Change search
Link to record
Permanent link

Direct link
BETA
Moradi, Isaac
Publications (5 of 5) Show all publications
Moradi, I., Buehler, S., John, V., Reale, A. & Ferraro, R. (2013). Evaluating instrumental inhomogeneities in global radiosonde upper tropospheric humidity data using microwave satellite data (ed.). Paper presented at . IEEE Transactions on Geoscience and Remote Sensing, 51(6), 3615-3624
Open this publication in new window or tab >>Evaluating instrumental inhomogeneities in global radiosonde upper tropospheric humidity data using microwave satellite data
Show others...
2013 (English)In: IEEE Transactions on Geoscience and Remote Sensing, ISSN 0196-2892, E-ISSN 1558-0644, Vol. 51, no 6, p. 3615-3624Article in journal (Refereed) Published
Abstract [en]

In this paper, the overall quality of the water vapor profiles of global operational radiosonde data for the period 2000-2009 is investigated using upper tropospheric humidity (UTH) retrieved from microwave satellite data. Overall, the nighttime radiosonde data showed a dry bias (-5% to-15%) over Europe, Australia, and New Zealand and systematically moist bias (greater than 30%) over China and the former Soviet Union. The nighttime sonde data from the U.S. and Canada showed a bias between-10% and 20%. Most stations indicated a daytime radiation dry bias, except for a few stations from the U.S. and the former Soviet Union. A sensorwise comparison showed a large nighttime wet bias for the Russian (MRZ-3A and MARS) and Chinese GZZ-2 sensors, a relatively small nighttime wet bias for the U.S. Sippican and VIZ-B2 sensors, and a nighttime dry bias for the Chinese GTS1, Vaisala (RS80-A, RS80-H, RS90, RS92K, and RS92-SGP), and the U.S. VIZ-MKII sensors. All sensors had a daytime radiation dry bias, except for the Russian MRZ-3A sensor that had a daytime radiation wet bias that could be because of the daytime radiation bias correction. Because of the large differences between different radiosonde sensors, it is essential for UTH studies to only use the data measured using a single type of sensor at any given station.

National Category
Aerospace Engineering
Research subject
Space Technology
Identifiers
urn:nbn:se:ltu:diva-3967 (URN)10.1109/TGRS.2012.2220551 (DOI)000320941300012 ()2-s2.0-84878126576 (Scopus ID)1d04c04a-5b4b-4f70-87bd-8f9e5a3c16a8 (Local ID)1d04c04a-5b4b-4f70-87bd-8f9e5a3c16a8 (Archive number)1d04c04a-5b4b-4f70-87bd-8f9e5a3c16a8 (OAI)
Note
Validerad; 2013; 20130611 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Moradi, I., Buehler, S., John, V. & Eliasson, S. (2010). Comparing upper tropospheric humidity data from microwave satellite instruments and tropical radiosondes (ed.). Journal of Geophysical Research, 115(24), Article ID D24310.
Open this publication in new window or tab >>Comparing upper tropospheric humidity data from microwave satellite instruments and tropical radiosondes
2010 (English)In: Journal of Geophysical Research, ISSN 0148-0227, E-ISSN 2156-2202, Vol. 115, no 24, article id D24310Article in journal (Refereed) Published
Abstract [en]

Atmospheric humidity plays an important role in the Earth's climate. Microwave satellite data provide valuable humidity observations in the upper troposphere with global coverage. In this study, we compare upper tropospheric humidity (UTH) retrieved from the Advanced Microwave Sounding Unit (AMSU-B) and the Microwave Humidity Sounder (MHS) against radiosonde data measured at four of the central facilities of the Atmospheric Radiation Measurement (ARM) program. The Atmospheric Radiative Transfer Simulator (ARTS) was used to simulate satellite brightness temperatures from the radiosonde profiles. Strong ice clouds were filtered out, as their influence on microwave measurements leads to incorrect UTH values. Day and night radiosonde profiles were analyzed separately, to take into account the radiosonde radiation bias. The comparison between radiosonde and satellite is most meaningful for data in cloud free, night time conditions, and with a time difference of less than 2 hours. We found good agreement between the two data sets. The satellite data are slightly moister than the radiosonde data, with a mean difference of 1-2.3 %RH, depending on the radiosonde site. Monthly gridded data were also compared, and showed slightly larger mean difference of up to 3.3 %RH, which can be explained by sampling issues.

National Category
Aerospace Engineering
Research subject
Space Technology
Identifiers
urn:nbn:se:ltu:diva-8505 (URN)10.1029/2010JD013962 (DOI)000285642300001 ()2-s2.0-78650946846 (Scopus ID)70556760-bbee-11df-a707-000ea68e967b (Local ID)70556760-bbee-11df-a707-000ea68e967b (Archive number)70556760-bbee-11df-a707-000ea68e967b (OAI)
Note

Validerad; 2011; 20100909 (isamor)

Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Moradi, I., Buehler, S. & John, V. O. (2010). Comparing upper tropospheric humidity from microwave satellite instruments and IGRA radiosonde data (ed.). In: (Ed.), (Ed.), 11th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment, MicroRad: . Paper presented at Specialist Meeting on Microwave Radiometry and Remote Sensing Applications : 01/03/2010 - 04/03/2010 (pp. 146-151). New York: IEEE Communications Society
Open this publication in new window or tab >>Comparing upper tropospheric humidity from microwave satellite instruments and IGRA radiosonde data
2010 (English)In: 11th Specialist Meeting on Microwave Radiometry and Remote Sensing of the Environment, MicroRad, New York: IEEE Communications Society, 2010, p. 146-151Conference paper, Published paper (Refereed)
Abstract [en]

In this study, Advanced Microwave Sounding Unit (AMSU-B) and Microwave Humidity Sounder (MHS) observations are compared to radiosonde data from the Integrated Global Radiosonde Archive (IGRA) dataset. This comparison can be used to evaluate the overall quality of the radiosonde data. Microwave satellite data are influenced by thick ice clouds and radiosonde data show a day-time radiation dry bias. Therefore, we used night-time cloud-free data of the year 2009 for the comparison. Overall, radiosonde data from the former Soviet Union were up to 30 %RH moister than satellite data and the the rest of the world were up to 6 %RH drier than satellite data.

Place, publisher, year, edition, pages
New York: IEEE Communications Society, 2010
National Category
Aerospace Engineering
Research subject
Space Technology
Identifiers
urn:nbn:se:ltu:diva-35384 (URN)10.1109/MICRORAD.2010.5559573 (DOI)2-s2.0-77958086416 (Scopus ID)9e6a3900-cae4-11df-a707-000ea68e967b (Local ID)978-1-4244-8120-0 (ISBN)9e6a3900-cae4-11df-a707-000ea68e967b (Archive number)9e6a3900-cae4-11df-a707-000ea68e967b (OAI)
Conference
Specialist Meeting on Microwave Radiometry and Remote Sensing Applications : 01/03/2010 - 04/03/2010
Note
Godkänd; 2010; 20100928 (ysko)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-07-10Bibliographically approved
Moradi, I., Alijani, B., Muller, R. & Kamali, G. A. (2009). Evaluation of the Heliosat-II method using daily irradiation data for four stations in Iran (ed.). Paper presented at . Solar Energy, 83(2), 150-156
Open this publication in new window or tab >>Evaluation of the Heliosat-II method using daily irradiation data for four stations in Iran
2009 (English)In: Solar Energy, ISSN 0038-092X, E-ISSN 1471-1257, Vol. 83, no 2, p. 150-156Article in journal (Refereed) Published
Abstract [en]

Efficient use of solar radiation needs detailed knowledge of its spatial and temporal variations. Such information can be achieved using interpolating measured irradiance by ground stations. But more reliable results can be obtained by processing geostationary satellite images. Heliosat is an algorithm which has been developed to estimate global horizontal irradiance at ground level from images taken in the visible band by the Meteosat satellites. The aim of this study was to evaluate the Heliosat-II model by using daily global solar irradiation data measured at the four radiometric stations in Iran as well as Meteosat-5 images which are recorded by a spacecraft over 63°E. Mean RMSD% and MBD% for all stations were 11.7% and 1.9%, respectively. The mean values of intercept, slope and correlation coefficient were 0.82 (kWhm-2), 1.05 and 0.93, respectively. Seasonally, the maximum RMSD occurs in autumn (22.1%) and the minimum is experienced in spring (8.4%). This accuracy is a great achievement for producing a high quality solar radiation atlas in a country such as Iran with very sparse radiometric network and frequently unreliable measured irradiation data.

National Category
Aerospace Engineering
Research subject
Space Technology
Identifiers
urn:nbn:se:ltu:diva-13101 (URN)10.1016/j.solener.2008.07.010 (DOI)000263318500003 ()2-s2.0-58149199884 (Scopus ID)c44e6600-e738-11dd-88bb-000ea68e967b (Local ID)c44e6600-e738-11dd-88bb-000ea68e967b (Archive number)c44e6600-e738-11dd-88bb-000ea68e967b (OAI)
Note
Validerad; 2009; 20090120 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Moradi, I. (2009). Quality control of global solar radiation using sunshine duration hours (ed.). Paper presented at . Energy, 34(1), 1-6
Open this publication in new window or tab >>Quality control of global solar radiation using sunshine duration hours
2009 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 34, no 1, p. 1-6Article in journal (Refereed) Published
Abstract [en]

The aim of this study was to develop a new and automatic method for controlling the quality of daily global solar radiation, Gd, using sunshine duration hours. The new method has three levels of tests: first, Gd is compared against daily extraterrestrial radiation that is received on a horizontal surface (0.03×God≤Gdod); second, Gd should only exceed by a small amount of the daily clear sky irradiation that is observed under highly transparent clear skies (Gd<1.1Gcd); and third, the method uses a series of persistence checks that utilize the relation between daily global solar radiation and relative sunshine duration hours. The method is capable of identifying systematic and non-systematic errors and its ability has been shown in three different climates including semi-arid, coastal humid and very arid climates.

National Category
Aerospace Engineering
Research subject
Space Technology
Identifiers
urn:nbn:se:ltu:diva-4887 (URN)10.1016/j.energy.2008.09.006 (DOI)000262658200001 ()2-s2.0-57449108695 (Scopus ID)2e3bbee0-dcbd-11dd-bf31-000ea68e967b (Local ID)2e3bbee0-dcbd-11dd-bf31-000ea68e967b (Archive number)2e3bbee0-dcbd-11dd-bf31-000ea68e967b (OAI)
Note
Validerad; 2009; 20090107 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Organisations

Search in DiVA

Show all publications