2005年12月12日 · The daily PNA index corresponds to the PNA patterns, which vary from one month to the next. Click here for the methodology used to calculate the daily PNA index. The daily PNA index for the past 120 days.

2005年5月18日 · The loading patterns for January, April, July, and October, are displayed so that the plotted value at each grid point represents the temporal correlation between the monthly standardized height anomalies at that point and the teleconnection pattern time series valid for the specified month.

2021年9月8日 · The PNA is largely driven by the pressure pattern over the Aleutian Islands, which forms a dipole with the pressure over Western Canada. The 500mb maps below show a positive PNA occurs when we see low pressure over the Aleutians and, in winter at least, Western Canada ridging, and a trough downstream over the Southeastern US.

The Pacific/ North American (PNA) pattern is one of the most prominent modes of low-frequency variability in the Northern Hemisphere extratropics, appearing in all months except June and July. The PNA pattern reflects a quadripole pattern of 500 millibar height anomalies, with anomalies of similar sign located south of the Aleutian Islands and ...

PNA series plotted for all calendar months, with positive and negative values during November through March indicated by red and blue shading, respectively. Pattern plotted as a regression map. Red, black, and blue contours on the maps indicate positive, zero, …

2009年9月1日 · This pattern, known as the Pacific-North American teleconnection pattern or PNA, influences regional weather by affecting the strength and location of the East Asian jet stream, and subsequently, the weather it delivers to North America.

2017年3月17日 · 太平洋－北美型遥相关（PNA）是北半球大气内部变化的一种重要模态，其异常可导致北半球大气环流格局发生改变，从而强烈影响北美地区的天气、气候、水文、生态及森林火灾发生频率。 仪器观测的PNA记录始于20世纪50年代，短期的观测资料极大地限制了我们对长期的PNA变化及其动力学机制的认识。...

2024年11月20日 · 针对这一问题，中国科学院大气物理研究所黄刚研究员团队基于观测和再分析数据发现，PNA波列在单年厄尔尼诺的发展年冬季、多年厄尔尼诺的第一个发展年冬季和第二个发展年冬季之间存在显著差异。 其中，针对PNA波列在北太平洋区域的异常，其差异表现为：与多年厄尔尼诺相比，单年异常的位置偏东南方向；在三种情况下，多年厄尔尼诺第二年异常的强度最强（图1）。 研究进一步利用多种动力诊断方法分析了造成这些差异的原因。

2019年4月23日 · Climate.gov map using NCEP/NCAR reanalysis data. These changes to the atmospheric circulation influence surface climate conditions. During the positive PNA, a big anomalous ridge of high pressure over Canada results in fewer cold air outbreaks over Alaska, Canada, and the northern tier of the United States (the opposite is true for negative PNA ...

2012年1月10日 · The Pacific/ North American teleconnection pattern (PNA) is one of the most prominent modes of low-frequency variability in the Northern Hemisphere extratropics. The positive phase of the PNA pattern features above-average heights in the vicinity of Hawaii and over the intermountain region of North America, and below-average heights located ...