The Limey’s Lament
Posted by sogasex on March 24, 2008
By Steve Archer, Plymouth Marine Laboratory
Us Brits are always talking about the weather, so here goes:
Mercury, that’s what the sea looks like today in the sunshine, albeit fast moving mercury. Somehow the cold makes it look even more metallic. The weather’s very ‘British’ in this part of the world, changing by the hour, four seasons in one day, ‘don’t forget your brolly’; that sort of weather. What’s driving this? At the moment we are sandwiched between a low pressure system tracking around the Southern Ocean and a high pressure system that has drifted east, off Argentina. This has compressed the isobars, increased the pressure gradient and we had some quite high winds last night, getting into the 35 knots region for sustained periods. Ideal for sea-to-air flux measurements. Interestingly to me, the increased wind and deteriorating weather at the time, coincided with rising barometric pressure; not something that happens in Britain very often. The southerly wind dropped the temperatures and made sampling the 11 pm CTD a f’f’f’f’freezing-fingers experience. Today’s sunshine made it feel less cold at 11 am.
How cloudy it is may be determined to some extent, by the cocktail of gases produced by the microbial biology in the surface oceans. Byron and I are interested in DMS a sulphur gas that may promote cloud formation (see earlier blogs: here and here). Other organic gases may also contribute to our changing weather. A substance called isoprene, is thought to be produced in large amounts by phytoplankton off the Patagonian coast, possibly enhancing cloud formation in this region. Forests produce isoprene and it’s responsible for the blue in scenic views, hence the Blue Ridge Mountains. Iodine-containing compounds may also help create clouds and importantly organic-iodine compounds produced in the oceans are transported onto the continents where life, including us before we added iodine to our table-salt, requires it. It’s obviously important to understand these links between ocean biology and the weather but tying the two together is tricky. The gases produced by the ocean biology here, today, will probably have more impact on the weather 1000s of miles east of us. Hopefully, not before England have beaten New Zealand in the cricket.
Here’s a joke for Maddy and Nicky, and their Welsh mum back in snow-bound Britain: Why don’t penguins come to Britain? Because they are scared of Wales!
Today’s metallic seas
Contrasting water sampling conditions last night
and this morning..