Table of Contents

11.C - Other Natural Sources

Short description

Within NFR 11.C - Other Natural Sources: Other, natural activities and resulting emissions other than volcanoes (11.A) and forest fires (11.B) are to be taken into account.

For the time being, the only natural emission source reported within NFR 11.C is lightning.

As NFR 11.C is a memo item category, emissions reported here are not accounted for in the National Totals.

Category Code Method AD EF
11.C T1 NS D

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Method(s) applied
D Default
T1 Tier 1 / Simple Methodology *
T2 Tier 2*
T3 Tier 3 / Detailed Methodology *
C CORINAIR
CS Country Specific
M Model
* as described in the EMEP/EEA Emission Inventory Guidebook - 2019, in category chapters.
(source for) Activity Data
NS National Statistics
RS Regional Statistics
IS International Statistics
PS Plant Specific
As Associations, business organisations
Q specific Questionnaires (or surveys)
M Model / Modelled
C Confidential
(source for) Emission Factors
D Default (EMEP Guidebook)
CS Country Specific
PS Plant Specific
M Model / Modelled
C Confidential


NOx NMVOC SO2 NH3 PM2.5 PM10 TSP BC CO Heavy Metals POPs
-/- NA NA NA NA NA NA NA NA NA NA
This memo item source category is not included in the key category analysis.


Lightning (and corona discharge) during thunderstorm events cause atmospheric chemical reactions to take place at high voltages and high temperatures. These reactions cause the production of NOx in the atmosphere.

Methodology

The calculation of NOx emissions from lightning uses strike counts from the German weather service and default emission factors from the 2023 EMEP/EEA guidebook 1).

For the complete time series, the emissions are calculated as follows:

EM = AD (number of lightning strikes) * EF (kg emission per strike)

Activity data

The number of lightning strikes in Germany is taken from a commercial system called “BLIDS” run by Siemens. The data has been cross-referenced with information from the German weather service. Consistent strike count data is available from 1992 onward and has been back-populated to cover the full time series since 1990. The following table shows the strike figures over time.

Table 1: Lightning strikes in Germany from 1990 onwards

Strike count [1000 strikes]
1990 443
1991 443
1992 370
1993 274
1994 429
1995 394
1996 218
1997 255
1998 428
1999 589
2000 1,026
2001 591
2002 1,023
2003 813
2004 741
2005 802
2006 1,001
2007 1,139
2008 990
2009 917
2010 589
2011 687
2012 656
2013 542
2014 623
2015 550
2016 432
2017 443
2018 446
2019 329
2020 399
2021 512
2022 242

Emission factor(s)

For the calculation of emissions in this category, the Guidebook emission factor of 2.75 kg NOx per strike is used.

Emission Trend

The emission value is solely dependent on the strike count and varies between 1 to 3 kilotons of NOx per year.

Figure 1: NFR 11.C, NOx emissions from lightning

Recalculations

With activity data and emission factors remaining unrevised, no recalculations were carried out compared to the previous submission.

Uncertainties

The AD from BLIDS does have a low uncertainty of ± 3%. The uncertainties for the emission factors are estimated to be relatively high, being a default value. Hence the overall uncertainty for the emission estimation of NOx from lightning is qualified estimated by expert judgement to be high (>50%).

Quality checks

No sector-specific quality checks are done.

Planned Improvement

Currently, no source-specific improvements are planned.