Back to the start

Dear readers,

I started my academic life in 2004 as a math student in University of Helsinki. I enjoined my time there, although, one of the best experiences of my “university years” was the academic year 2006/2007 that I got to spent in Roma Tre University as an Erasmus exchange student. During the later part of my studies, in 2008, I joined the Atmospheric Remote Sensing group of the Finnish Meteorological Institute first as a summer trainee, then as a master’s thesis worker, and finally as a research scientist. I never looked back, and went to do my PhD studies in Lappeenranta University of Technology (2011–2013). This means that I never actually worked for my alma mater.

Tomorrow that is about to change, as I will join the Inverse Problems research group in the Department of Mathematics and Statistics until the end of this year. I am excited about this opportunity and will try to learn as much as I can during the next seven months. Research-wise, this is also an excellent opportunity to study the different aspects of the inverse problems research.

Actually, I will start my first full week as a university employee in the “13th InternationalWorkshop on Greenhouse Gas Measurements from Space.” Finnish Meteorological Institute organizes the meeting, but it will be held in the main building of… University of Helsinki!

See you there!

Janne

Direct space-based observations of anthropogenic CO2 emission areas from OCO-2, Part II

Dear readers,

the previous blogpost was about the public outreach of our latest paper: "Direct space-based observations of anthropogenic CO₂ emission areas from OCO-2."

However, the blogpost itself did not mention the scientific content of that paper at all. As I presented this work as a poster at the OCO-2 Algorithm and Science Team Meeting at NCAR Mesa Lab in Boulder, Colorado earlier this year. I would like to share the poster with you now

The meeting itself was absolutely fantastic, and I learned a lot. We also got to see a AirCore launch which was fun

Janne

Direct space-based observations of anthropogenic CO2 emission areas from OCO-2

Dear readers,

it has been a while since I have blogged last time. But there has been a good reason. I have been busy with our latest work "Direct space-based observations of anthropogenic CO₂ emission areas from OCO-2". In comparison to many of my previous works, the public outreach with this one has been through the roof. For example JPL/NASA published a news feature about it

The same text was also published as a press release at the front page of FMI website. It was also picked-up by many news outlets like the Daily Mail and Tähdet ja Avaruus from Finland, to name a few. One of the funniest was this newspaper clipping we got all the way from Katmandu

We made also a Finnish press release about it.

NASA EarthObservatory made new elegant figures for their image of the day feature. Those images were further included for example in this inverse.com article.

I have gotten so many emails about this work from journalist, scientist, teachers, and ordinary people alike. Literally, everyday. Two of the questions from readers of NASA EarthObservatory, with responses, were published in a follow-up. 

Today also come out new Tiedelehti. There’s a "Tieteen tentti" with a familiar face

I wrote also an article, suitable for the general public, to the next Ilmansuojelu -lehti, 4/2016. It will come out later this month.

Earlier this week, I gave a guest lecture at Lappeenrant University of Technology. The XCO₂ anomaly data together with OMI NO₂ data were also given for the students for their study assignment related to cluster analysis.

This research has also trigged many new scientific collaborations, and there will be many new adventures. I will promise.

Stay tuned!

Janne

Pawan K. Bhartia – the man who created the first image of the ozone hole

Hi guys,

couple of days ago, I found this very interesting Youtube video of “Pawan K. Bhartia Maniac Lecture, August 27, 2014.”



In the video P.K. talks about his career and how the discovery of the ozone hole come about. It is a very interesting story.

See also “Discovering the Ozone Hole: Q&A With Pawan Bhartia” and “Ozone Hole History.”

Oh, and this is the very first image of the ozone hole:



Very powerful image!

Janne

CARB-ARC: Remote sensing of greenhouse gas concentrations #Arktiko

Hello,

next week I'm headed to the Academy of Finland's annual ARKTIKO seminar.  Below you can find the poster I'm about to present. It summarize the remote sensing activities done in our CARB-ARC project.

Cheers,
Janne

The Audacity of Hope: President Obama Explains How Pollution Affects Our Planet

Hello,

have you guys seen this already!? In this video President Obama speaks about OMI data. And if you didn't know, OMI  is a Dutch-Finnish satellite instrument  onboard NASA's Aura spacecraft etc.



Btw. See you next week in EGU! Maybe I will do some live posting from there...

Janne

Using OCO-2 Data to Analyze Anthropogenic CO2 Hotspots: First Preliminary Results

Hello,

just submitted the abstract below to the "12th International Workshop on Greenhouse Gas Measurements from Space." I am not going, but our boss Johanna Tamminen will present this.

Janne

Using OCO-2 Data to Analyze Anthropogenic CO₂ Hotspots:

First Preliminary Results

Janne Hakkarainen (1), Iolanda Ialongo (1), and Johanna Tamminen (1)

(1) Finnish Meteorological Institute (FMI)

NASA’s Orbiting Carbon Observatory 2 (OCO-2) was launched on 2 July 2014 to monitor global atmospheric concentration and flux of CO₂ from space. As of March 2016, the instrument has collected more than one year of data. In this paper, we utilize this data record to analyze hotspots of anthropogenic CO₂ sources. Our aim is to utilize advanced techniques developed to analyze spaceborne nitrogen dioxide (NO₂) and sulfur dioxide (SO₂)—both short-lived atmospheric trace gases with both anthropogenic and natural sources—datasets. Unfortunately, trends, seasonality, long lifetime, and large atmospheric background significantly complicate the analysis of CO₂ hotspots. Our methodology is based on simultaneously deseasonalizing and detrending the data, and then mapping the remaining—the so-called anomaly data—to a grid.  

In this paper, we show that the main anthropogenic pollution regions like eastern USA, Central Europe, East Asia, and Middle East are easily detectable from our OCO-2 CO₂ anomaly maps. In addition, also smaller sources are visible. In order to better understand CO₂ anomaly maps, we simultaneously analyze the established NO₂ and SO₂ maps—observed by Dutch-Finnish Ozone Monitoring Instrument (OMI) onboard NASA’s Aura spacecraft—and use these data records also to qualitatively validate our results. In future, as the OCO-2 data record gets longer, we hope to individually detect all the Megacities.

Keywords: OCO-2, carbon dioxide, anthropogenic emissions, hotspots, validation, OMI, nitrogen dioxide

Pavlof, Alaska volcanic eruption 2016

Hello,

yesterday OMPS observed volcanic SO₂ plume from Pavlof eruption with three overpasses:

The data are acquired and processed by GINA/UAF and posted at FMI Direct Readout web site: http://sampo.fmi.fi/

Note that also ash was observed:

Zoom it!

Janne

Generalized correlation integral vectors: A distance concept for chaotic dynamical systems

Hello,

I’ve been about to blog about our ”Generalized correlation integral vectors: A distance concept for chaotic dynamical systems” paper for a quite some time. Now, I have a good option, since I’m about to go EGU general assembly for the first time this April.

Below there’s my poster that I’m about to present. The motivation for this methodology comes from our NOVAC project where the aim was to analyze the climate models.

See you all in EGU,

Janne

Time series of methane and carbon dioxide

Hello,

my colleague Hannakaisa Lindqvist recently published a paper with a fancy title: “Does GOSAT capture the true seasonal cycle of carbon dioxide?” This summer we are taking a summer trainee to study that same question for methane.

Today I decided to do a little bit of our summer student's work and plotted TCCON time series of methane and carbon dioxide in the same figure. These figures came out so nice that I want to share theme with you guys.

Cheers,
Janne

Random projection in a nutshell

I was reading the random projection paper – written by Teija Seitola et al. – the other day, and I think I have now quite a good understanding of how the method works.

The whole thing is based on Johnson–Lindenstrauss lemma from 1984. The lemma says that random projection (nearly) preserves the distances.

Let X be a n×d-dimensional data matrix, where n is the number of data (or ensemble) points and d is the actual dimension. Let f be d×k-dimensional random projection matrix. Let x_i and x_j be d-dimensional data vectors and ε>0. Now we have that

(1-ε)×ǁx_i-x_jǁ² ≤ ǁf(x_i)-f(x_j)ǁ² ≤ (1+ε)×ǁx_i-x_jǁ².

In the paper there are also to explicit formulas for k that surprisingly do not depend on the dimension d, but only on the number of observations n and the error ε. For example, k > 4×(ε²/2-ε³/3)^-1×log(n).

So if, for example in correlation dimension, we set n = 2000 and ε = 0.1, we need k that is higher than 4*(.1^2/2-.1^3/3)^(-1)*log(2000) = 6515.1. I tested this with 320-dimensional Lorenz and set k to 10000 and the thing works since the curves became so similar (see figure below).

As a conclusion, I would say that random projection method works “better” in large than small dimensional problems, and that the dimension have to be really large before it is worth to use random projections in applications where the preservation of distances is very very important. Note that there are other kinds of applications too…

Below, there is a little Matlab example.

Ciao,

Janne

%% Random projection Matlab example

n = 2000; % Number of time points

d = 20000; % Dimension

k = 10000; % Random dimension

X = 10+5*randn(n,d); % Data matrix

R = randn(d,k); % Random projection matrix

for kkk = 1:d

   R(kkk,:) = R(kkk,:)/norm(R(kkk,:)); % Normalization

end

P = X*R; % Projection

% Distances

ii = 10; jj = 20;

norm(X(ii,:)-X(jj,:))

norm(P(ii,:)-P(jj,:))

Volcanic Sunsets

Hello,

just wanted to share an interesting Youtube video—Alan Robock's 5-minute Ignite talk at NCAR.

Janne

OCO-2 target measurements over Sodankylä TCCON station – 20 August 2015

Hello,

I wanted to share an animation showing what  NASA's OCO-2 instrument measured on target mode over Sodankylä TCCON site on 20 August 2015:

Sodankylä is one of the so-called OCO-2 target stations, i.e., once in awhile during one orbit, the instrument measures back and forth over Sodankylä. All those OCO-2 XCO₂ measurements shown in the animation were performed in about four minutes. During that day Sodankylä's TCCON FTS instrument measured XCO₂ of about 394.5 ppm.

Cheers,
Janne

2015 Dragon 3 Symposium and best poster award

Hello,

before summer holidays I had the pleasure to participate 2015 Dragon 3 Symposium held in beautiful city of Interlaken, Switzerland. Dragon program is about co-operation between ESA member states and China. The symposium had good atmosphere, and I personally was delighted to receive "best poster award" for my poster presentation. Thanks! Feels good.

As I mentioned the city of Interlaken – between two lakes – is beautiful and surrounded by great mountains. The mayor of Interlaken gave a nice opening to the symposium and told that these days Asians are the most important tourist group in the region, and they come to Switzerland to visit mountains and to buy watches. This fact can clearly be seen in Interlaken, although, I believe that this time around there were even more Chinese people than usual!

On the way back to Zürich Airport I had a chance to visit Bern, and the Einsteinhaus in particular. In that little apartment he wrote the "Annus Mirabilis papers". The one on the photoelectric effect got him Nobel Prize in 1921.

Below are some photos.

Ciao,
Janne

The symposium plenaries were held in a very fancy room. Probably an old theatre.

The workshops were held in normal rooms. Here Erkki is presenting something fancy with Einstein in the middle.

Nice view! 

These skydivers were everywhere!

The Einsteinhaus – right.

The Einsteinhaus – left.

The Einsteinhaus – center. The studio apartment was actually really small.

The Einsteinhaus – window.

Oh, and the "best poster award"!

Smoke to Europe from East and West

Hi guys,

SAMPO observed this nice little thing

Those clouds are smoke from Alaska and Canada, and came here from East and West. See also the "Smoke Goes Around the World" by NASA's Earth Observatory website.

Oh, and Happy Summer!

Janne