significantly correlates with summer sea level pressure (SLP). In particular, we find a significant improvement in predictive skill for SLP, geopotential height at 500 hPa, and 2 m temperature at 3–4 months lead time over Scandinavia, which is robust among the two sets of hindcast ensembles. Copyright © 2022 Carvalho-Oliveira, Borchert, Zorita and Baehr

Viewpoint: filovirus haemorrhagic fever outbreaks: much ado about nothing?

The recent outbreak of Marburg haemorrhagic fever in the Democratic Republic of Congo has put the filovirus threat back on the international health agenda. This paper gives an overview of Marburg and Ebola outbreaks so far observed and puts them in a public health perspective. Damage on the local level has been devastating at times, but was marginal on the international level despite the considerable media attention these outbreaks received. The potential hazard of outbreaks, however, after export of filovirus from its natural environment into metropolitan areas, is argued to be considerable. Some avenues for future research and intervention are explored. Beyond the obvious need to find the reservoir and study the natural history, public health strategies for a more timely and efficient response are urgently needed

Organisation of Health Care During an Outbreak of Marburg Haemorrhagic Fever in the Democratic Republic of Congo, 1999.

Organising health care was one of the tasks of the International Scientific and Technical Committee during the 1998-1999 outbreak in Durba/Watsa, in the north-eastern province (Province Orientale), Democratic Republic of Congo. With the logistical support of Médecins sans Frontières (MSF), two isolation units were created: one at the Durba Reference Health Centre and the other at the Okimo Hospital in Watsa. Between May 6th, the day the isolation unit was installed and May 19th, 15 patients were admitted to the Durba Health Centre. In only four of them were the diagnosis of Marburg haemorrhagic fever (MHF) confirmed by laboratory examination. Protective equipment was distributed to health care workers and family members caring for patients. Information about MHF, modes of transmission and the use of barrier nursing techniques was provided to health care workers and sterilisation procedures were reviewed. In contrast to Ebola outbreaks, there was little panic among health care workers and the general public in Durba and all health services remained operational

Application of ERTS-1 imagery to state wide land information system in Minnesota

There are no author-identified significant results in this report

Application of ERTS-1 imagery to state wide land information system in Minnesota

There are no author-identified significant results in this report

Measurement of the charged pion mass using X-ray spectroscopy of exotic atoms

The $5g-4f$ transitions in pionic nitrogen and muonic oxygen were measured simultaneously by using a gaseous nitrogen-oxygen mixture at 1.4\,bar. Due to the precise knowledge of the muon mass the muonic line provides the energy calibration for the pionic transition. A value of (139.57077\,$\pm$\,0.00018)\,MeV/c$^{2}$ ($\pm$\,1.3ppm) is derived for the mass of the negatively charged pion, which is 4.2ppm larger than the present world average