Diurnal variations in middle-atmospheric water vapor by ground-based microwave radiometry

Abstract. In this paper, we compare the diurnal variations in middle-atmospheric water vapor as measured by two ground-based microwave radiometers in the Alpine region near Bern, Switzerland. The observational data set is also compared to data from the chemistry–climate model WACCM. Due to the small diurnal variations of usually less than 1%, averages over extended time periods are required. Therefore, two time periods of five months each, December to April and June to October, were taken for the comparison. The diurnal variations from the observational data agree well with each other in amplitude and phase. The linear correlation coefficients range from 0.8 in the upper stratosphere to 0.5 in the upper mesosphere. The observed diurnal variability is significant at all pressure levels within the sensitivity of the instruments. Comparing our observations with WACCM, we find that the agreement of the phase of the diurnal cycle between observations and model is better from December to April than from June to October. The amplitudes of the diurnal variations for both time periods increase with altitude in WACCM, but remain approximately constant at 0.05 ppm in the observations. The WACCM data are used to separate the processes that lead to diurnal variations in middle-atmospheric water vapor above Bern. The dominating processes were found to be meridional advection below 0.1 hPa, vertical advection between 0.1 and 0.02 hPa and (photo-)chemistry above 0.02 hPa. The contribution of zonal advection is small. The highest diurnal variations in water vapor as seen in the WACCM data are found in the mesopause region during the time period from June to October with diurnal amplitudes of 0.2 ppm (approximately 5% in relative units).

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Diurnal variations in middle atmospheric water vapor by ground-based microwave radiometry

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-13-3859-2013 ◽

2013 ◽

Vol 13 (2) ◽

pp. 3859-3880 ◽

Cited By ~ 1

Author(s):

D. Scheiben ◽

A. Schanz ◽

B. Tschanz ◽

N. Kämpfer

Keyword(s):

Water Vapor ◽

Observational Data ◽

Climate Model ◽

Correlation Coefficients ◽

Diurnal Variations ◽

Atmospheric Water Vapor ◽

Atmospheric Water ◽

Data Set ◽

Diurnal Variability ◽

Time Periods

Abstract. In this paper, we compare the diurnal variations in middle atmospheric water vapor as measured by two ground-based microwave radiometers in the Alpine region near Bern, Switzerland. The observational data set is also compared to data from the chemistry-climate model WACCM. Due to the small diurnal variations of usually less than 1%, averages over extended time periods are required. Therefore, two time periods of five months each, December to April and June to October, were taken for the comparison. The diurnal variations from the observational data agree well with each other in amplitude and phase. The linear correlation coefficients range from 0.8 in the upper stratosphere to 0.5 in the upper mesosphere. The observed diurnal variability is significant at all pressure levels within the sensitivity of the instruments. Comparing our observations with WACCM, we find that the agreement of the phase of the diurnal cycle between observations and model is better from December to April than from June to October. The amplitudes of the diurnal variations for both time periods increase with altitude in WACCM, but remain approximately constant at 0.05 parts per million in the observations. The WACCM data is used to separate the processes that lead to diurnal variations in middle atmospheric water vapor above Bern. The dominating processes were found to be meridional advection below 0.1 hPa, vertical advection between 0.1 and 0.02 hPa and (photo-)chemistry above 0.02 hPa. The contribution of zonal advection is small. The highest diurnal variations in water vapor are found in the mesopause region during the time period from June to October with diurnal amplitudes of 0.2 ppm (approximately 5% in relative units).

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Evaluation of the atmospheric water vapor content in a regional climate model using ground-based GPS measurements

Journal of Geophysical Research Atmospheres ◽

10.1029/2012jd018053 ◽

2013 ◽

Vol 118 (2) ◽

pp. 329-339 ◽

Cited By ~ 33

Author(s):

T. Ning ◽

G. Elgered ◽

U. Willén ◽

J. M. Johansson

Keyword(s):

Water Vapor ◽

Regional Climate Model ◽

Climate Model ◽

Regional Climate ◽

Water Vapor Content ◽

Atmospheric Water Vapor ◽

Atmospheric Water ◽

Gps Measurements

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Terrestrial evaporation and global climate: lessons from Northland, a planet with a hemispheric continent

Journal of Climate ◽

10.1175/jcli-d-20-0452.1 ◽

2020 ◽

pp. 1-64

Author(s):

Marysa M. Laguë ◽

Marianne Pietschnig ◽

Sarah Ragen ◽

Timothy A. Smith ◽

David S. Battisti

Keyword(s):

Water Vapor ◽

Southern Hemisphere ◽

Northern Hemisphere ◽

Land Surface ◽

Large Scale ◽

Climate Model ◽

Global Climate ◽

Atmospheric Water Vapor ◽

Atmospheric Water ◽

Local Warming

AbstractMotivated by the hemispheric asymmetry of land distribution on Earth, we explore the climate of Northland, a highly idealized planet with a Northern Hemisphere continent and a Southern Hemisphere ocean. The climate of Northland can be separated into four distinct regions: the Southern Hemisphere ocean, the seasonally wet tropics, the mid-latitude desert, and the Great Northern Swamp. We evaluate how modifying land surface properties on Northland drives changes in temperatures, precipitation patterns, the global energy budget, and atmospheric dynamics. We observe a surprising response to changes in land-surface evaporation, where suppressing terrestrial evaporation in Northland cools both land and ocean. In previous studies, suppressing terrestrial evaporation has been found to lead to local warming by reducing latent cooling of the land surface. However, reduced evaporation can also decrease atmospheric water vapor, reducing the strength of the greenhouse effect and leading to large-scale cooling. We use a set of idealized climate model simulations to show that suppressing terrestrial evaporation over Northern Hemisphere continents of varying size can lead to either warming or cooling of the land surface, depending on which of these competing effects dominate. We find that a combination of total land area and contiguous continent size controls the balance between local warming from reduced latent heat flux and large-scale cooling from reduced atmospheric water vapor. Finally, we demonstrate how terrestrial heat capacity, albedo, and evaporation all modulate the location of the ITCZ both over the continent and over the ocean.

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Profiling of atmospheric water vapor with MIR and LASE

IEEE Transactions on Geoscience and Remote Sensing ◽

10.1109/tgrs.2002.800227 ◽

2002 ◽

Vol 40 (6) ◽

pp. 1211-1219 ◽

Cited By ~ 6

Author(s):

J.R. Wang ◽

P. Racette ◽

M.E. Triesky ◽

E.V. Browell ◽

S. Ismail ◽

...

Keyword(s):

Water Vapor ◽

Atmospheric Water Vapor ◽

Atmospheric Water

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New Gridded Product for the Total Columnar Atmospheric Water Vapor over Ocean Surface Constructed from Microwave Radiometer Satellite Data

Remote Sensing ◽

10.3390/rs13122402 ◽

2021 ◽

Vol 13 (12) ◽

pp. 2402

Author(s):

Weifu Sun ◽

Jin Wang ◽

Yuheng Li ◽

Junmin Meng ◽

Yujia Zhao ◽

...

Keyword(s):

Water Vapor ◽

Microwave Radiometer ◽

Atmospheric Water Vapor ◽

Global Ocean ◽

Optimal Interpolation ◽

Fusion Product ◽

Mean Deviation ◽

Atmospheric Water ◽

Absolute Deviation ◽

Better Than

Based on the optimal interpolation (OI) algorithm, a daily fusion product of high-resolution global ocean columnar atmospheric water vapor with a resolution of 0.25° was generated in this study from multisource remote sensing observations. The product covers the period from 2003 to 2018, and the data represent a fusion of microwave radiometer observations, including those from the Special Sensor Microwave Imager Sounder (SSMIS), WindSat, Advanced Microwave Scanning Radiometer for Earth Observing System sensor (AMSR-E), Advanced Microwave Scanning Radiometer 2 (AMSR2), and HY-2A microwave radiometer (MR). The accuracy of this water vapor fusion product was validated using radiosonde water vapor observations. The comparative results show that the overall mean deviation (Bias) is smaller than 0.6 mm; the root mean square error (RMSE) and standard deviation (SD) are better than 3 mm, and the mean absolute deviation (MAD) and correlation coefficient (R) are better than 2 mm and 0.98, respectively.

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Retrieval of atmospheric water vapor and land surface temperature from AVHRR thermal imagery

1995 International Geoscience and Remote Sensing Symposium, IGARSS '95. Quantitative Remote Sensing for Science and Applications ◽

10.1109/igarss.1995.524078 ◽

2002 ◽

Cited By ~ 1

Author(s):

Shunlin Liang ◽

S. Goward ◽

J. Ranson ◽

R. Dubayah ◽

S. Kalluri

Keyword(s):

Water Vapor ◽

Surface Temperature ◽

Land Surface Temperature ◽

Land Surface ◽

Atmospheric Water Vapor ◽

Atmospheric Water ◽

Thermal Imagery

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ARIS-Campaign: intercomparison of three ground based 22 GHz radiometers for middle atmospheric water vapor at the Zugspitze in winter 2009

Atmospheric Measurement Techniques ◽

10.5194/amt-4-1979-2011 ◽

2011 ◽

Vol 4 (9) ◽

pp. 1979-1994 ◽

Cited By ~ 11

Author(s):

C. Straub ◽

A. Murk ◽

N. Kämpfer ◽

S. H. W. Golchert ◽

G. Hochschild ◽

...

Keyword(s):

Water Vapor ◽

Noise Temperature ◽

Rotational Transition ◽

Atmospheric Water Vapor ◽

Transition Line ◽

Applied Physics ◽

Atmospheric Water ◽

Max Planck ◽

Institute Of Technology ◽

University Of Bern

Abstract. This paper presents the Alpine Radiometer Intercomparison at the Schneefernerhaus (ARIS), which took place in winter 2009 at the high altitude station at the Zugspitze, Germany (47.42° N, 10.98° E, 2650 m). This campaign was the first direct intercomparison between three new ground based 22 GHz water vapor radiometers for middle atmospheric profiling with the following instruments participating: MIRA 5 (Karlsruhe Institute of Technology), cWASPAM3 (Max Planck Institute for Solar System Research, Katlenburg-Lindau) and MIAWARA-C (Institute of Applied Physics, University of Bern). Even though the three radiometers all measure middle atmospheric water vapor using the same rotational transition line and similar fundamental set-ups, there are major differences between the front ends, the back ends, the calibration concepts and the profile retrieval. The spectrum comparison shows that all three radiometers measure spectra without severe baseline artifacts and that the measurements are in good general agreement. The measurement noise shows good agreement to the values theoretically expected from the radiometer noise formula. At the same time the comparison of the noise levels shows that there is room for instrumental and calibration improvement, emphasizing the importance of low elevation angles for the observation, a low receiver noise temperature and an efficient calibration scheme. The comparisons of the retrieved profiles show that the agreement between the profiles of MIAWARA-C and cWASPAM3 with the ones of MLS is better than 0.3 ppmv (6%) at all altitudes. MIRA 5 has a dry bias of approximately 0.5 ppm (8%) below 0.1 hPa with respect to all other instruments. The profiles of cWASPAM3 and MIAWARA-C could not be directly compared because the vertical region of overlap was too small. The comparison of the time series at different altitude levels show a similar evolution of the H2O volume mixing ratio (VMR) for the ground based instruments as well as the space borne sensor MLS.

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