Record Rainy, Cloudy, Humid February over the Oceans

March 2nd, 2016 by Roy W. Spencer, Ph. D.

It’s been about eight months since I’ve updated the SSM/I- and SSMIS-based satellite estimates of the RSS ocean products (vapor, clouds, rain, and surface wind speed). Given the record warm tropospheric temperatures in February, and the likely role of El Nino in that, I thought it would be interesting to see if (for example) there was a big increase in rain activity, which is how the troposphere can warm so rapidly…through the latent heating of the air as heat is transferred from the ocean surface to the atmosphere.

By way of background, here are the monthly HadSST3 sea surface temperature anomalies (thru January). The anomalies are calculated over the same period that we have SSM/I data (since July, 1987), and they indicate record-warmth in the global ocean average (60N to 60S):
HadSST3-thru-201602

The SSMIS vertically integrated water vapor anomalies, which are dominated by boundary layer vapor and are tightly coupled to SST variations, mirror the SST anomalies with record high vapor amounts in December and February:
SSMI-Vapor-thru-201602

When the anomalies are computed at the gridpoint level, we see that most of the “action” is occurring in the central tropical Pacific, consistent with the mature El Nino conditions (I’ve included Feb. 1998 for comparison):
ssmi-vapor-grids-201602-vs-199802
Note that the current El Nino does not seem to have the ring of depressed water vapor values around the region where the enhanced rainfall activity occurs in the high-vapor zone that was seen in 1998. That depression in 1998 was likely due to subsiding air driven by the convection pushing the top of the humid boundary layer downward, making a thinner layer of moist air. I have no explanation for this difference between the two El Ninos.

What is exceptional is the rainfall anomaly in February, with a global ocean anomaly of almost 16% above the 29-year average:
SSMI-rain-thru-201602

The total cloud water anomaly for February was also at a record high, at 13% above average:
SSMI-cloudwater-thru-201602

Finally, the ocean surface wind speeds from SSMIS are seen to be recovering in the last few months…they are typically low during El Nino…supporting the view that El Nino is beginning to weaken:
SSMI-windspeed-thru-201602

I will remind folks that I still think there are problems with the SSMIS water vapor, as it is increasing considerably faster than expected based upon a 7% increase per degree of SST increase. I believe this is due to assumptions in the water vapor retrieval algorithm. The retrieval assumes a vertical water vapor profile shape, and if that shape has changed, it can bias the retrieval. I believe RSS also assumes a climatological average SST field in the retrieval, which might also affect the results.

So, it seems that much of the exceptional tropospheric warmth in February was driven by a rather spectacular “burp” of convective energy released by storms into the troposphere.


64 Responses to “Record Rainy, Cloudy, Humid February over the Oceans”

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  1. “Note that the current El Nino does not seem to have the ring of depressed water vapor values around the region where the enhanced rainfall activity occurs in the high-vapor zone that was seen in 1998. That depression in 1998 was likely due to subsiding air driven by the convection pushing the top of the humid boundary layer downward, making a thinner layer of moist air. I have no explanation for this difference between the two El Ninos.”

    We now have much wavier jet stream tracks which takes the drier air away poleward more rapidly than in 1998.Hence the current absence of depressed water vapour values around the regions of enhanced rainfall activity.

  2. “So, it seems that much of the exceptional tropospheric warmth in February was driven by a rather spectacular burp of convective energy released by storms into the troposphere.”

    That seems to be correct since we have observed much more vigorous and wavier jet streams around the world such as have kept Western Europe relatively mild this winter season.

    However, warmth that is ‘burped out’ rapidly to space is no longer available to maintain surface warmth.

    • Bill Laurune says:

      It is sort of ironic that the satellites measure heat leaving the planet, so they report a spike just when the planet’s surface actually is cooling off.

      • Greg Goodman says:

        MSU = microwave sounding unit. Not heat.

        • Roy Spencer says:

          Thermistors used to measure surface (and deep ocean) temperature measure resistance. Not heat, either.

      • miker says:

        Stephen and Bill.

        The surface temperatures are also going through the roof. No sign of any corresponding surface cooling at this stage see -http://models.weatherbell.com/climate/cdas_v2_hemisphere_2016.png.

        Perhaps if the atmospheric dyspepsia continues for a lot longer we may see it, but we may possibly have to wait for a La-Nina, if it kicks in, later in the year.

        • David Appell says:

          It will be as absurd to use the next La Nina as proof against AGW as it was all the prior ones before.

          AGW simply doesn’t depend on one year’s temperature, El Nino spike or La Nina dip.

          You’re talking about noise, not climate data. Talk about noise if you want, but be sure to recognize that’s all it is.

        • Rob JM says:

          The Ocean heat content massively decreased in Feb. Thats where the energy came from. See NOAA Enso update.

  3. “The total cloud water anomaly for February was also at a record high, at 13% above average”

    Wavier jet stream tracks produce longer lines of air mass mixing, hence more clouds and less solar energy entering the oceans to replenish warmth lost from oceans to air by convection.

    • Rob JM says:

      A spike in clouds preceded the previous la nina. The situation you describe would suggest a similar situation. It would be great to see if albedo has increased.

  4. mpainter says:

    Thanks for this, Dr. Roy, lots of food for thought, very interesting data.

    So, the February spike is due to “convective energy”, and that is Ma Nature showing us how things happen on planet earth, would that her examples could be grasped by everyone.:-)

    • David Appell says:

      It appears to be a record-setting burp, bigger than 1997-98 or 1982-83.

      • mpainter says:

        Meridional ocean overturning will cause these fluctuations from time to time, David. It’s called ENSO. Now the question is how far, and how fast, the global temperature anomaly falls off of this spike. Myself, I don’t look forward to it. La Nina brings heat waves and severe drought to my neck of the woods.

  5. ehak says:

    Very nice Spencer.

    Re your comment that water vapor is increasing too fast. If correct that would also give faster decreasing water vapor during periods with cooling. Greater amplitude. If there was no warming that would give no increase in water vapor. Only bigger swings.

    So even if you were right that cannot explain the divergence between UAH v0.0 and RSS v3.3.

    Or the tight agreement between SST and water vapor….

    • mpainter says:

      Roy says (in your favorite link, by the way) that SST serves very well as a proxy for water vapor. So what’s your point?

      Also, Hilburn, the El Nino spike was due to a slowdown in vertical ocean circulation, mainly. Go get yourself a primer on oceanography and read up. Or you can pay attention here when Dr. Roy discusses the topic. So, the spike in water vapor this El Nino was due to…what, hak?
      No need to thank me.

      • ehak says:

        Point is of course RSS TLT 3.3 and UAH TMLT does not follow SST. After 1998 that is. Guess that makes sense when reading oceanography.

        Oceanography in the skies I guess. Never know with mpainter.

        RSS v 4.0 on the other hand….

        • mpainter says:

          So the spike in water vapor was due to …what, KAH? Any clues?

          • ehak says:

            Warm SST mpainter. Did you not read Spencer post?

          • mpainter says:

            Which was due to slowing of vertical ocean circulation. I suggest you pay closer attention to oceanographic aspects of climate.

          • ehak says:

            And UAH v6 and RSS v3.3 do not pick up that warming mpainter.

            You still did not got that point.

          • mpainter says:

            Fine, Hilburn, your point? That RSS V4 shows tmt warming and RSS v3.3 did not? That the “pause” is busted and that the collapsed AGW house of cards is rebuilt?
            Try this hak, put your thumb to your nose and waggle your fingers.

  6. Greg Goodman says:

    Dr Spencer, there some interesting stuff there, plenty of food for thought.

    Could you provide links to the data sources used in those graphs? It would be helpful in following up on some ideas if we did not have to hunt them dowm.

    Thanks, as always.

    • Roy Spencer says:

      the data are available at the link below, but they are binary gridpoint files. You need to use the read routines RSS provides within a computer program you must write to compute your own area averages, by satellite, then average the satellites together, compute anomalies, etc.

      ftp://ftp.ssmi.com/ssmi/

      • Greg Goodman says:

        Many thanks.

        Presumably one then needs to start adjusting overlaps of difference satellites and instruments for biases, calibration errors, drift, etc

        The try to find out, in view of their latest games, how much RSS have been rigging the data.

        OK, I thought since you were plotting numbers some data was available. Never mind.

      • David Appell says:

        Nothing whatsoever suggests that RSS is “rigging the data.” They are scientists doing the best they can to measure atmospheric temperatures that require very complicated data models.

        • mpainter says:

          The post above is peer review of Mears and Wentz. Mears never misses a chance to use the term “denialist”. Such bigoted behavior hardly indicates disinterested science.

  7. Interesting wind speed correlation with ENSO.

    Is that the mechanism of action?

    Windier: more OHC to the atmosphere,
    Calmer: less OHC to the atmosphere?

    • mpainter says:

      Or greater surface cooling vs less surface cooling or higher SST vs lower, etc.
      Note the decrease in wind prior to this El Nino. This should have an effect on SST. Conversely, if winds pick up substantially, it should cool the surface, increase atmospheric humidity, etc. Dr. Roy has presented a wealth of observations with this post. How much cooling does a 2% increase in wind yield, all else remaining the same? Puzzle, puzzle.

    • Greg Goodman says:

      TE, much of El Nino is about winds: trade winds. Warm air rising in the tropics pulls cooler air towards the equator from both N and S. Coriolis effects deflect this movement westwards in both hemispheres, as it does for the main ocean gyres. That creates the persistent trade winds.

      More wind; more evaporation; more uplift. It is a self reinforcing system ( positive feedback ) which locks in.

      These winds drive surface currents of warm tropical waters to the west contributing to the west Pacific warm pool: WPWP. This is generally the warmest part of the Pacific ( or SST anywhere ).

      At some point the winds weaken enough for some of the surface water to flow back, this can break the feedback and the collapse becomes self reinforcing. There is little idea what triggers this.

      My personal hypothesis is that it is a slow ( inter-annual ) tide on the thermocline. The water density difference is about 1/1000 that of the air/sea surface, which resonates most strongly with the 12h tidal forcing. By inference, the thermocline will respond to changes in tidal forcing of the order of a few years.

      There is many sloppy explanations about warm water “sloshing” back across the tropics. However, a few cm of extra height in WPWP can not account for tens of meters of warm water seen during El Nino. Also the warer mater is higher because it is less dense. It is not “piling up” as is often suggested, so it can not “slosh” back under gravity, it is just a lens of lighter water.

      However, a tidal upsurge of the thermocline in the west Pacific could lead to surface water being forced to flow back eastwards.

      Here we find a curious non-dispersive *surface* wave called a Kelvin wave occurs. These are similar to soliton waves in tidal esturies or on canals. Look it up , it’s interesting how it propagates.

      Ignore much of the garbage that gets written about “down-welling” Kelvin waves. K-waves are *by definition* a surface effect: if it’s down-welling it is not a Kelvin wave. ( Ah well, this is climatology, normal laws of physics may be ignored as required ).

      These fast propagating waves shoot warm tongues of water right across to central America where they can continue to follow the coasts both north and south.

      Cold nutrient rich waters are suppressed around Peru, anchivies have a bad year or two and peruvian fishermen get unhappy.

      Once it all flattens out the cycle starts again.

      Hope that helps.

      • mpainter says:

        Also Walker Cell Circulation, very important in ENSO events. La Nina = strong Walker Cell circulation at the equatorial east and central Pacific. El Nino = little or none.

        • Greg Goodman says:

          Walker cell is where I started with evaporative uplift drawing in air from N/S.

          • mpainter says:

            You have Hadley cell on the mind. Walker Cell is different. The former is meridional, the latter parallels the equator. It is the Walker circulation that is most influential in the ENSO cycles. This is an easterly that depends on cool east Pacific and warm west Pacific equatorial SST.

          • Greg Goodman says:

            I was not paying enough attention, sorry.

      • Rob JM says:

        Not quite back to the start!
        The decaying el nino humidifies the atmosphere. At some point that condenses resulting in more cloud cover and cooling into potentially a La nina. You cant have the boom without the bust!

  8. T. King says:

    Why has the ocean SST risen so dramatically in the last few years?
    Are there undersea cities contributing to an oceanic UHI?
    And where is the pause in SST rise?

    • mpainter says:

      See average wind velocity plot, above

      • Greg Goodman says:

        So the next question is why have winds been dropping 60N-60S ?

        • mpainter says:

          Excellent question. It would be useful to have some plot that gave wind variation data in spatial layout, as a map.

          • Greg Goodman says:

            Agreed, the 60-60 plots are interesting but such a general presentation is not really that informative.

            A lot of climate is about tropics vs extra-tropical regions. It is also necessary to separate ocean basins since each have their own inter-annual and inter-decadal cycles.

            Indian Ocean has a mind of its own since it does not have a major NH component.

            Tropics have their own climate and act as a stabilising influence on extra-tropics, which have a greater climate sensitivity.
            https://climategrog.wordpress.com/hadsst3-_stack_cdf_sh_zeroed-2/

            The way the warm water anomalies appear and disappear in vertical sections of the Pacific during El Nino shows that is must be N/S flow.

            The warmer anomaly at depth is surface water being pushed down over about over about 20m. That means deeper water moving N/S to make room, or more likely the surface water is flowing in to fill the gap.

            That is why I say the trigger is slow tidal movement of the thermocline.

  9. Greg Goodman says:

    Dr Spencer says; “I have no explanation for this difference between the two El Ninos.”

    The 1997/98 event was much more pronounced: it was much higher against a lower background SST. The current event has been building since 2011 and is less contrasted to the surrounding SST history.

    This is reflected in the lesser geographic contrast in current WV map.

    • mpainter says:

      So in 98 the flanking ocean waters were relatively cooler and hence became a locus of sinking air?

      Another interesting contrast between 98 and now is oceanic precipitation. Do you have any thoughts on that?

  10. gbaikie says:

    –So, it seems that much of the exceptional tropospheric warmth in February was driven by a rather spectacular burp of convective energy released by storms into the troposphere.–

    Wasn’t there less hurricanes than usual last year.
    Would hurricanes be a different way of “convective energy released by storms’. As in one hurricane doing more work in smaller region as compared to this burp?

    As general thing it seems to me what going create longer periods of warmth will be related to oceanic warming, rather than atmospheric warmth.

    Also I wonder if this “burping” is going to disrupt a “normal El Nino sequence”. Not that I know what such disruption could result in or actually know, how normal this “burping” is with most El Ninos.

  11. Greg Goodman says:

    ” The 11% per deg. relationship is considerably greater than the 7% per deg. expected from the assumption of constant relative humidity. ”

    Even that 11% slope will be under-estimated due to regression dilution, it is visible a bit low. Probably 13%.

    https://climategrog.wordpress.com/2014/03/08/on-inappropriate-use-of-ols/

    The constant RH assumption needs to be revisited.

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  13. Gordon Robertson says:

    This sudden burst perplexes me because it does not show up here in Vancouver which has a normally mild winter due to the Japanese Current. I have been refraining from long walks at night in the dark because it is just plain miserable outside at night.

    This spike is definitely not a global phenomenon. If it was, we’d be basking in late spring weather. Instead, we are mired in a cold, miserable spate of rotten, cold, damp weather.

    I heard from a relative in northern Scotland and she has complained about the same thing. I’d like to know where this inordinate warm weather is located.

    • dave says:

      “I’d like to know where this inordinate warm weather is located.”

      At the moment, over my house in Sussex, England.
      Our heating bills have been 20% lower this winter.

      • Gordon Robertson says:

        @dave ..”At the moment, over my house in Sussex, England.
        Our heating bills have been 20% lower this winter”.

        Spoke to a relative near Inverness a few days ago and she claimed it was still too cold to go outside for a walk. Funny what a difference a few hundred miles makes.

        Just looked up the weather report and it’s 6C at 1:30 pm, Thursday, March 3rd in Inverness. They are forecasting from -1C to 6C over the next week. Don’t know how cold it gets at night.

        We are having moderate weather during the day in Vancouver, At 5 AM it’s 8C, which is likely a bit warmer than usual this time of year, but when you walk out in it there’s a cold breeze blowing off the inland sea that sits between Vancouver and Vancouver Island. That is fed from the Pacific Ocean over and around the Island.

        I went outside and it hardly seems like 8C. It’s cold and damp and I can see my breath in the air. Mind you, I live near the point the Fraser River meets the inland sea (Gulf of Georgia) and it’s damp around here.

        I have to translate back to Fahrenheit. 8C = 46.4F so I can live with that. I played soccer in it most of my life during the winter, and colder.

        • dave says:

          Southern Kent and East Sussex often “get” their weather from central France. At least as often as getting it from the Atlantic. Seems to be connected with the exact path of the jet-stream. Apart from Westerly gales, the other times that the North and the South of Britain have the same weather is when an Easterly flow (a miserable wind) sets in, from Northern Russia. Of course, the West of England is much wetter than the East.

          My parents went to live in Abbotsford (for a rather complicated reason) on the basis of a delightful spell of sunshine in September 1975. They did not know that this is pretty much the only time of the year that Vancouver and its neighbourhood has clear skies. In the following winter, they counted 120 days in a row that it drizzled! Sold up and moved back to Toronto (which has the most hours of sunshine of any major city in Canada.)

    • David Appell says:

      Gordon: the global data are an average of local conditions. It does not mean you little region will react the same way.

      For the global average, Vancouver is basically irrelevant. (So are almost all large cities.)

    • David Appell says:

      Gordon wrote: “Id like to know where this inordinate warm weather is located.”

      Have you looked at the maps put out by NOAA and GISS?

      http://data.giss.nasa.gov/gistemp/maps/

  14. The “burp” is obviously a release of ocean heat where the heat has built up to levels that require an automatic transfer into the atmosphere in the form of water vapour. This seems obvious….however, what I find more interesting is the difference in previous El Nio events.

    • dave says:

      “…the heat has built up…”

      It is not really that “the oven has got hotter” but rather that a natural cycle in the trade-winds has “opened the door” for a moment. Even while the El Nino is subsiding, the extra heat is radiating away from the atmosphere to space in rough accordance with Newton’s Law of Cooling. The satellites notice this and interpret it as “anomalous”.

      It is a modest “burp” for the atmosphere but an insignificant one for the Ocean as the heat capacity of the Ocean is so much larger.

    • Rob JM says:

      The burp corresponds to the resumption of trade winds. Higher wind speed = more evaporation (aka transfer of energy from surface to atmosphere)