Showing papers by "Feifei Pan published in 2022"
TL;DR: In this article , the impacts of soil moisture on surface air temperature difference (Ts-Ta) at the global scale have been investigated based on ERA5-land reanalysis data from 1981 to 2019.
9 citations
TL;DR: In this article , the authors analyzed the global spatiotemporal heterogeneity and influencing factors of land surface-air temperature difference (Ts-Ta) and found that annual mean Ts-Ta exhibited a decreasing trend from the equator to polar areas.
3 citations
TL;DR: In this paper , the authors carried out extensive temporal-spatial variations of grassland water deficit/surplus (GWDS) and net primary productivity (NPP) of QTP grassland using meteorological data of 1981-2018.
Abstract: Abstract Grassland accounts for 67% of the land area in Qinghai–Tibet Plateau (QTP) to sensitive to climate. This article carried out extensive temporal–spatial variations of grassland water deficit/surplus (GWDS) and net primary productivity (NPP) of QTP grassland using meteorological data of 1981–2018. The results indicate that precipitation’s temporal variations are not related to potential evapotranspiration (PET). The maximum monthly precipitation occurs in July, while the maximum monthly PET appears in June. Precipitation is the second highest in spring when PET is the highest. The water deficit (PET-precipitation) from March to June takes up 51.4% of the total year. Therefore, droughts are more likely to happen in spring and June. This is the most important period for grassland protection. Water deficit is higher in the central and west and the highest in the northwest of QTP grasslands. This indicates the place where the droughts are more likely to occur. The grassland’s annual NPP is high in the southeastern part of QTP and low in the west. This shows the central and western parts of QTP grassland should receive more attention. The specific time and region obtained in this study are important for environmental protection policy-making and reducing grassland degradation in QTP.
1 citations
TL;DR: In this paper , two solar radiation parameters were introduced, i.e., the actual solar radiation and the clear sky solar radiation, and were incorporated into the loss function coefficient to improve its estimation.
Abstract: The soil moisture daily diagnostic equation (SMDE) evaluates the relationship between the loss function coefficient and the summation of the weighted average of precipitation. The loss function coefficient uses the day of the year (DOY) to approximate the seasonal changes in soil moisture loss for a given location. Solar radiation is the source of the energy that drives the complex and intricates of the earth-atmospheric processes and biogeochemical cycles in the environment. Previous research assumed DOY is the approximation of other environmental factors (e.g., temperature, wind speed, solar radiation). In this article, two solar radiation parameters were introduced, i.e., the actual solar radiation and the clear sky solar radiation and were incorporated into the loss function coefficient to improve its estimation. This was applied to 2 years of continuous rainfall, soil moisture data from USDA soil climate network (SCAN) sites AL2053, GA2027 MS2025, and TN2076. It was observed that the correlation coefficient between the observed soil moisture and B values (which is the cumulated average of rainfall to soil moisture loss) increased on average by 2.3% and the root mean square errors (RMSEs) for estimating volumetric soil moisture at columns 0–5, 0–10, 0–20, 0–50, 0–100 cm reduced on average by 8.6% for all the study sites. The study has confirmed that using actual solar radiation data in the soil moisture daily diagnostic equation can improve its accuracy.
1 citations
TL;DR: In this article , the authors quantified the effect of ENSO on the water vapour transport from ocean to land and identified its impact on tropical precipitation anomalies, which has important significance on regional water resource management and disaster risk assessment, especially as the extreme climate events have become increasingly frequent.
Abstract: Atmospheric water vapour transport is one of the most active components of the hydrological cycle, which shows great effects on the regional climate variability, while it is largely affected by the large‐scale circulation systems. El Niño–Southern Oscillation (ENSO) shows a remarkable influence on the atmospheric water circulation via disrupting the normal/regular water vapour transport processes, producing the anomaly water vapour fluxes input from ocean to land (Qnet), and leading to regional precipitation anomalies. However, their quantitative impact has not been fully studied. This study quantified the effect of ENSO on the water vapour transport from ocean to land and identified its impact on tropical precipitation anomalies. The results showed that the global detrended Qnet displayed a significantly negative correlation with the strength of ENSO. The notable impact of ENSO on Qnet was largely affected by the different patterns of the atmospheric moisture circulation during El Niño and La Niña and was responsible for the change of the spatial distribution of precipitation over the Tropics. El Niño reduced precipitation over the Malay Archipelago and increased precipitation over south China, especially in boreal winter, while La Niña enhanced precipitation over the Malay Archipelago. This study identified the impacts of ENSO on the circulation and water vapour transport process and improved our understanding of the influencing mechanism of ENSO on regional precipitation anomalies, which has important significance on regional water resource management and disaster risk assessment, especially as the extreme climate events have become increasingly frequent.