NASA: Sahara Dust And “Below Average Sea Surface Temperatures” Putting The Brakes On Hurricanes

At the online Spiegel magazine here science journalist and geology major Axel Bojanowski features his “Photo of the Week”, which this week shows a dust storm blowing across the East Atlantic off the African Sahara.

Dust Storm off Western Sahara

The above photo is provided by NASA Earth Observatory, taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. It shows dust sweeping off the coast of Western Sahara and Morocco on August 7, 2015.

NASA writes that this is just one of several outbreaks of Saharan dust that have occurred over the Atlantic this summer. The US space agency adds this is even a positive effect on the hurricane season, in combination with another factor (my emphasis):

While several factors influence hurricane formation, some research suggests that plumes of dry Saharan dust may help suppress storms over the Atlantic Ocean. In a recent update to its hurricane outlook for the Atlantic Basin, the National Oceanic and Atmospheric Administration’s Climate Prediction Center said a below-normal season appeared even more likely than it did in May. A strengthening El Niño, an atmospheric environment conducive to strong wind shear, and below average sea-surface temperatures in the Atlantic were cited as the primary factors limiting hurricane development. Dust outbreaks were not included as a factor because of their unpredictability, according to reporting by The Palm Beach Post.

Not only is the Saharan dust playing a role on dampening the Atlantic hurricane season, it is also transporting rich nutrients that are fertilizing the ocean, the Canary Islands and even the Caribbean and South American jungle, Spiegel writes.

 

8 responses to “NASA: Sahara Dust And “Below Average Sea Surface Temperatures” Putting The Brakes On Hurricanes”

  1. Ric Werme

    What the dust does is absorb some some sunlight in the mid-troposphere, thereby warming the air directly. The reduced insolation at the surface reduces the SST warming rate. Lower SST, increased atmospheric stability, no tropical cyclones unless the other drivers are really, really strong.

    I think the dust generally declines during the season, but the SSTs can’t recover.

  2. Green Sand

    NOAA, have just posted the joint lowest NAO Index (North Atlantic Oscillation) value of -3.18 since records started in 1950, last time it was achieved, July 1993.

    https://www.ncdc.noaa.gov/teleconnections/nao/

    What could it mean, always difficult when dealing with Gaia, but the guesses are, for Europe, dry warm in summer months, damn cold in winter (google) ‘negative NAO’ and choose your own poison.

    Personally I think I would prefer it if a significant negative NAO pattern did not persist into the winter.

    If there is an interest a good place to watch over the next few months:-

    Arctic Oscillation Analysis and Forecasts

    https://www.aer.com/science-research/climate-weather/arctic-oscillation

  3. John F. Hultquist

    Readers might find this paper of interest:
    http://journals.ametsoc.org/doi/pdf/10.1175/BAMS-D-11-00142.1

    Seasonality in European Red Dust/“Blood” Rain Events by Joshua R. White, et al.
    Sahara-derived dust rains, termed “red rains” or, more ominously, “blood rains,” are relatively rare meteorological phenomena associated with Saharan dust transport occurring across Europe. These red-rain events have been recorded throughout European history, with tales of ancient or medieval “blood rains” …

    So not a recent phenomenon then!
    The first word of title – seasonality – is the purpose of this paper. Many other sources are available if one wants to know more. Red-snow is also mentioned.

  4. Dr Tim Ball-Climatologist
  5. Kräftige kalte La Niña im Atlantik – Schwache Saison 2015 mit erstem Hurrikan! | wobleibtdieglobaleerwaermung
  6. sod

    Axel Bojanowski is again walking into the wrong direction. Basically all surface temperature sets are now showing, that July was the hottest month on record.

    http://edition.cnn.com/2015/08/20/us/noaa-global-climate-analysis/index.html

    Should we not stick to the facts and to the important stuff?

  7. sod

    to get some understanding, look at what Bojanowski wrote last:

    In march, he was making fun of climate scientists, being wrong on el nino.

    http://www.spiegel.de/wissenschaft/natur/el-nino-im-pazifik-blamage-fuer-meteorologen-a-1023161.html

    for some weird reasons he believes that you are wrong when you speak of a 80% chance of el niono, and it does not happen.

    Instead of admitting his own errors, he now has a new piece about el nino, blaming the scientists again for not forecasting it properly.

    http://www.spiegel.de/wissenschaft/natur/starker-el-nino-zieht-auf-wetter-aendert-sich-a-1048138.html

    I would basically advice everyone to ignore everything that he writes. This guy is allowed to write on climate, to keep advertisement customers happy. Basically his salery is paid by the automobile industry.

    1. AndyG55

      “I would basically advice everyone to ignore everything that he writes.”

      Do look in the mirror, sod! 🙂