Native Plants, Habitat Restoration, and Other Science Snippets from Athens, Georgia

Sunday: 29 August 2010

The Long Hot Summer, 2010  -  @ 08:06:47
It turns out to have been an extraordinary summer here, climate-wise. I knew it had been hot, but I tend to go by daytime highs. And we weren't particularly suffering from drought, which can seduce you into complaisance. Then I looked at the monthly average temperatures, and the average for the entire summer. Whoa.

I'm jumping the gun by a couple of days, but unless the sun goes out or blows up before Wednesday, we might as well have a special report on The Season of Summer 2010. I'd have to discuss it in a few days in The Month of August, so we might as well do it now, so we don't have to do it then!

Live in the Athens area? Think it was a hot summer? You're right, but maybe not for the reasons you thought.

I suspect it's been hotter approaching or exceeding record summer *mean* temperatures most everywhere in the eastern US from around our area, northward.

Here it has been the third hottest summer since 1920. By average daily temperatures, Jun-Aug this year is 82.1 degF. In 1925 the mean daily temperature for the three-month period was 82.1 degF too, and in 1931 it was 82.2 degF. The average mean summer temperature over 90 years is 78.8 degF.

Doesn't sound like much of a difference, 2.3 degF above average, but it takes a lot of heat over 90 days to amount to that kind of a record. I got cued into it gradually as I realized just how debilitating this summer has been. Was it just me? I didn't think so - there were just too many days, practically all of them up until the last week or so when sweat would bead up illuminating every pore on the skin, and then just sit there, eventually running down and soaking clothes in a few minutes.

Let's look at the numbers, and I'll keep them brief. Alright, I tried.

At least here it hasn't been because of extremely hot daily temperatures, as it was in August of 2007 (summery here). And by the way the mean summer temperature for 2007 Jun-Aug, as horrible as it seemed, was only 80.8 degF, compared to 82.1 degF this year, despite the incredible 13 days well above 100 degF in Aug 2007.

This year a hot summer, just by the measure of daytime highs, has transfigured into near record because of high nighttime lows.

If we look at the daytime highs for 2010, there are seven years since 1920 that averaged hotter than the 92.7F high average for our area. The hottest was in 1925: 95.9 degF. Normal summer highs average 89.1 degF.

But if we look at the nighttime lows for 2010, there are no years that are as hot as 2010: 71.5 degF, when the average is 68.1 degF. Only in 1993, at 70.1 degF, did Jun-Aug nighttime lows rise above 70 deg.

So there's the culprit - we did have some hot days, true, but things just didn't cool off at night.

So how does that look elsewhere? You can generate these same figures here, at the National Weather Service Climate Prediction Center.

Here's a map of the mean temperature anomalies for our summer. In case you forgot, I've marked the area of Athens, Georgia with a green dot. I think you could safely say that there's a large swath of the southeast reaching up above the 40th parallel that will probably have broken a summer record, or be within the top two or three.


Let's compare this, because we must, to the same 3-month period last year. Quite a bit of difference! Last year was a pretty normal summer here, although I see it was just a little warmer than usual. Much cooler in the northern midwest, though.


Now, let's look at the culprit, the nighttime lows, in the lower panel below:

We certainly had warmer than usual daytime temperatures during the summer, 2-4 degF higher than normal, but it was really the low temperatures that gave us the mean anomalies in the first figure above. Things just didn't cool off at night.

Last year, slightly above normal, we had a total of 69 nights below 70 degF between Jun 1 and Aug 31. This year, a total of twenty such nights (so far, could go to 21 by the end of August).

There are two things I know of that keep the heat in at night - cloud cover, which we haven't had a whole lot of, and humidity, which we most certainly have had. The latter humidity is almost certainly due to stagnant high atmospheric pressure we've experienced most of the summer.


How do things sort out by month? June and August are the months that most contributed to our high mean summer temperatures - and this was in spite of six days in July when the temperatures rose above 100 degF. We've had no such days in August, and only one in June.

Nighttime lows: June had the second highest nighttime temperatures in 90 years - only in 1981 was the average higher, and by only 0.1 degF. July was the eighth warmest in terms of nighttime lows, and August the hottest at night in 90 years, period.

As for daytime highs - June was the 13th hottest out of 90 years, July the fourth hottest - due I think to the six days above 100 degF, and August, amazingly, only the 18th hottest (plus two years equal).

How about our rain? It has been worse. The normal is 12.45 inches for the summer. Right here at Wolfskin we've had 9.28", so a bit over 75%. Oglethorpe County ranges 7.19-10.25" over six stations. Athens in Clarke County, next door to our west, did quite a bit better - 9.09-13.62" over five stations. The rain has been very heterogeneous this summer.

A word about the data I've used for comparison here:

Several years ago, all the KATH Athens Ben-Epps Airport data were available online free, back to 1879. A couple of years ago, it was removed and if you go to that website, this is what you see. Don't bother with the redirect - it won't get you anything without your paying. Fortunately I did with some effort transcribe a portion of the data going back to 1920 at least, before they disappeared. Now why on earth would you want to remove perfectly good official data from the web?

Friday: 27 August 2010

The Importance of Not Venting  -  @ 07:25:59
No, not that kind of venting, not this time.


Last week I mentioned that a few weeks ago we'd taken the pumper and the tanker up to a lake near Winterville to get them pump tested. You have to do this on an annual basis for satisfying insurance requirements for the class we're trying to achieve. The pumper did ok, but the Water Master tanker couldn't be tested. The guys couldn't figure out how to draft and pump simultaneously, so that had to be put on hold.

The reason you have to draft (suck water out of a pond or lake) and discharge at the same time is that you have to maintain 1000 gallons per minute discharge for twenty minutes, so you need a larger body of water as your reservoir. The guys knew how to do the pumpers, because they're common and well known.

I tried to describe to them how I thought it could be done with the tanker, but they were reluctant to try it. In their defense there was a secondary issue that made them reluctant to proceed further. The manufacturers of the fire pump had neglected to include a test specification plate with all the info, so they couldn't assure themselves of what the pumping capacity was and were skeptical of our recollection that it was 1000 gal/min (it is). They don't want to burn out someone's fire pump, so that ended it.

Fire Chief Ed did have an indirect conversation through one of the test guys to the company that makes the Water Master tankers. I'm giving the third hand report, but the upshot was that simultaneous discharge and drafting (sucking water out of the lake) couldn't be done.

Ed seemed willing to accept that assertion. It just didn't seem right to me, so I devised a procedure for doing it, and last night we tested it out and it worked just fine.

Here is how we normally use the tanker (called a "tender" in the West - in that part of the country, "tanker" is used to describe a plane or helicopter dropping water or other suppressant from the air).

The tanker is a modified septic tank sucker, with a big sealed 2500 gallon tank shown in red, sitting atop the truck. The fire pump pumps water out of the truck. There's a vent that you can open or close from a big panel with lots of switches and LEDs sitting between the driver and passenger seats. For the normal operation you keep the vent open, of course, for you do not want to develop a vacuum in the tank as water is pumped out of it.


Here is how we needed to operate the tanker. It's the same figure from above except that we also needed to pull water into the tank while we discharged. The main concern here was for pump testing, but in general we'd also need to do this for nursing other trucks when hydrants aren't present. In most parts of Oglethorpe County, hydrants aren't present, but there are little ponds and lakes around.


The big difference is that now we operate the fire pump with the vent *closed*, something you "never" do. As the fire pump removes water from the tank, a vacuum forms. This vacuum pulls water out of the lake to replace the water that has been removed from the tank.

And that's what we demonstrated last night. Very simple. We dumped water from the pumper into a drop tank, basically a portable collapsible 2000 gallon swimming pool, to serve as our "lake." From the tanker in the second figure above, we put our 6" suction hose. We hooked up our discharge to the pumper, and turned the fire pump on. And it filled the pumper while immediately beginning a suction from the drop tank, just as predicted.

Once the pumper was full again, we hooked up the deck gun and repeated the process, discharging into the air, until we'd emptied the drop tank first, and then the tanker at 400 gal/min. Worked fine!

Now, in defense of the assertions that we couldn't accomplish the intended goal, I'll have to introduce a complication. We have a *second* pump, a vacuum pump, that is normally used to fill the truck from a lake on a one-time basis. With the vent closed, you turn the vacuum pump on, it removes the air from the tank, and the water comes in to replace it. Simple! That's how the ancestors of this truck clean out septic tanks, only there it isn't simply water that is sucked into the tank.

So I think the testing guys, who knew something about the tanker, and the manufacturer guys too, were fixated on using the vacuum pump and the fire pump at the same time to accomplish our needs, and their conclusion was that it couldn't be done. They were also blindsided a bit by the rule that you never use a fire pump with the tank vent closed. And to do what we did means you had to violate that rule.

It may be that this is too technical or tedious to follow if you're not really engaged in solving the problem, but I felt pretty damn smug last night - we beat the experts who said it couldn't be done, and that includes some on our own team who were willing to accept that assertion. We still haven't fully tested it, since to achieve the 1000 gal/min we'll have to rev up the fire pump rpm's at least 2.5 times higher than we tested it out at. But that's what the fire pump is built to do, so I can't see why that would be problem.

I really wish I'd taken my camera - it was pretty impressive when we were pulling water out of the drop tank into the tanker, discharging it into the pumper, and then using the pumper's fire pump to return it back into the drop tank. We had a full circuit of water moving, with the physics of gravity and atmospheric pressure completing a critical portion of that loop.

(A version of this post was also posted on the Wolfskin Fire Department website. Not exactly a crosspost, but whatever.)

Tuesday: 24 August 2010

Pretty Red Things  -  @ 08:28:11
But first:

It's Week 2 after the beginning of Fall Semester. Traffic is becoming a little less chaotic as 40,000+ folks find their equilibrium and learn to avoid stupid times to be on the road.

For us, Week 1 is a rush to be ready for students' schedules as they made them sometimes months ago. Week 2 is extra busy as we redo a lot of work as students panic, reconsider, and drop or add courses during that short period when it is possible. Things stabilize during Week 3, at least until the midpoint of the Fall semester when another flurry of students withdraw from their courses because they're not doing so well. So long as they withdraw before that magic midpoint, they may get lucky and get a W instead of a WF, withdrawn failing. Afterwards, well, too bad.

An interesting tweak to the system began a year or two ago when the University imposed the rule that students could only have four such opportunities to withdraw without failing during their tenure at the University. After that a withdrawal is an automatic fail. Whoa!

But enough of that! The weather continues hot, but not quite so hot - highs in the low 90s but until yesterday the high humidity continued unabated. For the last week, we've had some amount of rain almost every day, once or twice accompanied by considerable lightning and thunder. I noticed around noon yesterday Monday that though the temperatures were around 90F, suddenly it wasn't all that bad. It turned out that at that time a weak cold front had moved quickly through the area, decreasing the humidity and drying things up a bit. These are the signs of autumn approaching.

But enough of that!

Here's another sign of late summer and impending autumn around here, Caesar's Amanita, or Amanita caesarea, (though see below). I came upon a dozen of these, down by SBS Creek under the oaks, on Sunday, a day after quite a vigorous thunderstorm Friday night. A nicer, brighter red and orange could not be found.

These emergences are well along their way. The one on the left is nearly fully expanded; the one on the right a little less so. They're not nearly as far along as some I posted on almost exactly four years ago.



Here are two that have just emerged from their "egg stage." The remnants of the "egg" are a little overexposed. Amanitas have the interesting development that for a time early on the baby mushroom is contained in a soft, egg-shaped encapsulation. This splits circumlaterally as the embryo grows. The cup which is the bottom part, and the veil that adheres to the stem as a ring are features that reveal the mushroom as a dreaded Amanita.

In this case, however, the amanita is not one of those dreaded ones - many Amanita species are deadly poisonous.


Here are two that are a little further along. The cup isn't visible but the shed remnants are. The smooth appearance of the cap differentiates this species from some extremely poisonous lookalikes.

At this point I should say that I *think* this is a Caesar's Amanita, and that it is nonpoisonous, even delicious. But I stay away from any temptation to sample anything that smacks of amanita. No one who isn't really really clear about the distinctions and lookalikes should be messing with eating amanitas. Unless you're a squirrel or a box turtle or something like that.


Parenthetically, you can see the ring on the stem of this lower angle photo of the first photo above. You'll get a larger version by clicking on the thumbnail.


As is always the case, Tom Volk has a nice exposition on Caesar's Amanita. One interesting thing is that the European version, from which the name comes, is considered to be not just edible, but delectible. Apparently the American version has diverged enough to not only be considered just good but inferior to the European version, but also to have acquired a different species name. I'm not enough of a fungal biologist to know if the species name for the American version has acquired official validity yet, but it seems that there are small differences more than just its flavor that distinguish it from its remote cousin in Europe.

One last thing, and this is technical but somewhat nostalgic.

The extremely toxic compound that makes a lot of amanitas (but not this one, apparently) something that is definitely to die for is alpha amanitin, one of the amatoxins produced by Amanita mushrooms. It's a complex molecule that binds to and inhibits RNA polymerase II. Without RNA polymerase II, cells cannot do transcription, which means they cannot make RNA and so they cannot make protein. It takes a long time to die from Amanita poisoning - up to a week - but it's because of this turning off of cell function at a very basic level. Because of the way food gets processed after digestion in mammals, the major effect is to kill the liver, and then the kidneys. Not a nice way to go.

The nostalgic part is that purified alpha amanitin was (and probably still is in some quarters) a reagent used to investigate certain developmental questions. This was not during the stone age of molecular biology - that would have been in the first half the 1900s. This is more like the bronze age, long before anyone had any expectation that we would be sequencing whole genomes. It's also a developmental molecular biology question, which is a little obliquely related, and so golden age questions about development could still be answered to this day with alpha amanitin.

In the early 80s, this bronze age period, Glenn and his colleagues used alpha amanitin to turn off transcription in germinating cotton seeds. By comparing the proteins made in germinating seeds that had or had not been treated this way, they were able to show the existence of large amounts of active RNA that had been stored before the seed dried out.

The significance of this was that developing plant seeds, at the end of their development before they dry out, suddenly produce a huge amount of certain messenger RNAs, that then get stored away, and go dormant along with the seed as it dries. Then weeks, months, or years later when the seed is watered and begins germinating, the RNAs are already there to begin making certain important proteins to help the baby plant along. They don't have to be made on the spot from scratch, which is good, because the germinating seedling has a whole of other stuff to worry about.


Sunday: 22 August 2010

Productivity Visualized  -  @ 06:52:17

Here is an interesting image, from a report in this week's Science. It's by M Zhao and SW Running (2010) Science 329, 940-943. That's probably behind a subscription wall, but NASA has a nice summary of the paper here.

The paper examines the net primary productivity (NPP) globally during the years 2000-2009 and determines that there has been an overall decline during the last decade. The summary map shows the trouble spots - southern hemisphere forests.

2000-2009:


Primary productivity is not hard to understand - it's the amount of photosynthesis going on, and so it's an indication of how much carbon dioxide is taken out of the atmosphere and converted into biomass. It's sort of like putting your entire paycheck in your bank account.

But of course you also withdraw money from the bank for all kinds of things, and at the end of the month you'll hope to have not withdrawn more than you put in.

All organisms, including plants, withdraw against that account in their moment to moment lives, and what's left over is net primary productivity. Among other things, if you have a surplus (green) then that means you've succeeded in a net removal of some carbon dioxide from the atmosphere. If you have a decline (red) then on balance atmospheric carbon dioxide has gone up.

Zhao and Running attribute the decline in NPP to drought. High latitude northern hemisphere productivity improved, mainly because of increasing temperatures during the last decade. But that increase was more than offset by the decline in southern hemisphere low latitude productivity.

Here's a comparison, a similar figure that appeared in Nemani, et al. (2003) Science 300, 1560-1563, again behind a subscription wall. It's a similar analysis for the 18 years between 1982 and 1999.

1982-1999:


The difference is pretty striking, especially in the three major tropical rainforests - the Amazon, Africa, and Asia. From 1982-1999, the period of interest in the 2003 paper, there was a 6% increase in NPP. From 2000 to 2009 there was a 1% decrease. That's not much, but it is concentrated in some pretty sensitive areas, not distributed evenly, and that makes it more disturbing.

Friday: 20 August 2010

Season of Busy  -  @ 09:39:43
Classes started last week, with the usual frenzy of activity, problem solving, and changing schedules. I'll use that as this week's excuse for poor posting. But wait, there's more!

Yesterday my email account of 20 years, (do not mail)hughes@plantbio.uga.edu(/do not mail), was disabled. A ticket of complaint was filed through Glenn's account, which is through the same domain. The response today was that apparently an email, a *single* email was sent to all the "guest/legacy" accounts 90 days ago, and since I did not respond (because it never got here), well, that's it.

What is a guest/legacy account? These are accounts of former professors, former graduate students and postdocs (me), spouses of faculty and staff (me), basically whoever requests it. It seems that there was a cabalistic cleanup crew who didn't bother letting anyone know that they were going through these, well, cleaning up.

How do I know this email did not arrive? Anyone who knows me knows I even check my junk mail box and meticulously delete it on a daily basis - a rare good citizen in the world of email. It is vanishingly improbable that I would have missed such a notice, much less fail to respond to it. I *never* lose an email, even when a legitimate one ends up in the junk mail folder.

But all that is so moot, for surely any competent system administrator could have told from logs and activity that I'm logged on 24/7, send out 10-20 emails a day, and the list of evidence of activity goes on and on. And of course no competent business, even UGA Parking Services, would terminate service on the basis of a lack of response to a single email supposedly sent 90 days ago. What we really have here is what we all have experienced from time to time - an arrogant system administrator.

So for the time being my email address is wayne@sparkleberrysprings.com. I've notified my base - my two professional ones, teaching and firefighting, - and the most likely correspondents, and cut off an email listserve to save them the hassle of getting "mailbox does not exist." But do you have any *idea* how many connections must be corrected when the connecting email address has been the One And Only One for twenty years??? So if worse comes to worst, I've started a list of literally a thousand connections that might have to be updated with a new email address.

Such crap we have to take care of, and for no really good reason at all except that some arrogant dweeb decided to make life miserable. We'll see how it works out, but I like Glenn's suggestion - a new email address hughes@plantbiologysux.uga.com .

So that's my rant for the day.

I actually had a post in the making today. Not very interesting but definitely falls into the category of busy. We're trying to get our two firetrucks pump tested. One did well a few weeks ago, but the tanker is such an oddball that no one could figure out how to get it to draft and discharge at the same time. This is necessary because to pass the test a truck has to spew water for at least twenty minutes. No truck can contain 20,000 gallons, and so it must be able to draft from a lake or pond.

I did devise a protocol to test out a possibile way to do this with the tanker. I even got partly through a nice figure showing how it might work, but then got distracted by the busy. Needless to say we need to get this done - gotta have records for two years in order to reduce fire insurance classification in the community. Last night we were supposed to get this done, but two able-bodied firefighters didn't show up so we had to defer the testing.

There's more, of course, there's always more, but increasingly so much more now begins to fall into the category of Things I Should Not Post, because they might hurt someone's fee fees, or they're probably not very interesting to others.

That felt good, though. Thank you.




Tuesday: 17 August 2010

In Transit  -  @ 10:47:02

I watched this tiny, likely ichneumon wasp canvassing the wooly crotons for a lengthy time. You can see from the photo that the antennae were waving wildly. But once I got the camera it was outta there. I had only three photos and this was the best of them.

Still, it was so jolly with its flagging antennae, constantly flitting wings, and brazen striping that I decided to go ahead and post it. I'll keep an eye out to try to get some better photos. If it makes a difference, that was manual flash, 1/100 second, and I'd definitely reduce the exposure time.

No way I'm going to try to identify it yet. There are huge numbers of ichneumon species. We'll see how it goes. Surely it must be called a zebra ichneumon.


Monday: 16 August 2010

Two Followups  -  @ 05:42:38

Yesterday's fly, by the way, was identified at Bugguide as a soldier fly, Ptecticus trivittatus. Everyone's photos there show the weird eyes, but several are so well-resolved that they give a much better impression of what's going on with reflection.

For the last few days we've been getting some little showers from the remnants of Tropical Depression Five, which formed in the eastern Gulf of Mexico at the end of last week. It hasn't amounted to much here (although other places close by have had considerably more rainfall). It has, however, ameliorated the high temperatures somewhat.

Something that might be of more interest to local folks:

Here's our weather during the course of 2010 (blue) compared with 2009 (red). The individual data points are Wolfskin temperature measurements, and the jagged lines are 25-point moving averages. Everything is plotted against a "normal" mean daily temperature curve. At the bottom in green are individual rainfall amounts, and a tracking cumulative rainfall curve. You can get a larger version on a new page by clicking the image.

2009 was just about as normal a year, temperature-wise, as you could expect, with just two major heat waves, one at the end of June and one soon after the beginning of August.

2010 is above the mean for almost its entirety since the beginning of April. It's easier to count the number of times when the moving average temperatures fell below the mean, and there are really only about three or four signficant periods since April 1. The most significant was the first week of July, otherwise it's been hot almost without relief.



In April, things were hot because of daytime highs - the nighttime lows were fairly normal. There were 17 days above 80 degF, compared to 8 and 7 in 2008 and 2009.

June and July were hot because of elevated daily highs AND elevated nightly lows. In both months there were more than twice as many days above 90 degF than in 2009. And in July we went above 100 degF on 6 days - in 2008 and 2009 there were no such days.

So far in August it's been above normal but not especially so. Daytime highs have not been unusually warm, but nighttime lows have been. In 2008 and 2009 we had 9 and 10 nights below 70 degF by this time in August. We've had no such nights this August.

Rainfall - it's not terrible. Only in July were things beginning to look stressed. Still we've had only about 26 inches of rain so far this year, and normally by this time of year we'd have had nearly 32 inches. 48 inches is normal, by the end of the year.


Sunday: 15 August 2010

Visitation  -  @ 09:25:56

I had a little visitor at the computer table yesterday.



This is not the first time we've seen this fly. This was one of the "corn husk" flies that gathered in profusion around freshly shucked husks that we'd put in the compost back in June.

I still haven't convinced myself that this is a druid fly, Clusiidae. I think I'm going to have to submit sized photos to Bugguide to find out what it is.

Look at the eyes. The orange pigmentation occupying distinct polygonal regions seems to change from image to image. Unlike the photos of the flies in the previous post linked above, these are of the same individual. It's almost like there's a reflection artifact brought on by use of the flash, but it's so distinctive and sharply bounded against the dark green of the rest of the eye that it's hard to believe it's simply a reflection.


I'm afraid that the wing venation is not going to be of much help to me, who doesn't really have an innate feel for it. But once again - the orange pigmentation of the eyes seems to be in a place that it wasn't in the second photo, and what was present in the first photo isn't visible here. I really don't know what to make of it.

Maybe flies have more mobility in their huge compound globes than I think, and it's swivelled the eyes around to fool me. But I don't think so - I don't get the impression that flies have *that* much flexibility in their eye movements.




Friday: 13 August 2010

Aftermath  -  @ 07:14:47
I did spend a couple of hours, once a little after midnight, and then again from 4-5am, watching for Perseid meteors. I'm a little rusty on what constitutes an impression of background, but in the latter hour I saw three bright meteors with trains, and perhaps a dozen much fainter meteors. That's a good bit lower than the 60 meteors per hour, but about right for the lower limit of 15 meteors per hour.

No regrets, but for the limited time I watched, not a particularly impressive display! If you missed it, you can console yourself with that ; - )  .

It was at least in the north and east where it mattered, quite clear with magnitude 4 or 5 stars easily seen. The west, I'm afraid, is now perpetually light polluted, even out here.

Wednesday: 11 August 2010

The Perseids, 2010  -  @ 06:35:09
Just to let you know a day or two in advance, so you can get your weather in proper order: the Perseid Meteor Shower will make its peak appearance, perhaps 60-100 per hour, on the night/morning of August 12/13. Lay back in a comfortable chezz lounge with a clear view a dark rural sky, relax, and enjoy.

The peak time for the Perseids is usually around 4am Aug 13. Since no time zone is attached, I assume this means that any is most likely to see the best Perseids possible at around that time. There *is* usually a predicted peak time given, but I haven't found it yet.

Since the meteors appear to radiate from Perseus in the sky, you should be approximately oriented toward the northeast, but the meteors can appear anywhere, really. The moon sets around your 10pm time (no matter where you are) on Aug 12, so the skies will be darkest afterward. Still, after midnight is probably better, and 4am is best.

(Why 4am? If you look up to the top of the sky at that time, you'll be looking in the direction the earth is travelling in its orbit. You'll catch more meteors that way, just as you'll get more bugs in your teeth facing ahead in your speeding motorcycle, rather than looking back the way you came.)

This is rather cool. It's a section of the earth as visualized by the Pentagon's Midcourse Space Experiment satellite, MSX, which orbits at that magic distance of 22,300 miles up. From there it was able to take a 48-minute exposure during the Leonid meteor shower of 1997. Twenty nine meteors are visible. OK, it's not the Perseids, but it could have been, and it's certainly not something anyone else has ever seen.

The MSX tries to keep track of lost space junk. Some of the space junk, and there's lots of it, is known, and poses a space hazard. Other space junk has been lost, and that's what the MSX is supposed to find.

In this case, the MSX visualized a period of the Leonid meteors entering the earth's atmosphere, probably from around less than a hundred miles up. It's blurry because the satellite was, after all, 22,300 miles away. Surely everyone aspires to some expression of artistry, and here it's the Pentagon. Let us celebrate.



Image Credit: Certainly the Pentagon, but also via AMS Meteor Showers, Peter Jenniskens.


Tuesday: 10 August 2010

Cooling Off, Maybe  -  @ 09:17:19
We have a camera lens crisis here, three of them. One of my two has developed a particulate coating on the surface that renders it fairly useless. Both Glenn's single lens for his camera, and my other one fail in the focus, which as you might imagine is not something you can work with.

My four-year-old Sigma lens focuses automatically without problem (other than those times when you'd really like to forego automatic). When put on manual there's a grinding granular jumpy feel as you rotate the lens focus, and it's impossible to do anything fine with it.

Now it's not like I've dragged the thing through the mud, or mistreated it in any way. I've taken very good care of it. And at least it still does focus automatically but that doesn't help for something like this, which has no real point of focus that trumps whatever is in the background. To take this one I brutalized the lens manually until I manhandled it according to several distances, one of which worked ok:



So that's the morning web of an orb spider, what I guess is one of our Neoscona species that makes its presence known this time of year. She must have been around all along, but feels now more confident about coming out into the open. Until the morning, when she flees into a tree or other attachment point. A couple of nights ago I watched her spinning her web thirty feet up while the bats were coming out. It seems a precarious existence!

That web is twenty feet up, and I've seen them far higher up than that. The other morning, I noted that she'd attached one of the anchoring strands to a birch leaf on the deck railing, and had anchored the leaf itself to the railing itself.

Starting to spot the webs of these orb weavers is a sign that things are cooling down, which is why I'm always glad to see them. Nonetheless we're still in the 97-99 degF high for the next few days, at least.


Sunday: 8 August 2010

Fifteen Minutes  -  @ 07:36:36
Is it worth fifteen minutes of your time? Yeah, I think so.

In 2003, Isao Hashimoto produced this video - nuclear bomb detonations 1945-1998. It seems fairly appropriate this week. If you're of a certain age, or have even a limited sense of history covering the 50's, the 60's and 70's, and the late 80's, this is both fascinating and disturbing in ways I haven't yet finished enumerating.

Note: The Limited Test Ban Treaty, which prohibited above-ground testing, went into effect October 1963. Of the countries with nuclear capability, China, North Korea, and France have not signed it.



Or you can go directly to the youtube video and also enjoy the smart, funny (I admit I liked the comment - "I had no idea how many times Britain had nuked the US"), vapid, ignorant, insipid, insane, and wtf comments. Since things change on youtube, you can always find it by searching on the author's name.

UPDATE: Just a little addition. If you're attuned carefully, you'll notice there's almost always a hiatus at the end and beginning of the year. I don't know if this is an artifact, or whether it's real, but it's interesting. Also, what's up with France?

It also strikes me that there are three different views of this: those of folks who went through World War II; those, who like me were post-WWII but enjoyed that legacy as children and maturing adults throughout the 60's and 70's and into the 80's; and the students I know now born post 1980 who wonder what all the fuss was about.

I'd love to see this extended to the present time.

Thursday: 5 August 2010

Close Encounters: A Quick Retrospective  -  @ 07:29:23
Let's go on a space trip. Let's not go to Mars or Jupiter or Venus, though they may figure in the trip. Let's visit some of the littler guys. For those of you who like rocks, I have a few for you.

I actually started this post a month ago, and then it languished for awhile. In the month leading up to July 11, there were a couple of events of interest. Perhaps you heard of them - they were on all the traditional news media outlets. Oh, no? Well.... maybe there weren't any.


Credit: ESA
Early Saturday evening, July 10, the European Space Agency's Rosetta spacecraft made a close flyby of of the asteroid 21 Lutetia, passing just 3162 km away.

At 132x101x76 km, Lutetia is the largest asteroid that has been encountered at close range by a spacecraft. You can tell that by the low number, 21, that precedes the name.

The numbers that designate an asteroid roughly indicate the size, in reverse order - the lower the number, the earlier they were discovered so the larger they are. The largest asteroid, Ceres, is 1 Ceres. Later on we'll see some in the five digits, and they're small indeed.


Within hours, images had been processed and put up for your inspection. The Rosetta Blog displayed those images, including a wonderful image of the asteroid from 36,000 km, with a tiny Saturn in the background.

Here is my own construction of a timeline of major events for four missions that have involved one or more close encounters with asteroids or comets. These spacecraft generally coast along at relatively low speeds, taking years to reach their targets. At one or more points they'll dive down in a planned encounter with a larger planet to get a slingshot boost during the flight. I've indicated these gravity assist flybys in blue.



Rosetta was launched in March 2004, and is ultimately destined to make a landing on a comet toward the end of 2014. Lutetia isn't the only asteroid Rosetta has flown by - it passed just 800 km from the smaller, 4.6 kilometer 2867 Steins on September 15 2008. To shape its orbit and adjust its velocity, Rosetta has made three gravity assist passes around Earth, and one around Mars.
Credit: ESA


Soon Rosetta will go into deep space hibernation as it moves toward a rendezvous with the comet 67P/Churyumov-Gerasimenko, on May 2014. After it lands, it will accompany the comet on its plunge around the sun.

Two months ago, on June 13, the Japanese aerospace exploration agency JAXA's Hayabusa spacecraft returned successfully to earth after a seven year mission, perhaps bearing a small sample of the asteroid 25143 Itokawa.


Credit: JAXA
Thirty months after its launch May 2003, it approached and landed on the asteroid 25143 Itokawa, and I wrote about that at the time, here. It attempted to take a sample of the asteroid surface, and return to space. There were some problems with communication for a month, and then a year after that Hayabusa started its ion engines up for a limping return to Earth.

Itokawa is a midget, compared to these other relative behemoths. It's less than a kilometer in all dimensions, much less, actually. Quite a performance to succeed in landing on it. Take a look at the very last image in this post, and see how small it is.


Here is a somewhat overwrought but still quite good nine minute youtube video summarizing Hayabusa's journey. And here is a very dramatic video of Hayabusa's breakup and the sample capsule's successsful descent to Australia a few weeks ago.


Here is a composite, rendered by NASA, of three asteroids visited by NEAR-Shoemaker and Galileo. NEAR passed just 1200 km from 253 Mathilde on June 27, 1997, just a flyby on its way to smaller and better things. At 59x47 km, Mathilde was considerably smaller than Lutetia, but a million times larger in volume than Itokawa above.



NEAR's destination was actually the smaller, elongated asteroid 433 Eros. On February 14, 2000, NASA succeeded in putting NEAR into an orbit around Eros. Over the next year, NEAR took wonderful photos and movies as NASA gradually lowered the orbit. On Feb 12, 2001, NEAR landed on Eros, where it still remains.
Credit: NASA


Galileo is the intrepid spacecraft, which along with a lander, spent years from 1995 until late 2003 swooping in complex orbits around Jupiter, doing flybys of the Jovian moons, sending back thousands of images. It discovered the likely oceans under Europa, and imaged the turbulent and volcanic surface of Io. It was finally dropped into Jupiter to avoid any possible contamination with potential oceans on Europa.

But before it did any of that, it made two close encounters with asteroids on its way out.


Credit: NASA
Two years after its launch October 1989, Galileo entered the asteroid belt and on October 29, 1991, passed within 1600 km of 951 Gaspra, the first-ever asteroid encounter. At 19x12x11 km, Gaspra is certainly not round.


Almost two years later into its flight, Galileo passed 2400 km from 243 Ida, another elongated asteroid. The amazing thing that came through on the images was that the 52 km long Ida had a tiny 1.2km moon, which was named Dactyl. Dactyl orbits about 90 km above Ida.

I recall my draw dropping when I saw this photo of Ida and Dactyl, in Nature or Science, 17 years ago.

Credit: NASA


The four spacecraft in my little timeline above are certainly not the only spacecraft to have flown by asteroids, and asteroids are not the only solar system objects that have had close encounters.

The Cassini mission to Saturn, a still ongoing counterpart to the Galileo mission to Jupiter, passed within 1.6 million km of 2685 Masursky on Jan 23 2000. Cassini. No need to present a photograph here - it was just a little dot in the images.

NASA's Stardust visited both an asteroid, 5535 Annefrank, on Nov 2, 2002, and a comet: Comet Wild 2, on Jan 2 2004.


Credit: NASA
Stardust flew by the 6 km nucleus of Comet Wild 2 and collected dust from the comet. It returned to Earth and on January 15 2006 released a sample capsule containing the dust. Stardust continues on its mission to Comet Tempel 1. It now goes by the mission name NExT, for New Exploration of Tempel 1, and is expected to fly by Tempel 1 February 14, 2011.


There's a good reason to mention Comet Tempel 1, sometimes called Comet 9P/Tempel, since it had previously been visited by NASA's Deep Impact, five years ago. On July 4, 2005, Deep Impact did just what its name suggested - it made a high energy crashlanding on Tempel 1. Tempel 1 has since rounded the sun, and newly named Stardust will be photographing the results of the crash and the changes in the comet after a close passage to the sun.
Credit: NASA


Let's round out the visits to asteroids and comets with the first such encounter to one of the most famous of comets, Comet Halley. Halley returned to our vicinity in 1986. It was something of a dud apparition to us, nothing like its 1910 appearance. But it was approached by a multinational fleet of spacecraft, two Vegas from the Soviet Union, and two probes from Japan, as well as a probe from the US. These five spacecraft preceded the ESA's Giotto, and transmitted information that allowed it to pass very closely (500km) to Halley's nucleus, which it did on March 13-14, 1986.


Credit: ESA

It had been expected that Giotto would be severely damaged or destroyed by the close passage through the halo and past the nucleus, but this turned out not to be the case. The ESA redirected Giotto toward Comet Grigg-Skjellerup, and on July 9, 1992, six years later, Giotto passed by *its* nucleus within 100km.

So there you have it. More than a dozen encounters with both asteroids and comets over the last 24 years. Some missions have done flybys on their way to other things (Galileo and Cassini), and some have been targeted. Some have landed on an asteroid or comet, and some of these have returned material to earth.

Wouldn't you know that someone else had this sort of idea, and went a step farther? Here's a nice treat, a composite put together by Emily Lakdawalla of The Planetary Society. It's of all the asteroids and comets, sized proportionately, that have been visited up through Lutetia last month. I said Lutetia was big, didn't I?

You can visit the Planetary Society Blog, which put together this composite, and get a much larger version. Very nice.

Remember that landings have been accomplished on Eros and Itokawa, the two asteroids at left center. You can barely see Itokawa in the image below, but that's the one that a sample was taken from and returned to earth two months ago.



I should say here that I used the excellent Wikipedia pages on each of these missions for dates and other basic information. I did not link to these, but they're very easy to find by searching on the spacecraft or asteroid or comet's name. I linked to the appropriate space agency's pages for credit to photographs and mission details. NASA is the US space agency, and ESA is the European Space Agency. JAXA is Japan's space agency.


Wednesday: 4 August 2010

What Fun is This?  -  @ 12:35:23
The sun, dormant for the last few years (and longer than might have been expected), is starting to get rowdy and rambunctious.

A coronal mass ejection has occurred on August 1, as detailed by NASA here, and should arrive... well, just about now. C-class, that's what they say, not huge, but big enough to generate lights in the sky.

Well all right, then. Folks in the north should get their butts outside and watch for aurorae. I doubt if we would see anything this far south, but how fine does it get to see an aurora?

We're starting to see the sun's 11-year cycle begin to ramp up and display now, and increasingly for the next few years. The sun will spew off lots of these CMEs, but most of them don't impact us - only the ones that are directed toward us. This one is, apparently.

If you're in the north, or even if you're not, have your camera on a tripod. Play around with it so that you know what exposures to take to grab a possible photo of an event that I'd describe as awesome, though my students use that term to describe a cold pizza for breakfast.

Cats Ear  -  @ 06:12:15

Contrary to predictions (in green, at left), the temperatures have been considerably mellow the last couple of days. Things are expected to get back to normal today, which is to say five or six degrees above normal highs.

There has also been unexpected rain. On Sunday we had a tiny bit, but other stations close by reported more rain than this (one 20 miles east reported 3.40"!). With rain, of course, comes infernal humidity, especially with the cooler temperatures. I'm not sure which I prefer, now!


Here's a tedious little analysis of a not especially spectacular plant identification. As tedious as it is, it's easier to write up than some things are.

I've paid this plant, found along the roadcut leading to the first deck, a couple of visits over the last few weeks. The first two photos below were made July 10, and I thought we had a hawkweed (Hieracium spp.) of some sort.



There are often identifying characters on the back of a flower, especially the head of an Asteraceae. The coloration of the bracts, presence of glands, and so forth can help in identifying a plant.



I'm always excited about a possible hawkweed. The notches in the petal tips are the right teases, but there were a few things about the plant that didn't seem right. Only eight petals, for instance - hawkweeds tend to have many more. And the stems don't have leaves on them (leaves on the stem are called cauline leaves), which is ok but then there must be some things about the bottom rosette leaves, which I had not examined. This demanded further visits, which netted additional information a week later.

Here are two flowers from the same plant. One resembles the eight-petaled ray flowers of the first photo above, but the other is older, and the inside disc flowers have now opened. This much more resembles a hawkweed, but I don't think the internal structure of the individual florets in the head is right.



The next thing is the stem. I had already suspected one alternative candidate, Cat's Ear (Hypochaeris spp.). A good indication of this would be the presence of little scale-like nubs instead of leaves, and in fact there they are.



Of the couple of possibilities of hawkweed, both would require colored venation on hairy leaves. While these are somewhat hairy, they don't have the pigmentation necessary. The are shallowly lobed, though, and that pretty much marks the plant as cat's ear.



Of the four possibilities, all of which are nonnative, the most likely one is Hairy Cat's Ear, Hypochaeris radicata. This one is probably considered the most invasive (although it certainly wasn't a problem here). It could still be one of the other three, but hairiness of stems and rosette leaves suggests not.

Basically, it's a dandelion ; - )  , although not the usual Taraxacum dandelion.

The keys I looked at were not especially useful - they rely eventually on seeds to get down to species, and there were no seeds to be examined, yet. What offered the cat's ear alternative was my Peterson's wildflower field guide - the keys did help by providing some additional pointers on hairiness, and the disposition of leaves.



Tuesday: 3 August 2010

Good Bad Badder  -  @ 08:50:12
Good.

In an unexpected development, the National Weather Service forecast for our area was completely wrong in the matter of yesterday's high temperatures. They were actually ten degrees lower - it never got above 85F. It was a nice relief!

Bad.

Microstegium eradication season starts here. Actually I've been pulling up some around the house already, but now it must continue in greater earnest. In some ways the conditions have been very conducive for Microstegium during the germination season - warmer than usual, and wetter for at least two months out of four. We'll see how that works out for us.

Now prepare yourself for the badder.

You might have heard or read, in the last week or so, of the discovery that phytoplankton populations in the world's oceans have diminished 40% since 1900. NPR's All Things Considered did a short five minute take on this, and it's fairly decent.

The paper, "Global phytoplankton decline over the past century," by DG Boyce, MR Lewis, and B Worm (Nature 466, 591-596 (2010)) can be found here. (Update, because I neglected this, the authors are with Dalhousie University, Halifax, Nova Scotia, Canada.)

Since 1900, hundreds of thousands of oceanographic measurements have been made. I'm not sure that the observers would have thought of this as a labor of love, but it is certainly a bequest to future generations. For this work, the authors took the half million turbidity measurements made by Secchi disk over the last century, including later direct chlorophyll measurements. They used these to estimate the phytoplankton levels over time in many locations.

Like local temperatures, the levels of phytoplankton rise and fall in complex cycles, depending on location, but overall there has been a massive decline in phytoplankton populations globally. The authors hypothesized that there might be a correlation with sea surface temperatures, and tested this. They found that increasing SSTs were positively correlated with increased phytoplankton in the Arctic, but overall negatively correlated in tropical and subtropical waters. They term this the SST effect.

Their tentative explanation - increased SSTs are stagnating the ocean circulation, preventing nutrients from rising from the bottom to the surface of the ocean in places where you normally get upwelling. We're not killing the phytoplankton, exactly. The inorganic nutrients that would support them are just not getting to the surface where they need it.

It strikes me that, if confirmed, this is likely to be a profound discovery. It's not the discovery of an unknown *thing*, but rather the kind of discovery that I might compare to sausage:

Everyone knows there's sausage, some may love it (or not). But suddenly, let's say, everyone finds out how sausage is made. It's not the discovery of sausage (or phytoplankton), but rather the discovery of a process - how it's made (or the fact of the phytoplankton decline).

Why is this profound? Because, and again if it's confirmed, it's a 40% decline, over a century, with the bulk of that decline actually occuring over the last half a century. My impression is that marine scientists have had a feeling about this all along, in smaller ways, but not perhaps a grasp of the totality of it. Certainly it's only percolated into the larger public view in a limited sort of way up to this point. The work has the potential of being a kind of a tour de force that we don't see all that often. It's nothing complicated, but it is a kind of an inspired achievement whose implications will leave us jaw-dropped.

So why is it important? Phytoplankton account for half the planetary biomass of producers: cyanobacteria, algae, and land plants. All animals, fungi, and many bacteria depend on them directly or indirectly. Phytoplankton put half of the oxygen into the atmosphere, and they take out half of the carbon dioxide, and for the rest of marine life they produce all the food. A reduction of this vast engine by half of 40% has a lot of implications:

1. Do global climate models incorporate these declines? I don't know, but if they don't I bet they're going to if the very heavy underscoring of this trend proves out. It will be very interesting to see how GCMs behave in view of this.

2. The NPR story focused on this: it's generally been concluded that overfishing has led mostly to the decline of populations of marine life used for food (as well as innocent bystanders). Surely that's true, but now there's the additional fact that the baseline of marine animal life must also haven been reduced by 40% as its pastures of the seas have diminished.

3. Never would I thought that oxygen, at a very stable 21% of the atmosphere, would be significantly affected, and I don't think this paper mentions any such thing. But if the rate at which it is replenished is reduced by 20% (half of 40%), then what? These are enormous numbers.

4. The biological pump, and I'll bet you had no idea about this:

We all know that carbon dioxide is taken out of the air by producers - half of which are the very phytoplankton we're talking about. But phytoplankton don't just recycle the carbon dioxide - a large portion of that carbon is permanently removed by the biological pump. Their little dead bodies, plus those of their eaters, can fall to the bottom and become part of the sediment. A good part of that carbon is removed for many hundreds of millions of years as it gets sucked into the earth by tectonic plate action, and it's only returned to the atmosphere by volcanos. Now that biological pump can be seen to be reduced in its effectiveness by possibly 40%.

5. Ocean acidification. This isn't really a part of this particular story, because as it is a more recent worrisome probem it can't explain how a 40% decline has occurred in a hundred years. Still, acidification of the surface oceans due to increased carbon dioxide in the air may further degrade the species of plankton that secrete calcium carbonate shells. Since those are the ones that drive the biological pump in 4 above, it's a further stress on that important mechanism for carbon removal.

What to watch for? Decline Denialists, for one thing, guarantee it. You'll hear that "phytoplankton decline in cycles," and "this is just a cycle," and "humans can't have an effect on phytoplankton." We've heard it all before, with climate change. I'd say you'll see more activity in monitoring phytoplankton decline, for another, and searching for more proxies that will confirm independently these results. There will of course be perfectly legitimate examination and testing of the data and interpretations of the Nature paper we're talking about here.

So here I've gone and spoiled your whole day, but not really. This is the discovery of a possibly suspected, but generally unknown trend. We didn't wake up this morning and find that 40% of phytoplankton that were there yesterday are gone today. What we find is that something disturbing has been going on for quite awhile, casting an influence that we may not have been taking into account. Now that trend can be estimated and incorporated, something that will take place over the next months and years. We just have to see where that leads us.



Monday: 2 August 2010

The Month of July  -  @ 04:25:49
It's The Month of July, Number 54 in a series. The word here, for July, was hot, as it was in April, May, and June. In June we had high temperatures above 90 degF for 20 straight days. In July we had 23 days of above 90 highs, with 15 of them above 95. We had six days that went over 100 degF, and broke a 120+ years high temperature record on July 26.

This time, they're hiding the usual temperature anomalies product here, at the National Weather Service Climate Prediction Center. Below are four panels - the top row is for high temperatures, the bottom for lows. On the left are the absolute temperatures in degF, and on the right are the anomalies. We're all used to doing anomalies by now, right?



As in April, May, and June, the eastern half of the US experienced hotter than usual temperatures in July, while parts of the west had cooler than normal high temperatures. Oddly, just about everyone experienced warmer than usual nighttime lows over the last thirty days. Things just didn't cool off at night.

We find the National Weather Service Climate Prediction Center's precipitation plots here these days.

The eastern US was a patchwork of mostly slightly below normal rainfall. Dry conditions abound in both the eastern and the western US. Looks like there was a superabundance of rainfall in the central states. I'll bet that bright green in Texas and surrounding had to do with a couple of tropical storms!



For Athens:

For Athens, we continued for the fourth month in a row a warmer than usual trend. Our high temperatures were 4.4 degF higher than normal; our lows 2.1 degF higher.

Here is my plot of high temperatures for the month of July in Athens. (It seemed appropriate to present high temperatures this time.) As usual, these data for Athens covers the period beginning 1990. 1990-2008 (black dots), 2010 (green line), and 2009 (red line).



We broke one high temperature record in July with 104 degF on July 26.

We had 14 days of high temperatures that were at least one standard deviation higher than average, and the usual number of such days is 4.9. That's pretty significant. We had 4 nights below the standard deviation for our usual lows, compared to 4.6 such nights, and that's probably not significant.

The figure below shows the Athens rainfall data which are official for our area. As usual the green line shows our actual rainfall, the red shows the average accumulation expected. The black dots are rainfall over the last 20 years, the vast river of peach shows the standard deviation.

In June, rainfall was very heterogeneous, netting a surplus 4.55" for Athens but 3.59" for Wolfskin, a deficit. July's rain evened out a bit more - we were both well under the average July rainfall of 4.41". Athens got 1.40", and Wolfskin got 1.82".



Not only will I continue to link to this neat prognosticator in which you can get variously timed precipitation and temperature outlooks, I show a screenshot of the three-month prediction made at the end of July:



For us, the long term (three months) continues to suggest that our summer will continue more than a little warmer than usual, with perhaps average rainfall. Let's hope for the latter, because we certainly haven't had it.

Geekstuff:

NOAA's weekly ENSO update tells us that we're now experiencing La Niña conditions. Climatologist expect to announce a La Niña in a couple of months. (Remember that since a formal La Niña or El Niño must last at least five months, you can only declare it after that period of time. We know we're in one, though, and have been since May.)

The last time we were in a significant La Niña was from Aug 2007 to May 2008 - August 2007 was the horrible month of 107 degF high temperatures, and very dry conditions.

Relive your favorite weather events, courtesy of NOAA. NOAA has a neat Monthly State of the Climate product, among the many interesting weather-related items to be found here.


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