Ask any weather expert, and they'll tell you that one of the main ingredients
for hurricane formation is rise in temperature of the ocean.
To me, at least, this argues that changes in other environmental conditions conducive to
major hurricane formation must have also occurred.
The perceptible (and perhaps measurable) impact of global warming on hurricanes in today's climate is arguably a pittance (or noise) compared to the reorganization and modulation
of hurricane formation locations and preferred tracks / intensification corridors dominated by ENSO (and other natural climate factors).
Overall, I'm enclined to believe that GW is likely to decrease Atlantic
hurricane formation rates slightly, while significantly increasing storm formation rates in the Pacific and Indian oceans.
The area was traditionally viewed as an unlikely region for
hurricane formation because of its cooler sea surface temperatures, however in 2004 conditions were more favourable than normal due to warmer ocean temperatures, spawning Hurricane Catarina off the coast of Brazil.
Here we have three (3) lessons that explore the science
behind hurricane formation, an analysis of the social and economic impact of hurricanes and finally a look at ways hurricanes can be managed to minimise the loss of lives.
This also feeds into the recent post about «globally decreasing winds», not that it seemed very well supported — but if wind shear is decreasing globally, that would also tend to
increase hurricane formation.
Records from the 20th Century suggest that
hurricane formation over the Atlantic has changed phase every few decades: the 1940s and 50s were active, the 70s and 80s less so, while the currently active phase appears to have commenced in 1995.
So if it becomes a permanent El Nino situation, you will still have the chaotic weather effects of when the «
hurricane formation destroying» wind shear misses the formating hurricane due to the shifting jet stream... and Voila...
For example, when there are large changes in wind speed at different altitudes (also known as «vertical wind shear») above an area of the ocean, those conditions can interfere
with hurricane formation.
A confluence of factors, including abundant sinking air and dry air, and possibly dust flowing out of North Africa's Sahara desert, kept a lid
on hurricane formation in 2013, according to many cyclone experts.
For ocean temperatures, the magic number
for hurricane formation is 26.5 degrees Celsius (or 79.7 degrees Fahrenheit).
The increase that Emanuel and Webster observed is six times the magnitude predicted by Emanuel's own model
of hurricane formation, notes Chris Landsea of the National Hurricane Center in Miami.
El Niño is a key factor in making hurricane seasonal forecasts because the changes in atmospheric patterns over the tropical Pacific that it ushers in have a domino effect on patterns over the Atlantic, tending to suppress
hurricane formation.
Those patterns «have a very, very different impact on the tropical climate and, most important, on
hurricane formation,» he says.
Much of the remainder of the western Pacific was much warmer than average, while the main development region for Atlantic hurricanes (10 ° N — 20 ° N) was near average to warmer than average, helping make this area conducive for
hurricane formation.
Conditions in the tropical Atlantic remain unfavorable for
hurricane formation.»
Multi-decadal variability in the North Atlantic also plays a role in Atlantic
hurricane formation (Goldenberg et al., 2001; see also Section 3.8.3.2).
Higher resolution models tended to get more
hurricane formation (perhaps unsurprisingly), with quarter - degree models parameterized using observed SSTs generally capturing historical hurricane formation rates fairly accurately.
Hi Roman, I do not think climate models have nearly small enough grid scale to accurately model
hurricane formation, although they apparently do show some (weaker) vortex formation.
But temperatures rising as far down as 1500 meters below the sea surface, and I believe eighty meters are what is of greatest concern to
hurricane formation.
Hurricanes are likely to become fewer in number, but fiercer in nature according to two recent studies assessing the impact of climate change on
hurricane formation.
Tropical Atlantic (10 ° N — 20 ° N) sea surface temperature annual anomalies (°C) in the region of Atlantic
hurricane formation, relative to the 1961 to 1990 mean.
Dates indicate initial date of
hurricane formation.
According to hurricane historian Jay Barnes of Pine Knoll Shores, North Carolina, ocean heat is the key ingredient for
hurricane formation.
And because it tends to ride dry desert air (duh), it can put a damper on
hurricane formation.
Multi-decadal variability in the North Atlantic also plays a role in Atlantic
hurricane formation (Goldenberg et al., 2001; see also Section 3.8.3.2).
The Lesser Antilles intersect the «main development region» for Atlantic
hurricane formation, making storm data there «our best source for historical variability of tropical cyclones in the tropical Atlantic in the past three centuries,» the researchers explain.
• It is very likely that the human - induced increase in greenhouse gases has contributed to the increase in sea surface temperatures in
the hurricane formation regions.
For example,
hurricane formations will change.
According to Gerry Bell, Ph.D., NOAA's lead seasonal hurricane forecaster, the major climate factors expected to influence this year's activity are the ongoing multi-decadal signal, which produces wind and atmospheric pressure patterns favorable for
hurricane formation, along with ongoing warmer - than - normal sea surface temperatures.