Atmosphere-Ocean最新文献

{"title":"A Circulation Model for Inlets Along the Central West Coast of Vancouver Island","authors":"M.G.G. Foreman, P.C. Chandler, L. Bianucci, D. Wan, M.V. Krassovski, P. Thupaki, G. Cooper, Y. Lin","doi":"10.1080/07055900.2023.2262957","DOIUrl":"https://doi.org/10.1080/07055900.2023.2262957","url":null,"abstract":"An ocean circulation model has been developed for the central west coast of Vancouver Island, with particular attention to the numerous inlets where salmon farms are located. The ultimate goal is to provide a tool to assist in informing decisions on the siting and management of fish farms and to further understanding of the regional coastal oceanography. The complicated coastline and bathymetry are approximated with an unstructured triangular grid in the horizontal direction and terrain-following coordinates in the vertical. The period of 1 March to 31 July 2016, is simulated using the Finite Volume Community Ocean Model and results are evaluated through comparisons with a combination of acoustic Doppler current profiler, tide gauge, and temperature and salinity observations. The model was found to be accurate in representing (i) tidal elevations and currents everywhere throughout the model domain and (ii) subtidal currents and temperature and salinity along the shelf. However, it fared poorly in inlets where (i) the tidal currents were relatively weak and not the dominant source of mixing and/or (ii) steep bathymetry necessitated smoothing. Sources of these and other inaccuracies, and the changes needed to overcome them, are discussed. Overall, this work highlights the complex and diverse dynamics at play in a glacially-carved coastal ocean, providing an extensive discussion of modelling challenges and potential solutions.","PeriodicalId":55434,"journal":{"name":"Atmosphere-Ocean","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135883439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of Ocean Temperature Trends for the Scotian Shelf and Gulf of Maine Using 22 CMIP6 Earth System Models","authors":"Zeliang Wang, David Brickman, Blair Greenan, James Christian, Brendan DeTracey, Denis Gilbert","doi":"10.1080/07055900.2023.2264832","DOIUrl":"https://doi.org/10.1080/07055900.2023.2264832","url":null,"abstract":"This study examined the results of 22 CMIP6 (Coupled Model Inter-comparison Project phase 6) Earth System Model (ESM) simulations for four regions on the Scotian Shelf and Gulf of Maine. A comparison between the historical simulations from the CMIP6 ESMs with observational sea surface and bottom temperature (SST, BT) data demonstrates that the eddy-permitting ESMs do not perform better than coarse-resolution non-eddy permitting models in terms of long-term trends. Eddy-permitting ESMs reduce model SST bias but not BT bias. In general, the 22 CMIP6 ESMs show limited skill for historical BT simulations in these shelf regions. Climate projections under ssp (Shared Socio-economic Pathways)245 and ssp370 for the 2020–2049 period suggest that the largest seasonal SST increase will occur in summer for both the Scotian Shelf and the Gulf of Maine. Under both climate scenarios, the SST of the Scotian Shelf (Gulf of Maine) increases by 1.2–1.8 °C (1.4–1.7 °C) for the 2040–2049 period relative to 1995–2014, and bottom temperature increases by 1.2–1.6°C (1.3–1.4 °C) for the same period. For SST, five models exhibit abnormally warm projections. The ESMs’ performance against observations suggest the SST changes are probably underestimated, while the BT changes are likely overestimated.","PeriodicalId":55434,"journal":{"name":"Atmosphere-Ocean","volume":"158 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135142209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Linking Historical and Projected Trends in Extreme Precipitation with Cumulative Carbon Dioxide Emissions","authors":"Travis R. Moore, H. Damon Matthews, Yann Chavaillaz","doi":"10.1080/07055900.2023.2259328","DOIUrl":"https://doi.org/10.1080/07055900.2023.2259328","url":null,"abstract":"AbstractExtreme weather events are expected to increase in frequency and intensity in response to higher global temperatures, augmenting societal exposure to these events. While the magnitude of projected changes in extremes varies considerably among future emission scenarios, a large part of this uncertainty is driven by the choice of scenario, rather than by the climate response to a particular emission scenario. A growing body of research has identified robust linear relationships between climate changes and cumulative carbon emissions; for global average temperature change, this relationship is known as the transient climate response to cumulative carbon emissions (TCRE). Extensions of the TCRE framework to other variables, such as regional and seasonal temperature and precipitation changes, have also shown to be effective, raising the possibility that changes in weather extremes could be linked to cumulative carbon dioxide (CO2) emissions. Here, we estimate changes in historical and projected trends in one-day (Rx1day) and five-day maximum precipitation (Rx5day) events as a function of cumulative carbon emissions across a range of future emission scenarios and global climate models. Our results show that median Rx1day and Rx5day generally increases linearly with increasing cumulative emissions, consistent with studies that have previously employed the TCRE framework to estimate changes in precipitation extremes, as well as other climate indicators. Overall, we show that a linear response to cumulative CO2 emissions is a good approximation for both historical and future trends in precipitation extremes.Résumé[Traduit par la redaction] La fréquence et l’intensité des phénomènes météorologiques extrêmes devraient augmenter en raison de la hausse des températures mondiales, ce qui accroît l’exposition de la société à ces phénomènes. Si l’ampleur des changements projetés en matière d’extrêmes varie considérablement selon les scénarios d’émissions futures, une grande partie de cette incertitude est attribuable au choix du scénario, plutôt qu’à la réaction du climat à un scénario d’émissions particulier. Un nombre croissant de recherches a permis de déterminer des relations linéaires solides entre les changements climatiques et les émissions cumulées de carbone; pour le changement de la température moyenne mondiale, cette relation est connue sous le nom de réponse climatique transitoire aux émissions cumulées de carbone (RCTE). L’extension du cadre RCTE à d’autres variables, telles que les changements régionaux et saisonniers de température et de précipitations, s’est également avérée efficace, ce qui soulève la possibilité que les changements dans les extrêmes météorologiques puissent être liés aux émissions cumulées de dioxyde de carbone (CO2). Nous estimons ici les changements dans les tendances historiques et projetées des précipitations maximales sur un jour (Rx1jour) et sur cinq jours (Rx5jour) en fonction des émissions de carbone cumulées à ","PeriodicalId":55434,"journal":{"name":"Atmosphere-Ocean","volume":"309 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135816084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Machine-Learning Method to Integrate Arctic Supersite Observations and Diagnose Weather Element Occurrence","authors":"Zen Mariani, William R. Burrows, Gabrielle Gascon, Robert Crawford","doi":"10.1080/07055900.2023.2257651","DOIUrl":"https://doi.org/10.1080/07055900.2023.2257651","url":null,"abstract":"The accurate detection and quantification of light precipitation is problematic, particularly in the Arctic region. Satellite and ground-based observations of light precipitation are frequently underestimated at high latitudes. Remote sensing and in-situ observations from the Iqaluit, NU supersite (64oN, 69oW) were integrated to train, develop, and validate a random forest (RF) model that can diagnose precipitation type and other weather element occurrences. Observations from multiple lidars, optical disdrometers, traditional precipitation gauges and meteorological aerodrome (METAR) reports from 2015–2020 were integrated and used in the RF model development. The model was trained at Iqaluit, validated over different time periods, and applied to another region (Whitehorse, YT; 61oN, 135oW). Results indicate the importance of accurate visibility observations to train the model. Overall, the RF model was capable of distinguishing precipitation types and demonstrated the potential to be used at all sites/networks where similar automated and cost-effective instruments are already deployed (e.g. radar sites, airports with ceilometers, etc.). This would reduce the dependency on METARs while improving weather element occurrence accuracy.","PeriodicalId":55434,"journal":{"name":"Atmosphere-Ocean","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136235486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of Tornado Alerting Performance for Canada","authors":"David M.L. Sills, Lesley Elliott","doi":"10.1080/07055900.2023.2257163","DOIUrl":"https://doi.org/10.1080/07055900.2023.2257163","url":null,"abstract":"The Northern Tornadoes Project (NTP) completed a first independent assessment of national tornado warning alerting (watches and warnings) in Canada covering the 2019–2021 period. The NTP undertook this study in the spirit of open data, understanding tornado warning issues unique to this country, and improving tornado warning performance. Utilizing the NTP tornado event database for verification, tornado alerts were reviewed for accuracy and timeliness. For the 250 tornadoes that occurred during the study period – and using a definition of what constitutes a warning ‘hit’ developed for the study – the standard 2 × 2 contingency table scores were Probability of Detection = 0.23, FAR = 0.78, and CSI = 0.13. Over 70% of tornadoes had no tornado warning, including 35 EF2 tornadoes. The tornado warning results were compared with US National Weather Service tornado warning scores for the US and US states along the southern Canadian border to provide context. NTP also developed a ‘report card’ aimed at public and media consumption that took into consideration Environment and Climate Change Canada’s national performance targets for tornado warning Probability of Detection (POD) and lead time as well as tornado watch issuance. Using weighted scores for these criteria, NTP assigned a total score of 33.3/100, indicating significant room for improvement. A follow-up assessment was conducted for the 2022 tornado season in Canada following the same established procedures. It was found that the number of both tornado watches and tornado warnings had roughly doubled, resulting in a significant increase in the POD for tornado warnings to 0.35. The report card score also improved to a passing grade of 56.6/100. Further exploration of the results showed enhanced performance for tornadoes that occurred within Doppler radar range, when the parent thunderstorm involved supercell processes, and for tornadoes rated EF2 or higher. A number of recommendations are made aimed at further improvements to tornado alerting performance.","PeriodicalId":55434,"journal":{"name":"Atmosphere-Ocean","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136154083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-Resolution Lead–Lag Relations Between Barents Sea Temperatures, the AMOC and the AMO During 1971–2018","authors":"Knut L. Seip, Hui Wang","doi":"10.1080/07055900.2023.2251426","DOIUrl":"https://doi.org/10.1080/07055900.2023.2251426","url":null,"abstract":"ABSTRACT The direction of heat transport from the atmosphere to the Barents Sea, and between the Barents Sea and the North Atlantic is important for understanding the interplay between Greenland ice melting and anthropogenic forcing. Here, we show how heat has been transported between water bodies by using a high-resolution lead-lag technique that identifies leading relations between cyclic temperature series. The results demonstrate that near-surface ocean temperature (0–30 m) in the Barents Sea led the temperature changes in its intermediate waters (100–200 m) during the period 1971 to 2018 inferring that heat transport is from the atmosphere to the intermediate waters. The Barents Sea’s temperatures lagged the Atlantic meridional overturning circulation (AMOC) and the Atlantic multidecadal oscillation (AMO) from 1971 to 2000. The AMOC was leading the Barents Sea near-bottom temperatures in the West (the Bear Island Through) during 1980–2018 but was both leading and lagging in the Barents Sea Northeast.","PeriodicalId":55434,"journal":{"name":"Atmosphere-Ocean","volume":"365 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135982139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characteristics of Rain-Snow Transitions Over the Canadian Rockies and their Changes in Warmer Climate Conditions","authors":"J. Thériault, Nicolas R. Leroux, Obert Tchuem Tchuente, Ronald E. Stewart","doi":"10.1080/07055900.2023.2251938","DOIUrl":"https://doi.org/10.1080/07055900.2023.2251938","url":null,"abstract":"ABSTRACT The southern Canadian Rockies are prone to extreme precipitation that often leads to high streamflow, deep snowpacks, and avalanche risks. Many of these precipitation events are associated with rain–snow transitions, which are highly variable in time and space due to the complex topography. A warming climate will certainly affect these extremes and the associated rain–snow transitions. The goal of this study is to investigate the characteristics and variability of rain–snow transitions aloft and how they will change in the future. Weather Research and Forecasting (WRF) simulations were conducted from 2000 to 2013 and these were repeated in a warmer pseudo-global warming (PGW) future. Rain–snow transitions occurred aloft throughout the year over the southern Canadian Rockies, but their elevations and depths were highly variable, especially across the continental divide. In PGW conditions, with future air temperatures up to 4–5°C higher on average over the Canadian Rockies, rain–snow transitions are projected to occur more often throughout the year, except during summer. The near-0°C conditions associated with rain–snow transitions are expected to increase in elevation by more than 500 m, resulting in more rain reaching the surface. Overall, this study illustrates the variability of rain–snow transitions, which often impact the location of the snowline. This study also demonstrates the non-uniform changes under PGW conditions, due in part to differences in the types of weather patterns that generate rain–snow transitions across the region.","PeriodicalId":55434,"journal":{"name":"Atmosphere-Ocean","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45279745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Introduction to the Special Issue on Polar Predictions","authors":"Hai Lin, William J. Merryfield, Bruno Tremblay","doi":"10.1080/07055900.2023.2252303","DOIUrl":"https://doi.org/10.1080/07055900.2023.2252303","url":null,"abstract":"The forecast skill of GEM-NEMO, one of two constituent models that together comprise CanSIPSv2, is found to generally exceed that of the other, CanCM4i. This difference is potentially due to substantial model drift of sea ice extent away from observations in CanCM4i, in addition to their different initializations of sea ice thickness. Both models show signi fi cant forecast skill exceeding that of an anomaly persistence forecast. Prediction skill was found to vary substantially across different sectors of the Southern Ocean. Moreover, their analysis also fi nds that CanSIPSv2 forecast skill in the Antarctic shows a dependence on time period, demonstrating generally lower skill than seen in the Arctic over the years 1980-2010, in contrast to generally higher skill than in the Arctic over the years 1980-2019","PeriodicalId":55434,"journal":{"name":"Atmosphere-Ocean","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135840402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Future Physical and Biogeochemical Ocean Conditions under Climate Change along the British Columbia Continental Margin","authors":"M. Peña, I. Fine","doi":"10.1080/07055900.2023.2239186","DOIUrl":"https://doi.org/10.1080/07055900.2023.2239186","url":null,"abstract":"","PeriodicalId":55434,"journal":{"name":"Atmosphere-Ocean","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43078510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal Predictions of Regional and Pan-Antarctic Sea Ice With a Dynamical Forecast System","authors":"R. Payne, J. Martin, A. Monahan, M. Sigmond","doi":"10.1080/07055900.2023.2252387","DOIUrl":"https://doi.org/10.1080/07055900.2023.2252387","url":null,"abstract":"ABSTRACT Operational seasonal to interannual forecasting systems are in continued development around the world. Various studies have applied models to the dynamical forecasting of sea ice, particularly in the Arctic. The Antarctic, however, has received relatively little attention, with few previous endeavours to quantify operational forecast skill of sea ice. This study assesses sea ice extent prediction skill of the Canadian Seasonal to Interannual Prediction System version 2 (CanSIPSv2) in the Pan-Antarctic domain as well as in various sectors of the Southern Ocean. The forecast skill of GEM-NEMO, one of two constituent models that together comprise CanSIPSv2, is found to generally exceed that of the other, CanCM4i. This difference is potentially due to substantial model drift of sea ice extent away from observations in CanCM4i, in addition to their different initializations of sea ice thickness. Both models show significant forecast skill exceeding that of an anomaly persistence forecast. Prediction skill was found to vary substantially across different sectors of the Southern Ocean. Moreover, our analysis also finds that CanSIPSv2 forecast skill in the Antarctic shows a dependence on time period, demonstrating generally lower skill than seen in the Arctic over the years 1980–2010, in contrast to generally higher skill than in the Arctic over the years 1980–2019.","PeriodicalId":55434,"journal":{"name":"Atmosphere-Ocean","volume":"61 1","pages":"273 - 292"},"PeriodicalIF":1.2,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48973069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}