Related Experiment Video
Updated: Sep 2, 2025
08:20
In Situ Soil Moisture Sensors in Undisturbed Soils
Published on: November 18, 2022
6.5K
Temperature lapse rate estimation and snowmelt runoff simulation in a high-altitude basin
Keke Zhao1, Dingzhi Peng2, Yu Gu1
1College of Water Sciences, Beijing Normal University, Beijing, China.
Scientific Reports
|August 10, 2022
Summary
This study estimates the near-surface air temperature lapse rate in the Lhasa River Basin, finding an annual average of 0.62°C/100m. Seasonal variations were observed, with higher rates in May and lower rates from September to January.
Area of Science:
- Hydrology
- Climatology
- Environmental Science
Background:
- Near-surface air temperature lapse rate is crucial for hydrological modeling in alpine regions.
- Alpine basins often lack sufficient ground-based observational data for accurate lapse rate estimation.
- Understanding vertical temperature changes is vital for climate and water resource studies.
Purpose of the Study:
- To estimate the near-surface air temperature lapse rate in the Lhasa River Basin (LRB) using a decadal dataset.
- To analyze the seasonal and annual variations of the air temperature lapse rate in the LRB.
- To investigate the relationship between snow cover distribution and air temperature variations.
Main Methods:
- Utilized a monthly air temperature dataset (2001-2015) for the LRB.
- Derived the air temperature dataset by establishing relationships between ground-observed temperatures and MODIS land surface temperatures.
- Calculated the annual average and monthly air temperature lapse rates.
Main Results:
- The estimated annual average air temperature lapse rate for the LRB was approximately 0.62°C/100m.
- Monthly lapse rates varied seasonally between 0.45-0.8°C/100m, peaking in May and reaching minimums from September to January.
- Seasonal snow cover at lower altitudes correlated with air temperature variations, while permanent snow cover was observed above 5000m.
Conclusions:
- The study provides valuable data on the near-surface air temperature lapse rate in a data-scarce alpine basin.
- Seasonal and altitudinal variations in temperature lapse rates and snow cover have been quantified.
- Findings contribute to improved hydrological process modeling and climate change impact assessments in high-altitude environments.
Related Concept Videos
01:03Precipitation Gravimetry
7.0K
Precipitation gravimetry is based on converting an analyte into a sparingly soluble precipitate, which is separated by filtration and weighed. An ideal precipitate should be pure, insoluble, of known composition, and easily filtered from the reaction mixture.
In determining nickel by gravimetric analysis, a precipitant of ethanolic dimethylglyoxime is added to a hot nickel salt solution. This is quickly followed by the dropwise addition of dilute ammonia solution until precipitation occurs. A...
In determining nickel by gravimetric analysis, a precipitant of ethanolic dimethylglyoxime is added to a hot nickel salt solution. This is quickly followed by the dropwise addition of dilute ammonia solution until precipitation occurs. A...
7.0K
01:12Precipitation Processes
573
The experimental conditions in a gravimetric analysis should be optimized to maximize the particle size and purity of the obtained precipitate. Ideally, the concentration of the precipitating reagent should be low with effective stirring to maintain low relative supersaturation for the growth of large crystals. In homogeneous precipitation, the precipitant is slowly generated by a chemical reaction in the solution to avoid local reagent excesses. For example, urea decomposes gradually to...
573
01:17Precipitation and Co-precipitation
2.0K
Precipitation and coprecipitation methods can be used to separate a mixture of ions in a solution. In qualitative inorganic analysis, ions that form sparingly soluble precipitates with the same reagent are separated based on the differences in solubility products. For example, consider the separation of Cu(II) and Fe(II) ions by precipitation as insoluble sulfides. First, copper(II) sulfide is precipitated by the addition of acidic H2S, where the dissociation of H2S is suppressed. Adding H2S...
2.0K
01:19Precipitation Titration: Endpoint Detection Methods
2.0K
In argentometric precipitation titrations, endpoints can be detected visually by the Mohr, Volhard, and Fajans methods. In the Mohr method, adding a soluble chromate indicator gives an initial yellow color to the analyte solution. As the titrant is added, the first excess of silver ions forms a red silver chromate precipitate, marking the endpoint. The solution pH should be maintained at about 8 by adding solid CaCO3.
In the Volhard method, a standard excess of AgNO3 is first added to the...
In the Volhard method, a standard excess of AgNO3 is first added to the...
2.0K
01:21Precipitation Titration Curve: Analysis
1.2K
The precipitation titration curve demonstrates the change in concentration of one reactant with the volume of titrant added. During the titration of chloride ions with silver nitrate, the precipitation titration curve is divided into three regions: before, at, and after the equivalence point. Before the equivalence point, low redissolution of the sparingly soluble silver chloride precipitate gives a low silver ion concentration. However, in the second region, representing the equivalence point,...
1.2K
01:26Precipitation Titration: Overview
6.8K
Precipitation titration involves the reaction of a titrant and an analyte to generate an insoluble precipitate. While precipitation titration uses various precipitating agents, silver nitrate is the most common precipitating reagent; titrations involving Ag+ are called argentometric titrations. Usually, the endpoint in a precipitation titration can be detected by visual indicators.
A precipitation titration curve demonstrates the change in concentration of the titrant or analyte upon adding the...
A precipitation titration curve demonstrates the change in concentration of the titrant or analyte upon adding the...
6.8K