This page has only limited features, please log in for full access.

Unclaimed
Roderick van der Linden
Institute of Meteorology and Climate Research Karlsruhe Institute of Technology (KIT) Karlsruhe Germany

Honors and Awards

The user has no records in this section


Career Timeline

The user has no records in this section.


Short Biography

The user biography is not available.
Following
Followers
Co Authors
The list of users this user is following is empty.
Following: 0 users

Feed

Research article
Published: 17 August 2020 in International Journal of Climatology
Reads 0
Downloads 0

The seasonal cycle of rainfall over the Greater Horn of Africa (GHA) is dominated by the latitudinal migration and activity of the tropical rain belt (TRB). The TRB exhibits high interannual variability in the Greater Horn of Africa (GHA) and the reasons for the recent dry period in the Long Rains (March–May) are poorly understood. In addition, few studies have addressed the rainfall fluctuations during the Msimu Rains (Dec.–Mar.) in the southern GHA region. Interannual variations of the seasonal cycle of the TRB between 1981 and 2018 were analysed using two statistical indices. The Rainfall Cluster Index (RCI) describes the seasonal cycle as a succession of six characteristic rainfall patterns, while the Seasonal Location Index (SLI) captures the latitudinal location of the TRB. The SLI and RCI depict the full seasonal cycle of the TRB supporting interpretations of the interannual variations and trends. The Msimu Rains are dominated by two clusters with opposite rainfall characteristics between the Congo Basin and Tanzania. The associated anomalies in moisture flux and divergence indicate variations in the location of the TRB originating from an interplay between low‐level air flows from the Atlantic and Indian Oceans and tropical and subtropical teleconnections. The peak period of the Long Rains shows a complex composition of five clusters, which is tightly connected to intraseasonal and interannual variability of latitudinal locations of the TRB. A persistent location of the TRB near the equator, evidenced in a frequent occurrence of a cluster related to an anomalously weak Walker circulation, is associated with wet conditions over East Africa. Dry Long Rains are associated with strong and frequent latitudinal variations of the TRB position with a late onset and intermittent rainfall. These results offer new opportunities to understand recent variability and trends in the GHA region. This article is protected by copyright. All rights reserved.

ACS Style

Larisa S. Seregina; Andreas H. Fink; Roderick Van Der Linden; Chris Funk; Joaquim G. Pinto. Using seasonal rainfall clusters to explain the interannual variability of the rain belt over the Greater Horn of Africa. International Journal of Climatology 2020, 41, 1 .

AMA Style

Larisa S. Seregina, Andreas H. Fink, Roderick Van Der Linden, Chris Funk, Joaquim G. Pinto. Using seasonal rainfall clusters to explain the interannual variability of the rain belt over the Greater Horn of Africa. International Journal of Climatology. 2020; 41 (S1):1.

Chicago/Turabian Style

Larisa S. Seregina; Andreas H. Fink; Roderick Van Der Linden; Chris Funk; Joaquim G. Pinto. 2020. "Using seasonal rainfall clusters to explain the interannual variability of the rain belt over the Greater Horn of Africa." International Journal of Climatology 41, no. S1: 1.

Journal article
Published: 29 June 2020 in Climate
Reads 0
Downloads 0

The impact of climate and land use/land cover (LULC) change continues to threaten water resources availability for the agriculturally used inland valley wetlands and their catchments in East Africa. This study assessed climate and LULC change impacts on the hydrological processes of a tropical headwater inland valley catchment in Uganda. The hydrological model Soil and Water Assessment Tool (SWAT) was applied to analyze climate and LULC change impacts on the hydrological processes. An ensemble of six regional climate models (RCMs) from the Coordinated Regional Downscaling Experiment for two Representative Concentration Pathways (RCPs), RCP4.5 and RCP8.5, were used for climate change assessment for historical (1976-2005) and future climate (2021-2050). Four LULC scenarios defined as exploitation, total conservation, slope conservation, and protection of headwater catchment were considered. The results indicate an increase in precipitation by 7.4% and 21.8% of the annual averages in the future under RCP4.5 and RCP8.5, respectively. Future wet conditions are more pronounced in the short rainy season than in the long rainy season. Flooding intensity is likely to increase during the rainy season with low flows more pronounced in the dry season. Increases in future annual averages of water yield (29.0% and 42.7% under RCP4.5 and RCP8.5, respectively) and surface runoff (37.6% and 51.8% under RCP4.5 and RCP8.5, respectively) relative to the historical simulations are projected. LULC and climate change individually will cause changes in the inland valley hydrological processes, but more pronounced changes are expected if the drivers are combined, although LULC changes will have a dominant influence. Adoption of total conservation, slope conservation and protection of headwater catchment LULC scenarios will significantly reduce climate change impacts on water resources in the inland valley. Thus, if sustainable climate-smart management practices are adopted, the availability of water resources for human consumption and agricultural production will increase.

ACS Style

Geofrey Gabiri; Bernd Diekkrüger; Kristian Näschen; Constanze Leemhuis; Roderick Van Der Linden; Jackson-Gilbert Mwanjalolo Majaliwa; Joy Apiyo Obando. Impact of Climate and Land Use/Land Cover Change on the Water Resources of a Tropical Inland Valley Catchment in Uganda, East Africa. Climate 2020, 8, 83 .

AMA Style

Geofrey Gabiri, Bernd Diekkrüger, Kristian Näschen, Constanze Leemhuis, Roderick Van Der Linden, Jackson-Gilbert Mwanjalolo Majaliwa, Joy Apiyo Obando. Impact of Climate and Land Use/Land Cover Change on the Water Resources of a Tropical Inland Valley Catchment in Uganda, East Africa. Climate. 2020; 8 (7):83.

Chicago/Turabian Style

Geofrey Gabiri; Bernd Diekkrüger; Kristian Näschen; Constanze Leemhuis; Roderick Van Der Linden; Jackson-Gilbert Mwanjalolo Majaliwa; Joy Apiyo Obando. 2020. "Impact of Climate and Land Use/Land Cover Change on the Water Resources of a Tropical Inland Valley Catchment in Uganda, East Africa." Climate 8, no. 7: 83.

Preprint content
Published: 23 March 2020
Reads 0
Downloads 0

The Kilombero catchment is a meso-scale catchment of 40,240 km² in south central Tanzania and is characterized by overall data scarcity like many other African catchments. The catchment consists of a highly dynamic floodplain system at its centre which is sustained by water from the surrounding uplands. It also contains a Ramsar site giving evidence to its valuable ecosystem and importance concerning biodiversity conservation. However, in the last decades land use and land cover changes (LULCC) accelerated drastically towards an agriculturally-shaped landscape, especially at the fringes of the wetland. The wetland system provides fertile soils, water as well as other water-related ecosystem services. Nevertheless, the increasing pressure on natural resources jeopardizes the sustainability of the socio-ecological system, especially in the face of climate change.

 

In this study, methods of hydrology, meteorology and remote sensing were used to overcome data-scarcity and gather a sound representation of natural processes in the catchment. The Soil and Water Assessment Tool (SWAT) was applied to represent the hydrological processes in the catchment. We utilized Landsat images from several decades to simulate the impact of LULCC from the 1970s until today. Furthermore, we applied the Land Change Modeller (LCM) to simulate potential LULCC until 2030 and their impact on water resources. To account for climatic changes, a regional climate model ensemble of the Coordinated Regional Downscaling Experiment (CORDEX) Africa project was analysed and bias-corrected to investigate changes in climatic patterns until 2060, according to the RCP4.5 (representative concentration pathways) and RCP8.5 scenarios.

 

The climate change signal indicates rising temperatures, especially in the hot dry season, which reinforces the special features of this season. However, the changes in precipitation signals among the analysed RCMs vary between -8.3% and +22.5% of the annual mean values. The results of the hydrological modelling also show heterogeneous spatial patterns within the catchment area. LULCC simulation results show a 6-8% decrease in low flows for the LULCC scenarios, while high flows increase by up to 84% for combined LULCC and climate change scenarios. The effect of climate change is more pronounced compared to the effect of LULCC, but also contains higher uncertainties. This study exemplarily quantifies the impact of LULCC and climate change in a data-scarce catchment and therefore contributes to the sustainable management of the investigated catchment, as it shows the impact of environmental change on hydrological extremes and determines hot spots, which are crucial for more detailed analyses like hydrodynamic modelling. The information from this study are an essential part to assist local stakeholders protecting the wetlands integrity on the one hand and to ensure sustainable agricultural practices in order to guarantee food security on the other hand in a catchment that has already changed tremendously and is still target to manifold future plans.

ACS Style

Kristian Näschen; Bernd Diekkrüger; Mariele Evers; Britta Höllermann; Larisa S. Seregina; Stefanie Steinbach; Frank Thonfeld; Roderick Van Der Linden. The impact of climate change and land use/land cover change on water resources in a data-scarce catchment in Tanzania. 2020, 1 .

AMA Style

Kristian Näschen, Bernd Diekkrüger, Mariele Evers, Britta Höllermann, Larisa S. Seregina, Stefanie Steinbach, Frank Thonfeld, Roderick Van Der Linden. The impact of climate change and land use/land cover change on water resources in a data-scarce catchment in Tanzania. . 2020; ():1.

Chicago/Turabian Style

Kristian Näschen; Bernd Diekkrüger; Mariele Evers; Britta Höllermann; Larisa S. Seregina; Stefanie Steinbach; Frank Thonfeld; Roderick Van Der Linden. 2020. "The impact of climate change and land use/land cover change on water resources in a data-scarce catchment in Tanzania." , no. : 1.

Research article
Published: 03 March 2020 in Quarterly Journal of the Royal Meteorological Society
Reads 0
Downloads 0

During the DACCIWA (Dynamics–Aerosol–Chemistry–Cloud Interactions in West Africa) field campaign ∼900 radiosondes were launched from 12 stations in southern West Africa from 15 June to 31 July 2016. Subsequently, data‐denial experiments were conducted using the Integrated Forecasting System of the European Centre for Medium‐range Weather Forecasts (ECMWF) to assess the radiosondes' impact on the quality of analyses and forecasts. As observational reference, satellite‐based estimates of rainfall and outgoing long‐wave radiation (OLR) as well as the radiosonde measurements themselves are used. With regard to the analyses, the additional observations show positive impacts on winds throughout the troposphere and lower stratosphere, while large lower‐tropospheric cold and dry biases are hardly reduced. Nonetheless, downstream, that is farther inland from the radiosonde stations, we find a significant increase (decrease) in low‐level night‐time temperatures (monsoon winds) when incorporating the DACCIWA observations, suggesting a possible linkage via weaker cold air advection from the Gulf of Guinea. The associated lower relative humidity leads to reduced cloud cover in the DACCIWA analysis. Closer to the coast and over Benin and Togo, DACCIWA observations increase low‐level specific humidity and precipitable water, possibly due to changes in advection and vertical mixing. During daytime, differences between the two analyses are generally smaller at low levels. With regard to the forecasts, the impact of the additional observations is lost after a day or less. Moderate improvements occur in low‐level wind and temperature but also in rainfall over the downstream Sahel, while impacts on OLR are ambiguous. The changes in precipitation appear to also affect high‐level cloud cover and the tropical easterly jet. The overall rather small observation impact suggests that model and data assimilation deficits are the main limiting factors for better forecasts in West Africa. The new observations and physical understanding from DACCIWA can hopefully contribute to reducing these issues.

ACS Style

Roderick Van Der Linden; Peter Knippertz; Andreas H. Fink; Bruce Ingleby; Marlon Maranan; Angela Benedetti. The influence of DACCIWA radiosonde data on the quality of ECMWF analyses and forecasts over southern West Africa. Quarterly Journal of the Royal Meteorological Society 2020, 146, 1719 -1739.

AMA Style

Roderick Van Der Linden, Peter Knippertz, Andreas H. Fink, Bruce Ingleby, Marlon Maranan, Angela Benedetti. The influence of DACCIWA radiosonde data on the quality of ECMWF analyses and forecasts over southern West Africa. Quarterly Journal of the Royal Meteorological Society. 2020; 146 (729):1719-1739.

Chicago/Turabian Style

Roderick Van Der Linden; Peter Knippertz; Andreas H. Fink; Bruce Ingleby; Marlon Maranan; Angela Benedetti. 2020. "The influence of DACCIWA radiosonde data on the quality of ECMWF analyses and forecasts over southern West Africa." Quarterly Journal of the Royal Meteorological Society 146, no. 729: 1719-1739.

Research article
Published: 31 October 2019 in International Journal of Climatology
Reads 0
Downloads 0

In this study, different criteria to determine the rainy season onset date (RSOD) and its predictability in the Central Highlands (CH) of Vietnam are investigated. Using daily rainfall amounts from ten meteorological stations for the period 1981–2015, four criteria to determine the RSOD were tested in order to select the one that most reasonably depicts the climatology of the RSOD over the CH. Results show that the RSOD varies strongly from year to year. In the long‐term mean, the onset starts first in southern parts of the CH and then progresses to the northern parts. The earliest onset date is around the beginning of April, and the latest in the second half of May. The average RSOD is on 28 April with a standard deviation of 14 days. Thus, the RSOD is distinct from the summer monsoon onset, namely leading the mean summer monsoon onset by about three weeks in some years. In terms of remote influences, the RSOD in the CH has a high correlation with the El Niño–Southern Oscillation phenomenon, with most RSODs being later during El Niño years, while being earlier during La Niña years. The RSOD in the CH also shows high correlations with sea surface temperatures (SSTs), 850‐hPa zonal winds (U850) and mean sea level pressures (PMSL) over certain regions of the Pacific and Indian Oceans. Building on these relationships, the RSOD can be successfully predicted using large‐scale fields of SST, U850, and PMSL as predictors in two different approaches, namely stepwise regression and principle component analysis. This suggests that the overall approach can also be applied in predicting the RSOD in the CH on sub‐seasonal to seasonal timescales. This article is protected by copyright. All rights reserved.

ACS Style

Ha Pham‐Thanh; Roderick van der Linden; Thanh Ngo‐Duc; Quang Nguyen‐Dang; Andreas H. Fink; Tan Phan‐Van. Predictability of the rainy season onset date in Central Highlands of Vietnam. International Journal of Climatology 2019, 40, 3072 -3086.

AMA Style

Ha Pham‐Thanh, Roderick van der Linden, Thanh Ngo‐Duc, Quang Nguyen‐Dang, Andreas H. Fink, Tan Phan‐Van. Predictability of the rainy season onset date in Central Highlands of Vietnam. International Journal of Climatology. 2019; 40 (6):3072-3086.

Chicago/Turabian Style

Ha Pham‐Thanh; Roderick van der Linden; Thanh Ngo‐Duc; Quang Nguyen‐Dang; Andreas H. Fink; Tan Phan‐Van. 2019. "Predictability of the rainy season onset date in Central Highlands of Vietnam." International Journal of Climatology 40, no. 6: 3072-3086.

Journal article
Published: 24 April 2019 in Water
Reads 0
Downloads 0

This article illustrates the impact of potential future climate scenarios on water quantity in time and space for an East African floodplain catchment surrounded by mountainous areas. In East Africa, agricultural intensification is shifting from upland cultivation into the wetlands due to year-round water availability and fertile soils. These advantageous agricultural conditions might be hampered through climate change impacts. Additionally, water-related risks, like droughts and flooding events, are likely to increase. Hence, this study investigates future climate patterns and their impact on water resources in one production cluster in Tanzania. To account for these changes, a regional climate model ensemble of the Coordinated Regional Downscaling Experiment (CORDEX) Africa project was analyzed to investigate changes in climatic patterns until 2060, according to the RCP4.5 (representative concentration pathways) and RCP8.5 scenarios. The semi-distributed Soil and Water Assessment Tool (SWAT) was utilized to analyze the impacts on water resources according to all scenarios. Modeling results indicate increasing temperatures, especially in the hot dry season, intensifying the distinctive features of the dry and rainy season. This consequently aggravates hydrological extremes, such as more-pronounced flooding and decreasing low flows. Overall, annual averages of water yield and surface runoff increase up to 61.6% and 67.8%, respectively, within the bias-corrected scenario simulations, compared to the historical simulations. However, changes in precipitation among the analyzed scenarios vary between −8.3% and +22.5% of the annual averages. Hydrological modeling results also show heterogeneous spatial patterns inside the catchment. These spatio-temporal patterns indicate the possibility of an aggravation for severe floods in wet seasons, as well as an increasing drought risk in dry seasons across the scenario simulations. Apart from that, the discharge peak, which is crucial for the flood recession agriculture in the floodplain, is likely to shift from April to May from the 2020s onwards.

ACS Style

Kristian Näschen; Bernd Diekkrüger; Constanze Leemhuis; Larisa S. Seregina; Roderick Van Der Linden. Impact of Climate Change on Water Resources in the Kilombero Catchment in Tanzania. Water 2019, 11, 859 .

AMA Style

Kristian Näschen, Bernd Diekkrüger, Constanze Leemhuis, Larisa S. Seregina, Roderick Van Der Linden. Impact of Climate Change on Water Resources in the Kilombero Catchment in Tanzania. Water. 2019; 11 (4):859.

Chicago/Turabian Style

Kristian Näschen; Bernd Diekkrüger; Constanze Leemhuis; Larisa S. Seregina; Roderick Van Der Linden. 2019. "Impact of Climate Change on Water Resources in the Kilombero Catchment in Tanzania." Water 11, no. 4: 859.

Research article
Published: 07 October 2018 in International Journal of Climatology
Reads 0
Downloads 0

Previous studies on observed or projected rainfall trends for the Greater Horn of Africa (GHA) generally focus on calendric 3‐month periods, and thus partly neglect the complexity of rainfall seasonality in this topographically heterogeneous region. This study introduces a novel and flexible methodology to identify the rainfall seasonality, the onset, cessation and duration of the rainy seasons and the associated uncertainties from rainfall time series. The definition is applied to the Climate Hazards Group InfraRed Precipitation with Stations (CHIRPS) satellite product and an extensive rain gauge data set. A strong agreement with known seasonal dynamics in the region and the commonly used calendric rainy seasons is demonstrated. Compared to the latter definition, a clear added value is found for the new approach as it captures the local rainfall features (associated with, for example, the sea breeze), thus facilitating evaluations across rainfall seasonality borders. While previously known trends are qualitatively confirmed, trends are amplified in some regions using the flexible definition method. Notably, a drying trend in Tanzania and Democratic Republic of Congo and a wetting trend in central Sudan and parts of eastern Ethiopia and Kenya can be detected. The trends are regionally associated with changes in rainy season cessation. CHIRPS and station trend patterns are consistent over larger regions of the GHA, but differ in regions with known rainfall contributions from warmer cloud tops. Discrepancies are found in coastal and topographically complex areas, and regions with an unstable seasonality of rainfall. As expected, CHIRPS shows spatially more homogeneous trends compared to station data. The more precise definition of the rainy season facilitates the assessment of rainfall characteristics like intensity, rainfall amounts or temporal shifts of rainy seasons. This novel methodology could also provide a more adequate calibration of climate model simulations thus potentially enabling more realistic climate change projections for the GHA.

ACS Style

Larisa S. Seregina; Andreas H. Fink; Roderick Van Der Linden; Nadir A. Elagib; Joaquim G. Pinto. A new and flexible rainy season definition: Validation for the Greater Horn of Africa and application to rainfall trends. International Journal of Climatology 2018, 39, 989 -1012.

AMA Style

Larisa S. Seregina, Andreas H. Fink, Roderick Van Der Linden, Nadir A. Elagib, Joaquim G. Pinto. A new and flexible rainy season definition: Validation for the Greater Horn of Africa and application to rainfall trends. International Journal of Climatology. 2018; 39 (2):989-1012.

Chicago/Turabian Style

Larisa S. Seregina; Andreas H. Fink; Roderick Van Der Linden; Nadir A. Elagib; Joaquim G. Pinto. 2018. "A new and flexible rainy season definition: Validation for the Greater Horn of Africa and application to rainfall trends." International Journal of Climatology 39, no. 2: 989-1012.

Journal article
Published: 04 May 2018 in Water
Reads 0
Downloads 0

Deterioration of upland soils, demographic growth, and climate change all lead to an increased utilization of wetlands in East Africa. This considerable pressure on wetland resources results in trade-offs between those resources and their related ecosystem services. Furthermore, relationships between catchment attributes and available wetland water resources are one of the key drivers that might lead to wetland degradation. To investigate the impacts of these developments on catchment-wetland water resources, the Soil and Water Assessment Tool (SWAT) was applied to the Kilombero Catchment in Tanzania, which is like many other East African catchments, as it is characterized by overall data scarcity. Due to the lack of recent discharge data, the model was calibrated for the period from 1958–1965 (R2 = 0.86, NSE = 0.85, KGE = 0.93) and validated from 1966–1970 (R2 = 0.80, NSE = 0.80, KGE = 0.89) with the sequential uncertainty fitting algorithm (SUFI-2) on a daily resolution. Results show the dependency of the wetland on baseflow contribution from the enclosing catchment, especially in dry season. Main contributions with regard to overall water yield arise from the northern mountains and the southeastern highlands, which are characterized by steep slopes and a high share of forest and savanna vegetation, respectively. Simulations of land use change effects, generated with Landsat images from the 1970s up to 2014, show severe shifts in the water balance components on the subcatchment scale due to anthropogenic activities. Sustainable management of the investigated catchment should therefore account for the catchment–wetland interaction concerning water resources, with a special emphasis on groundwater fluxes to ensure future food production as well as the preservation of the wetland ecosystem.

ACS Style

Kristian Näschen; Bernd Diekkrüger; Constanze Leemhuis; Stefanie Steinbach; Larisa S. Seregina; Frank Thonfeld; Roderick Van Der Linden. Hydrological Modeling in Data-Scarce Catchments: The Kilombero Floodplain in Tanzania. Water 2018, 10, 599 .

AMA Style

Kristian Näschen, Bernd Diekkrüger, Constanze Leemhuis, Stefanie Steinbach, Larisa S. Seregina, Frank Thonfeld, Roderick Van Der Linden. Hydrological Modeling in Data-Scarce Catchments: The Kilombero Floodplain in Tanzania. Water. 2018; 10 (5):599.

Chicago/Turabian Style

Kristian Näschen; Bernd Diekkrüger; Constanze Leemhuis; Stefanie Steinbach; Larisa S. Seregina; Frank Thonfeld; Roderick Van Der Linden. 2018. "Hydrological Modeling in Data-Scarce Catchments: The Kilombero Floodplain in Tanzania." Water 10, no. 5: 599.

Journal article
Published: 27 April 2017 in Weather and Forecasting
Reads 0
Downloads 0

A record-breaking rainfall event occurred in northeastern Vietnam in late July–early August 2015. The coastal region in Quang Ninh Province was hit severely, with station rainfall sums in the range of 1000–1500 mm. The heavy rainfall led to flooding and landslides, which resulted in an estimated economic loss of $108 million (U.S. dollars) and 32 fatalities. Using a multitude of data sources and ECMWF ensemble forecasts, the synoptic–dynamic development and practical predictability of the event is investigated in detail for the 4-day period from 1200 UTC 25 July to 1200 UTC 29 July 2015, during which the major portion of the rainfall was observed. A slowly moving upper-level subtropical trough and the associated surface low in the northern Gulf of Tonkin promoted sustained moisture convergence and convection over northeastern Vietnam. The humidity was advected in a moisture transport band lying across the Indochina Peninsula and emanating from a tropical storm over the Bay of Bengal. Analyses of the ECMWF ensemble forecasts clearly showed a sudden emergence of the predictability of the extreme event at lead times of 3 days that was associated with the correct forecasts of the intensity and location of the subtropical trough in the 51 ensemble members. Thus, the Quang Ninh event is a good example in which the predictability of tropical convection arises from large-scale synoptic forcing; in the present case it was due to a tropical–extratropical interaction that has not been documented before for the region and season.

ACS Style

Roderick Van Der Linden; Andreas H. Fink; Joaquim G. Pinto; Tan Phan-Van. The Dynamics of an Extreme Precipitation Event in Northeastern Vietnam in 2015 and Its Predictability in the ECMWF Ensemble Prediction System. Weather and Forecasting 2017, 32, 1041 -1056.

AMA Style

Roderick Van Der Linden, Andreas H. Fink, Joaquim G. Pinto, Tan Phan-Van. The Dynamics of an Extreme Precipitation Event in Northeastern Vietnam in 2015 and Its Predictability in the ECMWF Ensemble Prediction System. Weather and Forecasting. 2017; 32 (3):1041-1056.

Chicago/Turabian Style

Roderick Van Der Linden; Andreas H. Fink; Joaquim G. Pinto; Tan Phan-Van. 2017. "The Dynamics of an Extreme Precipitation Event in Northeastern Vietnam in 2015 and Its Predictability in the ECMWF Ensemble Prediction System." Weather and Forecasting 32, no. 3: 1041-1056.

Article
Published: 23 April 2017 in International Journal of Climatology
Reads 0
Downloads 0

Precipitation over Southeast Asia is primarily controlled by the Southeast Asian monsoon system. This area features complex orography and morphology, and has limited surface precipitation observations. In this study, a statistical-dynamical downscaling approach that combines weather typing and dynamical downscaling is developed to obtain a high-resolution precipitation climatology for tropical Southeast Asia. A transient simulation with the regional climate model COSMO-CLM (COnsortium for Small Scale MOdelling-Climate Limited-area Modelling Community) driven by ERA-Interim (1979–2008) is performed for the study region. Focussing on Vietnam, six weather types (WTs) are selected for the Indochina Peninsula during the wet season (April to October) using a k-means cluster approach on daily 850 and 200 hPa zonal wind components from ERA-Interim reanalysis. The six WTs can be physically interpreted as different stages of the seasonal progression of the planetary-scale monsoon circulation. For each WT, selected representatives from the COSMO-CLM run are dynamically downscaled to a resolution of 0.0625° × 0.0625° (∼7 km). Using the present-day WT frequencies, the simulated COSMO-CLM representatives at 7 km are recombined to a high-resolution rainfall climatology for the recent decades. The resulting high-resolution precipitation climatology is generally able to capture the present-day precipitation estimates derived from APHRODITE (Asian Precipitation – Highly Resolved Observational Data Integration Towards Evaluation of Water Resources) and station data. In spite of systematic biases our approach provides a valuable tool to obtain more robust regional climate change projections for the study area.

ACS Style

David Schubert; Roderick Van Der Linden; Mark Reyers; Andreas H. Fink; Klaus Massmeyer; Joaquim G. Pinto. Statistical-dynamical downscaling of precipitation for Vietnam: methodology and evaluation for the recent climate. International Journal of Climatology 2017, 37, 4211 -4228.

AMA Style

David Schubert, Roderick Van Der Linden, Mark Reyers, Andreas H. Fink, Klaus Massmeyer, Joaquim G. Pinto. Statistical-dynamical downscaling of precipitation for Vietnam: methodology and evaluation for the recent climate. International Journal of Climatology. 2017; 37 (11):4211-4228.

Chicago/Turabian Style

David Schubert; Roderick Van Der Linden; Mark Reyers; Andreas H. Fink; Klaus Massmeyer; Joaquim G. Pinto. 2017. "Statistical-dynamical downscaling of precipitation for Vietnam: methodology and evaluation for the recent climate." International Journal of Climatology 37, no. 11: 4211-4228.

Book chapter
Published: 18 February 2017 in Meteorology of Tropical West Africa
Reads 0
Downloads 0

This chapter introduces the physical and meteorological conditions that define the climate of West Africa on the continental scale. Two of the most important climatic surface variables in West Africa are rainfall (P) and actual evapotranspiration (ET). A common approach to infer reasonable patterns of ET is to force an ensemble of land surface models with observed rainfall, radiation and other reanalysed surface meteorological variables. The inland penetration of the West African monsoon (WAM) in the summer months is determined by the recycling of water at the surface, through P-ET, and by the horizontal transport and mixing of water vapour and clouds in the atmosphere. The chapter continues with observables closely tied to the energy and bio-terrestrial water cycle of the WAM. Finally, it deals with climatologies of some classical surface observables recorded at weather stations, such as pressure, temperature, humidity and wind.

ACS Style

Andreas H. Fink; Thomas Engel; Volker Ermert; Roderick van der Linden; Malvin Schneidewind; Robert Redl; Ernest Afiesimama; Wassila M. Thiaw; Charles Yorke; Matthew Evans; Serge Janicot. Mean Climate and Seasonal Cycle. Meteorology of Tropical West Africa 2017, 1 -39.

AMA Style

Andreas H. Fink, Thomas Engel, Volker Ermert, Roderick van der Linden, Malvin Schneidewind, Robert Redl, Ernest Afiesimama, Wassila M. Thiaw, Charles Yorke, Matthew Evans, Serge Janicot. Mean Climate and Seasonal Cycle. Meteorology of Tropical West Africa. 2017; ():1-39.

Chicago/Turabian Style

Andreas H. Fink; Thomas Engel; Volker Ermert; Roderick van der Linden; Malvin Schneidewind; Robert Redl; Ernest Afiesimama; Wassila M. Thiaw; Charles Yorke; Matthew Evans; Serge Janicot. 2017. "Mean Climate and Seasonal Cycle." Meteorology of Tropical West Africa , no. : 1-39.

Chapter
Published: 18 February 2017 in Meteorology of Tropical West Africa
Reads 0
Downloads 0

This chapter considers a set of challenges in weather forecasting for specific geographic locations, such as a particular village, town or airport. It describes some basic principles that relating to the offshore environment. The diurnal pattern of the surface energy balance is the primary control on local weather conditions in West Africa. There is a strong control of African weather by the surface energy balance, and in particular by the sensible and latent heat fluxes of energy from the surface to the atmosphere. In terms of local weather forecasting, the nocturnal jet causes significant wind shear that may require notifications being issued for aviation. Forecasting of daily maximum (Tx) and minimum (Tn) temperatures is a priority in the West African region, for various economic sectors and for the general public. Quantitative temperature prediction involves the integration of different sources of information.

ACS Style

Douglas J. Parker; Abdou Kassimou; Bernard N. Orji; David Perry Osika; Ibrahim Hamza; Mariane Diop-Kane; Andreas Fink; Jim Galvin; Françoise Guichard; Benjamin L. Lamptey; Hama Hamidou; Roderick van der Linden; Robert Redl; Thierry Lebel; Chris Tubbs. Local Weather. Meteorology of Tropical West Africa 2017, 130 -174.

AMA Style

Douglas J. Parker, Abdou Kassimou, Bernard N. Orji, David Perry Osika, Ibrahim Hamza, Mariane Diop-Kane, Andreas Fink, Jim Galvin, Françoise Guichard, Benjamin L. Lamptey, Hama Hamidou, Roderick van der Linden, Robert Redl, Thierry Lebel, Chris Tubbs. Local Weather. Meteorology of Tropical West Africa. 2017; ():130-174.

Chicago/Turabian Style

Douglas J. Parker; Abdou Kassimou; Bernard N. Orji; David Perry Osika; Ibrahim Hamza; Mariane Diop-Kane; Andreas Fink; Jim Galvin; Françoise Guichard; Benjamin L. Lamptey; Hama Hamidou; Roderick van der Linden; Robert Redl; Thierry Lebel; Chris Tubbs. 2017. "Local Weather." Meteorology of Tropical West Africa , no. : 130-174.

Journal article
Published: 28 July 2016 in Journal of Climate
Reads 0
Downloads 0

Rainfall extremes have a large socioeconomic relevance for southern Vietnam. More than 30 million people live in this low-lying, flood-prone region in Southeast Asia. In this study the influence of the Madden–Julian oscillation (MJO) and convectively coupled equatorial waves on the modulation of daily rainfall during the rainy season (May–October) is evaluated and quantified using an extensive station database and the gridded Asian Precipitation–Highly Resolved Observational Data Integration Toward Evaluation of Water Resources (APHRODITE) product for different phases of the equatorial waves. The MJO, Kelvin, and equatorial Rossby (ER) waves significantly modulate daily rainfall in Vietnam south of 16°N. The MJO shows the most coherent signals across the region, followed by ER waves, whose influence is strongest in central Vietnam; Kelvin waves only affect the southern parts of Vietnam. For all waves, the frequency of occurrence of intense daily rainfall larger than 25 mm is significantly enhanced during wet phases, whereas the magnitude of rainfall anomalies is related to the wave’s amplitude only in the MJO and ER cases. A novel wave interference diagram reveals strong positive interferences of dry and wet anomalies when the MJO occurs concurrently with Kelvin and ER waves. In terms of causes of rainfall anomalies, the waves modulate tropospheric moisture convergence over the region, but a strong influence on the depth of the monsoon flow and the vertical wind shear is discernible from radiosonde data only for the MJO. The results suggest new opportunities for submonthly prediction of dry and wet spells in Indochina.

ACS Style

Roderick van der Linden; Andreas H. Fink; Joaquim G. Pinto; Tan Phan Van; George N. Kiladis. Modulation of Daily Rainfall in Southern Vietnam by the Madden–Julian Oscillation and Convectively Coupled Equatorial Waves. Journal of Climate 2016, 29, 5801 -5820.

AMA Style

Roderick van der Linden, Andreas H. Fink, Joaquim G. Pinto, Tan Phan Van, George N. Kiladis. Modulation of Daily Rainfall in Southern Vietnam by the Madden–Julian Oscillation and Convectively Coupled Equatorial Waves. Journal of Climate. 2016; 29 (16):5801-5820.

Chicago/Turabian Style

Roderick van der Linden; Andreas H. Fink; Joaquim G. Pinto; Tan Phan Van; George N. Kiladis. 2016. "Modulation of Daily Rainfall in Southern Vietnam by the Madden–Julian Oscillation and Convectively Coupled Equatorial Waves." Journal of Climate 29, no. 16: 5801-5820.

Journal article
Published: 29 March 2016 in Monthly Weather Review
Reads 0
Downloads 0

The Central Highlands are Vietnam’s main coffee growing region. Unusual wet spells during the early dry season in November and December negatively affect two growing cycles in terms of yield and quality. The meteorological causes of wet spells in this region have not been thoroughly studied to date. Using daily rain gauge measurements at nine stations for the period 1981–2007 in the Central Highlands, four dynamically different early dry-season rainfall cases were investigated in depth: 1) the tail end of a cold front, 2) a tropical depression–type disturbance, 3) multiple tropical wave interactions, and 4) a cold surge with the Borneo vortex. Cases 1 and 4 are mainly extratropically forced. In case 1, moisture advection ahead of a dissipating cold front over the South China Sea led to high equivalent potential temperature in the southern highland where this air mass stalled and facilitated recurrent outbreaks of afternoon convection. In this case, the low-level northeasterly flow over the South China Sea was diverted around the southern highlands by relatively stable low layers. On the contrary, low-level flow was more orthogonal to the mountain barrier and high Froude numbers and concomitant low stability facilitated the westward extension of the rainfall zone across the mountain barrier in the other cases. In case 3, an eastward-traveling equatorial Kelvin wave might have been a factor in this westward extension, too. The results show a variety of interactions of large-scale wave forcings, synoptic-convective dynamics, and orographic effects on spatiotemporal details of the rainfall patterns.

ACS Style

Roderick Van Der Linden; Andreas H. Fink; Tan Phan-Van; Long Trinh-Tuan. Synoptic-Dynamic Analysis of Early Dry-Season Rainfall Events in the Vietnamese Central Highlands. Monthly Weather Review 2016, 144, 1509 -1527.

AMA Style

Roderick Van Der Linden, Andreas H. Fink, Tan Phan-Van, Long Trinh-Tuan. Synoptic-Dynamic Analysis of Early Dry-Season Rainfall Events in the Vietnamese Central Highlands. Monthly Weather Review. 2016; 144 (4):1509-1527.

Chicago/Turabian Style

Roderick Van Der Linden; Andreas H. Fink; Tan Phan-Van; Long Trinh-Tuan. 2016. "Synoptic-Dynamic Analysis of Early Dry-Season Rainfall Events in the Vietnamese Central Highlands." Monthly Weather Review 144, no. 4: 1509-1527.

Journal article
Published: 10 February 2015 in Journal of Geophysical Research: Atmospheres
Reads 0
Downloads 0

Synoptic observations and various satellite products have been utilized for computing climatologies of low‐level stratus over southern West Africa for the wet monsoon seasons July‐September 2006‐2011. Previous studies found inconsistencies between satellite cloud products; climate models often fail to reproduce the extensive stratus decks. Therefore a better observational reference and an understanding of its limitations are urgently needed to better validate models.

ACS Style

Roderick Van Der Linden; Andreas H. Fink; Robert Redl. Satellite-based climatology of low-level continental clouds in southern West Africa during the summer monsoon season. Journal of Geophysical Research: Atmospheres 2015, 120, 1186 -1201.

AMA Style

Roderick Van Der Linden, Andreas H. Fink, Robert Redl. Satellite-based climatology of low-level continental clouds in southern West Africa during the summer monsoon season. Journal of Geophysical Research: Atmospheres. 2015; 120 (3):1186-1201.

Chicago/Turabian Style

Roderick Van Der Linden; Andreas H. Fink; Robert Redl. 2015. "Satellite-based climatology of low-level continental clouds in southern West Africa during the summer monsoon season." Journal of Geophysical Research: Atmospheres 120, no. 3: 1186-1201.