The following image is a look at each December’s monthly average temperature, beginning in 1995.  The black line represents the temperature trend over the seventeen years that this school has collected data – an estimated increase of .1601°C over the 17 year period.

A timeseries showing December monthly temperatures from 1995-2011 for Zakladni Skola – Ekolog. Praktikum in Jicin, Czech Republic;
All data is GLOBE student collected data.

Using this knowledge, and setting the base 10 year reference period of 1998-2007, it is easy to calculate the short-term average for this station to determine the departure from that average.  The average temperature for December is 0.211°C.  This average is easy to calculate.  First, you calculate the average daily temperature by averaging the observed maximum and minimum temperatures.  Then, you average the daily average temperatures together to obtain the average temperature for the month of December.  Once you’ve done that for each of the Decembers from 1998-2007, you can average those together to get your average December temperature.  From here you can examine how each December departs from that average, and put it into graphical format, like below.

Departure from 10 year (1998-2007) average December temperature for Zakladni Skola – Ekolog. Praktikum in Jicin, Czech Republic; All data is GLOBE student collected data

Notice that at the beginning of the time period the occurrence of below normal temperatures was more common.  As time progressed, temperatures became more above normal, which supports the trend in monthly temperature.  Globally, the month of December 2011 was the 322^nd consecutive month where global average temperature was above the 20^th century normal – the last month that was below normal across the globe was February 1985.

Another school, Primarschule Neufeld in Thun, Bern Switzerland, has been collecting atmosphere data since 1998.  The graph below shows the monthly average temperature for each December since 1998, which indicates a positive temperature trend of 0.088°C over the entire time period.

A timeseries showing December monthly temperatures from 1998-2012 for Primarschule Neufeld in Thun, Bern Switzerland;
All data is GLOBE student collected data

Using the same base 10 year reference period of 1998-2007 as we did for the school from the Czech Republic, it is found that the average temperature for December for the school in Switzerland is 1.101°C.

Departure from the 10 year (1998-2007) average December temperature for Primarschule Neufeld in Thun, Bern Switzerland; All data is GLOBE student collected data.

It is very important, as a member of the GLOBE community, to continue building this observational record for your site.  Every data point is important in describing the bigger picture.

Suggested activity: Over the next 12 years, GLOBE students will collect enough data to be able to examine long-term changes in variables such as air temperature.  However, you can start examining your data, or data of a nearby school now.  You can even examine the data from these two schools to look at the trends for June.  What do you think you will find? We’d love to hear from you.  Leave us a comment, send us an email or get in touch on our Facebook Page.

Early sailors traveling the world’s oceans were all too familiar with an area of the tropical seas characterized by lack of winds and violent thunderstorms.  They called this zone “the doldrums” and dreaded being “stuck in the doldrums.” In his Rhyme of the Ancient Mariner, English poet Samuel Taylor Coleridge offered the following description of the Pacific doldrums:

All in a hot and copper sky,
The bloody Sun, at noon,
Right up above the mast did stand,
No bigger than the Moon.

Day after day, day after day,
We stuck, no breath no motion;
As idle as a painted ship
Upon a painted ocean.

Today, we have a better understanding of this phenomenon and now know this area as the Intertropical Convergence Zone, or ITCZ.  It shapes atmospheric circulation patterns throughout the world and is considered to be the most prominent rainfall feature on the planet; critical in determining who gets fresh water and who doesn’t in the world’s equatorial regions.  The ITCZ is defined by the coming together, or convergence, of the northern and southern hemisphere trade winds and a decrease in the pressure gradient.  Specifically, in the north, trade winds move in a southwesterward direction originating from the northeast, with somewhat of the opposite effect in the southern hemisphere (where trade winds blow from the southeast to the northwest).

A) Idealized winds generated by pressure gradient and Coriolis Force. B) Actual wind patterns owing to land mass distribution.
From: Figure 7.7 in The Atmosphere, 8th edition, Lutgens and Tarbuck, 8th edition, 2001.

The intense tropical sun pours heat into the atmosphere forcing the air to rise through convection and results in precipitation.  Rain clouds up to 9,144 m (30,000 ft) thick can produce up to 4 m (or 13ft) of rain per year in some places.  The ITCZ is not a stationary phenomenon nor are its movements symmetrical above and below the equator.  Many factors, including seasons and land masses, influence its overall movement.

Southern shift of ITCZ in January.
From Figure 7.9 in The Atmosphere, 8th edition, Lutgens and Tarbuck, 8th edition, 2001.

Northern shift of ITCZ in July.
From Figure 7.9 in The Atmosphere, 8th edition, Lutgens and Tarbuck, 8th edition, 2001.

With this knowledge in mind, we first encountered some of the effects of the ITCZ last year, as we approached the Caribbean coast of Panama aboard our sailing research vessel (RV) Llyr in July 2012. The map above shows the ITCZ located very near to Panama, the narrow strip of land that connects North, Central and South America.   At a latitude of about 9°North, we met up with the storms of the ITCZ during the night.  We could see the arrival of a band of storms on our ship’s radar and plotted a course to avoid them.  The storms had other plans, and we spent the night in their midst, at times feeling like they were chasing us as we tried to take evasive action while they kept building right overhead. Lightning lit the sea around us in an eerie glow and we could see, through the rain, bolts striking not far from the ship.  The next morning, tired but safe, we sailed into the harbor in Bocas del Toro, Panama, having had our introduction to the ITCZ.

Image of the RV Llyr. From Berkshire Sweet Gold

We came to Panama as part of a multi-year research expedition aboard RV Llyr, studying coral reefs, sustainable fisheries and changes taking place in the ocean.  As farmers, we have studied weather for many years, understanding oceans and atmospheric circulation as integrated systems that help produce weather at our forest farm in New England. As social scientists and human ecologists, our interest lies in researching the myriad links between biological and cultural diversity as key elements in sustainable development.  In the coming weeks, we will transit the famous Panama Canal aboard our 53′ steel ketch, and once again pass through “the doldrums” as we make passage for the Marquesas in French Polynesia.  During the 30+ day passage, we’ll be participating in global plankton studies and weather surveys. During our passages through the Pacific Islands, specifically French Polynesia, the Cook Islands, Tonga, and finally Fiji, we’ll perform reef surveys on scuba and hopefully meet with local schools to share the findings and experiences of our expedition.  We are a family of five, with three boys on board, and additional crew members and scientists joining us on expedition.  We look forward to sharing our journey.

Suggested activity: Do you live in a region affected by the ITCZ?  We’d love to hear about your experience as these storms pass through.  Send us a story or an image you have captured about the ITCZ either through a comment here, our website, or our Facebook page.  Be sure to collect temperature and precipitation data to document how your location is affected by the ITCZ, and think about what influence these two atmospheric variables may have on other GLOBE protocols.

The Maldives are a great location for such an experiment because during the months of November through March, the country experiences its dry season with respect to the monsoon, and pollutant heavy air can be seen traveling from thousands of kilometers away from countries like India and Pakistan.  Furthermore, the island nation has a low elevation and is extremely sensitive to changes in sea level rise.

A map of the Maldives. From Worldatlas.com

Through the research, Ramanathan and his colleagues discovered that these pollutants are primarily composed of black carbon soot that comes from the burning of fossil fuels and biomass.  With the longevity of the research, they were able to understand that there is a strong heating effect of these pollutants.   But black carbon soot affects more than air temperature – it destroys millions of tons of crops annually and causes human health concerns.  The good news is that this type of emission is easy to reduce due to the face that its lifespan in the atmosphere is short.

Sources of black carbon emission. From AGU.org

If these types of pollutants are reduced quickly, the long-term negative effects of climate change can be reduced by nearly 50% in the next 20-30 years.  With Ramanathan’s research, The Climate and Clean Air Coalition (CCAC) was established.  The CCAC is focusing on the reduction of short lived pollutants by nearly one third to protect and improve human health and agriculture.

And while the relationship between black carbon soot and warming is better understood, and has recently been presented by the International Global Atmospheric Chemistry Project, the affect the black carbon has on clouds and the type that form is still unknown.  Further research is necessary to understand the feedback between black carbon affected clouds and climate change.

Suggested activity: If you’re a GLOBE school in an area that sees seasonal fluctuations in air quality, you can perform your own research study to see the affect that air pollution has on your local temperature, cloud type and cloud cover.  Start by taking air temperature, cloud clover, cloud type and aerosol measurements and enter them into the GLOBE database.  Then as your database grows, start to examine the relationships that exist between the variables.  Then, be sure to tell us about it.  You can share your future research plans with us through a comment, email or on our Facebook Page.  For more information on Ramanathan’s research, watch this video.

-Jessica Mackaro