The dustier, the better, but I don't want summer to get TOO cool because of dust. It just has to be enough dust to tamp down hurricane season so that it wouldn't be anywhere NEAR as productive as is being forecast.
Some Copernicus reports are specifically on dust plumes heading to Europe, but many others address the Atlantic and South America. From the link above:
"In recent months the Copernicus Atmosphere Monitoring Service (CAMS) observed at least three major Saharan dust transport episodes over the Atlantic and towards continental Europe." So the dust is blowing West from Africa over the Atlantic and then North towards Europe.
Hi Patrick, thanks for great observation. The analysis here is based on daily satellite data of aerosol optical depth 550 nm collected from NASA's MODIS instrument, a common way to derive daily dust cover. This analysis is specific to the main development region of the tropical Atlantic (between Africa and the Caribbean), notably during the traditionally dustier summer months, which is what matters for our hurricane season. The article you cite references episodic dust outbreaks over a subsection of Europe last winter only, when dust is typically at its lowest. My assessment is based on overall dust concentrations across the tropical Atlantic vs a few wintertime dust episodes over Europe, so they're not necessarily in conflict. We always have dust outbreaks during the year, but in 2023 they were significantly muted for the hurricane zone. In fact, research from NASA scientists suggests dust outbreaks will actually shrink over the next century due to climate change --> https://climate.nasa.gov/news/3076/earth-day-connections-nasa-study-predicts-less-saharan-dust-in-future-winds
Thanks, that is very interesting. It certainly seemed as though 2023 was a high dust year. So if not the dust, what other factors made it such an uneventful year, and is 2024 similar?
Dunion et al said in "New evidence for a relationship between Atlantic tropical cyclone activity and African dust outbreaks" that:
"However, over the last 25 years regional tropical cyclone activity and sea surface temperature exhibit an upward trend, while dust activity shows a downward one. The partial correlation coefficients of the de-trended time series are both 0.50, significant at 98.5%. Implying that Saharan dust activity can account for variance in the tropical cyclone record that cannot be attributed to ocean temperature. Furthermore, both sea surface temperature records utilize AVHRR data, so it is possible that the presence of dust aerosols over the North Atlantic negatively bias the retrieved ocean temperature [Rayner et al., 2003], resulting in artificially low partial correlation coefficients."
Is better measurements what the new PACE satellite all about? When will it come online?
I should add that Dunion et al is from 2006, but they give a figure showing that there are major up and down swings in dust superimposed on a long term decline. Can you get an updated figure through 2024?
Here is hoping the dust picks up for us.
The dustier, the better, but I don't want summer to get TOO cool because of dust. It just has to be enough dust to tamp down hurricane season so that it wouldn't be anywhere NEAR as productive as is being forecast.
Thank you again for a very informative post. Fingers crossed for significant saharan dust to tamp down some of our hurricanes during this season!
Thank you for the post about the dust, but what is the source for the claim that 2023 was a record low year? The graph just says "NASA". It seems very out of step with previous reports of the European atmospheric science groups that in both 2023 and 2024 the dust is at historic highs? E.g., see https://atmosphere.copernicus.eu/repeated-saharan-dust-intrusions-raise-questions-about-increasing-frequency
Some Copernicus reports are specifically on dust plumes heading to Europe, but many others address the Atlantic and South America. From the link above:
"In recent months the Copernicus Atmosphere Monitoring Service (CAMS) observed at least three major Saharan dust transport episodes over the Atlantic and towards continental Europe." So the dust is blowing West from Africa over the Atlantic and then North towards Europe.
Clearly a lot of the 2023 plumes reached the Caribbean and Gulf Coast of the USA, making for spectacular sunsets all year. e.g., https://modis.gsfc.nasa.gov/gallery/individual.php?db_date=2023-08-16#
Hi Patrick, thanks for great observation. The analysis here is based on daily satellite data of aerosol optical depth 550 nm collected from NASA's MODIS instrument, a common way to derive daily dust cover. This analysis is specific to the main development region of the tropical Atlantic (between Africa and the Caribbean), notably during the traditionally dustier summer months, which is what matters for our hurricane season. The article you cite references episodic dust outbreaks over a subsection of Europe last winter only, when dust is typically at its lowest. My assessment is based on overall dust concentrations across the tropical Atlantic vs a few wintertime dust episodes over Europe, so they're not necessarily in conflict. We always have dust outbreaks during the year, but in 2023 they were significantly muted for the hurricane zone. In fact, research from NASA scientists suggests dust outbreaks will actually shrink over the next century due to climate change --> https://climate.nasa.gov/news/3076/earth-day-connections-nasa-study-predicts-less-saharan-dust-in-future-winds
Thanks, that is very interesting. It certainly seemed as though 2023 was a high dust year. So if not the dust, what other factors made it such an uneventful year, and is 2024 similar?
Dunion et al said in "New evidence for a relationship between Atlantic tropical cyclone activity and African dust outbreaks" that:
"However, over the last 25 years regional tropical cyclone activity and sea surface temperature exhibit an upward trend, while dust activity shows a downward one. The partial correlation coefficients of the de-trended time series are both 0.50, significant at 98.5%. Implying that Saharan dust activity can account for variance in the tropical cyclone record that cannot be attributed to ocean temperature. Furthermore, both sea surface temperature records utilize AVHRR data, so it is possible that the presence of dust aerosols over the North Atlantic negatively bias the retrieved ocean temperature [Rayner et al., 2003], resulting in artificially low partial correlation coefficients."
Is better measurements what the new PACE satellite all about? When will it come online?
I should add that Dunion et al is from 2006, but they give a figure showing that there are major up and down swings in dust superimposed on a long term decline. Can you get an updated figure through 2024?