Total Ozone Thickness

Location	Date	UTC Time	Thickness [DU]	Sky Condition	Ozone&NO2 [ug/m³] **
Diekirch	30Dec20	12:00	349.5	heavy clouds	21.3
Diekirch	26Dec20	10:30	288.5	some clouds	40.4
Diekirch	25Dec20	11:36	316.1	some clouds	46.6
Diekirch	24Dec20	09:14	242.9	some clouds	43.6
Diekirch	20Dec20	13:51	363.1	heavy clouds	41.7
Diekirch	19Dec20	12:10	254.9	light haze	42.4
Diekirch	17Dec20	11:13	261.2	many clouds	47.8
Diekirch	14Dec20	11:17	246.2	heavy clouds	26.1
Diekirch	13Dec20	12:06	255.2	hazy	41.5
Diekirch	05Dec20	11:12	348.9	many clouds	42.5
Diekirch	30Nov20	12:24	275.2	many clouds	12.7
Diekirch	29Nov20	12:03	269.5	some clouds	22.5
Diekirch	28Nov20	13:58	252.6	blue sky	43.8
Diekirch	25Nov20	12:04	276.5	light haze	25.4
Diekirch	21Nov20	12:29	257.7	some clouds	33.8
Diekirch	20Nov20	12:19	279.4	heavy clouds	42.5
Diekirch	19Nov20	13:18	297.0	many clouds	52.2
Diekirch	18Nov20	12:27	208.5	blue sky	44.3
Diekirch	14Nov20	12:17	286.0	some clouds	41.5
Diekirch	13Nov20	12:17	279.6	hazy	37.7
Diekirch	12Nov20	12:08	280.6	blue sky	60.1
Diekirch	09Nov20	12:10	276.9	light haze	15.9
Diekirch	08Nov20	12:06	276.5	light haze	31.6
Diekirch	06Nov20	12:03	278.2	blue sky	46.8
Diekirch	05Nov20	12:51	283.5	blue sky	54.2
Diekirch	04Nov20	12:07	282.5	blue sky	38.3
Diekirch	31Oct20	12:02	283.3	blue sky	43.7
Diekirch	28Oct20	11:14	280.6	heavy clouds	50.6
Diekirch	26Oct20	12:25	327.4	many clouds	52.0
Diekirch	22Oct20	11:26	265.1	many clouds	63.3
Diekirch	21Oct20	11:51	267.0	many clouds	70.0
Diekirch	19Oct20	11:12	279.9	some clouds	43.4
Diekirch	14Oct20	11:23	293.0	heavy clouds	44.3
Diekirch	12Oct20	11:54	269.1	heavy clouds	45.0
Diekirch	11Oct20	08:51	307.7	some clouds	34.4
Diekirch	10Oct20	10:57	290.4	many clouds	65.6
Diekirch	07Oct20	11:58	256.6	many clouds	53.2
Diekirch	06Oct20	11:14	288.8	many clouds	46.9
Diekirch	29Sep20	13:12	268.1	heavy clouds	50.0
Diekirch	25Sep20	11:15	313.6	heavy clouds	43.3
Diekirch	24Sep20	09:48	273.4	heavy clouds	65.9
Diekirch	23Sep20	11:16	270.7	heavy clouds	81.9
Diekirch	21Sep20	11:01	250.2	blue sky	130.6
Diekirch	20Sep20	11:30	257.3	hazy	116.5
Diekirch	13Sep20	12:30	267.5	blue sky	111.1
Diekirch	12Sep20	10:10	274.1	blue sky	72.4
Diekirch	11Sep20	12:06	310.4	some clouds	95.3
Diekirch	10Sep20	10:30	281.3	many clouds	44.1
Diekirch	08Sep20	10:10	266.7	blue sky	78.6
Diekirch	07Sep20	10:05	286.0	blue sky	75.7
Diekirch	06Sep20	11:50	301.3	many clouds	71.2
Diekirch	05Sep20	10:40	292.8	many clouds	69.1
Diekirch	04Sep20	10:50	280.1	many clouds	99.4
Diekirch	22Aug20	11:50	298.2	some clouds	78.4
Diekirch	20Aug20	10:55	278.3	blue sky	97.7
Diekirch	19Aug20	10:30	290.4	many clouds	47.9
Diekirch	18Aug20	10:05	303.8	many clouds	92.7
Diekirch	17Aug20	09:20	300.8	some clouds	75.6
Diekirch	16Aug20	09:30	305.8	some clouds	103.6
Diekirch	15Aug20	10:10	299.8	some clouds	104.4
Diekirch	14Aug20	11:25	293.9	many clouds	92.3
Dîekirch	13Aug20	12:40	287.9	many clouds	148.4
Diekirch	12Aug20	10:53	286.4	many clouds	148.3
Diekirch	11Aug20	10:10	290.0	many clouds	153.7
Diekirch	10Aug20	11:05	293.3	some clouds	158.4
Diekirch	09Aug20	12:10	293.6	blue sky	176.0
Diekirch	08Aug20	11:10	295.2	some clouds	154.3
Diekirch	07Aug20	11:43	306.4	blue sky	155.1
Diekirch	06Aug20	10:18	295.4	light haze	110.5
Diekirch	05Aug20	11:30	301.2	blue sky	133.5
Diekirch	04Aug20	12:07	305.7	many clouds	97.4
Diekirch	02Aug20	10:55	300.9	many clouds	57.2
Diekirch	01Aug20	11:15	286.5	many clouds	114.0
Diekirch	31Jul20	10:43	288.0	blue sky	160.0
Diekirch	30Jul20	10:49	290.3	blue sky	123.6
Diekirch	29Jul20	09:56	296.6	some clouds	76.9
Diekirch	28Jul20	10:55	298.4	some clouds	65.4
Diekirch	27Jul20	11:10	298.1	many clouds	113.6
Diekirch	26Jul20	09:57	324.8	many clouds	66.4
Diekirch	25Jul20	11:28	303.9	many clouds	74.6
Diekirch	24Jul20	09:00	307.8	very hazy	108.6
Diekirch	23Jul20	11:40	306.7	light haze	105.7
Diekirch	22Jul20	11:10	301.3	light haze	109.7
Diekirch	21Jul20	10:50	312.8	blue sky	95.1
Diekirch	20Jul20	12:57	313.0	many clouds	69.4
Diekirch	19Jul20	11:50	316.5	many clouds	106.8
Diekirch	18Jul20	09:48	307.2	many clouds	95.8
Diekirch	14Jul20	11:55	319.0	heavy clouds	125.2
Diekirch	12Jul20	11:05	315.3	many clouds	105.0
Diekirch	11Jul20	11:06	339.8	many clouds	84.7
Diekirch	09Jul20	11:02	298.6	some clouds	41.3
Diekirch	07Jul20	11:35	303.3	many clouds	83.3
Diekirch	05Jul20	11:58	286.9	some clouds	29.4
Diekirch	04Jul20	12:40	303.7	many clouds	71.4
Diekirch	03Jul20	11:07	305.7	many clouds	65.4
Diekirch	01Jul20	13:11	293.0	heavy clouds	39.5
Diekirch	29Jun20	11:52	300.5	some clouds	82.0
Diekirch	25Jun20	11:01	303.6	blue sky	131.0
Diekirch	24Jun20	11:15	304.1	blue sky	128.2
Diekirch	23Jun20	10:51	298.8	blue sky	117.1
Diekirch	22Jun20	11:08	299.3	some clouds	74.9
Diekirch	21Jun20	11:20	308.4	many clouds	83.8
Diekirch	18Jun20	11:46	334.4	many clouds	83.3
Diekirch	16Jun20	11:09	325.6	heavy clouds	89.1
Diekirch	13Jun20	11:34	313.9	heavy clouds	104.9
Diekirch	10Jun20	10:48	333.6	heavy clouds	92.8
Diekirch	08Jun20	11:51	355.1	many clouds	93.6
Diekirch	06Jun20	12:01	333.1	some clouds	73.6
Diekirch	03Jun20	11:30	328.7	some clouds	133.5
Diekirch	02Jun20	11:15	313.5	blue sky	124.9
Diekirch	01Jun20	11:32	315.3	blue sky	104.5
Diekirch	31May20	11:16	321.7	some clouds	84.5
Diekirch	30May20	10:49	323.7	some clouds	97.9
Diekirch	29May20	11:36	329.6	some clouds	103.5
Diekirch	28May20	12:30	342.3	blue sky	96.8
Diekirch	27May20	11:12	315.4	blue sky	106.7
Diekirch	26May20	11:20	314.7	light haze	100.5
Diekirch	24May20	10:34	343.1	heavy clouds	70.0
Diekirch	22May20	10:52	294.9	very hazy	50.4
Diekirch	21May20	11:10	298.9	blue sky	118.7
Diekirch	20May20	12:20	300.5	many clouds	91.0
Diekirch	19May20	12:04	308.4	blue sky	117.6
Diekirch	18May20	11:01	311.9	blue sky	107.0
Diekirch	17May20	11:19	313.3	blue sky	99.3
Diekirch	16May20	10:09	328.3	blue sky	99.1
Diekirch	15May20	11:19	328.1	blue sky	87.0
Diekirch	14May20	11:47	334.1	many clouds	83.2
Diekirch	13May20	12:33	324.3	many clouds	87.4
Diekirch	12May20	11:24	353.1	blue sky	64.4
Diekirch	10May20	11:12	326.9	many clouds	93.6
Diekirch	08May20	11:21	322.1	hazy	140.0
Diekirch	07May20	11:18	331.2	blue sky	108.9
Diekirch	06May20	11:17	343.5	blue sky	92.6
Diekirch	05May20	11:20	337.5	some clouds	84.3
Diekirch	04May20	11:04	324.4	heavy clouds	71.5
Diekirch	03May20	12:11	340.0	many clouds	94.5
Diekirch	02May20	14:08	363.7	many clouds	90.1
Diekirch	01May20	10:26	367.2	some clouds	70.3
Diekirch	30Apr20	09:52	366.0	heavy clouds	69.8
Diekirch	29Apr20	11:06	344.6	some clouds	61.3
Diekirch	27Apr20	11:05	345.4	many clouds	98.9
Diekirch	26Apr20	10:58	353.1	blue sky	81.9
Diekirch	25Apr20	11:04	318.9	blue sky	53.0
Diekirch	24Apr20	11:22	302.6	light haze	105.5
Diekirch	23Apr20	11:29	305.2	blue sky	98.3
Diekirch	22Apr20	11:27	309.4	blue sky	91.2
Diekirch	21Apr20	11:03	321.9	some clouds	96.3
Diekirch	20Apr20	11:10	329.6	blue sky	98.4
Diekirch	19Apr20	13:30	328.7	some clouds	65.4
Diekirch	18Apr20	12:14	332.9	heavy clouds	74.2
Diekirch	17Apr20	11:13	336.5	some clouds	89.1
Diekirch	16Apr20	11:05	338.7	some clouds	80.8
Diekirch	15Apr20	11:03	300.0	many clouds	74.4
Diekirch	14Apr20	11:10	309.7	some clouds	67.1
Diekirch	13Apr20	11:02	334.9	light haze	55.1
Diekirch	12Apr20	11:00	319.5	blue sky	86.7
Diekirch	11Apr20	11:01	296.4	light haze	83.5
Diekirch	10Apr20	11:07	274.7	light haze	98.1
Diekirch	09Apr20	11:01	300.7	light haze	109.8
Diekirch	08Apr20	11:01	317.9	blue sky	84.2
Diekirch	07Apr20	11:00	287.3	blue sky	63.4
Diekirch	06Apr20	12:00	285.7	blue sky	92.9
Diekirch	05Apr20	11:51	291.5	blue sky	76.7
Diekirch	04Apr20	11:05	301.5	blue sky	64.2
Diekirch	02Apr20	11:24	338.8	blue sky	57.8
Diekirch	01Apr20	11:00	337.7	blue sky	61.7
Diekirch	31Mar20	11:16	355.8	many clouds	60.5
Diekirch	30Mar20	11:05	389.7	blue sky	60.9
Diekirch	29Mar20	07:19	315.2	heavy clouds	48.6
Diekirch	28Mar20	12:20	345.6	blue sky	81.8
Diekirch	27Mar20	13:26	366.4	blue sky	71.7
Diekirch	26Mar20	12:26	362.4	blue sky	66.4
Diekirch	25Mar20	12:24	332.8	blue sky	75.8
Diekirch	24Mar20	12:21	352.3	blue sky	72.1
Diekirch	23Mar20	12:09	371.2	blue sky	73.4
Diekirch	22Mar20	11:38	359.1	blue sky	74.3
Diekirch	20Mar20	11:49	304.8	some clouds	59.1
Diekirch	19Mar20	12:16	311.8	some clouds	92.7
Diekirch	17Mar20	11:21	341.2	many clouds	80.0
Diekirch	16Mar20	11:32	367.0	many clouds	65.0
Diekirch	15Mar20	13:31	342.7	heavy clouds	92.5
Diekirch	12Mar20	12:31	311.3	heavy clouds	95.0
Diekirch	08Mar20	12:22	355.7	heavy clouds	85.0
Diekirch	04Mar20	13:11	354.8	heavy clouds	62.3
Diekirch	01Mar20	13:02	332.6	many clouds	71.5
Diekirch	28Feb20	13:00	281.2	many clouds	80.7
Diekirch	25Feb20	10:15	356.5	many clouds	92.5
Diekirch	21Feb20	12:25	306.6	many clouds	63.1
Diekirch	19Feb20	12:09	318.0	many clouds	73.0
Diekirch	17Feb20	12:30	319.5	many clouds	84.2
Diekirch	16Feb20	11:30	279.1	many clouds	70.5
Diekirch	15Feb20	12:36	294.8	many clouds	76.2
Diekirch	11Feb20	11:26	298.8	heavy clouds	83.1
Diekirch	10Feb20	12:13	309.7	heavy clouds	82.1
Diekirch	07Feb20	12:05	311.4	blue sky	40.0
Diekirch	06Feb20	12:12	325.2	blue sky	23.8
Diekirch	05Feb20	12:22	325.8	blue sky	83.0
Diekirch	04Feb20	12:06	406.8	heavy clouds	81
Diekirch	29Jan20	11:52	356.4	many clouds	80.2
Diekirch	28Jan20	11:49	426.5	heavy clouds	80.2
Diekirch	22Jan20	12:07	300.8	blue sky	27.5
Diekirch	21Jan20	12:06	333.0	blue sky	42.3
Diekirch	20Jan20	11:32	336.2	some clouds	64.9
Diekirch	18Jan20	12:28	412.5	heavy clouds	74.7
Diekirch	16Jan20	12:30	314.0	some clouds	59.7
Diekirch	15Jan20	12:07	317.3	many clouds	84.1
Diekirch	13Jan20	11:54	320.8	heavy clouds	84.1

The total thickness of the (stratospheric) ozone layer is measured at unspecified, irregular intervals using the handheld Microtops II sensor manufactured by Solar Light Company of Philadelphia. This instrument measures the thickness of the ozone layer by computing the ratios of UVB irradiances measured at three different wavelengths; the water vapour content of the atmosphere and the AOT (aerosol optical thickness) are also measured by the instrument.
The measurement results are given in DU (Dobson Unit). 100 DU correspond to a total thickness of 1 mm, if the ozone layer were at a standard atmospheric pressure of 1013.25 [HPa]. Common values are in the 250..350 DU range.

The previous years dobsonyy.html files and the Microtops measurement files can be found in the data area!

1. Starting 01-May-2020 a new calibration factor of 0.9321 is applied to #3012 measurements by Mike Zimmer. This new factor is the result of a comparison made from 18 to 26 April 2020. #3012 readings multiplied by this factor are given in blue.

2. Green DU's correspond to a new calibration factor of 0.9422 applied to #3012 measurements by Mike Zimmer starting 02Jun16 ! This new calibration factor has been found by a new comparison over several measurements made from March to July 2016.

Starting 15 Sep 2009, Microtops #5375 is back from calibration at Mauna Loa. Purple data correspond to the new calibrated readings. There is a big difference between the readings before and after calibration. For some time, measurements will be made with both Microtops, and a conclusion drawn thereafter.

(**) The O3&NO2 concentration is given for the actual temperature and pressure conditions. It is NOT corrected for STP conditions! As the NO2 concentrations is practically negligible (below the sensor threshold of 40 ug/m3, the readings should be taken as O3 concentration.

The "old" CAIRSENS O3&NO2 has been replaced by a new model the 15th May 2020. This new Cairsens seems to have a strong positive bias. As our O3 values are very close to those measured by the official station at Beckerich (confirmed by several comparisons), a calibration function will be applied in the datalogger starting 1st July. Correct_O3 = 1.074*reading - 36.309. This function as been applied to all the ground ozone values from 16 May to 29 June (numbers in red) which have not been corrected by the logger. Please read the NEWS from 1 July 20 for the various graphs.

Thickness of the ozone layer at Uccle	Measured by the Royal Meteorological Institute (RMI) of Belgium; shows mean and variance of all data from 1971 on (link has changed!)
Ozone Distribution (NH + SH)	Global Ozone maps from NASA
Northern Hemisphere Ozone Map (not available)	Ozone map generated from all Northern Hemisphere stations by the WOUDC

Total Ozone Thickness 2020