Connect with us

Environment & Nature

Rip currents are dangerous for swimmers but also ecologically important – here’s how scientists are working to understand these ‘rivers of the sea’

waves

All rip currents have similar effects, but they can form in several ways. (File Photo: Axel Antas-Bergkvist/Unsplash)

If you’ve ever waded into the ocean for a swim and suddenly realized that the shore is getting farther away, not closer, you may have encountered a rip current. Common at beaches worldwide, these powerful currents flow from the shore toward the sea at speeds up to several feet per second.

It’s important to know what rip currents are and how to look for them, because they are a leading cause of drownings in the surf zone near shore. According to one recent estimate, rip currents have accounted for 435 drownings in the U.S. since 2017.

National Weather Service offices that serve coastal communities issue forecasts that predict where and when rip currents are likely to occur. Those forecasts draw on decades of research into the physics of rip currents. Many scholars, including our research group, are finding innovative ways to discover more about rip currents – including their important roles in coastal marine ecosystems.

Rip currents are narrow currents in the surf zone that move quickly away from shore.

Not all rip currents are the same

All rip currents have similar effects, but they can form in several ways.

One type of rip, known as a bathymetric or channel rip current, forms when there are gaps between breaking waves. As waves break, they push water toward the beach and raise the level of the water slightly.

If waves break on a sandbar, but not in a deeper channel that cuts through the sandbar, the extra water that the waves have pushed toward the beach escapes back to the ocean through the channel. The flow of the escaping water acts like a conveyor belt, moving water, unsuspecting swimmers and small marine organisms offshore.

Another type, known as a transient or flash rip current, forms when surf is choppy. The edges of breaking waves push on the water and make it spin, like a fast ice skater bumping into someone.

This creates whirls known as eddies, which can combine to form larger whirls, with currents that act like temporary conveyor belts. Flash rip currents are an active area of research.

Swim, float, call for help

Choosing beaches with lifeguards and paying attention to beach flag warnings are the best ways to avoid rip currents. However, if you get caught in one, here are some techniques for getting safely back to shore.

Think of a rip current as a swift river cutting through the surf away from the shore. Swimming against the current is going to tire you out and put you at risk of drowning. Instead, swim parallel to the beach – think of heading for the “river banks” – until you are out of the rip current’s pull. Once you’re no longer fighting it, you can swim back to shore.

Another strategy is to float until the rip current carries you offshore beyond the breaking waves. Rip currents slow down here, so you can swim away from the rip current and back to shore.

If you believe you’re in danger, try to stay calm. Wave your arms and call for help. If you see someone caught in a rip current, throw them a flotation device and alert a lifeguard.

Forecasting rip currents

The National Oceanic and Atmospheric Administration’s rip current hazard model provides advance forecasts of the likelihood of encountering hazardous rip currents given wave conditions at specific beaches. NOAA works continually to make these hazard forecasts more accurate, including through an ongoing partnership with the U.S. Lifesaving Association. This partnership works to compare modeled predictions with lifeguard reports of rip current hazards and to recalibrate the model for different regions and waves.

At the University of Washington, we are evaluating NOAA hazard forecasts against the latest rip current science. This helps us assess predictions for different types of rip currents, such as unexpected flash rips.

To measure rip currents, we sometimes put on scuba gear and battle the waves to set up instruments in the surf. But this work can be expensive, and it relies on knowing where rips will occur beforehand. That isn’t possible for flash rips, so we need different methods to analyze those.

We use supercomputers and massive wave tanks the size of an Olympic swimming pool, with paddles at one end that produce waves, to simulate flash rips. Wave tank laboratory experiments and computer simulations allow us to control the types of waves we produce and make it easier to collect a lot of data. This work is improving our understanding of the relationship between wave conditions and flash rips, which can help improve hazard predictions.

Expressways for marine life

Rip currents aren’t just a safety issue. Scientists are beginning to better understand the crucial ecological role they play in redistributing small marine organisms, as well as plastic, pollutants, sediment and debris in coastal waters.

Many marine organisms, including oysters, barnacles, fish and coral, rely on ocean currents during their larval stage to find suitable habitats. These organisms swim up or down or attach to floating or sinking material and are transported by multiple ocean processes.

Rip currents are a key mechanism for dispersing larvae to deeper waters or recirculating them in shallow waters. The rip current type and behavior may affect the movement of marine organisms.

Water temperature and salinity can change the behavior of rip currents – and send organisms on alternate routes – by modifying the water’s density. Our group has analyzed imagery taken from low-flying planes and found that warmer rip currents carry water farther offshore at the surface, whereas cooler rip currents spread beneath the surface in different patterns.

Our research group and other scientists are using computer simulations and numerical “larvae” to investigate how temperature, salinity and other factors may affect transport of marine organisms. With better understanding of these surf-zone conveyor belts, we aim to help keep swimmers safe and assess how rip currents affect aquatic ecosystems near the shore.The Conversation

Emma Shie Nuss, PhD Student in Civil and Environmental Engineering, University of Washington; Audrey Casper, Data Analyst, NOAA Hazard Forecasting, University of Washington; Christine M. Baker, Postdoctoral research scholar, North Carolina State University; Melissa Moulton, Research Scientist/Engineer, Applied Physics Laboratory, University of Washington, and Walter Torres, Postdoctoral Scholar, Applied Physics Laboratory, University of Washington

This article is republished from The Conversation under a Creative Commons license. Read the original article.

xosotin chelseathông tin chuyển nhượngcâu lạc bộ bóng đá arsenalbóng đá atalantabundesligacầu thủ haalandUEFAevertonxosofutebol ao vivofutemaxmulticanaisonbethttps://bsport.fithttps://onbet88.ooohttps://i9bet.bizhttps://hi88.ooohttps://okvip.athttps://f8bet.athttps://fb88.cashhttps://vn88.cashhttps://shbet.atbóng đá world cupbóng đá inter milantin juventusbenzemala ligaclb leicester cityMUman citymessi lionelsalahnapolineymarpsgronaldoserie atottenhamvalenciaAS ROMALeverkusenac milanmbappenapolinewcastleaston villaliverpoolfa cupreal madridpremier leagueAjaxbao bong da247EPLbarcelonabournemouthaff cupasean footballbên lề sân cỏbáo bóng đá mớibóng đá cúp thế giớitin bóng đá ViệtUEFAbáo bóng đá việt namHuyền thoại bóng đágiải ngoại hạng anhSeagametap chi bong da the gioitin bong da lutrận đấu hôm nayviệt nam bóng đátin nong bong daBóng đá nữthể thao 7m24h bóng đábóng đá hôm naythe thao ngoai hang anhtin nhanh bóng đáphòng thay đồ bóng đábóng đá phủikèo nhà cái onbetbóng đá lu 2thông tin phòng thay đồthe thao vuaapp đánh lô đềdudoanxosoxổ số giải đặc biệthôm nay xổ sốkèo đẹp hôm nayketquaxosokq xskqxsmnsoi cầu ba miềnsoi cau thong kesxkt hôm naythế giới xổ sốxổ số 24hxo.soxoso3mienxo so ba mienxoso dac bietxosodientoanxổ số dự đoánvé số chiều xổxoso ket quaxosokienthietxoso kq hôm nayxoso ktxổ số megaxổ số mới nhất hôm nayxoso truc tiepxoso ViệtSX3MIENxs dự đoánxs mien bac hom nayxs miên namxsmientrungxsmn thu 7con số may mắn hôm nayKQXS 3 miền Bắc Trung Nam Nhanhdự đoán xổ số 3 miềndò vé sốdu doan xo so hom nayket qua xo xoket qua xo so.vntrúng thưởng xo sokq xoso trực tiếpket qua xskqxs 247số miền nams0x0 mienbacxosobamien hôm naysố đẹp hôm naysố đẹp trực tuyếnnuôi số đẹpxo so hom quaxoso ketquaxstruc tiep hom nayxổ số kiến thiết trực tiếpxổ số kq hôm nayso xo kq trực tuyenkết quả xổ số miền bắc trực tiếpxo so miền namxổ số miền nam trực tiếptrực tiếp xổ số hôm nayket wa xsKQ XOSOxoso onlinexo so truc tiep hom nayxsttso mien bac trong ngàyKQXS3Msố so mien bacdu doan xo so onlinedu doan cau loxổ số kenokqxs vnKQXOSOKQXS hôm naytrực tiếp kết quả xổ số ba miềncap lo dep nhat hom naysoi cầu chuẩn hôm nayso ket qua xo soXem kết quả xổ số nhanh nhấtSX3MIENXSMB chủ nhậtKQXSMNkết quả mở giải trực tuyếnGiờ vàng chốt số OnlineĐánh Đề Con Gìdò số miền namdò vé số hôm nayso mo so debach thủ lô đẹp nhất hôm naycầu đề hôm naykết quả xổ số kiến thiết toàn quốccau dep 88xsmb rong bach kimket qua xs 2023dự đoán xổ số hàng ngàyBạch thủ đề miền BắcSoi Cầu MB thần tàisoi cau vip 247soi cầu tốtsoi cầu miễn phísoi cau mb vipxsmb hom nayxs vietlottxsmn hôm naycầu lô đẹpthống kê lô kép xổ số miền Bắcquay thử xsmnxổ số thần tàiQuay thử XSMTxổ số chiều nayxo so mien nam hom nayweb đánh lô đề trực tuyến uy tínKQXS hôm nayxsmb ngày hôm nayXSMT chủ nhậtxổ số Power 6/55KQXS A trúng roycao thủ chốt sốbảng xổ số đặc biệtsoi cầu 247 vipsoi cầu wap 666Soi cầu miễn phí 888 VIPSoi Cau Chuan MBđộc thủ desố miền bắcthần tài cho sốKết quả xổ số thần tàiXem trực tiếp xổ sốXIN SỐ THẦN TÀI THỔ ĐỊACầu lô số đẹplô đẹp vip 24hsoi cầu miễn phí 888xổ số kiến thiết chiều nayXSMN thứ 7 hàng tuầnKết quả Xổ số Hồ Chí Minhnhà cái xổ số Việt NamXổ Số Đại PhátXổ số mới nhất Hôm Nayso xo mb hom nayxxmb88quay thu mbXo so Minh ChinhXS Minh Ngọc trực tiếp hôm nayXSMN 88XSTDxs than taixổ số UY TIN NHẤTxs vietlott 88SOI CẦU SIÊU CHUẨNSoiCauVietlô đẹp hôm nay vipket qua so xo hom naykqxsmb 30 ngàydự đoán xổ số 3 miềnSoi cầu 3 càng chuẩn xácbạch thủ lônuoi lo chuanbắt lô chuẩn theo ngàykq xo-solô 3 càngnuôi lô đề siêu vipcầu Lô Xiên XSMBđề về bao nhiêuSoi cầu x3xổ số kiến thiết ngày hôm nayquay thử xsmttruc tiep kết quả sxmntrực tiếp miền bắckết quả xổ số chấm vnbảng xs đặc biệt năm 2023soi cau xsmbxổ số hà nội hôm naysxmtxsmt hôm nayxs truc tiep mbketqua xo so onlinekqxs onlinexo số hôm nayXS3MTin xs hôm nayxsmn thu2XSMN hom nayxổ số miền bắc trực tiếp hôm naySO XOxsmbsxmn hôm nay188betlink188 xo sosoi cầu vip 88lô tô việtsoi lô việtXS247xs ba miềnchốt lô đẹp nhất hôm naychốt số xsmbCHƠI LÔ TÔsoi cau mn hom naychốt lô chuẩndu doan sxmtdự đoán xổ số onlinerồng bạch kim chốt 3 càng miễn phí hôm naythống kê lô gan miền bắcdàn đề lôCầu Kèo Đặc Biệtchốt cầu may mắnkết quả xổ số miền bắc hômSoi cầu vàng 777thẻ bài onlinedu doan mn 888soi cầu miền nam vipsoi cầu mt vipdàn de hôm nay7 cao thủ chốt sốsoi cau mien phi 7777 cao thủ chốt số nức tiếng3 càng miền bắcrồng bạch kim 777dàn de bất bạion newsddxsmn188betw88w88789bettf88sin88suvipsunwintf88five8812betsv88vn88Top 10 nhà cái uy tínsky88iwinlucky88nhacaisin88oxbetm88vn88w88789betiwinf8betrio66rio66lucky88oxbetvn88188bet789betMay-88five88one88sin88bk88xbetoxbetMU88188BETSV88RIO66ONBET88188betM88M88SV88Jun-68Jun-88one88iwinv9betw388OXBETw388w388onbetonbetonbetonbet88onbet88onbet88onbet88onbetonbetonbetonbetqh88mu88Nhà cái uy tínpog79vp777vp777vipbetvipbetuk88uk88typhu88typhu88tk88tk88sm66sm66me88me888live8live8livesm66me88win798livesm66me88win79pog79pog79vp777vp777uk88uk88tk88tk88luck8luck8kingbet86kingbet86k188k188hr99hr99123b8xbetvnvipbetsv66zbettaisunwin-vntyphu88vn138vwinvwinvi68ee881xbetrio66zbetvn138i9betvipfi88clubcf68onbet88ee88typhu88onbetonbetkhuyenmai12bet-moblie12betmoblietaimienphi247vi68clupcf68clupvipbeti9betqh88onb123onbefsoi cầunổ hũbắn cáđá gàđá gàgame bàicasinosoi cầuxóc đĩagame bàigiải mã giấc mơbầu cuaslot gamecasinonổ hủdàn đềBắn cácasinodàn đềnổ hũtài xỉuslot gamecasinobắn cáđá gàgame bàithể thaogame bàisoi cầukqsssoi cầucờ tướngbắn cágame bàixóc đĩaAG百家乐AG百家乐AG真人AG真人爱游戏华体会华体会im体育kok体育开云体育开云体育开云体育乐鱼体育乐鱼体育欧宝体育ob体育亚博体育亚博体育亚博体育亚博体育亚博体育亚博体育开云体育开云体育棋牌棋牌沙巴体育买球平台新葡京娱乐开云体育mu88qh88
Continue Reading
Click to comment

Leave a Reply

Your email address will not be published. Required fields are marked *

WordPress Ads