Archive for April, 2014

Lake Superior Freeze/Thaw Time Lapse: Ice Until June?

Tuesday, April 29th, 2014

I put together this time lapse video of Lake Superior satellite imagery, from MODIS on NASA’s Aqua and Terra satellites, which spans Dec. 11, 2013 through yesterday, April 28, 2014. I included only days when the lake was not overcast with clouds.

As the lake cooled from strong arctic air mass outbreaks in December and January, lake effect convective snow bands predominate. Then, as the lake gradually freezes, there are more clear days as the moisture source for the clouds is shut off.

Note how much the ice moves from wind changes, just as it does in the Arctic Ocean. It used to be that people ice fishing would become stranded when the wind shifted and blew the ice floe they were on out onto the lake.

With record-high ice coverage for the end of April, and more cold weather on the way, it is possible that Superior might not be entirely ice-free until June. I used to live on the St. Marys River, which drains out of Lake Superior, and I remember a couple of years in the 1970s when ice was still floating downstream by late Spring.

Some great winter photography of Lake Superior is available at Lake Superior Photo, including ice caves, aurora, and various ice-scapes.

Skeptical Arguments that Don’t Hold Water

Friday, April 25th, 2014

There are some very good arguments for being skeptical of global warming predictions. But the proliferation of bad arguments is becoming almost dizzying.

I understand and appreciate that many of the things we think we know in science end up being wrong. I get that. But some of the alternative explanations I’m seeing border on the ludicrous.

So, here’s my Top 10 list of stupid skeptic arguments. I’m sure there are more, and maybe I missed a couple important ones. Oh well.

My obvious goal here is not to change minds that are already made up, which is impossible (by definition), but to reach 1,000+ (mostly nasty) comments in response to this post. So, help me out here!

1. THERE IS NO GREENHOUSE EFFECT. Despite the fact that downwelling IR from the sky can be measured, and amounts to a level (~300 W/m2) that can be scarcely be ignored; the neglect of which would totally screw up weather forecast model runs if it was not included; and would lead to VERY cold nights if it didn’t exist; and can be easily measured directly with a handheld IR thermometer pointed at the sky (because an IR thermometer measures the IR-induced temperature change of the surface of a thermopile, QED)… Please stop the “no greenhouse effect” stuff. It’s making us skeptics look bad. I’ve blogged on this numerous times…maybe start here.

2. THE GREENHOUSE EFFECT VIOLATES THE 2ND LAW OF THERMODYNAMICS. The second law can be stated in several ways, but one way is that the net flow of energy must be from higher temperature to lower temperature. This is not violated by the greenhouse effect. The apparent violation of the 2nd Law seems to be traced to the fact that all bodies emit IR radiation…including cooler bodies toward warmer bodies. But the NET flow of thermal radiation is still from the warmer body to the cooler body. Even if you don’t believe there is 2-way flow, and only 1-way flow…the rate of flow depends upon the temperature of both bodies, and changing the cooler body’s temperature will change the cooling rate (and thus the temperature) of the warmer body. So, yes, a cooler body can make a warm body even warmer still…as evidenced by putting your clothes on.

3. CO2 CANT CAUSE WARMING BECAUSE CO2 EMITS IR AS FAST AS IT ABSORBS. No. When a CO2 molecule absorbs an IR photon, the mean free path within the atmosphere is so short that the molecule gives up its energy to surrounding molecules before it can (on average) emit an IR photon in its temporarily excited state. See more here. Also important is the fact that the rate at which a CO2 molecule absorbs IR is mostly independent of temperature, but the rate at which it emits IR increases strongly with temperature. There is no requirement that a layer of air emits as much IR as it absorbs…in fact, in general, the the rates of IR emission and absorption are pretty far from equal.

4. CO2 COOLS, NOT WARMS, THE ATMOSPHERE. This one is a little more subtle because the net effect of greenhouse gases is to cool the upper atmosphere, and warm the lower atmosphere, compared to if no greenhouse gases were present. Since any IR absorber is also an IR emitter, a CO2 molecule can both cool and warm, because it both absorbs and emits IR photons.

5. ADDING CO2 TO THE ATMOSPHERE HAS NO EFFECT BECAUSE THE CO2 ABSORPTION BANDS ARE ALREADY 100% OPAQUE. First, no they are not, and that’s because of pressure broadening. Second, even if the atmosphere was 100% opaque, it doesn’t matter. Here’s why.

6. LOWER ATMOSPHERIC WARMTH IS DUE TO THE LAPSE RATE/ADIABATIC COMPRESSION. No, the lapse rate describes how the temperature of a parcel of air changes from adiabatic compression/expansion of air as it sinks/rises. So, it can explain how the temperature changes during convective overturning, but not what the absolute temperature is. Explaining absolute air temperature is an energy budget question. You cannot write a physics-based equation to obtain the average temperature at any altitude without using the energy budget. If adiabatic compression explains temperature, why is the atmospheric temperature at 100 mb is nearly the same as the temperature at 1 mb, despite 100x as much atmospheric pressure? More about all this here.

7. WARMING CAUSES CO2 TO RISE, NOT THE OTHER WAY AROUND The rate of rise in atmospheric CO2 is currently 2 ppm/yr, a rate which is 100 times as fast as any time in the 300,000 year Vostok ice core record. And we know our consumption of fossil fuels is emitting CO2 200 times as fast! So, where is the 100x as fast rise in today’s temperature causing this CO2 rise? C’mon people, think. But not to worry…CO2 is the elixir of life…let’s embrace more of it!

8. THE IPCC MODELS ARE FOR A FLAT EARTH I have no explanation where this little tidbit of misinformation comes from. Climate models address a spherical, rotating, Earth with a day-night (diurnal) cycle in solar illumination and atmospheric Coriolis force (due to both Earth curvature and rotation). Yes, you can do a global average of energy flows and show them in a flat-earth cartoon, like the Kiehl-Trenberth energy budget diagram which is a useful learning tool, but I hope most thinking people can distinguish between a handful of global-average average numbers in a conceptual diagram, and a full-blown 3D global climate model.

9. THERE IS NO SUCH THING AS A GLOBAL AVERAGE TEMPERATURE Really?! Is there an average temperature of your bathtub full of water? Or of a room in your house? Now, we might argue over how to do the averaging (Spatial? Mass-weighted?), but you can compute an average, and you can monitor it over time, and see if it changes. The exercise is only futile if your sampling isn’t good enough to realistically monitor changes over time. Just because we don’t know the average surface temperature of the Earth to better than, say 1 deg. C, doesn’t mean we can’t monitor changes in the average over time. We have never known exactly how many people are in the U.S., but we have useful estimates of how the number has increased in the last 50-100 years. Why is “temperature” so important? Because the thermal IR emission in response to temperature is what stabilizes the climate system….the hotter things get, the more energy is lost to outer space.

10. THE EARTH ISN’T A BLACK BODY. Well, duh. No one said it was. In the broadband IR, though, it’s close to a blackbody, with an average emissivity of around 0.95. But whether a climate model uses 0.95 or 1.0 for surface emissivity isn’t going to change the conclusions we make about the sensitivity of the climate system to increasing carbon dioxide.

I’m sure I could come up with a longer list than this, but these were the main issues that came to mind.

So why am I trying to stir up a hornets nest (again)? Because when skeptics embrace “science” that is worse that the IPCC’s science, we hurt our credibility.

NOTE: Because of the large number of negative comments this post will generate, please excuse me if I don’t respond to every one. Or even very many of them. But if I see a new point being made I haven’t addressed before, I’ll be more likely to respond.

American Thinker Publishes a Stinker

Thursday, April 24th, 2014

I really dislike going down this road, but it’s articles like this (Global Warming and Settled Science, in American Thinker) from today that confuse the global warming science debate and end up wasting my time as I get e-mails asking for comment.

Now, those familiar with my views KNOW I’m a huge critic of the climate models used to predict global warming. I believe there are serious biases in them. But most of the physics they involve are pretty good. Yet, it only takes one component (e.g. a cloud parameterization) to change a model’s response to increasing CO2 from catastrophic warming to benign warming.

So, when author Andre Lofthus throws around some radiation physics concepts and claims that the atmosphere cannot warm from more CO2 because (basically) the CO2 absorption bands are already 100% saturated, well, I have to respond. I’ve already done that once by e-mail this morning, but I’m sure more requests are coming, so I’m going to try to nip it in the bud here. (Awhile back a NASA story about CO2 cooling [GASP! COOLING!] in the upper atmosphere led to a Slayer blog post that I was getting e-mails about for months after. As if we didn’t already know that CO2 strongly cools the upper atmosphere. Geez.)

So, here we go again…

It doesn’t matter even if the CO2 absorption bands are 100% opaque to the transmission of IR radiation from the surface to the top of the atmosphere…adding more CO2 still causes a warming tendency in the lower atmosphere (and cooling in the upper atmosphere).

There are two reasons for this. The first is that pressure broadening of the absorption lines leads to the absorption lines influencing much wider ranges of wavelengths, which are not “saturated”, that is, not 100% opaque.

The second reason is that, even if there is 100% opacity (which there cannot be for gaseous absorption), if you add more and more CO2, the effective radiating altitude to space goes ever higher, which is colder, which means less IR radiation, which means a warming tendency for the lower atmosphere.

In other words, 100% opacity of the atmosphere to IR in the CO2 absorption bands — even IF it existed — would not prevent a lower atmospheric warming tendency (and upper atmospheric cooling tendency) in response to further increases in CO2. This is why the surface of Venus is hot enough to melt lead…the atmosphere is so strongly radiatively insulated against loss of IR to space that the temperatures climb until radiative energy balance is achieved. Models have quite adequately explained the temperature profile on Venus with the known atmospheric composition, just as they explain the temperature profile here on Earth.

And until the Slayers and Mr. DC and Mr. JP come up with an alternative time-dependent model that converges to the observed temperature profile, they are doing little more than hand-waving.

The best direct observational evidence I have seen that increasing CO2 causes less IR to escape from the Earth to space is the NASA AIRS CO2 retrievals. These retrievals measure and quantify the IR “trapping” effect (a poor term, I admit) at various IR wavelengths from the AIRS satellite measurements, which as I understand it, agrees quite well with established theory:

The real question for global warming is, what are the feedback responses of the climate system to the resulting warming tendency? I believe it is relatively strong negative feedback, and little net warming. Maybe with some deep-ocean heat storage thrown in (it won’t matter to anyone or anything if the deep ocean warms from 40.2 deg. F to 40.3 deg. F in the next 50 years).

Not all of global warming theory has to be wrong…just one weak link in the chain can cause the whole house of cards to fall. Oops…I think I just mixed my metaphors again. Oh well, that’s the way the cookie bounces.

Earth Day – A Time to Reflect on Greenland’s Destruction

Tuesday, April 22nd, 2014

The recent discovery of 80-year old photos of Greenland before we melted most of the ice there provides a stark reminder of how much humans have destroyed our home, Planet Earth.

One of the old photos shows the pristine, ice-covered landscape, no doubt home to all kinds of cold-weather species of organisms:

The view of the same landscape today (from a slightly different angle), sadly, shows how warming has decimated the region, with all kinds of invasive species taking hold in the fragile soil:

So, on this Earth Day, I hope we can all pause to reflect on what a warmer Earth means for our future.

And our children’s future.

And our grandchildren’s future.

And our great grandchildren’s future.

I think you see where I’m going.

I hope you all have a miserable, guilt-ridden Earth Day.

So that MY life might have meaning.


Some Earth Day Cartoons

Tuesday, April 22nd, 2014


As in other religions, most Earth worshipers are more or less hypocritical. Spend a day being “good”, spend the rest of the year failing.

Or maybe just fail every day…

Unless you live your life in as Spartan a manner as Ted Kaczynski, you are probably as big a drain on Earth’s resources as anyone else. I wonder how many people will drive to a tree-planting ceremony today, putting many more times as much carbon dioxide into the atmosphere as that single tree will ever remove? (Of course, when the tree dies, it’s mostly all released again anyway).

Some people mistakenly believe the internet has little impact on our resources:

Of course, we could go into the dark side of the environmental movement, which inevitably involves population control of one kind or another (usually forced upon some far-away people of a different skin color…not upon the enforcers):

I mostly find Earth Day just plain annoying for the rank hypocrisy on display. A state-sponsored religious day of worship, along with all of the 1st Amendment-violating regulations to codify it.

Maybe a nice bonfire to celebrate for those so inclined.

But for me,…

Can Infrared Radiation Warm a Water Body?

Monday, April 21st, 2014

I frequently see the assertion made that infrared (IR) radiation cannot warm a water body because IR only affects the skin (microns of water depth), whereas solar radiation is absorbed over water depths of meters to tens of meters.

Before discussing the issue, though, we first must agree that temperature and temperature change of a body is related to rates of energy gain and energy loss by that body. If we cannot agree on the basic concept that temperature changes when energy gain does not equal energy loss, then there is no basis for further discussion.

If the surface of a water body is emitting IR, then IR must be part of its energy budget, and therefore of its temperature. Evaporation only occurs at the skin, and we know that evaporation is the major component of heat loss by water bodies. How is it that evaporation can perform this function, and IR cannot?

The temperature of land clearly is affected by IR, and that only occurs at the surface of the soil. So, how can IR affect land temperature and not ocean temperature?

If you claim that any additional IR (say, due to increasing carbon dioxide) is immediately lost by the water body through evaporation, how exactly does that occur? The surface doesn’t know why it has the temperature it does, it will evaporate water based (partly) on surface temperature, and it does not distinguish where the heat comes from (solar radiation from above, mixing from below, IR from above, sensible heat flux across the air/water interface). To claim that any energy gain from IR is immediately lost by evaporation is just an assertion.


It might well be that solar radiation is more efficient (on a Watt per Watt basis) than IR radiation at changing ocean temperature. In other words, that IR warming of a water body is more likely to be lost through evaporation, since its warming effect does occur only at the surface, and so that energy is more likely to be lost through evaporation than absorbed solar radiation would be.

The effect would be greatest during low wind conditions, when vertical mixing of the water is weakest.

From what little I know of ocean modelling, this potential effect – which I presume is what people are talking about — is not taken into account. I suspect it would have to be parameterized, because it occurs on such a small scale. As far as I know, a Watt of IR is treated the same as a Watt of solar in the energy budget of the top ocean layer in a model.

I would like to hear what others know about this issue. I suspect it is something that would have to be investigated with a controlled experiment of some sort.

Life on Earth: Principal control knob governing Earth’s temperature

Thursday, April 17th, 2014

tropical-rainforestThe title of this post is a purposeful play on the title of a 2010 paper by Lacis, Schmidt, Rind, and Ruedy, entitled Atmospheric CO2: Principal control knob governing Earth’s temperature.

In that paper, the authors claimed that the existence of CO2 is what provides enough warming to keep the Earth from becoming an ice planet. They also claim that, because CO2 is “non-condensing” (whereas water vapor, Earth’s most abundant greenhouse gas, does condense) this gives it special status as some sort of primary control knob governing Earth temperatures.

That latter argument has never quite convinced me of anything…both CO2 and water vapor have various sources and sinks, and just because water vapor goes through a phase change and CO2 doesn’t is, in my mind, irrelevant. Yes, the CO2 source/sink processes act more slowly than the water vapor ones (evaporation and precipitation) do, but on the long time scales of Earth’s history, who cares?

But the main point of the current post is to stimulate some thought regarding another possibility regarding how we view carbon dioxide: rather than the existence of CO2 being the primary warming mechanism of climate, maybe it is the existence of life on Earth which provides the primary cooling mechanism.

Think about this: What is the natural state of of the planets closest to Earth? Both Mars and Venus have atmospheres which are nearly 100% carbon dioxide. Presumably, without life on Earth, we too would have a planet with nearly 100% CO2.

So doesn’t it make more sense to use THAT as a starting point for discussion, rather than a hypothetical Earth with NO carbon dioxide?

The small amount of CO2 in Earth’s atmosphere (about 4 parts per 10,000) is presumably due to biological processes “sucking on” that “food” source as hard as possible (further evidenced by the fact that our production of CO2 through fossil fuel burning is 50% consumed by natural processes).

So, maybe it is life on Earth that should be viewed as the primary CO2 cooling mechanism for the Earth’s climate system, by reducing atmospheric CO2 concentrations from nearly 10,000 parts per 10,000, to only 4 parts per 10,000.

Just thinking out loud…

ENSO, SST, CERES, forcing, and feedback: The travesty continues

Wednesday, April 16th, 2014

Now that the CERES radiative flux products from the NASA Terra and Aqua satellites have been updated through October, 2013, I thought I would update the comparison between global average SST variations and CERES to examine forcing and feedback issues.

As in my recent post on SSM/I ocean variables, all plots below are for the global area-average ice-free ocean between 60 deg. North and South latitudes.

Starting with the SST variations, with the anomalies computed relative to the CERES period (March 2000 thru October 2013), we see that global average SST is reasonably well correlated with ENSO activity, which I am representing with the Multivariate ENSO Index (MEI). (Linear trend lines are for entertainment purposes only).

Fig. 1. Three-month anomalies in global average SST and MEI (scaled to SST) between March 2000 and October 2013.

Fig. 1. Three-month anomalies in global average SST and MEI (scaled to SST) between March 2000 and October 2013.

The corresponding CERES radiative flux anomalies computed over the ocean also show a response to ENSO activity.

Fig. 2. Three-month global ocean anomalies in CERES all-sky radiative fluxes.

Fig. 2. Three-month global ocean anomalies in CERES all-sky radiative fluxes.

But in order to put the above pieces of the puzzle together, I have found that lag regression between SST and the other variables leads to considerable physical insight. The following plot shows how different variables change before and after SST during the 13+ year CERES period of record.

Fig. 3. Lag regression coefficients between SST and several other variables, based upon monthly running 3-month average anomalies.

Fig. 3. Lag regression coefficients between SST and several other variables, based upon monthly running 3-month average global ocean anomalies.

We see that 12-18 months before peak SST is reached, there is a radiative accumulation of energy, both solar shortwave (SW) and infrared longwave (LW). (Net is close to the sum of the two, but with the sign flipped, so that positive numbers represent energy lost by the climate system).

The curve based upon SSM/I cloud water shows that there is a ~1% decrease in cloud water over the ocean about 9-18 months before peak SST anomalies of ~0.1 deg. C are reached, which probably explains the solar SW curve. This is the “internal radiative forcing” we talk about…the climate system’s cloud cover is not constant, and varies depending on circulation regime (El Nino or La Nina), creating a forcing of later temperature change.

As peak temperatures are approached (at zero time lag), the radiative fluxes change to a net loss, which continues for many months as SSTs then cool.

As long-time loyal readers of my blog are aware, the regression relationships at zero time lag are what are traditionally used to estimate feedbacks in the climate system, a methodology which I (and Lindzen) believe is seriously in error. Since feedbacks determine climate sensitivity, and sensitivity determines how much anthropogenic global warming there will be, this is a critical issue.

I’ve spent years studying this problem in considerable detail, and I don’t see any way yet to diagnose feedback (the radiative response to a temperature change) when there is a simultaneous, unknown, radiative forcing of temperature change going on.

The climate system is constantly out of balance, and without knowing how much internal radiative forcing is occurring, you can’t know the size of the net feedback. Radiative forcing always opposes net radiative feedback, and if forcing is occurring, any estimate of feedback is biased in the direction of positive feedback (high climate sensitivity).

We have three papers published on this (Lindzen has others), and as far as I can tell, the climate community still does not understand the implications of our work.

What we do know is that the climate models we have analyzed show relationships that depart significantly from the observations, and in the direction of high climate sensitivity. Our most significant papers on this, which I fully stand behind, are here and here. (The latter paper is the one that led to the journal editor resigning and apologizing to Trenberth for allowing to be published…even though it was peer reviewed, and never retracted.)

This is a subject on which the scientific consensus, as far as I can tell, is clueless. Attempts to refute our work have been feeble at best. Andy Dessler claims the radiative signals are all feedback (no “internal forcing”) and are a response to previous temperature changes.

Well, if that is the case (as I have asked him), why doesn’t he then use a time lag in his feedback diagnoses? As Lindzen has shown, when this is done you diagnose strong negative feedback. Oops…wrong answer for the IPCC.

To paraphrase Trenberth, we can’t account for the IPCC’s continuing to ignore this issue, and it is a travesty that we can’t. ;-)

For those interested in the data which went into the above plots, here is the spreadsheet.

Do aliens cause global warming? The data say ‘yes!’

Tuesday, April 15th, 2014

It’s been over 11 years since the late novelist Michael Crichton advanced the hypothesis that aliens cause global warming.

I decided it was time to test his claim with real data.

Well, sure enough, the monthly UFO reports in recent decades are highly correlated with the increase in global ocean heat content. In fact, the relationship is so strong, if this was an epidemiological study it would be time to regulate UFOs.

Between 1979 and 2011 the number of UFO reports has been increasing right along with the average temperature of the upper 700 meters of ocean:

Fig. 1. Time series of monthly UFO reports and global average ocean temperature anomalies from the surface to 700 m depth. Trailing 12-month averages are also shown.

Fig. 1. Time series of monthly UFO reports and global average ocean temperature anomalies from the surface to 700 m depth. Trailing 12-month averages are also shown.

The correlation between UFO reports and ocean temperature is over 0.95, clearly better than the correlation between that boring old carbon dioxide and ocean warming:

Fig. 2. Lag correlations between UFO reports vs. upper ocean temperature, and CO2 versus upper ocean temperature.

Fig. 2. Lag correlations between UFO reports vs. upper ocean temperature, and CO2 versus upper ocean temperature.

In fact, note the tendency for CO2 to follow ocean temperature , suggesting a weak tendency for warming ocean water to outgas CO2 (or reduce the uptake of atmospheric CO2). In other words, warming causes a CO2 increase, versus the common view that CO2 causes warming. In contrast, the peak correlation between UFO reports and ocean temperature is at zero time lag. UFOs visit, the ocean warms.

(And for you alien deniers out there, here’s the spreadsheet with the data and links.)

But correlation isn’t necessarily causation. We need some sort of hypothesized mechanism for how — any maybe why — aliens cause global warming.

My hypothesis is that the extraterrestrials’ spaceships have some sort of powerful heat generators which are dumping energy into the ocean. Maybe an antigravity-based thermogenic flux capacitor technology (that’s just a guess…I’m only a rocket scientist, not a nuclear physicist or movie star).

But why? Why are the aliens trying to warm our oceans?

Do they come from a warm waterworld? Do they want to colonize our ocean after it is sufficiently heated up? Or are we just the proverbial frogs in a pot of water on the stove?

Clearly, aliens like warmer weather, because there is a strong annual cycle in UFO reports, with the peak number of visitations in July, which is when global average temperatures also peak:

Fig. 3. Average number of UFO reports by calendar month, illustrating aliens' affinity for warmer weather.

Fig. 3. Average number of UFO reports by calendar month, illustrating aliens’ affinity for warmer weather.

This is also consistent with the fact that aliens are known to not have any fur, let alone any clothes, probably because their home planets are so warm:

Fig. 4. Famous aliens have no fur or clothes, suggesting their home planet(s) are quite warm.

Fig. 4. Famous aliens have no fur or clothes, suggesting their home planet(s) are quite warm.

Or, maybe they just like to people-watch. More people are out and about in the summer. That would make abductions easier, too. A two-fer.

On an unrelated matter, I’ve also been working on a new generalized theory of where straight lines come from. Since they are all perfectly correlated with one another, I believe they have a common origin…maybe a super line that extends to infinity and beyond, which generates all other, lesser lines. But the linear algebra is proving to be kinda messy. Stay tuned.

Finally, I’d like to conclude with a quote from Mark Twain:

“There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.”

A Closing Thought I talked with Michael Crichton before his death about his experiences getting involved in the global warming debate through his lectures, his book State of Fear (in which John Christy and I were represented by a lady scientist), and his congressional testimony on the subject of climate change. I think he believed he was doing a public service, but the politicization of the issue (and the way he was treated in congress) took him totally by surprise. That left a bad taste in his mouth, and he said he would no longer be involved in the climate issue. This is a crazy business we work in, and most sane people choose not to get involved in the public debate.

SSM/I Global Ocean Product Update: Increasing clouds with a chance of cooling

Monday, April 14th, 2014

SSMIMy research field of satellite passive microwave remote sensing took off like a rocket (pun intended) when the first Special Sensor Microwave/Imager (SSM/I, built by Hughes Aircraft) was launched in mid-1987 on the DoD series of weather satellites (DMSP).

We SO anticipated that first instrument…good calibration, and high frequency channels to estimate precipitation over land. The previous NASA instruments (ESMR-5, -6, and SMMR) were a good start, but had limited channel selection and less than optimal calibration strategies.

The SSM/I instrument series was later redesigned to incorporate the temperature sounding channels (SSMIS, built by Aerojet). (By the way, we don’t use these in our UAH global temperature monitoring work, since we receive very little money to produce the UAH datasets and incorporating an entirely new series of instruments would be a major effort).

But the real benefit of the SSM/I series of satellite sensors was the production of the “ocean suite” of products: integrated water vapor, surface wind speed, integrated cloud water, and rain rate. These continue to be produced by several investigators, and I use those produced by Remote Sensing Systems (RSS).

To help interpret the SSM/I measurements, let’s start with the HadSST3 sea surface temperatures (SSTs) measured since July, 1987, which is when SSM/I data first became available. (All of the following time series are monthly global anomalies since July, 1987; some have trailing 6-month averages plotted as well). It shows the well-known warming up until the 1997/98 El Nino, then roughly level temperatures since then.

HadSST3 monthly anomalies for the global oceans from July 1987 thru Feb. 2014.

Fig. 1. Monthly global oceanic HadSST3 anomalies from July 1987 thru Feb. 2014.

The first SSM/I field to address is total vertically-integrated water vapor, which closely follows the SST variations:

Fig. 2. Monthly global ocean anomalies in SSM/I total integrated water vapor.

Fig. 2. Monthly global oceanic anomalies in SSM/I total integrated water vapor.

The water vapor variations lag the SST variations by an average of one month. A regression relationship reveals an average 10.2% increase in vapor per deg. C increase in SST. This is larger than the theoretically-expected value of 6.5% to 7% increase, a discrepancy which can be interpreted in different ways (more evaporative cooling of the ocean stabilizing the climate, or more water vapor feedback destabilizing the climate — take your pick).

Next, let’s examine the surface wind speed variations from SSM/I. These have been compared to literally millions of buoy wind measurements, and are quite accurate. In fact, I would wager these are by far the best estimate of changes in global ocean wind speed we have:

Fig. 3.  Global average ocean surface wind speed anomalies from SSM/I.

Fig. 3. Monthly global oceanic anomalies in surface wind speed from SSM/I.

We see there was a slight (1-2%) increase in ocean wind speed from before the 1997/98 El Nino to after, which at least qualitatively might be supportive of Trenberth’s claim of increase ocean heat storage and surface cooling temporarily cancelling out anthropogenic global surface warming. I have not looked into whether a 1-2% change in wind speed could have such an effect, so feel free to comment on this. Note also that the last year or so hints at a reversal of this increase back to pre-1998 wind speeds. If wind speeds remain at the lower level, it will be interesting to see if surface warming resumes. I’m making no predictions on this.

The SSM/I rain rate variations are always quite noisy. Warm conditions tend to show more rainfall, but the strong 1997/98 El Nino curiously shows little effect, and there is a hint of increasing ocean rainfall in recent years:

Fig. 4. Monthly global ocean anomalies in rainfall from the SSM/I.

Fig. 4. Monthly global oceanic anomalies in rainfall from SSM/I.

Finally, let’s look at what I think is the most interesting SSM/I variable from a climate change standpoint, total integrated cloud liquid water (CLW):

Monthly global ocean anomalies in integrated cloud water from SSM/I.

Fig. 5. Monthly global oceanic anomalies in integrated cloud water from SSM/I.

The variations in cloud water show some interesting low-frequency behavior. I have previously discussed the fact that these cloud water variations are correlated with CERES-measured net radiative flux, and so provide a proxy measurement for the net radiative imbalance over the ocean which suggest some portion of recent warming was simple due to a natural decrease in cloud cover.

The updated regression relationship I get is 0.24 W/m2 loss in Net (solar plus IR) radiative energy for each percent increase in SSM/I cloud water, a scale factor we can then apply to the cloud water graph to get a Net radiative flux graph:

Fig. 6. Monthly global oceanic anomalies in Net radiative flux estimated from SSM/I cloud water variations, using a CERES-based scale factor of 0.24 W/m2 per percent cloud water.

Fig. 6. Monthly global oceanic anomalies in Net radiative flux estimated from SSM/I cloud water variations, using a CERES-based scale factor of 0.24 W/m2 per percent cloud water change.

Why use an SSM/I estimate of CERES Net radiative flux, instead of CERES directly? Mostly because CERES is available only since 2000, whereas SSM/I is available since 1987. But also, the CERES measurements are very difficult, with the reflected solar flux (which dominates the CERES-SSM/I relationship) having a strong angular dependence. The SSM/I measurements are instead thermally-based (microwave emission) and have no such angular dependence. Finally, radiative fluxes are so important (e.g. being the basis for global warming theory) that any independent means of estimating them are worth looking into.

Be careful in interpreting the estimated radiative fluxes in Fig. 6 because they could have an offset. Since the anomalies I compute (by definition) sum to zero over the entire time series, that means the total time-integrated radiative energy flux also sums to zero. So, while the graph in Fig. 6 suggests energy loss by the global oceans over the last 5 years, it could be the whole curve needs to be shifted upward. There is no way to know. The CERES fluxes have already been adjusted to match the increase in oceanic heat content, which was a logical thing for the CERES Team to do since the absolute accuracy of CERES is ~10 W/m2, whereas the increase in ocean heat content in recent years (IF you believe the warming estimates) correspond to only a few tenths of a W/m2 imbalance. The main value in the graph is to identify possible changes over time.

Others might see some relationships in the above plots that I haven’t noticed; I’ve made the Excel spreadsheet available for those who want to play with the data.

(Note that a possible El Nino this year would temporarily dominate everything else, as would any La Nina afterward. I’m instead talking about the longer term evolution of the cloud cover of the global oceans and what it might mean for global temperatures on decadal time scales.)