28 research outputs found

    Frequent but Predictable Droughts in East Africa Driven by a Walker Circulation Intensification

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    During and after recent La Niña events, the decline of the eastern East African (EA) March-April-May (MAM) rains has set the stage for life-threatening sequential October-November-December (OND) and MAM droughts. The MAM 2022 drought was the driest on record, preceded by three poor rainy seasons, and followed by widespread starvation. Connecting these dry seasons is an interaction between La Niña and climate change. This interaction provides important opportunities for long-lead prediction and proactive disaster risk management, but needs exploration. Here, for the first time, we use observations, reanalyses, and climate change simulations to show that post-1997 OND La Niña events are robust precursors of: (a) strong MAM “Western V sea surface temperature Gradients” in the Pacific, which (b) help produce large increases in moisture convergence and atmospheric heating near Indonesia, which in turn produce (c) regional shifts in moisture transports and vertical velocities, which (d) help explain the increased frequency of dry EA MAM rainy seasons. We also show that, at 20-year time scales, increases in atmospheric heating in the Indo-Pacific Warm Pool region are attributable to warming Western V SST, which is in turn largely attributable to climate change. As energy builds up in the oceans and atmosphere, during and after La Niña events, we see stronger heating and heat convergence over warm tropical waters near Indonesia. The result of this causal chain is that increased Warm Pool atmospheric heating and moisture convergence sets the stage for dangerous sequential droughts in EA. These factors link EA drying to a stronger Walker Circulation and explain the predictable risks associated with recent La Niña events

    Explaining Extreme Events of 2012 from a Climate Perspective

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    Attribution of extreme events is a challenging science and one that is currently undergoing considerable evolution. In this paper are 19 analyses by 18 different research groups, often using quite different methodologies, of 12 extreme events that occurred in 2012. In addition to investigating the causes of these extreme events, the multiple analyses of four of the events, the high temperatures in the United States, the record low levels of Arctic sea ice, and the heavy rain in northern Europe and eastern Australia, provide an opportunity to compare and contrast the strengths and weaknesses of the various methodologies. The differences also provide insights into the structural uncertainty of event attribution, that is, the uncertainty that arises directly from the differences in analysis methodology. In these cases, there was considerable agreement between the different assessments of the same event. However, different events had very different causes. Approximately half the analyses found some evidence that anthropogenically caused climate change was a contributing factor to the extreme event examined, though the effects of natural fluctuations of weather and climate on the evolution of many of the extreme events played key roles as well.Peer Reviewe

    Frequent but Predictable Droughts in East Africa Driven by a Walker Circulation Intensification

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    Abstract During and after recent La Niña events, the decline of the eastern East African (EA) March‐April‐May (MAM) rains has set the stage for life‐threatening sequential October‐November‐December (OND) and MAM droughts. The MAM 2022 drought was the driest on record, preceded by three poor rainy seasons, and followed by widespread starvation. Connecting these dry seasons is an interaction between La Niña and climate change. This interaction provides important opportunities for long‐lead prediction and proactive disaster risk management, but needs exploration. Here, for the first time, we use observations, reanalyses, and climate change simulations to show that post‐1997 OND La Niña events are robust precursors of: (a) strong MAM “Western V sea surface temperature Gradients” in the Pacific, which (b) help produce large increases in moisture convergence and atmospheric heating near Indonesia, which in turn produce (c) regional shifts in moisture transports and vertical velocities, which (d) help explain the increased frequency of dry EA MAM rainy seasons. We also show that, at 20‐year time scales, increases in atmospheric heating in the Indo‐Pacific Warm Pool region are attributable to warming Western V SST, which is in turn largely attributable to climate change. As energy builds up in the oceans and atmosphere, during and after La Niña events, we see stronger heating and heat convergence over warm tropical waters near Indonesia. The result of this causal chain is that increased Warm Pool atmospheric heating and moisture convergence sets the stage for dangerous sequential droughts in EA. These factors link EA drying to a stronger Walker Circulation and explain the predictable risks associated with recent La Niña events

    Comparison of diagnoses of early onset sepsis associated with use of Sepsis Risk Calculator versus NICE CG149: a prospective, population-wide cohort study in London, UK, 2020-21

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    Objective: We sought to compare the incidence of early-onset sepsis (EOS) in infants ≥34 weeks’ gestation identified > 24 hours after birth, in hospitals using the Kaiser Permanente sepsis risk calculator (SRC) with hospitals using the NICE guidance. Design and setting: Prospective observational population-wide cohort study involving all 26 hospitals with neonatal units co-located with maternity services across London (10 using SRC, 16 using NICE). Participants: All livebirths ≥34 weeks’ gestation between September 2020 and August 2021. Outcome measures: EOS was defined as isolation of a bacterial pathogen in the blood or CSF culture from birth to 7 days of age. We evaluated the incidence of EOS identified by culture obtained >24 hours to 7 days after birth. We also evaluated the rate empiric antibiotics were commenced >24 hours to 7 days after birth, for a duration of ≥5 days, with negative blood or CSF cultures. Results: Of 99,683 livebirths, 42,952 (43%) were born in SRC hospitals and 56,731 (57%) in NICE hospitals. The overall incidence of EOS (24 hours was 2.3/100,000 (n=1) for SRC versus 7.1/100,000 (n=4) for NICE (odds ratio 0·5, 95%CI [0·1; 2·7]). This corresponded to (1/20) 5% (SRC) versus (4/45) 8.9% (NICE) of EOS cases (chi=0.3, p=0.59). Empiric antibiotics were commenced >24 hours to 7 days after birth in 4·4/1000 (n=187) for SRC versus 2·9/1000 (n=158) for NICE (odds ratio 1·5, 95%CI [1·2; 1·9]). 3111 (7%) infants received antibiotics in the first 24 hours in SRC hospitals versus 8428 (15%) in NICE hospitals. Conclusion: There was no significant difference in the incidence of EOS identified >24 hours after birth between SRC and NICE hospitals. SRC use was associated with 50% fewer infants receiving antibiotics in the first 24 hours of life

    Picturing Validity: autoethnography and the representation of self?

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    In considering issues of “representation” and “realism,” the visual is inevitably invoked, yet in the current Western episteme, the relationship between the visible and the readable constitutes an enduring problem in which the image is generally subordinate to the text. In this article, the author examines what would happen if the usual relationship between verbal and visual was overturned and images were used to analyze text. In doing this, the author draws on the concept of “reverse ekphrasis” in the creation of a “gallery of validity,” which constitutes an interpretive framework for her autoethnographic research. The author situates this work within an approach characterized as the baroque, arguing that this provides a useful metaphor for qualitative research in the current moment
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