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Some Nigerian communities face radiation risk, says CAR’s director

Professor A. Babatunde Rabiu, arguably Africa’s leading space physicist, specializes in Space Weather and is founding Director of the Centre for Atmospheric Research (CAR), Anyigba, Kogi State.
*In this expository interview,  Rabiu  unravels the complex dynamics of the upper and lower atmospheres—prime investigative domains, of the National Space Research and Development Agency’s (NASRDA’s) newest subunit.
*Over the past five years, CAR has been collecting data on the physical processes at work in the Earth-Sun vicinity—”from the seabed, … to the centre of the Sun,” as  Rabiu  put to  J.K. Obatala.
*An ardent activist,  Rabiu  belongs to the Network of  Space and Atmospheric Scientists and  was, until 2016, president of the African Geophysical Society—which he helped to establish.
*He is a member of the United Nations Expert Group On Space Weather and serves on the Steering Committee of  the International Space Weather Initiative, also a UN body.
*Rabiu  came to NASRDA from Federal University of Technology, Akure,  Ondo State, where he is Professor of Physics.

Prof. A. Babatunde Rabiu

Give me an overview, of the Centre for Atmospheric Research (CAR).

CAR is engaged in every kind of investigation, that has to do with the atmosphere including the lower and upper atmosphere, the space environment and even the ocean.

Our physical domain, starts from the seabed and continues through the atmosphere, to the space environment where Nigeria has orbiting satellites onward to the centre of the Sun.

But you don’t have an oceanographer, on staff?

No. We’re not involved in oceanographic studies, yet. The closest we’ve come, is to look at the chemical composition of water, in some riverine areas.

Our priority, is research that will impact contemporary Nigerian society. So, we study both the lower and upper atmospheres.

Through a project we call the “Tropospheric Data Acquisition Network” (TODAN), CAR has automatic weather stations, at about 18 locations, within Nigeria.

These stations measure various parameters in the lower atmosphere,wind-speed, solar radiation, temperature, pressure and other properties.We hope to deploy 72, nationally.

But, as I’ve said, CAR is also interested in monitoring the upper atmosphere which starts, from an altitude of 40 to 50 km.

This environment interests us, because 160 km and upward, is where you have orbiting satellites. Our satellites, are domiciled in this region.

Hence, we need a continuous flow of data, denoting conditions in the upper atmosphere. Are Nigerian satellites safe? What happens to radio waves, propagated through this medium?

Disturbances in the ionosphere, for instance, can cause loss of radio signal, due to wave absorption. It behooves us, therefore, to understand the upper atmosphere.

Accordingly, Nigeria is involved in a global study. We have installed magnetometers and GPS stations, at different places, to monitor space weather parameters.

Is there a coordinating agency, for this worldwide study?

No, not as such. But we do collaborate with the International Space Weather Initiative,a United Nations project, to which CAR belongs. In fact, I am the African Coordinator.

Incidentally, three of the magnetometers we’ve deployed,to record fluctuations in Earth’s magnetic field,came from the Japanese government.

We set up the first one in Lakoja, last year, and later installed another in Abuja, with U.S. government support.

How does CAR’s research, fit into the national development agenda?

It fits in many ways. Keep in mind, that the “atmosphere” is a natural resource, to be exploited! But first, we must understand, it know its content, and behavior.

There is no communication gadget, for example, that does not have its own specification for operating in the atmospheric medium.

The upper atmosphere, impacts very high frequency signals. The lower atmosphere, also affects certain frequencies. Then, rainfall, must be factored in.

These parameters vary, both with the time of the day and the seasons. So, continuous monitoring of the atmosphere, is vitally important to radio transmission.

Another aspect, is atmospheric chemistry. This is where we get into monitoring air quality, at the tropospheric level, for microscopic particles.

If you keep close tabs on this area, you’ll know when danger lurks. Toxic substances can find their way into an unguarded atmosphere.

What causes the chemical and physical properties of the atmosphere to vary? 

There are numerous contributing factors. First, the atmosphere contains a mixture of natural gases,oxygen, hydrogen, nitrogen etc. And you have them in different proportions.

Now, humans also generate gases. We run power plants. Our vehicles release dangerous carbon dioxide fumes. These gases too, come in different proportions and affect air quality.

Another thing, is that the Sun beams infrared, visible and ultraviolet radiation onto Earth’s surface.  This energy drives the wind system and moves these gases around and stirs them up.

The intensity of sunlight of solar radiation varies with passing hours of the day, causing the temperature to fluctuate. Wind speeds, in turn, vary, due to energy fluctuations.

I think the sum total of these conditions, and movements, is what you call “space weather”?

Well, not exactly. “Space Weather” is a term that only applies to the space environment. This does not include the lower atmosphere, where you and I are now.

Up to about 40 to 50 km, is still the lower atmosphere… “Tropospheric” weather the weather that meteorologists predict occurs below 40 km.

  So, your discipline touches on, meteorology?

Yes. Initially before CAR was created the Tropospheric Data Acquisition Network was a joint venture, between NASRDA and the Nigerian Meteorological Agency (NIMET).

“Weather station,” is the generic term for instruments that measure the atmospheric parameters we study. But CAR doesn’t predict weather. That’s NIMET’s mandate.

Has any new light been shed, on what happened to NigComSat-1,Nigeria’s lost communications satellite?

Well, all I know, is that the satellite developed a fault, while still in the observation stage. It had a power problem and went out of control.

NigComSat-1 was then being managed by our collaborators, the Chinese and had not been handed over to Nigeria.

But the lost satellite has long been replaced, with “NigComSat-1r” (the “r” stands for “replacement”). This was, it needs to be stressedat no cost to Nigeria.

Is it true, that solar flares explosions on the Sun’s surface can not only affect the electrical systems of orbiting satellites, but also oil pipelines?

Yes. Solar flares emit charged particles, which move through the solar system at great speed bathing planets, moons, artificial satellites and everything else, in electricity.

These particles can short circuit satellites systems and produce surface currents that overload powerlines as happened in Quebec, Canada, and the northern U.S.A., in 1989.

The electrons and protons involved, don’t reach us. Rather, it is the effect of these ions on Earth’s magnetic field, that wreaks the havoc.

Variations in the magnetic field, generates a secondary field of intense electrical energy which, during flare activity, extends to the surface and passes through conducting matter.

Physicists refer to this phenomenon, as “geomagnetically induced currents” (GIC). It affects electric cables and transformers, sometimes causing explosions.

How though, does GIC damage oil pipelines?

Geomagnetic induction exacerbates and expedites corrosion. That, in simple terms, is the explanation.  Cracks occur. Before you know it, oil starts oozing out, and vandals come.

But if scientists monitor the pipelines, the problem can be averted.

The last time we talked, you said CAR was conducting some radiation studies in the Niger Delta and in Kogi Stae. What did you find?

Yes. CAR tested samples from Kogi and Delta States, for uranium, thorium and radioactive potassium,and obtained some very interesting results.

We found exceptionally high levels of radiation in some Local Government Areas (LGA’s) of Kogi State, then made recommendations to the state government.

Igaliwo, has the highest concentrations of uranium and thorium nuclides. We’ve presented our results at conferences, and also published some. This should be a warning to policymakers.

Samples from all the LGA’s showed high concentrations of radioactive potassium. The exception, was Ajaokuta, where the steel industry is based.

Our analysis indicated that the absorbent dose-rate and the annual effective dose-rate, as well as the gamma ray exposure level, were higher than the recommended limits.

This was the case in  Odogbe,  Okaba, Salem University, Geregu, Igaliwo (again),  Edeke, Bagana  and Abejukolo.

We suggested imposing a levy on culpable companies, hosted in these communities as motivation, for them to protect the environment.

Are you going to expand this research, to other states?

This was our intention. The 40 sites tested in Kogi State, was seen as a pilot project, a model, to guide us, in testing elsewhere. But our handicap is resources, funds and equipment.

What about the Niger Delta?

We tested at more than 50 locations, there. In the riverine areas, we took fish from the sea and the rivers. Then, working with our Canadian collaborators, we sampled the water.

Analysis showed, that some oil producing regions are at risk i.e., people have a higher than normal chance of getting unacceptable doses of radiation, from their surroundings.

Is your research in the Niger Delta suspended as well, because of money?

We completed the pilot stage. But, again, our intention, was to encompass the region which proved unfeasible.

Do you use balloons or sounding rockets, in your study of the atmosphere?

We plan to send up balloons. There’s a radiosonde system, on one of our buildings. But it has not been possible to acquire the helium gas generator, that is needed to inflate the crafts.

Why not present your problem, to the natural gas companies? Most of them, especially the LNG plants generate helium. They may either fill your balloons, or donate a generator.

O.k. I’ll look into it because we need the helium generator.

Is  NIMET  involved, in your atmospheric research?

Only in the lower atmosphere. Otherwise, we’re working with the Office of the Surveyor General of the Federation (OSGOF).

They use GPS stations for land mapping, to know the coordinates, for land allocation. OSGOF has 12 monitors, in various locations. So, we use their data for space weather studies…

How does OSGOF data benefit you?

They have antennae, GPS receivers, which sight satellites, orbiting some 22,000 km away, and take information from them.

This information, consists of “latitude,” “longitude,” “altitude” and “time” which are important, for navigation and map-making purposes.

CAR uses the same generic parameters that generates those four coordinates, but in a different way.

In space weather research, GPS data is needed to compute the  total electron content  of the upper atmosphere, at a given time. The electron content, is a key space weather indicator.

Your  Japanese collaborators, brought an Optical Imager to NASRDA, sometime ago. What kind of data, are you getting from the Imager?

The Imager, covers a roughly 500 km radial and altitudinal swathe of the upper atmosphere.      It  makes the space environment visible, after dark, at a certain wavelength.

Using the Optical Imager, we can detect plasma bubbles, in the ionosphere,and thus anticipate disruptions, in communication.

Does the equatorial impact of the solar wind, come within your purview, Nigeria being a tropical country?

Yes.    We are privileged to have the “magnetic equator,” passing right through northern Nigeria!    .…This is fortuitous, for our research.

The magnetic equator, is different from the geographical equator. It’s an extension of Earth’s magnetic field, which profoundly impacts the space environment.

This would, it seems, make CAR a very attractive partner, for foreign collaborators?

Yes. That’s why scientists, from so many countries, bring equipment here. In fact, it’s only in Africa and South America, that you have the magnetic equator passing inland.

This is what makes Abuja so important, for our research. It is about 0.5 degrees south of the geomagnetic equator.


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