Cruising_World_2016-06-07

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Here’s What A Leading Sailing Educator Says

About ASA’s New Book:

"ASA’s new Cruising Catamarans Made Easy

book is the one we’ve all been waiting for!

ASA has written the essential educational and

reference source for any capable monohull

sailor wishing to become a competent multihull

sailor. This new book is chocked full of technical

illustrations, beautiful photos and up to date

information. "We at Blue Water Sailing School

are looking forward to using this book in all of

our Catamaran courses.”

NEW

David Pyle - President

Blue Water Sailing School

Leader in Sailing Education Since 1983

The Fun Starts Here!

ASA.COM/BK11 4

Are two hulls better than one...?

Find out by reading the book and taking the

corresponding ASA 114 Course.

Let an ASA sailing school give you the confidence

you need to live the lifestyle of your dreams.

this intertropical convergence

zone that I mentioned.

The Sahel region of Africa,

a band between the Sahara and

the savanna, is drying up as a

result of precipitation being

moved into new circulation

patterns. This climate feature

over Africa also sets loose

easterly wave patterns in the

atmosphere that are the pro-

genitors of tropical cyclones.

Small shifts in weather pat-

terns over land can have huge

infl uences on what happens

over the oceans.

PV: We hear a lot of confl ict-

ing speculation about climate

change infl uencing both the

strength and frequency of

major storms. What can the

models tell us about emerg-

ing storm patterns?

Rasch: Let me answer that by

saying a lot of people are wor-

ried about the eff ects of surface

fl ow, like the Gulf Stream in

the Atlantic and the Kuroshio

Current in the Pacifi c. These

warm rivers of water in the

oceans carry heat away from

the equatorial region and send

it north toward the poles.

We’re very interested in get-

ting a better understanding

of how those circulation pat-

terns will infl uence storms and

the distribution of heat to the

Pacifi c Northwest and north-

ern Europe.

These are complex systems.

Warmed water is carried

north, and then another cir-

culation pattern returns the

cooled water to the equatorial

region, like a continual heat

sink. This circulation takes

place over centuries, but it

has a huge infl uence on ocean

temperatures and storm

formation. The more heat

carried in the surface water,

the more intense the storms

will be that are fueled by

that energy. This is called the

meridional overturning cir-

culation, or MOC, and while

most people have never heard

of it, it’s very important,

especially as ice sheets in the

Antarctic and Greenland melt

at faster and faster rates.

PV: So Greenland ice melt

could play a role in the for-

mation of tropical storms?

Rasch: Yes, it already does. You

have to look at the storm track

regions across the planet. Each

one is diff erent, but overall,

storm track regions are pro-

jected to move closer to the

poles. ... As they move closer

to the poles in these wavy,

meandering currents of air, the

amplitude of the storms is also

projected to change.

PV: If you were planning a

long-distance cruise with

your family, which feature

of climate change would

loom large?

Rasch: As the planet con-

tinues to warm, there’s the

expectation that wave heights

at midlatitudes will con-

tinue to get higher. Tropical

cyclones and hurricanes are

going to get stronger. In the

overall pattern, wet places are

going to get wetter, and the

dry places drier.

Ten years ago, the IPCC

[Intergovernmental Panel

on Climate Change] reports

weren’t terribly concerned

about sea-level rise, but they

are now. That shows you how

fast things have changed.

As more ice melts in the

polar regions and the oceans

warm, the volume of water

not only increases, but the

water itself expands. We

used to think low-lying island

groups like the Maldives, in

the Indian Ocean, were safe

through the end of the cen-

tury. No longer. The Maldives

will be underwater in the next

few decades.

PV: That’s a sobering

prediction.

Rasch: Yes, it is. In terms of

climate, we’re in uncharted

waters.

Pacifi c Northwest sailor Paul

VanDevelder is a regular contrib-

utor to the Los Angeles Times

and The New York Times on the

environment and natural resources.

GREEN WAKES