Increased light, moderate, and severe clear-air turbulence in response to climate change

Anthropogenic climate change is expected to strengthen the vertical wind shears at aircraft cruising altitudes within the atmospheric jet streams. Such a strengthening would increase the prevalence of shear instabilities, which generate clear-air turbulence. Climate modelling studies have indicated that the amount of moderate-or-greater clear-air turbulence on transatlantic flight routes in winter will increase significantly in future as the climate changes. However, the individual responses of light, moderate, and severe clear-air turbulence have not previously been studied, despite their importance for aircraft operations. Here we use climate model simulations to analyse the transatlantic wintertime clear-air turbulence response to climate change in five aviation-relevant turbulence strength categories. We find that the probability distributions for an ensemble of 21 clear-air turbulence diagnostics generally gain probability in their right-hand tails when the atmospheric carbon dioxide concentration is doubled. By converting the diagnostics into equivalent eddy dissipation rates, we find that the ensemble-average airspace volume containing light clear-air turbulence increases by 59% (with an intra-ensemble range of 43–68%), light-to-moderate by 75% (39–96%), moderate by 94% (37–118%), moderate-to-severe by 127% (30–170%), and severe by 149% (36–188%). These results suggest that the prevalence of transatlantic wintertime clear-air turbulence will increase significantly in all aviation-relevant strength categories as the climate changes

Приклади завдань для позакласної роботи з інформатики у початковій школі

У статті коротко описана методика проведення позакласної роботи з інформатики у початковій школі

Leveraging ITS Data for Transit Market Research: A Practitioner\u27s Guidebook

This guidebook describes currently used intelligent transportation systems (ITS) and Transit ITS technologies that have the greatest promise for transit market research. It documents ITS and Transit ITS technologies currently in use, assesses their potential to provide market research data, and presents methods for collecting and analyzing these data. Also, the guidebook provides three in-depth case studies that illustrate how ITS data have been successfully used to improve market research practices. The guide should be useful to small, medium, and large transit agencies

Decision-Making Toolbox to Plan and Manage Park-and-Ride Facilities for Public Transportation: Guidebook on Planning and Managing Park-and-Ride

The objective of TCRP Project H-52, Decision-Making Toolbox to Plan and Manage Park-and-Ride Facilities for Public Transportation, was to develop a guidebook to better plan and manage park-and-ride facilities for public transportation. The guidebook builds on relevant completed research to address both of these important concerns. TCRP Report TBD: A Guidebook on Planning and Managing Park-and-Ride provides transit agencies with guidance to develop park-and-ride facilities from concept through operation. The guidebook presents information about best practices and lessons learned gathered via a literature review, an industry scan, and detailed case study research with transit agencies in the United States and Canada. The guidebook is a resource for transit staff seeking to better plan and manage park-and-ride facilities for public transportation by incorporating improved strategies and best practices