气候变化领域集成服务门户(CCPortal): Climatology and Variability of Warm and Cold Fronts over North America from 1979 to 2018

CCPortal

DOI	10.1175/JCLI-D-19-0680.1
	Climatology and Variability of Warm and Cold Fronts over North America from 1979 to 2018
	Lagerquist R.; Allen J.T.; McGovern A.
发表日期	2020
ISSN	0894-8755
起始页码	6531
结束页码	6554
卷号	33 期号:15
英文摘要	This paper describes the development and analysis of an objective climatology of warm and cold fronts over North America from 1979 to 2018. Fronts are detected by a convolutional neural network (CNN), trained to emulate fronts drawn by human meteorologists. Predictors for the CNN are surface and 850-hPa fields of temperature, specific humidity, and vector wind from the ERA5 reanalysis. Gridded probabilities from the CNN are converted to 2D frontal regions, which are used to create the climatology. Overall, warm and cold fronts are most common in the Pacific and Atlantic cyclone tracks and the lee of the Rockies. In contrast with prior research, we find that the activity of warm and cold fronts is significantly modulated by the phase and intensity of El Ninõ-Southern Oscillation. The influence of El Ninõ is significant for winter warm fronts, winter cold fronts, and spring cold fronts, with activity decreasing over the continental United States and shifting northward with the Pacific and Atlantic cyclone tracks. Long-term trends are generally not significant, although we find a poleward shift in frontal activity during the winter and spring, consistent with prior research. We also identify a number of regional patterns, such as a significant long-term increase in warm fronts in the eastern tropical Pacific Ocean, which are characterized almost entirely by moisture gradients rather than temperature gradients. © 2020 American Meteorological Society. All rights reserved.
英文关键词	Atmospheric pressure; Climatology; Storms; Atlantic cyclones; Eastern tropical pacific; Frontal regions; Long-term trend; Moisture gradient; Regional pattern; Southern oscillation; Specific humidity; Convolutional neural networks; artificial neural network; climate conditions; cold front; El Nino-Southern Oscillation; spatiotemporal analysis; surface temperature; temperature effect; trend analysis; tropical cyclone; Pacific Ocean; Pacific Ocean (Tropical)
语种	英语
来源期刊	Journal of Climate
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/171205
作者单位	School of Meteorology, University of Oklahoma, Norman, OK, United States; Department of Earth and Atmospheric Sciences, Central Michigan University, Mt. Pleasant, MI, United States; School of Computer Science, University of Oklahoma, Norman, OK, United States
推荐引用方式 GB/T 7714	Lagerquist R.,Allen J.T.,McGovern A.. Climatology and Variability of Warm and Cold Fronts over North America from 1979 to 2018[J],2020,33(15).
APA	Lagerquist R.,Allen J.T.,&McGovern A..(2020).Climatology and Variability of Warm and Cold Fronts over North America from 1979 to 2018.Journal of Climate,33(15).
MLA	Lagerquist R.,et al."Climatology and Variability of Warm and Cold Fronts over North America from 1979 to 2018".Journal of Climate 33.15(2020).