Most recent 40 articles: Ocean2Climate - Climate Weather
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ENSO forecasts extended to 18 months? - Ocean2Climate - Climate Weather (Jun 27) |
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Jun 27 · According to the recharge-discharge oscillator theory (Jin, 1997), the leading mode of tropical Pacific upper ocean heat content anomalies is a predictor (or a precursor) for the onset of El Niño – Southern Oscillation (ENSO) at the interannual time scale. A new study published in Nature (Zhao et al., 2024) utilized multiple global sea surface temperature (SST) climate indices, which are known to be linked to ENSO such as Indian Dipole mode (IOD), Atlantic Niño/Niña (ATL3 index), and Pacific Meridional Mode (PMM), to extend the current ENSO predictability from ~6 months to 16~18 months. The authors named this prediction tool an extended nonlinear recharge oscillator (XRO) ... Read more ...
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Atlantic Niña brewing: An implication for the 2024 hurricane season - Ocean2Climate - Climate Weather (Jun 24) |
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Jun 24 · Currently (as of June 22, 2024), a phenomenon known as Atlantic Niña is brewing in the tropical Atlantic Ocean. As the Atlantic counterpart of La Niña in the Pacific, Atlantic Niña is characterized by the appearance of cold sea surface temperature anomalies (SSTAs) in the eastern equatorial Atlantic. It is known to reduce rainfall and the frequency of extreme flooding over the West African countries bordering the Gulf of Guinea and northeastern South America (e.g., Vallès-Casanova et al., 2020). A recent study published in Nature Communications (Kim et al., 2023) showed that Atlantic Niña may also interfere with the formation of powerful hurricanes in the deep tropics, known as Cape ... Read more ...
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Climate and weather scientists in the U.S. don’t talk to each other - Ocean2Climate - Climate Weather (Feb 02, 2024) |
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Feb 02, 2024 · As a climate scientist, I have worked and interacted with many weather scientists in the past 20 years or so. I am also currently in a task force team to advance subseasonal (2~4 weeks) forecasts of severe weather activity in the U.S. I have learned so much from weather scientists about how longer-term climate processes interact with shorter-term weather to produce extreme weather events such as tornadoes and severe thunderstorms. However, I must say that some of those weather scientists are quite ignorant about the role of climate in extreme weather. That is really okay because we can always learn from each other. But, I know several weather scientists that I can only describe as ... Read more ...
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Why is it hard to identify the subpolar and subtropical jets from zonal-mean zonal wind profiles? - Ocean2Climate - Climate Weather (Jan 03, 2024) |
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Jan 03, 2024 · Two important atmospheric jet streams that shape the extratropical zonal wind field in both hemispheres are the subtropical jet and the subpolar jet. The subtropical jet is located around 30° latitude line at the boundary between the Hadley cell and the Ferrel cell, and is predominantly a high-altitude feature. Since it is largely in thermal-wind balance (i.e., the meridional thermal gradient is proportional to the vertical wind shear), it is usually referred to as a thermally driven jet. On the other hand, the subpolar jet is located around 50°-60° latitude lines between the Ferrel cell and the Polar cell, and is much deeper than the subtropical jet, and thus often extends to the ... Read more ...
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MJO-driven onset of the 2021 Atlantic Niño - Ocean2Climate - Climate Weather (Aug 23, 2023) |
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Aug 23, 2023 · Atlantic Niño is the Atlantic counterpart of El Niño in the Pacific, often referred to as El Niño’s little brother. It was previously thought to have only regional influence on rainfall variability in West Africa, but a growing number of studies have shown that Atlantic Niño also plays an important role in the development of El Niño–Southern Oscillation, as well as in the formation of powerful hurricanes near the coast of West Africa. In a study published in Geophysical Research Letters, Lee et al. (2023) investigated the development of an extreme Atlantic Niño in the summer of 2021. The study showed that the 2021 event was preconditioned by warm waters piled up near the South ... Read more ...
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Atlantic Niño, known as El Niño’s little brother, may not be so little when it comes to its impact on hurricanes - Ocean2Climate - Climate Weather (Jun 22, 2023) |
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Jun 22, 2023 · Atlantic Niño, characterized by warm sea surface temperature (SST) anomalies in the eastern equatorial Atlantic, is the Atlantic counterpart of the Pacific El Niño, and thus is often referred to as El Niño’s little brother. It was previously thought to have a limited regional influence on rainfall variability in West Africa, but a new study published in Nature Communcations showed that Atlantic Niño increases Cape Verde hurricanes. What is the Cape Verde hurricane? According to Wikipedia, “a Cape Verde hurricane or Cabo Verde hurricane is an Atlantic hurricane that originates at low-latitude in the deep tropics from a tropical wave that has passed over or near the Cape Verde ... Read more ...
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Java-Sumatra Niña: a long-lost sister of El Niño - Ocean2Climate - Climate Weather (Jun 08, 2022) |
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Jun 08, 2022 · There are many siblings, cousins, and distant relatives of El Niño spanning the Pacific, Atlantic, and Indian Oceans who share a feature in common: ocean surface temperature anomalies along eastern boundaries linked to changes in the upwelling of cooler water from below. So far, climate scientists have identified a total of 14 members of this extended family. Atlantic Niño is a little brother of El Niño in the Atlantic Ocean. We have two sisters, La Niña and Atlantic Niña. There are four more siblings in the Atlantic Ocean, Benguela Niño/Niña along the coast of Angola and Namibia, and Dakar Niño/Niña along the east coast of West Africa. There are four more in the Pacific, California ... Read more ...
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ENSO plays little role in early-season Atlantic hurricane activity - Ocean2Climate - Climate Weather (Feb 11, 2022) |
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Feb 11, 2022 · This is a guest blog by Robert West. Robert is a postdoctoral research associate in the Northern Gulf Institute (NGI) at the Mississippi State University and is also affiliated with NOAA’s Atlantic Oceanographic and Meteorological Laboratory.
Differences in sea surface temperature anomalies (SSTAs) between the tropical Atlantic and Pacific oceans are known to influence atmospheric circulation patterns that modulate Atlantic hurricane activity. For instance, El Niño in the Pacific causes tropospheric warming over the tropical Atlantic increasing atmospheric static stability and thus suppressing the formation and development of tropical cyclones over the Atlantic hurricane ... Read more ...
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A Seasonal Probabilistic Outlook for Tornadoes (SPOTter) in the Contiguous U.S. - Ocean2Climate - Climate Weather (Jan 01, 2021) |
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Jan 01, 2021 · This new study accepted in Monthly Weather Review (Lee et al., 2021) presents an experimental model for Seasonal Probabilistic Outlook for Tornadoes (SPOTter) in the contiguous U.S. for March, April and May, and evaluates its forecast skill. This forecast model uses the leading empirical orthogonal function modes of regional variability in tornadic environmental parameters (i.e., low-level vertical wind shear and convective available potential energy), derived from the NCEP Coupled Forecast System version 2, as the primary predictors. A multiple linear regression is applied to the predicted modes of tornadic environmental parameters to estimate U.S. tornado activity, which is ... Read more ...
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Co-variability of Pacific-Atlantic SST contrast, Caribbean Sea Convection and U.S. summer to fall rainfall variability - Ocean to Climate - Ocean2Climate - Climate Weather (May 25, 2020) |
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May 25, 2020 · In the U.S., peak summer (June-July) rainfall variability, especially east of the Rockies, is largely linked to North Atlantic sea surface temperature (SST) anomalies and associated variations in the Bermuda High. However, these well-established relationships almost completely break down in late summer to mid fall (August-October). Thus, operational seasonal forecast models have generally low skill in August-October season for U.S. regional rainfall, leaving a large portion of U.S. populations vulnerable to unpredictable extreme events in that season. In a new article published in the Geophysical Research Letters (Kim et al., 2020), a team of scientists at NOAA's Atlantic ... Read more ...
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MJO-induced suppression of northeast Pacific convection increases U.S. tornadogenesis - Ocean to Climate - Ocean2Climate - Climate Weather (Apr 18, 2020) |
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Apr 18, 2020 · The National Oceanic and Atmospheric Administration’s Storm Prediction Center (NOAA SPC) provides one day to eight days lead-time severe weather forecast, including tornado watch, based on the probability of convective outlook. This severe weather forecast is based on synoptic-scale atmospheric instability (e.g., convective available potential energy and low-level wind shear) from numerical weather forecast models and observations. In order to extend the current forecast lead time for tornadogenesis to subseasonal time scales (i.e., 14-30 days of lead time), several studies have explored a potential link between U.S. tornado activity and the Madden-Julian oscillation, the convective ... Read more ...
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Spatiotemporal diversity of Atlantic Niño and associated rainfall variability over West Africa and South America - Ocean to Climate - Ocean2Climate - Climate Weather (Apr 18, 2020) |
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Apr 18, 2020 · A phenomenon known as Atlantic Niño is characterized by the appearance of warm sea surface temperature anomalies (SSTAs) in the eastern equatorial Atlantic in northern summer. When it attains its full strength, it increases rainfall and the frequency of extreme flooding over the West African countries bordering the Gulf of Guinea and in northeastern South America. Atlantic Niño thus has a direct socioeconomic impact in emerging countries in these regions. However, not all Atlantic Niño events are alike. Some appear earlier than others or persists longer. These variabilities during the onset and dissipation phases are well captured by the four most recurring Atlantic Niño varieties ... Read more ...
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