UGA Tifton Farm Chat

12/06/11 – Climatology Report
Audio Transcript

Kyle Dean, Host: We are back here on WTIF. Time now for our UGA Tifton Farm Chat. We let you know what's going on in the world of agriculture and today special guest with us Ms. Pam Knox, a UGA Climatologist in Bio and Ag Engineering. Good morning to you, Pam. How are you?

Pam Knox, UGA Athens Campus Climatologist: Good morning. It's great to be with you this morning, Kyle.

Kyle Dean, Host: Thanks for coming on with us. First off, let our listeners know about you. Of course, you are in Athens. Let us know a little bit about yourself.

Pam Knox, UGA Athens Campus Climatologist: Alright. I've worked in the Bio and Engineering Department since 2001, and prior to that I worked in Wisconsin as the Wisconsin State Climatologist. I've done a number of other jobs because I have a husband who is also a meteorologist, so we've been kind of switching back and forth, the 2-career couple thing, but always having something to do with the weather wherever we've gone.

Kyle Dean, Host: What is it about weather? I can remember being a kid and just really trying to emulate a guy down here, who a lot of our listeners will know when I say this, Gill Patrick who was on WALB Television for a number of years down here. What is it about weather that's so fascinating to you?

Pam Know, UGA Athens Campus Climatologist: The weather is something that's just unique.  It changes every day and it's at a scale that people can relate to. I got interested in the weather in the 3rd grade when a tornado came 2 blocks from my house. I grew up in Michigan and it caused quite a bit of devastation. Although it wasn't really a bad tornado, it was pretty small, but it made a big impression on me. My husband also experienced a tornado when he was younger. But, some people get interested in the weather just because they like the variety, and it's certainly something that you can talk about with just about anybody.

Kyle Dean, Host: What are we seeing as it relates to weather? I know people say it’s getting warmer, what does the model show?

Pam Knox, UGA Athens Campus Climatologist: Well, warmer just kind of depends on where you start from. If you look at Georgia's temperature history, if you go back all the way to 1895 when we really started to keep good records and you look at how temperature has changed between now and then, if you look at a long term average, temperature in Georgia has actually gone down over the last 100 years or so. Probably some of that relates to changes in the land use over time. If you could think back 100 years ago, there were a lot of cotton, row crops, a lot of bare ground and of course, now Georgia is over 70% forested, so a lot of that bare ground has been replaced by trees. We think that’s really had an impact on the climate if you look at it as a 100 year period.

Now, if you start looking, for example, a little shorter periods say around 1970, and look at how the Georgia temperatures changed since then, we actually see that Georgia temperatures have been rising since about 1968-1970. The last few years, we've actually seen a cooling trend, say from about 1998 to the present. But overall it has been warmer. So, whether or not it's warming or cooling kind of depends on the time period you are looking at.

Kyle Dean, Host: Of course, we talk with your former contemporary and former state climatologist, David Stooksbury, on this program before.  And now, as we move into 2012 and in 2011, he really predicted what we were going to see to a 'T' as it related to, I believe, a La Niña that was in the forecast. What are the models showing for next year as farmers, and just normal everyday people, get prepared for 2012? What are we seeing?

Pam Knox, UGA Athens Campus Climatologist: If you look back to last year, Dr. Stooksbury predicted a La Niña which we did have last year. But, and we are actually pretty good on with prediction of our lack of rain fall. We kind of blew it on the temperatures last year. It was much colder than we expected due to some unexpected influence from what we call the artic oscillation which is something that occurs from time to time.

This coming year it looks like we are going back into a 2nd year of La Nina. Now this doesn’t happen every time we have one, but it's happened often enough in the past to know that if we do have a 2nd year, which is pretty likely at this point, we will expect to see warmer and dryer conditions continue.

Of course this is not good news for areas that are already in drought because it means that we're not going to really see as much recovery as we would like to see over the course of the winter. Winter is usually the time period that we recharge the soil.

Kyle Dean, Host: It’s going to be another warm one. I know you mentioned you were quoted in an Athens Banner Herald article saying that most models agree that temperatures will increase as we get back to the warming part of our conversation. How much is another question and how much at day and at night? Can you kind of expound on that a little?

Pam Knox, UGA Athens Campus Climatologist: Well, daytime temperatures respond directly to sunlight. In other words, if you've got sun coming in, it warms up the soil and things heat up pretty much during the day. At night, you have more influence of clouds and clouds are something that climate models don’t have a very good handle on. They don't handle rainfall real well. They don't handle cloudiness real well. Part of the reason is those are real small scale things. You look at a typical cloud. The size of the cloud is less than a square mile if you look at the surface area. Usually the climate models are looking at something at a much broader resolution. So they don't handle clouds too well. And, if you don't know what the clouds are doing on a small scale basis, it's hard to really get a good prediction of night time temperatures.

Another issue with night time temperatures is urbanization. If you live in an area with a lot of cement and things like that, concrete, that will heat up during the day and it will stay warm at night.

A third issue is how much air pollution there is. Air pollution is partly related to drought because of the dry conditions, you don't have particles washing out of the air and so that tends to affect things as well.

Kyle Dean, Host: Of course, we are talking with Pam Knox, a UGA Climatologist in Bio and Ag Engineering, on our UGA Tifton Farm Chat on WTIF.  It is 9:48. Dr. Knox, I tell you, there were a lot of magazines in the 1960's, I can remember seeing these quotes in there that were saying that we could see another ice age in the future. You actually mentioned that or the article mentions that, about a little ice age that happened for about a 300-year period. Can you talk about that?

Pam Knox, UGA Athens Campus Climatologist: If you can think back to your history classes back in grade school, you might remember stories about Valley Forge in Pennsylvania and how General Washington had a hard time because it was so cold. That was right at the end of the period that we call the little ice age where, if you look at numbers of sun spots and things like that, most scientists believe that the sun was a little bit less active during that period. And, you know, the sun really drives the weather and climate system. So if you had less input of energy from the sun, things tend to be a bit colder.

If you look at the really long term history going back to the ice ages and so on, we know that ice ages are determined in large part by sunlight that comes in and changes in earth’s orbit around the sun. And just based on that alone, we see that we are likely at the end of another warm period and headed back ultimately to another ice age. Now, you know this is something that happens over the course of 10's of 1000's of years, it's not going to happen 10 years and 100 years down the road. But it is certainly something that we’d expect to see eventually.

Kyle Dean, Host: Do we, as we talk about the now and the right now for these farmers that really endured  a dry, dry year this past year, are we expecting more of the same in 2012?

Pam Knox: UGA Athens Campus Climatologist: Well, I think we really are going to have to watch what happens over the winter. We do expect it to continue to be dry. That doesn't mean we are not going to get any rain at all because in the winter, we have more rain. Also, with the cooler temperatures, we have less evaporation. So, whatever we can get will be to the good of the soil. But we are expecting that we may go into the next spring season with relatively dry soils and of course, that's a concern if you are worried about germination of seeds and thing like that. Also, it really depends if we get timely rain. We've been hurt the last couple years because we haven't had any tropical systems that have come over us. And, with La Niña, we are supposed to be at a more active season and we were the last 2 years, but it just hasn't hit Georgia at all.

Kyle Dean, Host: I'm glad you mentioned the tropical seasons because we just got out of the hurricane season in the last week or two. How important are those tropical systems and how important is the wet stuff that we get from that?

Pam Knox, UGA Athens Campus Climatologist: The tropical system and the tropical rainfall in Georgia is really vital for keeping up our normal rainfall. The direct estimates of rainfall effects from tropical storms are only about 8 to 10% of the total rainfall in the tropical season. But once you get that moisture into the soil, you get a lot more recycling with daily thunder storms. So if the soils are dry to begin with you, don't get any of that benefit. And so I think, really, the ultimate effect of not having the tropics active and bringing rain to Georgia, probably accounts for maybe 20 - 30% of the loss of rainfall that we have had the last couple years.

Kyle Dean, Host: Well, Pam this is great information. We certainly appreciate your time and thank you for joining us here on our UGA Tifton Farm Chat.

Pam Knox, UGA Athens Campus Climatologist: It's been a pleasure.

Kyle Dean, Host: Alright. That's Dr. Pam Knox, UGA Climatologist in Bio and Ag Engineering on our UGA Tifton Farm Chat. We will come back and wrap up the show after this. You're listening to Hometown Country 107.5 WTIF.