Figure 2: Pressure Patterns at the Surface (image) Research Organization of Information and Systems Share Print E-Mail Caption Pressure patterns at the surface (isobars, hPa) and air temperatures at around 1,500 meters for the Japan cold wave (Feb. 9, 2015) and North America cold wave (Feb. 16, 2015). There is a west-high, east-low pressure pattern, and low pressure troughs have developed at sea. Credit NIPR/JAMSTEC Usage Restrictions Credit required Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.