How I (almost) became a hydrologist

Contributed by Anders Persson, a HEPEX guest columnist for 2014

As you can imagine by the headline, I am not a hydrologist, but a meteorologist.

I was employed at SMHI in Sweden in 1967 and have since then been involved in forecasting problem, both operationally and theoretically. During 1983-2011 I enjoyed on and off positions at ECMWF, full time from 1991 to 2001. However, it took some time before I develop an interest in hydrology.

The Swedish HBV model was always close to my heart, but that was because got to know Sten Bergström (the father of the HBV model) in 1972 and then followed his career through frustrations, setbacks and final successes.

A deeper relationship with hydrology came first thirty years later. During a coffee break with Göran Lindström (or was it Martin Häggström?) I learned that hydrologists at SMHI were not entirely satisfied with the rainfall forecasts they received from ECMWF through the meteorologists.

–Have you tried “ensemble forecasts”? I wondered

–No, we understand they are not so good, was the answer I got.

Now I really became curious.

During the ensuing conversation it transpired that the hydrologists had not been properly informed about the “ensembles” by the, at the time, sceptical meteorologists. I did my best to give my version and to my surprise, it took only ten minutes for the hydrologists to understand what I had sought to explain to the meteorologists for ten years. So when the hydrologists at SMHI shortly afterwards decided to modernize their forecast service the ECMWFs ensembles became the meteorological backbone of the system.

It was a pleasure over the next few years (along with my colleague Per Kållberg) to provide meteorological expertise to our hydrological colleagues. Particularly stimulating was their culture. They seemed to work for a common good. I did not notice any of the rivalry and infighting between theoreticians and practitioners which poisoned forecast meteorology. In hydrology, physicists and statisticians seemed to work in harmony and there was no obvious antagonism between computer-based and empirical approaches.

After a while I felt a need to learn more about hydrology.

The books in the SMHI library were quite thick and technical, but at the city library I found a 60-page booklet by the prominent Swedish hydrologist Malin Falkenmark: “Känn ditt vatten” (“Know your water”).

I knew her name, but now I learned that she has been professor of applied international hydrology at the Natural Science Research Council since 1986 and held many other prestigious international positions. It did not take many pages into the book before I realized that this was not any normal popular science book. The language was vivid, smooth and easy, the content interesting in the way that the book became a “page turner “. She achieved this not only through her deep knowledge of the subject but also by an ability to highlight contradictions, paradoxes and counterintuitive features. In other words, she succeeded to present hydrology as an exciting science.

According to my diary, it was during the weekend 17-18 July 2004 I read the book sitting in our summerhouse. Outside the rain was pouring down. When I came to work on Monday, I learned that large parts of southernmost Sweden had been hit by serious flooding. The newspapers were calling in, but the few hydrologists who were not on summer vacation had to prioritize the warning service. Here I saw my chance:

• Let me handle the journalists. After reading Malin’s book, I know “everything” about hydrology!

Said and done, I took on the onslaught from the journalist horde and even managed to make the country’s largest newspaper publish a probability map from the ensemble system. It showed that hydrologist had indeed warned about floodings well in advance.

When, at the end of the week, the dust settled, I was appointed “honorary hydrologist” and it was decided that next summer I would function as some kind of hydrological “press ombudsman”.

But the summer of 2005 was dry and some trouble with the ECMWFs ensemble system kept me fully occupied on the meteorological side for most of the time. My potential defection from meteorology to hydrology dried up.

The new hydrological forecasting service stood ready in 2006.When I had visitors at SMHI, I proudly first took them there. One day I had the pleasure to show it to my colleague from various WMO missions, Paul Davies from Exeter. Paul told me that the British were developing something similar and were interested in our experiences.

In spring 2008 the hydrologists arranged a big party celebrating 100 years of hydrology at SMHI. Again I was struck by the cultural difference with meteorologists.

During the entertainment theorists brought down applauds with funny stories about programming error and the frustration of dropping thousands of computer card in a mess on the floor. They were succeeded by sturdy weathered colleagues who told exciting stories from Lapland campaigns about dangerous bears and life threatening spring floods.

A similar “come together party” had not been possible in the meteorological community where theorists and practitioners, if indeed they can remain in the same room, tend to stay at opposite ends.

But again my potential hydrological career was thwarted by a meteorological engagement, this time at the Met Office in Exeter. It turned out to be emotionally and intellectually the most satisfying part of my professionally career. But that is another story . . .

Next post: 21 March 2014.

Anders will be contributing to this blog over the year. Follow his columns here.