tag:blogger.com,1999:blog-4572286363399496963.post3521830938580980001..comments2024-03-28T07:09:59.093-08:00Comments on Deep Cold: Alaska Weather & Climate: Seasonality of PDO InfluenceRickhttp://www.blogger.com/profile/03946704894714514716noreply@blogger.comBlogger7125tag:blogger.com,1999:blog-4572286363399496963.post-43778701916526097402014-12-16T18:28:45.144-09:002014-12-16T18:28:45.144-09:00Thanks Richard. In the last year plus that I'...Thanks Richard. In the last year plus that I've been following this blog, I've learnt a thing or two about using proper statistics, ie median is usually more stable than mean. There has been too much bad science because of the use of bad stats. Luckily, you seem to get it right. :)<br /><br />I've long noticed that there is a warming in the record lows of December as compared to November and January. Your graphs suggest that a weak PDO brought those on so now I have a more detailed reason for such behavior. I'll be waiting for the digging into of that Dec spike.Eric Lundellhttps://www.blogger.com/profile/17914784378747801359noreply@blogger.comtag:blogger.com,1999:blog-4572286363399496963.post-92077770517833052002014-12-16T13:43:37.750-09:002014-12-16T13:43:37.750-09:00Got it Gary! With Brian's help I realized tha...Got it Gary! With Brian's help I realized that I was inexplicably looking at Figure 6 rather than Figure 4. I most certainly deserve the switching for wasting your time. Thanks for persevering.<br />Richard Jameshttps://www.blogger.com/profile/08313902028896263276noreply@blogger.comtag:blogger.com,1999:blog-4572286363399496963.post-936103085277332542014-12-16T11:14:15.597-09:002014-12-16T11:14:15.597-09:00Still confused. Not about the thin Upper/Lower Qua...Still confused. Not about the thin Upper/Lower Quartile Temperature Anomaly range lines, but the labeling of the Top/Bottom Quartile heavy lines. Seems intuitive the Top should be Red; the Bottom Blue. Maybe a good switching in front of the class is in order, followed by me standing in the corner. Been there so no problem.<br /><br />Summer versus winter versus PDO. I suspect that insolation and advection (or the lack of) have a more pronounced effect than clouds in determining summer temperatures in Interior Alaska. Without an examination of seasonal cloud cover versus phase of the PDO it's just an assumption. That's where a model of the joint distributions you suggest would be instructive.<br /><br />GaryNL7Yhttps://www.blogger.com/profile/15874712728971005352noreply@blogger.comtag:blogger.com,1999:blog-4572286363399496963.post-39311683597352325432014-12-16T08:32:12.841-09:002014-12-16T08:32:12.841-09:00Gary, I think Figure 4 is OK - for negative PDO, w...Gary, I think Figure 4 is OK - for negative PDO, winter temperature anomalies are usually negative (black line, left axis) and the probability of warmth is low (blue line, right axis). Click on the chart for a larger version. Let me know if you still think it's wrong.<br /><br />Interesting point on clouds: if the negative PDO causes reduced cloud cover year-round, this would favor warming in the summer when rates of advection are small. But the positive PDO is also warm in summer. As you suggest, the joint distribution of PDO/clouds and PDO/advection would be instructive.<br />Richard Jameshttps://www.blogger.com/profile/08313902028896263276noreply@blogger.comtag:blogger.com,1999:blog-4572286363399496963.post-81177172511071572762014-12-16T07:51:50.168-09:002014-12-16T07:51:50.168-09:00Eric, there is obviously some sampling noise in th...Eric, there is obviously some sampling noise in the daily charts, but the sample is fairly large (and I looked at median, not mean) so will not be dominated by a single extreme year. I'll try to show this later by looking at the December spike in temperatures for negative PDO.<br /><br />In general I would expect larger PDO anomalies to have larger effects on temperature, so the major influences shown in the charts should show up more reliably and/or strongly when the PDO index is large in magnitude. One could look at the more extreme PDO cases separately, but of course the sample size gets smaller...<br /><br />Good question on the analog outlook for January; I'll see if I can pull out some similar years and find anything other than "warm" as a forecast.<br />Richard Jameshttps://www.blogger.com/profile/08313902028896263276noreply@blogger.comtag:blogger.com,1999:blog-4572286363399496963.post-20493145342915722012014-12-15T19:02:16.631-09:002014-12-15T19:02:16.631-09:00I need new glasses but are the top and bottom Quar...I need new glasses but are the top and bottom Quartile ID's reversed in Fig. 4? <br /><br />Very nice examination Richard. But you know me, I have to ask how cloud cover and warm/cold advection relate to + and - PDO's, especially in winter. In summer the reverse may be true...clouds cool and advection may upset the insolation-induced temp stratification. <br /><br />Back when, the Professor would suggest ANOVA class analyses and the class would groan. I'm not the Professor.<br /><br />GaryNL7Yhttps://www.blogger.com/profile/15874712728971005352noreply@blogger.comtag:blogger.com,1999:blog-4572286363399496963.post-57506918398273308622014-12-15T17:01:28.378-09:002014-12-15T17:01:28.378-09:00Are we taken care that an outlining year doesn'...Are we taken care that an outlining year doesn't overwhelm the signal? How would removing the sudden warm up of spring 2013 or the falling strange winter before change things?<br /><br />I also read the first chart as saying that as the PDO anomoly increases so does the temperature anomaly. Would this be true? Or is the winter temp variation fairly stable despite the PDO?<br /><br />I think we need an analog forecast based on current conditions. How cold is it going to get next month?Eric Lundellhttps://www.blogger.com/profile/17914784378747801359noreply@blogger.com