Locked In (IMAGE) Columbia Climate School Caption Researchers have identified two wavelengths of meanders in the northern hemisphere jet stream that can cause massive heat waves across several major agricultural regions at once. Here, a wave-7 pattern, which over the past 40 years has hurt crop yields in the red-marked areas of central/west North America, western Europe and western Asia. Credit Adapted from Kornhuber et al., Nature Climate Change 2019 Usage Restrictions Credit must be given. License Licensed content 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.