scholarly journals The Diurnal Variations of GPS PWV near Poyang Lake in China during Midsummer

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Shanshan Wu ◽  
Haibo Zou ◽  
Junjie Wu
Keyword(s):  
Diurnal Variation ◽  
Global Positioning System ◽  
Diurnal Cycle ◽  
Poyang Lake ◽  
Precipitable Water ◽  
Diurnal Variations ◽  
Diurnal Cycles ◽  
Global Positioning ◽  
Variance Contribution ◽  
Gps Observation

With the 1 h-averaged data of atmospheric precipitable water vapor (PWV) for 2015–2018 retrieved from 18 ground-based Global Positioning System (GPS) observation stations near Poyang Lake (PL), China, the diurnal variations of the PWV during midsummer (July-August) are studied by the harmonic method. Results show that significant diurnal variations of PWV are found at the 18 GPS stations. The harmonics with 24 h cycle (diurnal cycle) over PL (i.e., Duchang and Poyang) and Nanchang city only have about 50% (or even smaller than 50%) of variance contribution with the amplitude of about 0.2 mm, while above 70% (or even 80%) of variance contribution occurs elsewhere around PL, with the amplitude of about 0.9 mm. The harmonics with diurnal cycles in most stations peak from afternoon to evening (i.e., 1200-2000 LST), but one exception is Duchang site, where the diurnal cycle peaks in the morning (i.e., 1000 LST). Moreover, the harmonics with 12 h cycle (semidiurnal cycle) have the relatively uniform amplitude of about 0.2 mm, but their variance contributions show uneven distribution, with the contributions of about or above 50% in PL and Nanchang city (the semidiurnal cycles peak about 0000 LST or 1200 LST) and below 30% (or even 10%) in other areas. The preliminary diagnosis analysis shows that the diurnal variation of the low-level (below 850 hPa) air temperature (increasing after the sunrise, decreasing after the sunset, and peaking around 1400-1800 LST) may be responsible for the diurnal cycle. Moreover, in PL (Duchang and Poyang) and Nanchang city, the effects (heating or cooling) of lake and urban, the diurnal variation of the 10 m wind over PL, and the acceleration of PL on overlying air also contributed to the diurnal variation of PWV.

scholarly journals On the Climatology of Precipitable Water and Water Vapor Flux in the Mid-Atlantic Region of the United States

2015 ◽  
Vol 16 (1) ◽  
pp. 70-87 ◽  
Author(s):  
Young-Hee Ryu ◽  
James A. Smith ◽  
Elie Bou-Zeid
Keyword(s):  
United States ◽  
Water Vapor ◽  
Diurnal Cycle ◽  
Precipitable Water ◽  
The United States ◽  
Radiosonde Data ◽  
Atlantic Region ◽  
Water Vapor Flux ◽  
Vapor Flux ◽  
Diurnal Cycles

Abstract The seasonal and diurnal climatologies of precipitable water and water vapor flux in the mid-Atlantic region of the United States are examined. A new method of computing water vapor flux at high temporal resolution in an atmospheric column using global positioning system (GPS) precipitable water, radiosonde data, and velocity–azimuth display (VAD) wind profiles is presented. It is shown that water vapor flux exhibits striking seasonal and diurnal cycles and that the diurnal cycles exhibit rapid transitions over the course of the year. A particularly large change in the diurnal cycle of meridional water vapor flux between spring and summer seasons is found. These features of the water cycle cannot be resolved by twice-a-day radiosonde observations. It is also shown that precipitable water exhibits a pronounced seasonal cycle and a less pronounced diurnal cycle. There are large contrasts in the climatology of water vapor flux between precipitation and nonprecipitation conditions in the mid-Atlantic region. It is hypothesized that the seasonal transition of large-scale flow environments and the change in the degree of differential heating in the mountainous and coastal areas are responsible for the contrasting diurnal cycle between spring and summer seasons.

Variability of GPS water vapor associated with warming activity in Peninsular Malaysia during the period of 2008–2011

2015 ◽  
Vol 7 (1) ◽  
pp. 240-250 ◽  
Author(s):  
Wayan Suparta ◽  
Maszidah Muhammad ◽  
Mandeep Singh Jit Singh ◽  
Fredolin T. Tangang ◽  
Mardina Abdullah ◽  
...  
Keyword(s):  
Water Vapor ◽  
Global Positioning System ◽  
Positive Relationship ◽  
Precipitable Water ◽  
Peninsular Malaysia ◽  
Positioning System ◽  
Dry Spells ◽  
Global Positioning ◽  
Semiannual Variation ◽  
Monthly Variations

This study utilizes the precipitable water vapor (PWV) parameter retrieved from ground-based global positioning system (GPS) to detect warming activity in Peninsular Malaysia from 2008 to 2011. Daily average of GPS PWV and surface meteorology data taken from six selected stations over Peninsular Malaysia are analyzed. Prior to warming detection, GPS PWV results are compared with PWV obtained from Radiosonde and found a positive relationship. The daily GPS PWV variability was characterized as high during the inter-monsoon seasons (April-May and October-November) and lower at the beginning, middle and the end of the year. For the monthly variations, GPS PWV increased by about 2.40 mm, which is correlated with an increase in surface temperature of 0.20 °C. We detected variability of PWV with a semiannual variation and the pattern is opposite to the accumulated precipitation, indicating that wet and dry spells coincide with local monsoon and intermonsoon periods. The warming effect in this study was felt over all selected stations with northern parts of Peninsular Malaysia affected significantly. The results imply that GPS is a powerful tool for analysis of warming effects and the mechanism of how it affects the circulation of water vapor is discussed in this study.

scholarly journals Diurnal Cycle of Convective Instability around the Central Mountains in Japan during the Warm Season

2005 ◽  
Vol 62 (5) ◽  
pp. 1626-1636 ◽  
Author(s):  
Tomonori Sato ◽  
Fujio Kimura
Keyword(s):  
Water Vapor ◽  
Diurnal Cycle ◽  
Convective Instability ◽  
Potential Temperature ◽  
Warm Season ◽  
Precipitable Water ◽  
Specific Humidity ◽  
High Temporal Resolution ◽  
Mountainous Areas ◽  
Diurnal Cycles

Abstract Convective rainfall often shows a clear diurnal cycle. The nighttime peak of convective activity prevails in various regions near the world's mountains. The influence of the water vapor and convective instability upon nocturnal precipitation is investigated using a numerical model and observed data. Recent developments in GPS meteorology allow the estimation of precipitable water vapor (PWV) with a high temporal resolution. A dense network has been established in Japan. The GPS analysis in August 2000 provides the following results: In the early evening, a high-GPS-PWV region forms over mountainous areas because of the convergence of low-level moisture, which gradually propagates toward the adjacent plain before midnight. A region of convection propagates simultaneously eastward into the plain. The precipitating frequency correlates fairly well with the GPS-PWV and attains a maximum value at night over the plain. The model also provides similar characteristics in the diurnal cycles of rainfall and high PWV. Abundant moisture accumulates over the mountainous areas in the afternoon and then advects continuously toward the plain by the ambient wind. The specific humidity greatly increases at about the 800-hPa level over the plain at night, and the PWV reaches its nocturnal maximum. The increase in the specific humidity causes an increase of equivalent potential temperature at about the 800-hPa level; as a result, the convective instability index becomes more unstable over the plain at night. These findings are consistent with the diurnal cycle of the observed precipitating frequency.

scholarly journals Diurnal cycle of ozone throughout the troposphere over Frankfurt as measured by MOZAIC-IAGOS commercial aircraft

Elem Sci Anth ◽  
2016 ◽  
Vol 4 ◽  
Author(s):  
H. Petetin ◽  
V. Thouret ◽  
G. Athier ◽  
R. Blot ◽  
D. Boulanger ◽  
...  
Keyword(s):  
Diurnal Cycle ◽  
High Frequency ◽  
Diurnal Variations ◽  
Vertical Profiles ◽  
Commercial Aircraft ◽  
Surface Deposition ◽  
Diurnal Cycles ◽  
Mixing Ratios ◽  
First Time ◽  
Lower Production

Abstract Ozone is generally assumed to have weak diurnal variations in the free troposphere due to lower production rates than in the boundary layer, in addition to a much lower NO titration and the absence of dry deposition at the surface. However, this hypothesis has not been proven due to a lack of high frequency observations at multiple times per day. For the first time, we take benefit from the frequent O3 vertical profiles measured above Frankfurt in the framework of the MOZAIC-IAGOS program to investigate the diurnal variations of O3 mixing ratios at multiple pressure levels throughout the troposphere. With about 21,000 aircraft profiles between 1994 and 2012 (98 per month on average), distributed throughout the day, this is the only dataset that can allow such a study. As expected, strong diurnal variations are observed close to the surface, in particular during spring and summer (enhanced photochemistry and surface deposition). Higher in altitude, our observations show a decrease of the diurnal cycle, with no diurnal cycle discernible above 750 hPa, whatever the season. Similar results are observed for the different percentiles of the O3 distribution (5th, 25th, 50th, 75th, 95th). An insight of the changes of the diurnal cycles between 1994–2003 and 2004–2012 is also given. We found higher O3 mixing ratios during the latter period, particularly on the lowest pressure levels, despite lower mixing ratios during summer.

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