There are about 46 countries around the world doing weather modification to enhance precipitation, snow, or hail mitigation. As the first country to use this technology, USA has developed it for about 70 years. During the time of CMA holding the training course on weather modification, Roelof T. Bruintjes, the Doctor of NCAR (National Center for Atmospheric Research, USA) accepted the interview of China Meteorological News Press and Xinhua News. He introduced the detailed conditions of weather modification in America and the world.

 

Chinese Version: http://www.cma.gov.cn/2011wmhd/2011wzbft/2011wftzb/20140904ft/index.htm

  The effect evaluation needs to be developed

Now we have much better measurements of certain circumstances, like aerosols in the atmosphere. With weather radars, we can much better evaluate these types of systems. I think one of the big problems is the evaluation. Many countries do cloud seeding, but they don't evaluate or the means to evaluate. But this is an important part, because either you want to stop the rainfall or make more rainfall, the question is how much more rainfall we want to make, how much does it cost per cubic of water. There are new technologies available to get some answers to those questions, but this would take some investment in terms of having the right human resources, the equipment etc.

  Weather modification has no negative impact on environment

It has no impact on the environment, neither there has any negative effects. You need cloud to do the cloud seeding experiments, then you can make the process more efficiently. So in terms of the weather modification technology, it is safe. In the US, we use particles depending on the size and concentration, cloud can develop rain more efficiently or less efficiently. Maybwe the most of the adverse impact is the particle of cloud seeding. More than 7% the whole particulate matter in atmosphere are now human produce like the haze. The particle of cloud seeding be used just more than inhalable particle size, so there is no obvious impact for environment if use it properly.  

  Weather modification developed rapidly in China, still need innovation

China is basically one of the first countries that use the technology and develop it from the late of 1950s. And they quickly went to the operational cloud seeding in the past ten years. I think in China now there are many new technologies and equipment, like weather radars, and now use the opportunity do much better evaluation. China has been really rapidly developing in the past twenty years in terms of science and a lot of new young scientists. And maybe there were some of them of lacking experience to innovation.

  Global collaboration be enhanced to address to climate change

I think we all have to work together and enhance collaboration. If everybody does good science, we all will make progress much quicker, especially for the new technologies now. And we have much better chance in terms of really evaluating. I think there is an exciting opportunity in the next twenty years to really get answers. We can develop it in terms of communication and computing power.

Weather Modification in Progress

 

There are about 46 countries around the world doing weather modification to enhance precipitation, snow, or hail mitigation. As the first country to use this technology, USA has developed it for about 70 years. During the time of CMA holding the training course on weather modification, Roelof T. Bruintjes, the Doctor of NCAR (National Center for Atmospheric Research, USA) accepted the interview of China Meteorological News Press and Xinhua News. He introduced the detailed conditions of weather modification in America and the world.

 

 

Reporter: Please introduce the status of weather modification research in USA and  the application?

 

ROELOF BRUINTJES: Weather modification has a long history in terms of cloud seeding that started in the late 1940s, however it has also had some controversy during that period because although initially it seems like we could modify clouds very easily, the more we learned about clouds, we also learned about the complexity of clouds. So in the scientific community this has been a very difficult problem. Cloud seeding can work under certain conditions. However, what we did find out is that those conditions can change in one region from one day to another day, but also from month to month, from one place to another place. Technologies are not always transferable, so at this moment since the past 20 years there have been tremendous advances in computer power, where we can get bigger models and do better simulations. Also we now have Doppler radar and satellite radar, which we didn't previously have, that we can deeply look into the clouds and see how precipitation forms. We know that cloud can make ice crystals, cloud seeding can make larger droplets, but does this really transform into more rainfall at the surface and so those are the things we can have a better hand on. The importance of modern technologies is to really have a new look at this so we can quantify some of the results better. Because most cloud seeding program in the world still use the technology that is 50 years old. People have not really updated the knowledge and look into how to do this. So in that sense, it is important to educate the operators, the scientists, but also the operational program in terms of what can be done better and what can we do to make it better.

 

As to the reason why most cloud seeding program in the world are still using the technology that is 50 years old, I think to a large extent is based on knowledge and research, especially in the last 20 years. There's been a lot of research that provide new technologies and insights. In some sense, we really have to rethink what we are doing with cloud seeding, how we do it and what is the most efficient way to use it. We now have data that shows that under certain conditions it may not work. One of the purposes of the course like this is to inform people what are the latest developments and the latest technologies.

 

If we could perfectly predict the weather, we could perfectly predict the change. But we cannot perfectly predict the weather, and so even our seeding methods may not be totally applicable for certain clouds at certain moment. Now we have much better measurements of certain circumstances, like aerosols in the atmosphere. With weather radars, we can much better evaluate these types of systems. I think one of the big problems is the evaluation. Many countries do cloud seeding, but they don't evaluate or the means to evaluate. But this is an important part, because either you want to stop the rainfall or make more rainfall, the question is how much more rainfall we want to make and how much it cost per cubic of water. There are new technologies available to get some answers to those questions, but this would take some investment in terms of having the right human resources, the equipment etc.

 

In terms of summertime convection thunderstorms, it's more difficult because our models can't simulate those very well yet. We lack theory and understanding. The physical understanding, if I can understand what's happening in the cloud, I can also understand what my seeding will do .So the very important point is what is happening in the cloud, that's why we take measurements. The second one is statistics. Because no cloud is the same as another, it may does not work if you use the same kind of statistics as you use in the medical community. The more theory you know, the more knowledge you have, you can put them into the models and simulate it. But the important part is to make sure your model simulate nature. In the States, there are about 36 programs and most of them are winter time programs in the western US, trying to enhance winter snow packs, it's fairly well established. Some programs have been running for more than 50 years. There are also some programs in the summertime for hail suppressions in North Dakota and also in Texas for rain enhancement. Those programs are now implementing some new technologies in terms of evaluation and seeding methods. It is progressing. There is now more funding in terms of research. It is clear in my mind that under certain conditions you can enhance rainfall with cloud seeding, but these conditions depend on the national background cloud,and those can change. In high pollution days ,you may have better effects on less pollution days,so there are all kinds of circumstances that you have to take into account.

 

Reporter: What is your main content in this training?

 

ROELOF BRUINTJES: The main content of the training is to try to enhance the knowledge of experts on weather modification, and to get them to think what are we doing is good, how can we do things better, and how can we improve. The training course also aims to explain to them what new technologies are available, what are the latest results and how can we move forward.

 

Reporter: If the weather modification technique is safe? Is there any negative impact on the environment?

 

ROELOF BRUINTJES: It has no impact on the environment, neither there has any negative effects. Weather modification or cloud seeding to enhance rainfall is not a drought solution, because in drought you don't have a cloud. Nobody can make a cloud. Nobody can chase away a cloud. You need cloud to do the cloud seeding experiments, then you can make the process more efficiently. So in terms of the weather modification technology, it is safe. Also when compared with other technologies for water resources, it should be seen as a long-time water resource management too.  In the US, we use particles. Depending on the size and concentration, cloud can develop rain more efficiently or less efficiently. For large droplets to form, we use salts. Salts are abundant in the atmosphere. Maybe the most of the adverse impact is the particle of cloud seeding. More than 7% the whole particulate matter in atmosphere are now human produce like the haze. The particle of cloud seeding be used just more than inhalable particle size, so there is no obvious impact for environment if use it properly.  

 

Reporter: So What's the significance of weather modification for the development and utilization of climatic resources?

 

ROELOF BRUINTJES: Water is very important, which is the basic substance of life. So people are looking at any kind of technology that could help in terms of water resources. Cloud seeding is one of these. The other part is we believe their quality.

 

It's an important performance ofcloud seeding that can help the clouds to produce the rain in certain higher blue areas on the certain conditions. Water resources do also for health. If it works you'll have less damage. So in some programs in North Dakota of USA and in Canada, the insurance company had been supporting health pressure program so long time.

Doctor Roelof T. Bruintjes

 

Reporter:  Are there any concrete facts in service, such as fighting the drought, etc?

 

ROELOF BRUINTJES:  We cannot fight the drought. Because there's no clouds to make seeding during the time of drought.  Climate change makes the drought, flood and more severe weather occur often.  Drought is a more long term, so the effect is limited which used weather modification to add precipitation.
In the other aspects of application mainly in terms of the certain conditions,  which can help water resources if have clouds.  

 

Reporter: Material shows that the United State Federal Government doesn't support the weather modification study, and gradually reduce the investment since the 1980s, is it true? And what's about now?

 

ROELOF BRUINTJES: It's not the thing they don't support the study. They're supporting more research in this area. The most of the programs in the US are supported by states and by private companies. In 1980s, the primary reason of they gradually reducing the investment is that the climate change is not a big issue in that time. So people don't mean clouds play a very important role in addressing to climate change. But later, cloud study is also again a key the experiment like the fogs.

 

Now for research, the federal government and the international science foundation do some research in this area. They raise more and more supports for weather modification research. The other big issue is government in terms of climate change geo-engineering while people will make proposals for mitigating globe warming by seeding clouds.  

 

Reporter: How much do you know about China's weather modification? What is your comment? Can you give us like brief introduction comment on the weather modification around the world?

 

ROELOF BRUINTJES: China is basically one of the first countries that use the technology and develop it from the late of 1950s. And they quickly went to the operational cloud seeding in the past ten years. I think in China now there are many new technologies and equipment, like weather radars, and now use the opportunity do much better evaluation what the clouds seeding affects the world. China has been really rapidly developing in the past twenty years in terms of science and a lot of new young scientists. And maybe there were some of them of lacking experience to innovation. But I think now they are in the much bright position to reevaluate what they are doing. 

 

There were about 46 countries around the world doing cloud seeding operation, such as Russia, USA, Australia, Israel, China, Thailand, Indonesia, Philippines, Malaysia, Vietnam, Germany, France, Italy, Bulgaria, Romania and others. Like Indonesia and in Thailand, they have gotten a lot of rainfall. But the agriculture need more water. Australia has tremendous lack of fresh water and don’t has lots of big harbors around the ocean. So some of the longest programs in Tasmania are used to look for unseen snow and rainfall in the winter. At all the calculations that have been done in terms of cloud seeding to show it about five to fifteen times, which is the cheapest one  than other alternatives. The weather modification is also mainly used for hail mitigation, like Italy, North Africa, Greece, Spain, some of parts in France. In lots of countries, they do rainfall enhancement especially in South Africa.

 

Reporter: How to evaluate the effects of weather modification?

 

ROELOF BRUINTJES: So this is, first of all the physical understanding if we can mention radars, thunder lightning sensors and other things. Then you also use statistics like in a medical community. So we do that in terms of we see some clouds and not see other clouds. We select the same clouds, like the double blind this experiment and you compared. Then you can do quantity of analysis see how much water you made.

 

Reporter: What are the expectations for the future research and application about this job in your country? Can you give us like brief introduction comment on the weather modification around the world?

 

ROELOF BRUINTJES:  I think we all have to work together and enhance collaboration. If everybody does good science, we all will make progress much quicker, especially for the new technologies now. And we have much better chance in terms of really evaluating. How long it works, when it works and quantifying those results so that we can optimize our seeding methodologies than in the past. I think there is an exciting opportunity in the next twenty years to really get answers. We can develop it in terms of communication and computing power.

 

Editor Hao Jing