Latest / THE DAILY BRIEF / Tokyo’s endless rain

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Tokyo’s endless rain · THE DAILY BRIEF

• 0:00
  Speaker 1: When did it last rain where you are? Yesterday? Last week? Well,
• 0:04
  Speaker 1: in Tokyo, you'd have to ask the opposite. When did
• 0:08
  Speaker 1: it last not rain? Take a look at this. It
• 0:11
  Speaker 1: has rained in the Japanese capital every single day for
• 0:15
  Speaker 1: 35 days. That is the longest streak since record-keeping began
• 0:18
  Speaker 1: in 1886. Nearly 630 millimeters have fallen since the start
• 0:21
  Speaker 1: of September. That's almost three times the normal amount. So
• 0:29
  Speaker 1: the people in Tokyo, they have, well, been living under
• 0:32
  Speaker 1: an umbrella for over a month, and some are starting
• 0:35
  Speaker 1: to wonder if the sun will ever come back. Japan's
• 0:38
  Speaker 1: weather agency points to El Nino and stubborn Aldean rain
• 0:42
  Speaker 1: fronts and says a warming climate is changing the country's
• 0:45
  Speaker 1: weather over the long term, and it's being felt everywhere
• 0:50
  Speaker 1: from tourism to grocery prices and, not least... You're seeing
• 0:55
  Speaker 1: it in people's moods. Except for Matthew Capucci. He's always
• 1:00
  Speaker 1: in a good mood. He has explained plenty of weather
• 1:03
  Speaker 1: and climate phenomena for us. He's a senior meteorologist at
• 1:06
  Speaker 1: MyRadar in the U.S. Matthew, it's good to see you. Yeah,
• 1:09
  Speaker 1: I mean, I guess you have to try to force
• 1:11
  Speaker 1: yourself to smile. I mean, what is keeping the rain
• 1:14
  Speaker 1: over Tokyo for more than a month?
• 1:16
  Speaker 2: That's a really good question. You know, when y'all first
• 1:20
  Speaker 2: reached out to me, I was rather incredulous saying, could
• 1:22
  Speaker 2: it really rain for 35 days? And I took a
• 1:24
  Speaker 2: look at the different weather stations around the Tokyo metro area.
• 1:28
  Speaker 2: This was weather station 47662, which is located in Kitanomaru Park.
• 1:33
  Speaker 2: For the past 35 days, they've had some amount of
• 1:36
  Speaker 2: measurable rainfall. In at least 10 days, that's meant only
• 1:39
  Speaker 2: about half a millimeter or less, so just a little
• 1:41
  Speaker 2: bit of drizzle. But there have been two days that
• 1:43
  Speaker 2: saw more than 150 millimeters of rainfall in a single day.
• 1:47
  Speaker 2: Both of those came down from typhoons. September 6th through
• 1:51
  Speaker 2: the 7th, that was Kravon. And then September 21st, that
• 1:54
  Speaker 2: was Dujuan. And my apologies if I pronounce that incorrectly,
• 1:57
  Speaker 2: but both those storms dropped upwards of 15 centimeters. Now,
• 2:01
  Speaker 2: the reason we've seen all this rainfall is sort of
• 2:04
  Speaker 2: a stalled frontal boundary that lurks nearby. It's something called
• 2:07
  Speaker 2: the Mayu Front. It sets up every summertime and into
• 2:10
  Speaker 2: early fall from roughly Tibet through China, near Taiwan, and
• 2:14
  Speaker 2: then near the southern side of Japan. And waves of
• 2:17
  Speaker 2: precipitation work along it. But when you have a warming world,
• 2:21
  Speaker 2: in addition to El Nino... He tended to have more
• 2:23
  Speaker 2: moisture to work with, and we just had incessant downpours.
• 2:27
  Speaker 1: So maybe you've answered it a little bit, but I'll ask,
• 2:30
  Speaker 1: how do El Nino and climate change, how do they
• 2:33
  Speaker 1: each fit into this?
• 2:36
  Speaker 2: Yeah, so both of those are kind of sources of moisture,
• 2:39
  Speaker 2: but you need a trigger. So this frontal boundary is
• 2:42
  Speaker 2: kind of like a railroad track along which waves of
• 2:44
  Speaker 2: moisture can propagate along, just like train cars ride along
• 2:46
  Speaker 2: that train track. When you have a frontal boundary like
• 2:49
  Speaker 2: this that is stalled, you get something called baroclinicity. which
• 2:53
  Speaker 2: is essentially an instability that results when you have air
• 2:55
  Speaker 2: masses of different temperatures and therefore densities that are trying
• 3:00
  Speaker 2: to mix. And they don't mix all that gracefully. They
• 3:03
  Speaker 2: mix via kind of eddies and weather systems, low pressure
• 3:05
  Speaker 2: systems that produce rainfall. Now, El Nino features a warming
• 3:09
  Speaker 2: of water temperatures in the eastern tropical Pacific that lifts moisture.
• 3:12
  Speaker 2: And that can even translate into the western Pacific. For example,
• 3:15
  Speaker 2: around Japan, there's a slight correlation between increased late summer,
• 3:19
  Speaker 2: early fall rainfall in Japan, parts of southern Japan, central Japan, too,
• 3:24
  Speaker 2: and El Nino. Moreover, a warming world, climate change is
• 3:27
  Speaker 2: a wetter world. For every degree Celsius the air temperature warms,
• 3:30
  Speaker 2: the air can hold 7% more water, so you get
• 3:32
  Speaker 2: more rainfall.
• 3:33
  Speaker 1: Wow. I mean, I was looking at the numbers here,
• 3:35
  Speaker 1: and just for Tokyo, over the month of September, 629
• 3:41
  Speaker 1: millimeters fell. Can you put that in a way that
• 3:45
  Speaker 1: people can picture how much precipitation that is?
• 3:51
  Speaker 2: Yeah, I think you made a great point earlier on
• 3:53
  Speaker 2: when you said that is three times what's normal. I mean,
• 3:55
  Speaker 2: we're talking 60 centimeters worth of rainfall. That's pretty impressive,
• 4:00
  Speaker 2: especially for such a major metro area. You know, we
• 4:03
  Speaker 2: talk about rain of that magnitude. That's something we would
• 4:05
  Speaker 2: see in more tropical climates. And certainly, Japan is near
• 4:08
  Speaker 2: the Kuroshio Current. You have access to tropical moisture from
• 4:13
  Speaker 2: time to time. We're getting kind of late in the
• 4:15
  Speaker 2: season to see this much moisture, unless it's being dragged
• 4:17
  Speaker 2: north by typhoons. But the other issue, too, infrastructure. Whenever
• 4:22
  Speaker 2: you have a city, even if there's very advanced infrastructure
• 4:25
  Speaker 2: like in Japan, Tokyo especially, I've been there several times.
• 4:28
  Speaker 2: I love it. But cities are not meant to handle
• 4:31
  Speaker 2: downpours and drain that water out very quickly. And so
• 4:34
  Speaker 2: when you have saturated soils from a long-duration flood event
• 4:38
  Speaker 2: or heavy rainfall event like we've seen, it makes it
• 4:40
  Speaker 2: tougher to drain. I will also note that I went
• 4:42
  Speaker 2: back in the data. They saw even more rainfall during July.
• 4:46
  Speaker 2: They had an extremely anomalously wet summer. So going into this,
• 4:50
  Speaker 2: there were antecedent moist conditions and soil moisture was through
• 4:53
  Speaker 2: the roof.
• 4:54
  Speaker 1: When you have a city like Tokyo that goes weeks
• 4:57
  Speaker 1: or months with hardly any sunshine, is that just an inconvenience? Obviously,
• 5:04
  Speaker 1: people are going to complain about it. Or does it,
• 5:06
  Speaker 1: you know, when you're talking about it as a meteorologist,
• 5:08
  Speaker 1: does it become then a public health issue?
• 5:13
  Speaker 2: I would say so, and it's intriguing because we've certainly seen,
• 5:18
  Speaker 2: both anecdotally and in quantitative data, a relationship between people's
• 5:22
  Speaker 2: moods and the weather. Certainly, if it's cloudy and dreary
• 5:26
  Speaker 2: and dismal, people's moods tend to be a little bit
• 5:29
  Speaker 2: depressed too. But there was a paper, and I'd have
• 5:31
  Speaker 2: to go back and pull up that paper, but there
• 5:32
  Speaker 2: was a paper a while back that found, at least
• 5:34
  Speaker 2: in U.S. cities, there is an optimal temperature at which
• 5:38
  Speaker 2: crime rates actually drop. If the temperatures get too hot,
• 5:42
  Speaker 2: people get more antsy, the crime goes up until a
• 5:44
  Speaker 2: certain point when people don't want to go outside and
• 5:46
  Speaker 2: crime rates go down. So there are actually optimal conditions
• 5:49
  Speaker 2: for people's moods. In this case, of course, we're not
• 5:51
  Speaker 2: talking crime. We're talking just general happiness. And I venture
• 5:54
  Speaker 2: to say that even though Japan is very accustomed to
• 5:56
  Speaker 2: cloudy skies, this can't be cheering people up.
• 5:59
  Speaker 1: Yeah, well, I mean, we live through the gray skies
• 6:01
  Speaker 1: here in Berlin in the winter. We can feel for
• 6:03
  Speaker 1: the folks in Tokyo. I've got 10 seconds. Let me
• 6:06
  Speaker 1: just ask you, what's the outlook for the people of Tokyo?
• 6:08
  Speaker 1: Is the sun going to come out soon?
• 6:11
  Speaker 2: Well, Annie said that the sun will come out tomorrow,
• 6:13
  Speaker 2: but I don't believe her. All right.
• 6:16
  Speaker 1: Meteorologist Matthew Capucci with a silver lining, searching for a
• 6:19
  Speaker 1: silver lining there. Matthew, as always, thank you.