The oceans tallest waves are getting taller


first_img By Colin BarrasApr. 25, 2019 , 2:05 PM Country * Afghanistan Aland Islands Albania Algeria Andorra Angola Anguilla Antarctica Antigua and Barbuda Argentina Armenia Aruba Australia Austria Azerbaijan Bahamas Bahrain Bangladesh Barbados Belarus Belgium Belize Benin Bermuda Bhutan Bolivia, Plurinational State of Bonaire, Sint Eustatius and Saba Bosnia and Herzegovina Botswana Bouvet Island Brazil British Indian Ocean Territory Brunei Darussalam Bulgaria Burkina Faso Burundi Cambodia Cameroon Canada Cape Verde Cayman Islands Central African Republic Chad Chile China Christmas Island Cocos (Keeling) Islands Colombia Comoros Congo Congo, the Democratic Republic of the Cook Islands Costa Rica Cote d’Ivoire Croatia Cuba Curaçao Cyprus Czech Republic Denmark Djibouti Dominica Dominican Republic Ecuador Egypt El Salvador Equatorial Guinea Eritrea Estonia Ethiopia Falkland Islands (Malvinas) Faroe Islands Fiji Finland France French Guiana French Polynesia French Southern Territories Gabon Gambia Georgia Germany Ghana Gibraltar Greece Greenland Grenada Guadeloupe Guatemala Guernsey Guinea Guinea-Bissau Guyana Haiti Heard Island and McDonald Islands Holy See (Vatican City State) Honduras Hungary Iceland India Indonesia Iran, Islamic Republic of Iraq Ireland Isle of Man Israel Italy Jamaica Japan Jersey Jordan Kazakhstan Kenya Kiribati Korea, Democratic People’s Republic of Korea, Republic of Kuwait Kyrgyzstan Lao People’s Democratic Republic Latvia Lebanon Lesotho Liberia Libyan Arab Jamahiriya Liechtenstein Lithuania Luxembourg Macao Macedonia, the former Yugoslav Republic of Madagascar Malawi Malaysia Maldives Mali Malta Martinique Mauritania Mauritius Mayotte Mexico Moldova, Republic of Monaco Mongolia Montenegro Montserrat Morocco Mozambique Myanmar Namibia Nauru Nepal Netherlands New Caledonia New Zealand Nicaragua Niger Nigeria Niue Norfolk Island Norway Oman Pakistan Palestine Panama Papua New Guinea Paraguay Peru Philippines Pitcairn Poland Portugal Qatar Reunion Romania Russian Federation Rwanda Saint Barthélemy Saint Helena, Ascension and Tristan da Cunha Saint Kitts and Nevis Saint Lucia Saint Martin (French part) Saint Pierre and Miquelon Saint Vincent and the Grenadines Samoa San Marino Sao Tome and Principe Saudi Arabia Senegal Serbia Seychelles Sierra Leone Singapore Sint Maarten (Dutch part) Slovakia Slovenia Solomon Islands Somalia South Africa South Georgia and the South Sandwich Islands South Sudan Spain Sri Lanka Sudan Suriname Svalbard and Jan Mayen Swaziland Sweden Switzerland Syrian Arab Republic Taiwan Tajikistan Tanzania, United Republic of Thailand Timor-Leste Togo Tokelau Tonga Trinidad and Tobago Tunisia Turkey Turkmenistan Turks and Caicos Islands Tuvalu Uganda Ukraine United Arab Emirates United Kingdom United States Uruguay Uzbekistan Vanuatu Venezuela, Bolivarian Republic of Vietnam Virgin Islands, British Wallis and Futuna Western Sahara Yemen Zambia Zimbabwe The ocean’s tallest waves are getting taller iStock.com/Bobbushphoto The frigid Southern Ocean is well known for its brutal storms, which can sink ships and trigger coastal flooding on distant tropical islands. Now, a new study suggests the biggest waves there—already the world’s largest—are getting bigger, thanks to faster winds attributed to climate change.Peter Ruggiero, a geophysicist at Oregon State University in Corvallis who was not involved in the study, calls the increase “substantial,” and says he is particularly concerned by evidence that the tallest waves are gaining height at the fastest rate. “If [those waves hit] at high tide, it could be potentially catastrophic.”For the past 33 years, global satellites have been collecting data on ocean waves—and the winds that drive them. By bouncing energy pulses off wave crests and measuring the time those pulses take to come back, instruments called altimeters aboard satellites can measure wave height—the taller the waves, the faster the signal returns. Other satellite instruments monitor changes in the reflectivity of the ocean surface, which is reduced by wind-generated ripples, to estimate the speed of ocean winds. But interpreting the data is difficult: Different satellites can give different estimates of wind speed, for instance. Emailcenter_img Sign up for our daily newsletter Get more great content like this delivered right to you! Country To minimize those discrepancies, physical oceanographer Ian Young at the University of Melbourne in Australia, and mathematician Agustinus Ribal at Hasanuddin University in Makassar, Indonesia, compared information from different satellites and calibrated their data against an independent data set collected by a global network of buoys floating in the ocean. When they were done, two trends stood out: Since 1985, average ocean wind speeds in most of the world have increased between 1 centimeter and 2 centimeters per second per year, leading to increases in wave height in many places.In the Southern Ocean, the trends are particularly strong. For instance, although average wind speeds there have increased by 2 centimeters per second each year, the speed of the top 10% fastest winds has increased by 5 centimeters per second per year. And although average wave heights there have increased by just 0.3 centimeters per year, the top 10% highest has grown by an average of 1 centimeter per year—a growth of 30 centimeters since 1985, they report today in Science.The trends could be bad news for coastal communities, which face serious risks from sea level rise and extreme storm events, Young says. If oceanic winds are stronger and waves are taller, storms could be far more damaging.Young and Ribal have done a good job of cross-checking and double-checking data from the three different types of satellite instrument, says Ole Johan Aarnes at the University of Bergen in Norway. But, he adds, it might be “optimistic” to think that the data now contain no errors. Confirming the trends will likely require more work, he believes.The new paper doesn’t say definitively why wave height and wind speed is changing, although Young suspects a link with climate change. Ruggiero thinks that makes sense: He points out that a recent study in Nature Communications suggests higher global temperatures related to climate change are driving an expansion of the tropics—and an increase in wind speed there. “These are the secondary effects of climate change, not the obvious ones like sea level rise,” Young says. “This is where a lot of the research emphasis is now being placed.” Click to view the privacy policy. Required fields are indicated by an asterisk (*) Waves in the stormy Southern Ocean have grown an average of 30 centimeters since 1985.last_img